O
Field Manual
Models: HG1 & HG2
Field Manual
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TM
HVAC GUIDE
Tester
Field Manual
HG1 & HG2
Do it right the rst time!
Minimize call-backs. Reduce testing and diagnosis time. Improve the technician’s technical capability.
Minimize reliance on outside technical help. e HVAC
TM
Guide
the most common HVAC tests. It then makes a diagnosis and recommends action. e HVAC Guide
makes the service call or installation faster, easier, cleaner, and more complete.
reasons for call-backs. It can cause compressor noise,
shorten compressor life, and lower capacity. Using the
built-in Superheat and Subcooling tests, the HVAC
Guide
step procedure to determine if the refrigerant charge
is correct. With the proper accessory heads, no calculations, charts, or data entry are needed.
that they are too hot or too cold. Once you’ve checked
the duct system for restrictions and leaks, adjust the air ow with the Target Evaporator Exit Temperature procedure that’s built into the HVAC Guide
cause your customers to call you and complain about
the temperature being too cold or the hot water not being hot enough. Use the Combustion test built into the
HVAC Guide
air/fuel mixture by analyzing the combustion products.
You can then make adjustments to make sure the equipment works as it should.
more sophisticated air conditioner test procedure that
will help diagnose more complex problems by looking
at the air conditioning system as a whole.
it more completely and avoid call-backs in the process.
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Guided Probe Tester can do all that and more.
e display leads the technician step by step through
TM
tester
Improper refrigerant charge is one of the primary
TM
tester leads the technician through a step by
Improper air ow can cause customers to complain
TM
tester.
An improperly adjusted furnace or water heater will
TM
tester to determine if you have the right
e CheckMe!® test (model HG2 only) is a much
Do it right the rst time, do it faster, do it easier, do
2
Table of Contents
Do it Right the First Time! . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Table of Contents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
HVAC GuideTM Tester Controls . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Select the Test (Switch Positions). . . . . . . . . . . . . . . . . . . . . . . 6
Fill in the INPUT FORM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Read the OUTPUT FORM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
What Accessory Heads Do I Need? . . . . . . . . . . . . . . . . . . . . 10
How to Connect an Accessory Head. . . . . . . . . . . . . . . . . . . 11
Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Target Evaporator Exit Temperature . . . . . . . . . . . . . . . . . 12
Superheat. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Superheat and Subcooling FAQ part 1 . . . . . . . . . . . . 21
Subcooling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Superheat and Subcooling FAQ part 2 . . . . . . . . . . . . 27
Combustion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
“CheckMe!®” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Advanced Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Memory (MEM). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Units. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Customer ID. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Clearing a single input or INPUT FORM . . . . . . . . . . . . . . 52
Saving Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Recalling Saved Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Contrast Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
PC Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Installing the PC Software . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Communicating with a PC . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Transfer Tests from the HVAC GuideTM Tester to a PC . . 56
Transfer Tests From the PC to the HVAC GuideTM Tester. . 58
Looking at Downloaded Data. . . . . . . . . . . . . . . . . . . . . . . 60
Other Operations with PC Software . . . . . . . . . . . . . . . . . . . 61
Air Conditioning Basics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Combustion Basics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
Product Speci cations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
Limited Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Obtaining Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
Disclaimer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
John Proctor and Title 24 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
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© Copyright Fieldpiece Instruments 2007
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HVAC GUIDETM Tester Controls
Input Jacks
Connect accessory heads
here.
Input Button
Returns you to the INPUT
FORM.
Backlight Button
Turns on the backlight for
30 sec.
Arrow Buttons
Navigate within FORMS
and screens.
Switch Position Dial
Rotate to select test.
Clear Button
Clears a single input or
the entire INPUT FORM by
holding for 3 seconds.
Top View
Dot Matrix LCD Display
Displays INPUT FORMS and
OUTPUT FORMS.
Output Button
Triggers calculations and takes
you to the OUTPUT FORM.
Enter Button
Makes a selection or enters
data.
Battery Cover
After "POWER OFF" clears,
unscrew the two screws to
replace the 6AA batteries.
Save Button
Saves the current INPUT FORM.
Inputs are saved with Customer
ID and Time Stamp. See Saving
Data section for details.
Recall Button
Recalls previous tests within
each switch position. Previous
tests can only be accessed
through the switch position in
which they were performed
and are sorted by Customer ID
and Time Stamp.
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PC Cable Interface
PC cable plugs into the
bottom to transfer data.
Bottom View
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Select the Test
Switch Positions
MEM: Erase a single test, an entire customer’s set of
tests, or all data. MEM also allows you to check
memory status, rmware version, and communicate with a PC for data transfer.
TIME: Set current time and date for internal clock. All
tests are time stamped and cannot be changed later.
Target Evaporator Exit Temperature: By mea-
suring the return wet bulb and dry bulb, the HVAC
TM
Guide
temperature. To ensure that the A/C system has the
proper air ow per tonnage, the actual evaporator
exit temperature must be within ±3°F of the target
evaporator exit temperature as outlined in CA title
24.
Superheat: For a xed restrictor air conditioning sys-
tem, the HVAC Guide
bulb and outside dry bulb to calculate a target superheat and uses the suction line temperature and
pressure to calculate actual superheat.
tester calculates a target evaporator exit
TM
tester uses the indoor wet
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Subcooling: For a TXV/EXV air conditioning system,
the HVAC Guide
ture and pressure to calculate actual subcooling. If
the manufacture’s target subcooling is not available,
the HVAC Guide
estimate.
TM
tester uses liquid line tempera-
TM
tester provides a conservative
Combustion: For combustion equipment, the HVAC
TM
Guide
temperature and CO ppm to calculate %CO
tester uses %O2, ue temperature, primary
, % Ex-
2
cess Air, CO (air free), Net Temperature, Standard
E ciency and Siegert E ciency.
CheckMe!® (model HG2): is is a more advanced
test for determining the overall state of an air conditioning system. e CheckMe!® test will give you a
diagnosis of the system in plain English and a list of
potential problems in the system.
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Fill in the INPUT FORM
Read the OUTPUT FORM
Figure 1. INPUT FORM for the Superheat test.
e INPUT FORM lists parameters in the order of
expected entry.
ree ways to enter data:
1. Automatic: Attach appropriate head, select ap-
propriate line with the UP/DOWN arrows, press
ENTER to start measuring, and press ENTER
again to lock in the value.
2. Drop down menu: To change a parameter that
has a default, press RIGHT arrow or ENTER, use
UP/DOWN arrows to scroll through the drop-
down list, and press ENTER again.
3. Manual: Enter system data (or to enter test data
not taken with an accessory head) by pressing the
RIGHT arrow and then, character-by-character, use
the UP/DOWN arrows and the RIGHT arrow to
‘type in’ the value. When nished press ENTER. Tar-
get Evaporator Exit Temperature test has no system
data to enter.
Figure 2. OUTPUT FORM for the Superheat test.
To display the OUTPUT FORM, ll in the INPUT
FORM correctly and press the OUTPUT button or
scroll down. If the INPUT FORM is missing inputs, the
appropriate lines on the OUTPUT FORM will be blank.
If the data entered on the INPUT FORM is out of range
or physically impossible, an error message is displayed.
e OUTPUT FORM displays the results of the calculations.
• e “See Sec:” at the bottom of the OUTPUT FORM
tells you what section in the manual has more infor-
mation about how to perform the speci c test and
what the results mean.
• To ensure that your changes have optimized the sys-
tem, retest a er the system is stabilized.
e CheckMe!® test (model HG2) has a more detailed OUTPUT FORM. If everything on the INPUT
FORM is lled out properly, the CheckMe!® OUTPUT
FORM will rank the possible problems in order of likelihood and describe how to x them. If you haven’t taken
all the necessary measurements, the rst line will tell
you what you need to do for a complete diagnosis.
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What Accessory Heads
Do I Need?
Refer to the chart below to nd the recommended accessory head and thermocouple for each measurement. Automatically input measurements with
Fieldpiece accessory heads for maximum accuracy, or
manually input from non-Fieldpiece test equipment.
How to Connect an
Accessory Head
AOX2
ADMN2
ASX14
ACM3
ATH4 on
HVAC Guide
TM
tester
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Tests
A-Coil
Fan
Dry Bulb and
Wet Bulb T/C
Supply Plenum
C
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er
1.1
Evaporator Exit Temperature gives you an indication of
the proper indoor air ow. is test can be easily performed simultaneously with superheat or subcooling
tests.
3°F above or below the Target Evaporator Exit Temperature, an air ow problem may exist. Ensure that lters are
clear, dampers are adjusted properly and the fan speed
is set correctly if it can be varied. e Target Evaporator Exit Temperature switch position uses the table from
California Title 24.
