Munchkin VWH User Manual
HEAT TRANSFER PRODUCTS, INC.
120 BRALEY RD., E. FREETOWN, MA 02717
Installing, Operating & Maintaining
MUNCHKIN™ VWH HIGH EFFICIENCY
HOT WATER SUPPLY BOILER
Do not store or use gasoline or other flammable vapors and
liquids in the vicinity of this or any other appliance.
WHAT TO DO IF YOU SMELL GAS
• Do not try to light any appliance.
• Do not touch any electrical switch: do not use any phone in
your building.
• Immediately call your gas supplier from a neighbor's phone.
Follow the gas supplier's instructions.
• If you cannot reach your gas supplier, call the fire department.
Installation and service must be performed by a qualified
installer, service agency or the gas supplier.
WARNING
If the information in this manual is not followed exactly, a fire or explosion may
result causing property damage, personal injury or loss of life.
WARNING
This manual must only be used by a qualified heating installer / service
technician. Failure to comply could result in severe personal injury, death or
substantial property damage. It is also important to keep these Instructions
with the appliance.
MH27745
CONTROLS
USING THIS MANUAL
2
USING THIS MANUAL
SPECIAL ATTENTION BOXES
Throughout this manual you will see these
special attention boxes similar to this one,
which are intended to supplement the
instructions and make special notice of
potential hazards. These categories mean, in
the judgement of Heat Transfer Products, Inc.:
DANGER
DANGER indicates an imminently hazardous
situation which, if not avoided, will result in
death or serious injury.
WARNING
WARNING indicates a potentially hazardous
situation which, if not avoided, could result in
death or serious injury.
CAUTION
CAUTION Indicates a potentially hazardous
situtation which, if not avoided, may result in
minor or moderate injury.
CAUTION
CAUTION used without the safety alert symbol
indicates a potentially hazardous situation which,
if not avoided, may result in property damage.
WARNINGS
• THIS UNIT IS FOR CATEGORY IV VENTING - 2 PIPE ONLY. THIS IS A SEALED
COMBUSTION APPLIANCE.
• THIS HEATER INSTALLATION MUST CONFORM TO THE LATEST EDITION OF THE
“NATIONAL FUEL GAS CODE” ANSI Z223.1 NEPA 54 AND OR CAN/CGA B149
INSTALLATION CODES. STATE AND LOCAL CODES MIGHT ALSO APPLY TO
INSTALLATION.
• WHERE REQUIRED BY THE AUTHORITY HAVING JURISDICTION, THE
INSTALLATION MUST CONFORM TO THE STANDARDS FOR CONTROLS AND
SAFETY DEVICES FOR AUTOMATICALLY FIRED HEATERS, ANSI/ASME HEATER
AND PRESSURE VESSEL CODE, Section IV, ALONG WITH CSD1.
• THE HEATER, GAS PIPING, WATER PIPING, VENTING AND ELECTRICAL MUST BE
INSTALLED BY TRAINED & QUALIFIED PERSONNEL FAMILIAR WITH
INSTALLATION PRACTICES, LOCAL CODE, LICENSING REQUIREMENTS.
• IF THE INFORMATION IN THESE INSTRUCTIONS ARE NOT FOLLOWED EXACTLY,
A FIRE OR EXPLOSION MAY RESULT; CAUSING PROPERTY DAMAGE, PERSONAL
INJURY, OR DEATH.
• DO NOT STORE OR USE GASOLINE OR OTHER FLAMMABLE VAPORS AND
LIQUIDS IN THE VICINITY OF THIS OR ANY OTHER APPLIANCE;
• THE USE OF A LOW WATER CUT-OFF DEVICE MAY BE REQUIRED BY STATE OR
LOCAL CODES IF THE MUNCHKIN IS INSTALLED ABOVE RADIATION LEVELS.
TABLE OF CONTENTS
3
TABLE OF CONTENTS
PART 1 . . . . . . . . . . . . . . . . . . . . . .4 thru 8
GENERAL INFORMATION
A How It Operates . . . . . . . . . . . . . . . . . .4
B Munchkin Ratings and Dimensions . .5–7
C Pre-installation Requirements . . . . . . .7
D Pressure Relief Valve . . . . . . . . . . . . . .8
PART 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
ELECTRICAL
A Electrical Connection . . . . . . . . . . . . . .9
PART 3 . . . . . . . . . . . . . . . . . . . .10 thru 11
GAS CONNECTION
A Gas Connection . . . . . . . . . . . . . . . . . .10
B Gas Piping . . . . . . . . . . . . . . . . . . . . . .10
C Gas Table . . . . . . . . . . . . . . . . . . . . . . .10
PART 4 . . . . . . . . . . . . . . . . . . . .12 thru 18
VENTING
A Approved Venting Materials . . . . . . . .12
B Venting the Munchkin in
3”, 4” or 6” Plastic Pipe . . . . . . . . . . .12
C Longer Vent Runs . . . . . . . . . . . . . . .14
D Heater Removal from a
Common Vent System . . . . . . . . . . . .15
E Condensate Removal . . . . . . . . . . . . .16
PART 5 . . . . . . . . . . . . . . . . . . . .19 thru 29
PIPING
A Expansion Tank . . . . . . . . . . . . . . . . . .19
B High Velocity Circulator Pump . . . . . .19
PART 6 . . . . . . . . . . . . . . . . . . . .30 thru 34
START UP PROCEDURES
A Sequence of Operation . . . . . . . . . . .30