Target Evaporator Exit Temperature
For given return plenum air conditions, Target
If actual evaporator exit temperature is more than
Supply Plenum
Direction
of Air ow
Dry Bulb and
Wet Bulb T/C
Filter
Dry Bulb T/C
Fan
A-Coil
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12
Figure 3. Setting up the ATH4 and
HVAC Guide
TM
tester to measure dry
bulb and wet bulb temperatures
between fi lter and coil.
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1.2 Target Evaporator Exit Temperature
1.3 Target Evaporator Exit Temperature
INPUT FORM
Can be measured automatically with
Fieldpiece accessory heads.
Customer ID is useful for record keeping.
Units can be changed to either English
or Metric.
Figure 4. INPUT FORM for Target Evaporator Exit Temperature.
Into Evap Return Dry Bulb and Wet Bulb: Take
measurements as close to the inlet of the air handler
as possible. If the lter is just before the air handler,
the easiest way is to clip an ATWB1 and ATA1 to the
lter on the side facing the evaporator and take the
measurements. If the lter is not before the evaporator, make small holes in the return plenum just big
enough for the probes. Seal any holes before leaving
the jobsite.
Out of Evap Supply DB (dry bulb temp leaving
the evaporator): Measure in the center of the supply
plenum. Punch a small hole in the supply plenum
and insert a calibrated dry bulb thermocouple such
as the ATA1 or ATB1. Make sure the thermocouple
is in the center of the plenum cross-section. Seal the
hole when nished.
OUTPUT FORM
If Target and Actual are more than 3°F
apart a modification is needed.
Sections of manual with more
information about this test.
Figure 5. OUTPUT FORM for Target Evaporator Exit Temperature.
Press OUTPUT for the Target Evaporator Exit Tem-
perature OUTPUT FORM.
Target Evap Exit DB Temp (Target Evaporator
Exit Dry Bulb Temperature): is is the target exit
temperature based on the measured indoor conditions.
Actual Evap Exit DB Temp (Actual Evaporator
Exit Dry Bulb Temperature): is is the measured
temperature of the air in the supply.
e
Actual Evap Exit DB Temp should be
within ±3°F of the
the temperature is outside of this range, the technician
should make modi cations to correct the problem.
Target Evap Exit DB Temp. If
An Actual Evap Exit DB Temp below the
Target Evap Exit DB Temp indicates low air ow.
Increasing air ow can be accomplished by eliminating restrictions in the duct system, increasing blower
speed, cleaning lters or opening registers. A er corrective measures are taken, repeat measurement procedures as o en as necessary to establish adequate air ow
range. Allow system to stabilize for 15 minutes before
repeating measurement procedure.
1 2005 Residential ACM Manual, Page RD-5, (#5-7)
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An Actual Evap Exit DB Temp above the
Target Evap Exit DB Temp usually indicates low
capacity. Occasionally air ow is higher than expected.
Look for causes of low capacity such as refrigerant mischarge or dirty condenser coil. If the air ow is high,
correct by lowering the fan speed.
Because everything within the system is inter-dependent, one adjustment can a ect other parts of the
system. For example, increasing air ow increases the
superheat, which may require adding refrigerant. A er
modi cations, allow 15 minutes to stabilize and then
retest.
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2.1 Superheat
Superheat is the temperature rise above the boiling
point of the refrigerant a er the evaporator. Too high,
and the refrigerant boils o early in the evaporator and
‘wastes’ most of the capacity of the evaporator. Too low,
and you risk liquid going into the compressor.
Using superheat is the best way to obtain proper
refrigerant charge for a xed restrictor metering device
system.
If the air conditioner is in good working order and
the air ow is adjusted properly, comparing the actual
and target superheat will tell you if refrigerant needs to
be added or recovered. Ensure the pressure never exceeds the manufacturer's maximum overload pressure
guidelines.
On a xed restrictor system, the target superheat is
determined based upon the indoor wet bulb and outdoor dry bulb temperatures. Proper superheat ensures
the compressor doesn't ood under a low indoor load
and that the maximum e ciency and capacity are maintained.
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Figure 6. Using the ASX14 Superheat/Subcooling Head to gather suction line
temperature and pressure for the HVAC Guide
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TM
tester Superheat Test.
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2.2 Superheat INPUT FORM
Standard table uses the Title 24 target
superheat table.
Can be measured automatically with
Fieldpiece accessory heads.
Customer ID is useful for record keeping.
Figure 7. INPUT FORM for Standard Table Superheat Test.
Custom table allows you to enter your
own target superheat value.
Can be measured automatically with
Fieldpiece accessory heads.
Units can be changed to either English
or Metric.
Figure 8. INPUT FORM for Custom Table Superheat Test.
SH Table: Default: “Standard” uses the target super-
heat table from Title 24 for xed restrictor systems.
Other selection: “Custom” allows you to enter your
own target superheat by displaying the
input.
Target SH
air reaches the indoor coil). Wet the wet bulb sensor
(ATWB1) and insert it a er 15 minutes of continuous running. Clip downstream of the lter if the
lter is just before the air handler. Clip on the side
facing the evaporator and take the measurements.
If the lter is not before the evaporator, make small
holes in the return plenum just big enough for the
probes. Seal any holes before leaving the jobsite.
Watch the wet bulb temperature; it will drop and
then stabilize. e wet bulb temperature is the stabilized reading. If the sensor starts to dry out, the
reading will rise and the wrong temperature will be
recorded.
SL Pressure (suction line pressure): Connect the
ASX14 to the suction side service port. Select pressure mode on the ASX14 head. e system must be
stabilized before taking the measurements. Enter
data manually if you want to get pressure from your
gauges. e analysis is only as good as the measurements. e Fieldpiece ASX14 has better resolution
than most gauge sets.
Target SH (Custom SH Table): Change the SH Ta-
ble to Custom and enter the manufacturer’s recom-
mended superheat in the
Target SH input.
Refrigerant: Default: R-22. Other selections: R-410A,
R-134A, R-404A, R-407C, R-409A, R-408A, R-507A,
R-414B (Hotshot
(NU222B
TM
TM
), R-422C (OneshotTM), R-422B
) or R-12.
OD Dry Bulb (outdoor dry bulb, Standard SH Ta-
ble): Clip a calibrated ATA1 to the inlet of the con-
denser ns (typically on the side of the condenser),
in the shade if possible. Note that the temperature of
the air entering the outdoor coil can be considerably
di erent than the ambient temperature due to recir-
culation of air exiting the unit. Determine the aver-
age temperature of the air entering the condenser.
ID Wet Bulb (indoor wet bulb, Standard SH Table):
Take measurements very close or within the return
air side of the inlet to the air handler (not at the re-
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turn grill since temperatures change by the time the
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SL Temp (suction line temperature): Measure near SL
service port (within 6 inches). Use the ATC1, ATC2
or ATC3 to get a good pipe temperature. e clamp
should be perpendicular to the pipe and should be
securely seated with the sensor in contact with the
suction line. If working on a package unit make sure
you are at least 6 inches away from the compressor.
Figure 9. ATC1 pipe clamp thermocouple attached to a pipe correctly.
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2.3 Superheat OUTPUT FORM
Superheat and Subcooling FAQ
If Target SH and Actual SH are more than
5°F apart, as in this example, you need to
make adjustments to the system.
Boiling point is used to calculate Superheat.
Sections of manual with more information
about this test.
Figure 10. Superheat Test OUTPUT FORM.
Press OUTPUT for the Superheat OUTPUT FORM.
Target SH (Superheat): Indicates what the superheat
should be as calculated from outdoor dry bulb and
indoor wet bulb
Actual SH (Superheat): Shows the superheat calculated
from the measured suction line temperature and suc-
tion line pressure.
Boiling Point: is is the saturation temperature of the
refrigerant in the evaporator coil. It is one of the tem-
peratures from which superheat is calculated.
e
Actual SH (superheat) should be within ±5°F of
the Target SH to ensure optimum performance. If the
ac-
tual SH is outside this range, modi cations to the charge
or adjustments to the restrictor (TXV) are necessary.
Adding refrigerant lowers your Actual SH. Recovering refrigerant increases your Actual SH. e amount of
refrigerant necessary to add or recover will vary based on
the size of the system and the di erence between the Actual and Target SH.
Because everything within the system is inter-dependent, one adjustment can a ect other parts of the system.
For example, increasing air ow increases the superheat,
which may require adding refrigerant. A er modi cations, allow 15 minutes to stabilize and then retest.
Q: How do superheat/subcooling tools work?
A: Superheat tools measure suction line pressure and
suction line temperature, and calculate the actual superheat. Subcooling tools measure the liquid line pressure and liquid line temperature and calculate actual
subcooling. e refrigerant charts for calculations are
incorporated into the so ware of the HVAC Guide
tester.
TM
Q: When should I take my actual and target
superheat/subcooling?
A: Superheat and subcooling readings must be taken
when the system is in a steady state. Typically a residential system will be in a steady state a er 10-15 minutes. Turn the system on and set the thermostat low to
ensure that the system doesn’t turn o during your
testing. Once the system’s temperatures and pressures
are not uctuating, the system is in a steady state.
Wet bulb temperature, outdoor dry bulb, suction line
pressure and suction line temperature must be taken
within a short time period to ensure valid results.
Conditions that a ect your target superheat and target subcooling can change by the minute.
Q: What do I do with my ACTUAL superheat
or ACTUAL subcooling measurements?
A: Compare actual readings against the target superheat/
subcooling. As a general rule, if superheat is too high,
add refrigerant. If too low, remove refrigerant. If subcooling is too low, remove refrigerant. If subcooling is
too high, add refrigerant. Consult the manufacturer’s
speci cations before adding or recovering refrigerant
as further diagnostic tests may be needed
Continued on page 27
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3.1 Subcooling
Subcooling is the temperature decrease below the
boiling point (same as the condensing point) in the condenser. Too high, and refrigerant condenses too early in
the condenser and ‘wastes’ most of the capacity of the
condenser. Too low, and a mixture of gas and liquid can
be delivered to the expansion valve, reducing e ciency.
Subcooling is the best way to obtain proper refrigerant charge for a TXV/EXV system.
If the air conditioner is in good working order and
the air ow is adjusted properly, comparing the actual
and target subcooling will tell you if refrigerant needs
to be added or recovered (ensure the pressure never exceeds the manufacturer's maximum overload pressure
guidelines).
In a properly working TXV/EXV system, the superheat is held constant. Ensure the TXV/EXV bulb is installed properly, there is proper refrigerant to obtain target subcooling, and there are no liquid line restrictions.
Adjust refrigerant charge so that the actual subcooling is
within ±3°F of target subcooling.
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Figure 11. Using the ASX14 Superheat/Subcooling Head to gather liquid line
temperature and pressure for the HVAC Guide
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TM
tester Subcooling Test.
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3.2 Subcooling INPUT FORM
Target SC (WITH Manufacturer’s Data): Man-
ually input the manufacturer’s target subcooling.
Answering Yes or No takes you to a
different INPUT FORM. Always use
the manufacturer's recommended
subcooling when available.
Figure 12. Subcooling Test INPUT FORM question.
Target SC must be entered from the
equipment specifications.
Can be measured automatically with
Fieldpiece accessory heads.
Units can be changed to either English
or Metric.
Figure 13. Subcooling Test INPUT FORM with Manufacturer's Data.
Without manufacturer's recommended
subcooling data, the HVAC Guide
tester makes a conservative Target SC
estimate.
Can be measured automatically with
Fieldpiece accessory heads.
LL Pressure (liquid line pressure): Connect the
ASX14 to the liquid line service port. Set the accessory head to measure pressure and ensure the reading stabilizes before locking in the reading. Enter
data manually if you want to get pressure from your
gauges. e analysis is only as good as the measurements. e Fieldpiece ASX14 has better resolution
than most gauge sets.
LL Temp (liquid line temperature): Measure near the
same location LL Pressure was taken. Use the ATC1,
ATC2 or ATC3 to get a good pipe temperature. e
clamp should be perpendicular to the pipe and
should be securely seated with the sensor in contact
with the liquid line. If working on a package unit
make sure you are at least 6 inches away from the
compressor.
TM
Current time is set within TIME switch
position (see page 52).
Figure 14. Subcooling Test INPUT FORM without Manufacturer's Data.
Does the manufacturer have a recommended
subcooling? Default: Yes. Always answer "YES" if
you have a manufacturer’s recommended subcooling.
Other selection: "NO" will use a conservative estimate
for Target SC (Subcooling).
Refrigerant: Default: R-22. Other selections: R410A,
R-134A, R-404A, R-407C, R-409A, R-408A, R-507A,
R-414B (Hotshot
(NU222B
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TM
) or R-12.
), R-422C (OneshotTM), R-422B
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Figure 15. ATC1 pipe clamp thermocouple attached to a pipe correctly.
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3.3 Subcooling OUTPUT FORM
Superheat and Subcooling FAQ
Part 2 (continued from page 21)
If Target SC and Actual SC are more than
3°F apart, as in this example, you need to
make adjustments to the system.
Boiling point is used to calculate Subcooling.
Sections of manual with more information
about this test.
Figure 16. Subcooling Test OUTPUT FORM.
Press OUTPUT for the Subcooling OUTPUT FORM.
Target SC (Subcooling): Indicates what the subcool-
ing should be from the manufacturer’s speci cations.
e HVAC Guide
estimate when manufacturer’s speci cations are not
available.
TM
tester uses a built in conservative
Actual SC (Subcooling): Displays the subcooling calcu-
lated from the measured liquid line temperature and
liquid line pressure.
Boiling Point: is is the saturation temperature of the
refrigerant in the condenser coil. It is one of the tem-
peratures from which subcooling is calculated.
e
Actual SC (subcooling) should be within ±3°F
of the
Target SC for correct refrigerant charge. Tem-
peratures outside of this range indicate that you need to
make adjustments.
Adding refrigerant increases your
covering refrigerant decreases your
amount of refrigerant necessary to add or recover will
vary based on the size of the system and the di erence
between the Actual and Target SC.
Because everything is inter-dependent, changes in one
part of the system a ect other parts of the system. For example, increasing air ow decreases the subcooling, which
may require adding refrigerant. A er modi cations, allow
15 minutes for the system to stabilize and then retest.
Actual SC. Re-
Actual SC. e
Q: What if my ACTUALS are far di erent from
my TARGETS, but the system seems to be
running properly?
A: Many poor performing systems have actual super-
heat/subcooling measurements well outside the target. e system may be drastically overcharged or
undercharged. Comparing actual superheat/subcooling readings with the manufacturer’s equipment speci c target superheat/subcooling o en con rms the
system’s condition. Sometimes there is something else
wrong.
Make sure the system has been in operation for at least
15 minutes and is stable. Make sure it continues to
operate throughout the test. Take your readings in as
short of a time period as possible. ings can change,
even for a system that appears stable.
Make sure your test equipment is calibrated. Refer to
the manual of the accessory head for calibration instructions. Make certain the unit selected corresponds
to the reading you are taking. For superheat on accessory heads (ASX14, ASX24), make certain the large
switch on the face of the head is switched to superheat and small switch is in the “SH” position. Make
certain that you are testing for superheat/subcooling
at the proper location in the system. Test the evaporator/suction line side of the system for superheat. Test
the condenser/high side of the system for subcooling.
If you still get readings that don’t seem right, you can
perform a manual test using your gauges, a wet sock
for wet bulb (ATWB1 wet bulb thermocouple), thermometer, refrigerant chart, and manufacturer’s target
superheat chart. If it still appears your unit is reading
superheat/subcooling incorrectly, call Fieldpiece technical support.
Q: Where can I nd more info on Superheat
and Subcooling?
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A: Visit www. eldpiece.com
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4.1 Combustion
Supply
Plenum
Flue
Combustion Test helps you determine the e ectiveness of the combustion by analysis of combustion products and temperature.
e Combustion Test will only tell you about combustion and does not take into account any losses from
poor insulation, or cycling and standby losses. It does
not measure any losses in the distribution system such
as uninsulated hydronic piping, air duct leakage or insulation levels.
Properly tuned gas combustion equipment will
produce little or no carbon monoxide, no soot, and will
consume less fuel.
Supply
Plenum
Flue
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Figure 17. CO measurement of fl ue gas for the Combustion Test using an
ACM3 Carbon Monoxide Head and the pump that’s included with the AOX2
Combustion Check Head.
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4.2 Combustion INPUT FORM Overview
Select the Fuel and what type of
equipment you are working on.
Can be measured automatically with
Fieldpiece accessory heads.
Customer ID is useful for record keeping.
4.3 Combustion OUTPUT FORM Overview
Modify combustion equipment
to bring these calculations to the
manufacturer's specifications.
Sections of manual with more
information about this test.
Figure 18. Combustion Test INPUT FORM.
Combustion gases should be sampled close to the exit
from the heat exchanger within an area where all gasses
would be well mixed and before dilution air enters the
venting systems i.e., dra hoods, barometric dampers, etc.
Testing within 18 inches of the breech is a typical location
for most oil- red equipment. If the appliance is an atmospheric gas with a dra hood, the test would be taken in
the top ue passage prior to mixing with dilution air.
A er testing is complete, the hole in the ue/stack
must be patched with temperature silicone or a comparable plug.
Fuel: Select Natural Gas, Oil #2 or Propane for the fuel
type of the system or appliance.
Type : Default: Condensing. Other selection: Non-Con-
densing. e presence of a condensate line indicates
a condensing unit, otherwise it is a non-condensing
unit.
O2: Connect the AOX2 with the switch on %O
and take
2
a sample of the combustion products in the ue/stack
(within 18 inches from the start of the ue).
Flue Temp: Connect the ATR1 temperature probe to
the AOX2. Set the AOX2 on TEMP and measure the
temperature of the combustion products in the ue/
stack (18 inches from the start of the ue).
CO: Connect the ACM3 and take a sample of the com-
bustion products in the ue/stack in the same location
as the O2% measurement (within 18" from the start of
the ue).
Primary Temp: Measure the temperature of the air
being introduced to the combustion process. Measure
the air temperature as close as possible to the entry
point of the appliance.
Figure 19. Combustion Test OUTPUT FORM.
Press OUTPUT for the Combustion OUTPUT
FORM.
CO2: e %CO
Excess O2: e amount of O
in the combustion products.
2
above the minimum
2
theoretical amount needed for complete combustion. For complete and e cient combustion, excess
O
must be adjusted to manufacturer’s speci ca-
2
tions.
COAF (carbon monoxide air free): e amount of CO
in the combustion products taking into account the
dilution e ect of excess O
.
2
Net Temp: e stack (vent) temperature minus the
primary air temperature.
Standard E (E ciency): e actual e ciency of the
combustion equipment calculated by analyzing the
losses up the exhaust.
Siegert E (E ciency): e European standard for
combustion e ciency.
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e following tables show acceptable results from
the Combustion Test for di erent types of equipment
For all combustion equipment, ANSI Manufacturing
Standards recommends
carbon monoxide (CO)
2
.
should be below 400PPM in the ue. Technical
Standards and Safety Authority recommends repair
above 100PPM in the ue.
Erik Rasmussen
Atmospheric Fan Assisted Natural Gas or LPG
Oxygen (O2) 6-9%
Stack Temperature 325-500°F
Condensing Natural Gas or LPG
Oxygen (O2) 6-9%
Stack Temperature 90-140°F
Natural Gas/LPG Power Burners
Oxygen (O2) 3-6%
Stack Temperature 275-500°F
Fuel Oil Flame Retention Power Burners
Oxygen (O2) 3-7%
Stack Temperature 325-500°F
Fuel Oil Non-Flame Retention Power Burners
Oxygen (O2) 6-9%
Stack Temperature 400-600°F
Condensing Oil
Oxygen (O2) 3-7%
Stack Temperature 90-140°F
Erik Rasmussen has been an expert in the combustion analysis eld for over 20 years. Rasmussen has
helped Fieldpiece in providing much of the tables and
contents of the combustion section in this manual to
re ect the best real-world practices and knowledge of
today. Rasmussen has also authored and coauthored
several books on combustion analysis which go into
much greater depth on the fundamentals of the operation and diagnosis of combustion equipment.
• Sixteen 16 years as a service and installation
specialist of:
* Natural gas
* Propane
* Oil heat
* Air conditioning
• Contractor
• HVACR Instructor
• Co-author, "Carbon Monoxide: A Clear and Pres-
ent Danger", ESCO Press
• Author, “Combustion Analysis and Fuel E cien-
cy”, ESCO Press
• International Programs Director for COSA, the
Carbon Monoxide Safety Association
• Board Member HVAC Excellence
• President of ESCO press international, (Canada)
2 From Carbon Monoxide a Clear and Present Danger Third Edition, Dwyer,
Leatherman, Manclark, Kimball, Rasmussen, ESCO Press 2003.
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• Rasmussen continues to stay current on all tech-
nologies and procedures through the operation of
his own service organization.
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5.1 “CheckMe!®” (HG2 Only)
5.2 CheckMe!® INPUT FORM Overview
3
“CheckMe!®” is the most advanced real-world
method for troubleshooting A/C systems. It looks at the
big picture to diagnose problems. Superheat, Subcooling,
and Target Evaporator Exit Temperature tests look at individual performance indicators to determine if they are
within proper range.
a whole to give a more complete diagnosis.
CheckMe!® looks at the system as
CheckMe!®
saves time and money by quickly diagnosing a range of
problems or even multiple problems.
CheckMe!® rec-
ommends actions to tune the air conditioning system
to its optimum with minimal retests. is leads to even
fewer call backs.
e algorithms built into CheckMe!® are based
on the real world servicing of over 150,000 air conditioners. e testing procedure and accuracy of the
diagnosis have been re ned over many years by Proctor Engineering. e CheckMe!® switch position is a
real time-saver because it can give you a more accurate
diagnosis than looking at individual aspects of the air
conditioner.
e CheckMe!® has 35 diagnoses which will help
you pinpoint the problem with the air conditioning
system. In addition to giving you better diagnoses, the
CheckMe!® test will ensure that you have lled in the
form completely and warns you if conditions are unlikely to exist or impossible. In these cases, you will
want to retake some measurements.
CheckMe!® will analyze the system with almost any
amount of data. e more information supplied to the
program, the more accurate and comprehensive the diagnosis. CheckMe!® determines the current state of the
equipment. erefore you can pretest equipment prior
to any repairs.
General Information: The type of
system and the nominal tonnage.
Can be measured automatically with
Fieldpiece accessory heads.
True Flow: The measurements are
only visible if you select Yes for True
Flow. These are manual inputs.
Customer ID is useful for record
keeping.
Grant: These are all manual inputs
which are used for record keeping
when participating in a grant
program or third party verification.
Units can be changed to either
English or Metric.
Figure 20. CheckMe!® INPUT FORM.
e quickest way to an optimized system will be to
clean coils and lters prior to the initial test. en completely ll out the the CheckMe!® INPUT FORM for a
more comprehensive and accurate diagnosis of the system.
3 CheckMe!® is the registered trademark of Proctor Engineering Group, Ltd.
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CheckMe!® INPUT FORM
Sys Type (System Type): Default: AC (Air Condition-
ing). Other selections: H Pump Heat (heat pump in
heating mode), H Pump Cool (heat pump in cooling mode) or Geothermal.
Nom Ton: Nominal tonnage of the A/C system.
INDOOR UNIT
All temperature and pressure measurements must
be taken a er the unit reaches steady state (generally 15
minutes of continuous operation).
Metering Device: Default: TXV/EXV. Other selec-
tion: Fixed.
ID Volt (indoor unit voltage): Default: 120V 1 phase.
Other selections: 240V 1 phase, 240V 3 phase, 460V
3 phase or 575V 3 phase.
Return DB (dry bulb) and Return WB (wet bulb):
Take measurements very close or within the return
air side of the inlet to the air handler (not at the re-
turn grill since temperatures change by the time the
air reaches the indoor coil). Wet the wet bulb sen-
sor (ATWB1) and insert it a er 15 minutes of con-
tinuous running. Insert the dry bulb sensor (ATA1)
through the same hole. ey can be clipped together
on the downstream side of the lter if the lter is
just before the air handler.
Watch the wet bulb temperature; it will drop and
then stabilize. e wet bulb temperature is the sta-
bilized reading. If the sensor starts to dry out, the
reading will rise and the wrong temperature will be
recorded. If the lter is not directly upstream of the
air handler, make small holes in the return plenum
just big enough for the probes. Seal any holes before
leaving the jobsite.
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Supply DB (dry bulb leaving the indoor coil): Mea-
sure in the center of the supply plenum. Make a
small hole in the supply plenum and insert a calibrated dry bulb thermocouple such as the ATA1 or
ATB1. Determine the average air temperature in the
supply plenum.
OUTDOOR UNIT
Refrigerant: Default: R-22. Other selections: R410A,
R-134A, R-404A, R-407C, R-409A, R-408A, R-507A,
R-414B (Hotshot
(NU222B
TM
Rated Amps (Rated amperage of the outside unit):
is can be found on the nameplate along with the
outdoor voltage and the refrigerant.
OD Volts (outdoor unit voltage): Default: 240V 1phase.
Other selections: 120V 1 phase, 240V 3 phase, 460V
3 phase or 575V 3 phase.
Target Subcool: Manufacturer’s recommended
subcooling for TXV/EXV systems. is varies by
manufacturer , and may also change depending on
weather conditions. Always charge to the equipment manufacturer’s speci cations when available.
If no target subcooling is available then the HVAC
TM
Guide
tester will make a conservative estimate.
SL Pressure (suction line pressure): Connect the
ASX14 to the suction side service port. Select pressure mode on the ASX14 head. e system must be
stabilized before taking the measurements. Enter
data manually if you want to get pressure from your
gauges. e analysis is only as good as the measurements. e Fieldpiece ASX14 has better resolution
than most gauge sets.
SL Temp (suction line temperature): Measure near SL
service port (within 6 inches). Use the ATC1, ATC2
or ATC3 to get a good pipe temperature. e clamp
should be perpendicular to the pipe and should be
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TM
) or R-12.
), R-422C (OneshotTM), R-422B
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securely seated with the sensor in contact with the
suction line. If working on a package unit make sure
you are at least 6 inches away from the compressor.
TrueFlow®: Default: NO. If NO, skip ahead to the
Grant section. Answering YES unlocks the inputs
for this section.
LL Pressure (liquid line pressure): Connect the
ASX14 to the liquid line service port. Set the acces-
sory head to measure pressure and ensure the read-
ing stabilizes before locking in the reading. Enter
data manually if you want to get pressure from your
gauges. e analysis is only as good as the measure-
ments. e Fieldpiece ASX14 has better resolution
than most gauge sets.
LL Temp (liquid line temperature): Measure near the
same location LL Pressure was taken. Use the ATC1,
ATC2 or ATC3 to get a good pipe temperature. e
clamp should be perpendicular to the pipe and
should be securely seated with the sensor in contact
with the liquid line. If working on a package unit
make sure you are at least 6 inches away from the
compressor.
Condenser Air Enter Temp (Condenser Air En-
tering Temperature): Clip a calibrated ATA1 to the
inlet of the condenser ns (typically on the side of
the condenser), in the shade if possible. Note that
the temperature of the air entering the outdoor coil
can be considerably di erent than the ambient tem-
perature due to recirculation of air exiting the unit.
Determine the average temperature of the air enter-
ing the condenser.
Cond Amps Draw (Condensing unit amp draw):
Actual amperage of the outdoor unit. For a package
system this will be the total amp draw of the unit.
is measurement must be taken with another me-
ter with an AC Amp clamp (such as the SC77) and
then input manually.
Supply Plenum Press Without Grid: TrueFlow®
system operating pressure with the lter installed
and no TrueFlow® grid. is is the NSOP and is
measured using the static pressure probe included
with the TrueFlow® plate.
Grid Size: Default: 14 inches. Other selection: 20 inches.
Choose the grid size you are using.
Grid Pressure: is is the TFSOP and is measured
using the TrueFlow® plate.
GRANT
If you are working under a grant you must add additional information about the system to qualify for the
grant. In parts of the United States,
to qualify for tax rebates and/or nancial incentives.
ese programs have speci c requirements that will be
available in the HG2.
Residential and commercial air conditioning constitutes about 15% and 33% peak of the electricity consumed in this country. Utilities or regulatory committees o en o er grants to motivate consumers to save
energy.
In order to participate in these grants a technician
will usually have to work through a third party veri er.
Contact your local utility to learn on how to become a
grant participant.
Te s t : Default: Initial. e other selection is A er Re-
pair.
CheckMe!® is used
TrueFlow®
e TrueFlow® meter measures the air ow directly
via a grid installed in place of the lter (or other location
that has all the indoor unit air ow through it).
4 TrueFlow® is the registered trademark of The Energy Conservatory.
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Grant: Default: None. Other selections will be avail-
able as grants are included. Some grants require different calculations.
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5.3 CheckMe!® OUTPUT FORM Overview
5.401 Air ow OK: e indoor coil air ow was di-
rectly measured using the TrueFlow® grid and is
OK.
The diagnosis are displayed in order
of likelihood.
Shows you where in this manual
you can get more information about
what the diagnosis means and how
to correct the problems.
Figure 21. CheckMe!® OUTPUT FORM.
Press the OUTPUT for the CheckMe!® OUTPUT
FORM.
e diagnoses and recommendations are listed in
order with the most likely diagnosis rst.
Because all parts of an A/C system are inter-dependent, changes made to one part of the system can affect other parts of the system. For example, increasing
air ow may increase the superheat, which may require
adding refrigerant. To be e cient, continually check the
superheat and/or subcooling as you make refrigerant
charge adjustments. A er nal modi cations, allow 15
minutes to stabilize before your nal test.
5.402 Probable OK air ow: e indoor coil air-
ow was tested by an indirect means (temperature
split) and is probably OK.
5.403 Air ow unknown, check air ow: e
measurements are insu cient to diagnose the indoor coil air ow. Either measure the Return Plenum Dry Bulb, Wet Bulb and Supply Plenum Dry
Bulb or use a True Flow Plate.
5.404 Low air ow, increase air ow until actual temp split matches target temp split: e
indoor coil air ow is low based on the temperature
split. Check the lter and coil, inspect for any restrictions and blockages. Make sure all registers are
open. If the air ow remains low, consider increased
blower speed and duct system modi cations. Supply and return plenum static pressures can be used
to diagnose the causes of low air ow.
5.405 Low air ow, increase air ow: e indoor
coil air ow was directly measured using the TrueFlow grid and is low. Check the lter and coil, inspect for any restrictions and blockages. Make sure
all registers are open. If the air ow remains low,
consider increased blower speed and duct system
modi cations. Supply and return plenum static
pressures can be used to diagnose the causes of low
air ow.
5.4 Indoor Coil Air ow
Low air ow across the inside coil is one of the most
common problems and should be corrected before nal
decisions are made about refrigerant charge or many
other issues. Air ows in moist and wet climates should
usually be between 300 to 350 cfm per ton. Air ows in
Dry climates are limited by the rapidly increasing watt
draw of the fan motor at higher air ows.
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5.406 Low capacity or possible high air ow,
measure air ow directly: e temperature
split is low. is usually means that the capacity of
the system has been reduced due to incorrect refrigerant charge. Higher than expected air ow is rare,
but does occur occasionally. Measuring the air ow
directly would identify if high air ow is the cause of
the low temperature split.
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5.407 High air ow, possibly reduce air ow: e
indoor coil air ow was directly measured using the
TrueFlow grid and is higher than expected. Consider
reducing the air ow particularly if the unit is in a
damp climate. In heat pumps high air ow causes uncomfortably low delivery temperatures.
5.408 Possible plenum temperature measurement error, retake plenum temperatures:
e reported wet and dry bulb temperature readings
from the return and supply plenums are unlikely. Retake the measurements in the INPUT FORM. See Return DB and Return WB sections for detailed instructions on how to take these measurements properly.
5.501 Charge OK: Refrigerant charge was tested us-
ing the appropriate method and it is OK.
5.502 Possible OK charge: e primary indicator of
refrigerant charge (subcooling for TXV/EXV or superheat for non-TXV) indicates the refrigerant level
was OK. However, a secondary indicator reduces the
con dence in that diagnosis. Check out any other potential problems indicated.
5.503 Charge unknown, check charge: e mea-
surements are insu cient to diagnose the refrigerant
charge. For best results, measure both the suction line
temperature and pressure as well as the liquid line
temperature and pressure and press the OUTPUT
button again.
5.5 Refrigerant Charge
Incorrect refrigerant charge is the most common
problem with air conditioners and heat pumps. ere are
widespread poor practices and misinformation regarding
refrigerant levels.
e primary method speci ed by major manufactur-
ers for non-TXV ( xed metering device) systems is superheat. e superheat needs to be matched to the target
superheat, which changes with indoor and outdoor conditions. e optimum refrigerant charge as indicated by superheat is a ected by the air ow across both coils. Repair
any air ow problems before setting the nal refrigerant
charge.
e primary method for TXV or EXV systems is
subcooling. e subcooling needs to be matched to the
target subcooling. e target subcooling is usually on the
manufacturer's ID plate along with the model and serial
numbers.
For heat pumps, it is best to set the refrigerant levels
in the summer in the cooling mode. e HG2 can also
check the capacity of heat pumps in the winter as an indicator of correct refrigerant charge.
5.504 Possible undercharge, possibly add refrigerant: If no other conditions are triggered, con-
sider adding refrigerant to correct. ere is possibly
insu cient refrigerant in the system. e amount of
refrigerant necessary to add will vary based on the
size of the system and the di erence between Target
and Actual superheat/subcooling.
5.505 Probable undercharge, add refrigerant:
It is very likely that there is insu cient refrigerant in
the system. Add refrigerant to bring the superheat or
subcooling to within the target.
5.506 Undercharged, add refrigerant until actual superheat reaches target superheat: is
non-TXV system is low on refrigerant. Add refrigerant until the superheat is within the proper range
(usually ±5°F) of the target superheat. e closer the
superheat is to the target, the better.
5.507 Undercharged, add refrigerant to obtain
6°F of superheat: is non-TXV system is low on
refrigerant. Since the test conditions are hot outside,
dry inside, or both, the exact target superheat cannot
be determined. Because the superheat is greater than
6°F the unit is undercharged. Add refrigerant until the
superheat is 6°F.
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5.508 Charge unknown, raise indoor temperature to obtain a target superheat ≥ 5°F and
retest: Since the test conditions are hot outside, dry
inside, or both, the exact target superheat cannot be
determined. is non-TXV system may be correctly
charged or overcharged. It may be possible to open
windows or run the furnace to change the indoor
conditions enough to obtain a target superheat.
5.509 Possible overcharge, possibly remove refrigerant: If no other conditions are triggered, con-
sider recovering refrigerant to correct. e amount
of refrigerant necessary to recover will vary based on
the size of the system and the di erence between Target and Actual superheat/subcooling.
5.510 Overcharged, remove refrigerant until
superheat reaches target superheat: ere
is too much refrigerant in this non-TXV system. Remove refrigerant until the superheat is within ±5°F of
the target superheat. e closer the superheat is to the
target, the better.
5.511 Overcharged, remove refrigerant until
subcooling reaches target subcooling: ere
is too much refrigerant in this TXV/EXV system. Remove refrigerant until the subcooling is within ±3°F
of the target subcooling. e closer the subcooling is
to the target, the better.
5.512 Undercharged, add refrigerant until subcooling reaches target subcooling: is TXV/
EXV system is low on refrigerant. Add refrigerant
until the subcooling is ±3°F of the target subcooling.
e closer the subcooling is to the target, the better.
5.513 Overcharged, remove refrigerant until
actual subcooling reaches target subcooling: ere is too much refrigerant in the system. e
amount of refrigerant necessary to recover will vary
based on the size of the system and the di erence between Target and Actual subcooling.
5.514 Overcharged, remove refrigerant until
actual superheat reaches target superheat:
ere is too much refrigerant in the system. e
amount of refrigerant necessary to recover will vary
based on the size of the system and the di erence between Target and Actual superheat.
5.515 Possible low evaporator capacity: e
evaporator is suspected of being unable to deliver the
cooling load necessary to maintain the desired indoor
conditions. Check the refrigerant charge (most common), clean the evaporator and/or condenser coils
and verify that the indoor air ow is correct.
5.516 Probable oversized metering ori ce, consult manufacturer’s speci cations: e me-
tering ori ce is probably letting too much refrigerant through. Check that the ori ce is sized properly.
Find the metering device part number and obtain the
ori ce size from the manufacturer or distributor and
verify the size is appropriate for the air conditioner.
5.517 Probable undercharge, add refrigerant:
ere is probably insu cient refrigerant in the system. e amount of refrigerant necessary to add will
vary based on the size of the system and the di erence
between Target and Actual superheat/sub-cooling.
5.518 Superheat too high for TXV, check liquid
line for restriction: If there is a liquid line restric-
tion then the TXV/EXV will be unable to maintain a
proper superheat. Make sure the service shut-o valves
are open. Check the liquid line for kinks or sections
that may have been stepped on or crushed. Check for
a large temperature di erence between the liquid line
at the compressor and at the metering device.
5.519 Superheat too low for TXV, check TXV
to ensure proper functioning: If the TXV/EXV
is not set properly, then the TXV/EXV will be unable
to maintain a proper superheat. Check that the TXV/
EXV bulb is adjusted to the proper superheat, and is in
good contact with the suction line and insulated from
the environment.
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5.6 Refrigerant Lines and Metering Devices
Research has shown that refrigerant line restrictions, incorrect ori ce sizes, and TXVs improperly installed are far more common than originally thought.
All of these problems can lead to premature compressor
failure.
If there are restrictions in the refrigerant lines
(pinches, dirty lter driers) the charge measurements
will provide contradictory information and getting
proper performance will not be possible. Similarly if the
ori ce of the metering device is too small or partially
blocked by foreign material in the refrigerant (such as
chips and akes from improper brazing technique) the
unit will not perform to speci cations.
If a xed ori ce is too large (not matched to the inside coil), the refrigerant will not meter properly, contradictory measurements will be obtained, and performance will su er.
A thermostatic expansion valve (TXV) only works
when the sensing bulb is in solid contact with the suction line and only senses the temperature of the suction
line. erefore it must be well insulated from surrounding air. e TXV is designed to maintain a constant superheat.
5.601 Possible oversized metering ori ce,
consult manufacturer’s speci cations: e
metering ori ce is suspected of letting too much
refrigerant through. Check that the ori ce is sized
properly. Find the metering device part number and
obtain the ori ce size from the manufacturer or dis-
tributor and verify the size is appropriate for the air
conditioner.
5.602 Probable oversized metering ori ce,
consult manufacturer’s speci cations: e
metering ori ce lets too much refrigerant through.
Check that the ori ce is sized properly. Find the
metering device part number and obtain the ori ce
size from the manufacturer or distributor and verify
the size is appropriate for the air conditioner.
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5.603 Check TXV to ensure proper functioning: is TXV is not maintaining proper superheat.
Check that the TXV bulb is adjusted properly and
in continuous contact with the suction line and well
insulated from the surrounding air.
5.604 Probable liquid line restriction, check
liquid line: Make sure the service shut-o valves
are open. Check the liquid line for kinks, tight
bends or sections that may have been stepped on
or crushed. Check for a large temperature di erence
between the liquid line at the compressor and at the
metering device.
5.7 Condenser Coil Performance
5.701 Condenser air ow OK: e condenser air-
ow and capacity indications are OK.
5.702 Condenser approach unknown, check
condenser approach: Liquid line temperature
and liquid line pressure measurements need to be
taken at the condenser approach. ese measurements give indications of the performance of the
air conditioner including diagnoses of compressor
problems, low capacity, and low condenser air ow.
5.703 Low condenser air ow, clean condenser, check condenser fan motor bearings:
ere is insu cient air ow going across the condenser for the needed heat transfer. Check that the
condenser coils and ns are clean, aligned and free
of nearby obstructions. Check the fan motor bearings to ensure that the fan is rotating freely.
5.8 Outdoor Unit Amp Draw
e outdoor unit amp draw gives indications of the
health of the compressor as well as overcharge and condenser coil performance.
5.801 Outdoor amp draw OK: e outdoor unit
is running at the proper amperage for the current
conditions.
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5.802 Condensing unit amps unknown, check
condensing unit amps: e outdoor unit amp
draw was not measured.
5.803 High outdoor amp draw, probable excessive compressor friction: Check other possible
causes of high amp draw (low condenser air ow and
refrigerant overcharge) before condemning the compressor. Check that condenser coils and ns are clean,
aligned and free of nearby obstructions.
5.804 Low outdoor amp draw, possible compressor valve or motor problem: Check the re-
frigerant charge before condemning the compressor.
5.9 Cooling Capacity
e heat rejection at the outside unit is another mea-
surement that gives indication of the health of the compressor as well as other potential problems.
5.901 Condesner capacity OK: e condenser is
delivering the proper capacity.
5.902 Low condenser capacity, check charge,
retest: is unit is rejecting less heat than expected.
Check the refrigerant charge, repair if needed, and retest.
5.10 Heat Pump in Heating
Test the refrigerant charge for a heat pump in the summer in the cooling mode if possible. is procedure checks
the heating capacity of the heat pump against the expected
capacity for the test conditions. In order to determine the
capacity of a heat pump, the air ow through the inside
coil must be directly measured with the TrueFlow®.
5.1001 Heating Capacity OK: e heat pump is de-
livering the proper heating.
5.1002 Capacity unknown, check capacity: e
TrueFlow inputs, outdoor unit entering temperature,
return plenum temperature, and supply plenum tem-
perature need to be measured before determining ca-
pacity.
5.1003 Low capacity, defrost outside coil or ad-
just charge and retest: Verify that the outside coil
is not frosted or iced. Frost reduces the capacity of the
heat pump. If the unit is not frosted, adjust the refrig-
erant charge per the manufacturer’s speci cation.
5.1004 High temp split, make sure strip heat is
NOT on: Check amperage to the electric strip heat-
ers to verify they are turned o .
5.903 Low condenser capacity, check compressor amps and coil saturation temperatures:
Full diagnosis of this situation requires a complete set
of data including compressor amps, high and low side
pressures, and liquid and suction line temperatures.
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Advanced Operations
Time
e internal clock is the basis for the time stamps
saved with test data. e time cannot be altered once
data is taken; therefore, setting up the time before taking data is important to maintain records in the correct
order. e TIME is shown on the bottom of the LCD on
most INPUT FORMs.
• Rotate the dial to the TIME switch position.
• Press RIGHT arrow to change time if needed.
• LEFT and RIGHT arrows cycle through month,
day, year, military clock, and minutes.
• UP and DOWN arrows adjusts.
• Press ENTER to set time.
Memory (MEM)
Units
On every INPUT FORM there is a “Units” line. e
default is English units. Metric units can be used by
pressing the RIGHT arrow when “Units” is highlighted.
Scroll Up or DOWN to toggle between English and
Metric units. Press ENTER to lock in your selection. e
HVAC Guide
you have taken when units are changed mid test.
TM
tester will convert any measurements
CUSTOMER ID
On every INPUT FORM there is a Customer ID
line used for record keeping and long-term customer
tracking. Press ENTER when “CUSTOMER ID” is highlighted to select a previously saved Customer ID.
To enter a new (unsaved) Customer ID, press the
RIGHT arrow when “CUSTOMER ID” is highlighted.
Now adjust the value character-by-character using the
UP/DOWN arrows and the RIGHT arrow. When nished press ENTER to input the new Customer ID.
From the Memory switch position you can delete a
single test, entire customer le or all data. You can also
check your version of rmware to see if you are up to
date and your memory status, to see how much memory
you have le . You can also communicate with the PC
and transfer data to and from with the “Com with PC”
option. See page 56 for more details.
Figure 22. Screenshot of Memory (MEM) switch.
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Figure 23. Selecting a previously saved Customer ID.
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Clearing a single input or INPUT FORM
Recalling Saved Tests
Press CLEAR when an input is highlighted to erase
a single input. Hold the CLEAR button for three seconds
and select Yes to clear an entire INPUT FORM.
Figure 24. Deleting the entire INPUT FORM of a Superheat Test.
Saving Data
Press the SAVE button and press ENTER while Yes
is highlighted when in an INPUT FORM to save test
data. Test data is saved along with Customer ID and a
time stamp. You will be prompted to input a Customer
ID before saving.
While in the desired test, press the RECALL button to access previously saved test data. Highlight
the Customer ID from the list and press ENTER and
then highlight the date and time of the test you wish
to recall and press ENTER again. e INPUT FORM
for that switch position will then be populated with
the previous test’s data. No Outputs are saved on the
HVAC Guide
TM
tester, they are simply recalculated
from the saved inputs.
Figure 26. Selecting the Customer ID of the test to Recall.
Figure 25. Saving data for Superheat analysis.
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Figure 27. Selecting which test time to Recall.
Contrast Adjustment
To adjust the contrast level of the display hold the
BACKLIGHT button until the Contrast Adjustment
Screen shows. Press UP and DOWN arrows to adjust,
and ENTER to set.
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PC Software
Installing the PC Software
1. To install the HVAC Guide
your PC, insert the CD into the CD-ROM drive. e
installation window should pop-up automatically.
If not, manually open the CD contents through "My
Computer." Click the grey button next to "Install
PC So ware." Follow the on-screen instructions.
2. For your PC to recognize the HVAC Guide
a driver must be installed. Click on the grey button next to "Install USB Driver..." from the installation window. No new window will pop-up on your
screen.
3. Exit out of the installation screen.
TM
tester so ware onto
TM
tester
Communicating with a PC
1. Make sure the HVAC Guide
the IR2 USB cable into the bottom of the HVAC
TM
Guide
tester.
2. Plug the USB end of the IR2 USB cable into a USB
port of your PC.
TM
tester is o . Plug
Communicating with a PC (continued)
5. Launch the HVAC Guide
your Desktop or the Start menu on your PC.
6. e New Technician screen will pop-up. Fill out the
screen. Click save. is information will be printed
on work orders you generate.
7. e Data Transfer screen is displayed when the
HVAC Guide
to-Detect" on the Data Transfer screen.
TM
tester is detected. If not, click "Au-
TM
tester so ware from
3. Turn the dial to "MEM" on the HVAC Guide
TM
tes-
ter.
4. Scroll down to "Com with PC" and press ENTER.
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8. Click the red arrow pointing to the PC in order to
transfer data to the PC.
9. Click on desired les to transfer to the PC and click
the "Transfer to PC" button.
10. Close window when transfer is complete.
11. To open the les, go to My Documents/HVAC
Guide/Jobsite Files. e les will be listed by their
Customer IDs.
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Transferring Tests from the HVAC Guide
Tester to a PC
1. Press the Transfer arrow pointing to the right.
TM
3. If you want to change where the les are saved to,
press the "Browse Desination" button. Browse your
PC for a folder in which you would like to save the
les from the HVAC Guide tester and press "Select
Cur Dir" to assign.
2. Highlight the les you wish to transfer to the desti-
nation folder on your PC and press the "Transfer to
PC" button to transfer.
Destination folder
Click if you want to create a new folder.
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Click on headers to sort.
Files currently in the
destination folder on PC.
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Transferring Tests From the PC to the HVAC
Guide
1. Press the Transfer arrow pointing le .
TM
Tester
3. If you want to change where the les are located on
your PC, press the "Browse" button. Browse the PC
for a folder containing les for transfer the HVAC
Guide tester and click "Select Cur Dir" to bring
those les to the transfer screen.
2. Highlight the les you wish to transfer to the HVAC
TM
Guide
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tester and press "Transfer" to send.
Files applicable for transfer from
the destination folder on PC.
58
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Looking at Downloaded Data
Other Operations
Locate the HVAC GuideTM tester les on your PC
with Windows Explorer or My Computer. e les will
be located in the directory you speci ed them to be
transferred to when you clicked the Browse button on
the Transfer to PC screen. You must have a program that
opens .xls spreadsheets such as Microso Excel
TM
. Open
the le(s) by double clicking. e Filename is the customer ID followed by the test type and the time stamp
in the following format:
xxxxxxxxxxwwYYMMDDhhmmss.xls. Where x's represent the Customer ID and ww represents the abreviation of the test performed:
ET: Target Evaporator Exit Temperature
SH: Superheat
SC: Subcooling
CA: Combustion Analysis
CM: CheckMe!®
Once you have opened the le you can print it from
your PC.
Test type
Jobsite information
with PC Software
Editing Jobsite Information
You will get to the Editing Jobsite screen when
transferring data from the HVAC Guide
PC when the Customer ID is not in the PC database.
You can also edit jobsite information in the database by clicking on Setup then Edit Jobsite from the
drop-down menu.
TM
tester to the
Click to cancel without
saving changes.
Customer ID is linked to
Jobsite information.
Your company logo
Technician information
Customer ID
Measurements and
results of test
Technician information
Figure 28. Test Data on PC.
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Saves changes to a
jobsite.
Deletes a jobsite
Figure 29. New jobsite entered.
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Editing Technician Information
Problems Communicating with PC
You can edit technician information in the database
by clicking on "Setup" then "Edit Technician" from the
drop-down menu.
Using the Name select drop down menu select technician from the list or Select to create a new technician.
Click to browse for company
logo for technician.
Figure 30. Editing Technician Information.
You will be taken to the “Com Port Setup” screen
if there is any error in communicating with the HVAC
TM
Guide
tester while starting the program.
Only attempt to
manually select the
COM port if the AutoDetect has failed and
you are sure the meter
is connected and ready
for communication. The
COM port used can be
found in the hardware
wizard.
Figure 32. COM Port Setup.
Reconnect the HVAC Guide
TM
tester, select Com
with PC press ENTER and press AUTO-Detect to reestablish the connection with the HVAC Guide
TM
tester.
You can look in the Windows Hardware Wizard to see
if the HVAC Guide
TM
tester is communicating properly
with the PC and to troubleshoot the driver if it is not.
About
Click on “About” from the Setup drop down menu
to view the About screen.
e latest rmware and so ware will be available at
www.Fieldpiece.com .
Number of tests saved on
the HVAC GuideTM tester.
Figure 31. About.
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Air Conditioning Basics
e Evaporator, Condenser, Restrictor ( rottling
valve) and Compressor are the four basic components
of an air conditioner. Following one pound of refrigerant through the system shows the function of each component.
Subcooled liquid refrigerant at high pressure enters
the restrictor and is throttled to saturated refrigerant at
a lower pressure. e restrictor can be of either a xed or
TXV/EXV type. e xed type must be charged to a target superheat that varies with indoor and outdoor conditions. e evaporator capacity varies with the indoor
heat load on a xed restrictor. e TXV/EXV regulates
the size of the restriction to maintain a constant superheat. is essentially adjusts the capacity of the evaporator responding to the indoor heat load. TXV/EXV systems must be charged to subcooling.
A er the restrictor, refrigerant enters the evaporator
at a low temperature and pressure and boils (evaporates)
into a gas by absorbing heat from the indoor air. e refrigerant stays at the same temperature and pressure until all the refrigerant evaporates into a gas. A er the refrigerant becomes a gas, it will become superheated and
the temperature will change. e superheat measurement is the best indication of refrigerant charge level in
a xed restrictor system and a TXV/EXV system will
keep the superheat constant. ere must be superheat
present to ensure liquid does not ood the compressor.
Superheat measurements are taken on the suction line
between the evaporator and compressor.
is controlled by the throttle valve. Subcooling measurements are taken on the liquid line between the condenser and TXV/EXV. en the subcooled liquid enters the
restrictor and the cycle starts again.
e compressor takes this low temperature, low
pressure, slightly superheated refrigerant and compresses it into a much higher temperature and pressure.
e highly superheated gas enters the condenser
and rejects heat into the outside air. e refrigerant
condenses back into a liquid. Once all of the gas is condensed into a liquid then additional removal of heat
causes a temperature drop known as subcooling. TXV/
EXV systems are charged to subcooling since superheat
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Figure 33. The Refrigeration Diamond.
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Combustion Basics
Supply
Plenum
Flue
Combustion is the rapid oxidation of fuel. Oxygen
from air (20.9% oxygen & 79.1% Nitrogen) is used to
burn fuel producing heat. e appliances installed and
serviced by technicians, rely on clean e cient ames to
produce the energy needed to heat homes and hot water
etc. Combustion testing is necessary to maximize the ef ciency of the combustion systems and to minimize the
harmful emissions produced. Carbon monoxide and
carbon dioxide (greenhouse gas emissions) are products
of combustion. Proper tuning of the combustion process by combustion testing will reduce the production
of harmful carbon monoxide and decrease the amount
of fuel burned through the increase in e ciency.
Combustion e ciency can typically be increased by
creating a more balanced Air to Fuel ratio. e ratio of
air to fuel determines how much CO
how e cient the ame is.
Tuning of the O
, CO2 excess air, stack temperature
2
and temperature rise to match the appliance manufacturers speci cations will increase the e ciency and help
to maximize the performance and life expectancy of the
equipment.
A properly tuned atmospheric natural gas or propane red appliance will have approximately 6 to 9% O
in the ue gases. Fuel oil appliances with ame retention
burners will have approximately 3 to 7% O
gases. For a more detailed breakdown see the chart on
page 32.
Testing and adjustment to the combustion process
ensures that the highest combustion e ciency is safely
achieved, thereby reducing the overall amount of fuel
used in producing the energy needed. It is still necessary
to test and adjust the appliance to the manufacturers’
speci cation for air ow in the duct system, temperature
rise across the heat exchanger and anything else that
may need testing. Testing and balancing of appliances
to meet manufacturers’ speci cations helps to ensure
maximum system e ciency and equipment longevity.
Combustion testing does not take into account start
up losses, standby losses, cabinet/boiler body losses, or
distribution losses in ducts or piping.
is produced and
2
in the ue
2
2
5
Supply
Plenum
Flue
Figure 34. Entering the CO measurement for the Combustion Test us
ing an ACM3 Carbon Monoxide Head and the pump that's included
with the AOX2 Combustion Check Head.
Below is Fig 4-9 from the book Combustion Analy-
sis and Fuel E ciency, Erik Rasmussen ESCO Press
2007.
5 Content adapted from Erik Rasmussen's book Combustion Analysis and Fuel
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Product Specifications
Accessory Head Input Voltage
Features
Dot matrix display mode (128 x 64 dot)
Scrolling display
USB (RS-323 (232)) & PC dual way transmission
Input setting: drop down menu, signal (automatic) in-
put, manual input
Display Contrast adjustment
Firmware program & Table data update through PC
so ware
PC operation management; output report in (Excel
Blue Backlight
Test Data Diagnosis:
· Target Evaporator Exit Temperature
· Superheat Analysis
· Subcooling Analysis
· Combustion Analysis
· CheckMe!® Analysis (model HG2)
Data Record:
· Customer I.D./Time
· Time (Date/Time Setting)
· Accessing Saved Tests
· Clear Saved Data
TM
)
Range: 500mVDC, 5VDC (auto)
Accuracy: ±(0.5%rdg+2dgts)
Input protection: Max. 30VDC/24VAC
0.1mV = 1 count on 500mV range
1mV = 1 count on 5V range
Limited Warranty
is meter is warranted against defects in material
or workmanship for one year from date of purchase.
Fieldpiece will replace or repair the defective unit, at its
option, subject to veri cation of the defect.
is warranty does not apply to defects resulting
from abuse, neglect, accident, unauthorized repair, alteration, or unreasonable use of the instrument.
Any implied warranties arising from the sale of a
Fieldpiece product, including but not limited to implied
warranties of merchantability and tness for a particular purpose, are limited to the above. Fieldpiece shall
not be liable for loss of use of the instrument or other
incidental or consequential damages, expenses, or economic loss, or for any claim of such damage, expenses,
or economic loss.
Speci cations
Display: 21 characters X 8 rows
Low battery indication: " " is displayed when the
battery voltage drops below the operating level. To
prevent data corruption wait until "Power O " is
cleared from the display before removing batteries.
Battery: AA x 6.
Operating environment: 0°C (32°F) to 50°C (122°F) at
<70% R.H.
Storage temperature: -20°C (-4°F) to 60°C (140°F) to
80% R.H. with battery removed from meter.
Dimensions: 210mm (8.27in) (H) x 80mm (3.15in) (W)
x 30mm (1.18in) (D)
Weight: approx. 400g (0.88lb)including battery.
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State laws vary. e above limitations or exclusions
may not apply to you.
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O
Obtaining Service
John Proctor
Prior to sending the meter in for repair, try taking the batteries out and reinstalling them or replacing
them.
Send the meter freight prepaid to Fieldpiece Instruments. For warranty service, send proof of date and location of purchase. For out-of-warranty service, send
$100, check or money order. e meter will be repaired
or replaced, at the option of Fieldpiece, and returned via
same shipping service (speed) as shipped to Fieldpiece.
For Help with the CheckMe!® switch position (model HG2), contact Proctor Engineering:
Proctor Engineering
Phone: (415) 451-2480
Fax: (415) 451-2491
418 Mission Avenue
San Rafael, CA 94901
For Help with the PC So ware, or general How to
Use questions as well as Warranty Repair Issues contact
Fieldpiece Instruments. www. eldpiece.com.
Disclaimer
Neither this book nor the HVAC GuideTM tester
makes you an expert in HVAC. e purpose of the
HVAC Guide
necessary tests to optimize an air conditioner easier and
to refresh your memory on how to perform those tests.
is book and the HVAC Guide
replace experience or completion of an HVAC program
from a school.
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TM
tester and this manual, is to make the
TM
tester by no means
70
and Title 24
John Proctor and Proctor Engineering have been
working with Fieldpiece Instruments to create a better
tool for the diagnosis of air conditioning systems in the
real world. Proctor's research exposed the need for tuning air conditioners and prompted legislators to add the
procedures to Title 24.
John Proctor is a professional engineer, 1965 graduate of MIT, and wrote most of the residential cooling
section of California's Title 24. is work was based on
his close association with journeymen technicians working on air conditioners in residences and small commercial buildings and his scienti c research monitoring the
actual performance of systems installed in homes and
commercial buildings across North America.
Proctor’s research con rmed that the vast majority
of air conditioners were working well below their designed e ciency, were experiencing premature failures,
and were responsible for customer dissatisfaction and
expensive call backs. e cause was the widespread use
of rules of thumb and incorrect adjustment techniques.
His research combined with others prompted regulators
to add Manufacturer approved procedures to California's Title 24.
During the course of Proctor's work with technicians it became apparent that a straightforward system
to support and assist technicians in correctly implementing these techniques in the real world was needed.
is spawned the CheckMe!® program, the rst thirdparty computerized expert system for technicians.
CheckMe!® is based on data collected from over 150,000
real-world residential and commercial air conditioning
systems, over 1,000 laboratory tests on a wide variety of
makes and models, and thousands of hours of data from
monitored units operating in the eld and over 18 years
of continous re nement.
In 1989, John Proctor founded Proctor Engineering
Group to focus on methods of improving air conditioners. e company is based in San Rafael, California and
is in continual contact with CheckMe!® certi ed technicians from coast to coast.
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