B Items to be checked before
lighting the Munchkin . . . . . . . . . . . . .30
C Lighting Instructions . . . . . . . . . . . . . .31
D Operating Instructions . . . . . . . . . . . .31
E Adjusting the Operating Set Points
of the Munchkin VWH Display . . . . . .31
F Status Menu . . . . . . . . . . . . . . . . . . . .32
G Test Mode . . . . . . . . . . . . . . . . . . . . . .32
H To Turn Off Gas to Appliance . . . . . . .33
PART 7 . . . . . . . . . . . . . . . . . . . .35 thru 37
TROUBLESHOOTING
A Munchkin Error Code . . . . . . . . . . . . .35
B Boiler Error . . . . . . . . . . . . . . . . . . . . .35
C Boiler Fault . . . . . . . . . . . . . . . . . . . . .35
PART 8 . . . . . . . . . . . . . . . . . . . .38 thru 43
MAINTENANCE
A Maintenance Procedures . . . . . . . . . .38
B Annual Maintenance . . . . . . . . . . . . . .38
C Condensate Cleaning Instructions . . .38
D Combustion Chamber
Coil Cleaning Instructions . . . . . . . . . .39
E Munchkin Controllers . . . . . . . . . . . . .40
GENERAL INFORMATION
4
RECOMMENDED SERVICE CLEARANCES
PART 1. GENERAL INFORMATION
A. HOW IT OPERATES
The Munchkin VWH is a hot water supply boiler designed to operate in conjuction with a hot water
storage tank. Each Munchkin VWH is equipped with a high velocity pump to keep the unit running
efficiently for many years of service. A flow switch monitors the water flow through the heat exchanger
to make sure that the unit has an adequate flow rate during operation. The Munchkin VWH Controller
accurately monitors the return and supply temperature that controls the output range of the Munchkin
When the system has sensed a temperature drop below the set point and minus the differential set
point, The Munchkin VWH will activate the blower motor for a pre-purge of 5 seconds before going
into operation. Once in operation, the Munchkin controller will now start to modulate the pre-mix
burner based on analyzing the return, supply, differential and operating set point temperatures. By
compiling this information, the controller utilizes an algorithm to fully adjust the firing rate while
maintaining the desired output temperature. The pre-mix burner fan has direct drive current, lowvoltage motor with pulse relay counting. This system allows precise control over the fan speed and
combustion air volumes. Coupled with the fuel and air mixing system which are set to provide a one
to one ratio of precisely measured volumes of fuel to air, an accurate and instant burner output is
achieved. This keeps the Munchkin VWH running at the highest efficiency.
RECOMMENDED SERVICE CLEARANCES
Figure 1-1
GENERAL INFORMATION
5
B. MUNCHKIN RATINGS AND DIMENSIONS
MODEL INLET OUTLET RECOVERY RATE
FIRST HOUR RATING
W/ 80 GAL. STORAGE TANK
FIRST HOUR RATING
W/ 119 GAL. STORAGE TANK
199 VWH 40° 80° 573 GAL 626 GAL 652 GAL
199 VWH 40° 90° 458 GAL 511 GAL 537 GAL
199 VWH 40° 100° 382 GAL 435 GAL 461 GAL
199 VWH 40° 110° 327 GAL 380 GAL 406 GAL
199 VWH 40° 120° 287 GAL 340 GAL 366 GAL
199 VWH 40° 130° 255 GAL 308 GAL 334 GAL
199 VWH 40° 140° 229 GAL 282 GAL 308 GAL
199 VWH 40° 150° 208 GAL 261 GAL 287 GAL
199 VWH 40° 160° 191 GAL 244 GAL 270 GAL
199 VWH 40° 170° 176 GAL 229 GAL 255 GAL
199 VWH 40° 180° 163 GAL 216 GAL 242 GAL
399 VWH 40° 80° 1149 GPH 1202 GAL 1228 GAL
399 VWH 40° 90° 919 GPH 972 GAL 998 GAL
399 VWH 40° 100° 766 GPH 819 GAL 845 GAL
399 VWH 40° 110° 657 GPH 710 GAL 736 GAL
399 VWH 40° 120° 575 GPH 628 GAL 654 GAL
399 VWH 40° 130° 510 GPH 563 GAL 589 GAL
399 VWH 40° 140° 460 GPH 513 GAL 539 GAL
399 VWH 40° 150° 418 GPH 471 GAL 497 GAL
399 VWH 40° 160° 383 GPH 436 GAL 462 GAL
399 VWH 40° 170° 354 GPH 407 GAL 433 GAL
399 VWH 40° 180° 328 GPH 381 GAL 407 GAL
Model
Input
Modulation
Output
Modulation
Supply/Return
Connection
Gas Connection
Size
Intake/Exhaust
Dia.
Shipping
Weight
L W H
199VWH 66,000–199,000 48,000–191,040 1¼” NPT ¾” 3” PVC Sch. 40 126 lbs. 24.50 18.25 25.88
399VWH 100,000–399,000 96,000–383,040 2” NPT 1¼” 4” PVC Sch. 40 267 lbs. 44.25 18.25 25.88
199 VWH at 20GPM
Pressure Drop for Tube Length of 1¼” Copper
(10) 90° Elbows ad (2) Tees (Side Outlet)
with Munchkin 199 VWH
1¼” Tube Length 20’ 30’ 40’ 50’ 60’
20 GPM 21.65 22.62 23.6 24.56 25.53
399 VWH at 40GPM
Pressure Drop for Tube Length of 2” Copper
(10) 90° Elbows and (2) Tees (Side Outlet)
with Munchkin 399 VWH
2” Tube Length 20’ 30’ 40’ 50’ 60’
40 GPM 24 24.37 24.74 25.11 25.48
*Example recovery rate for 199VWH @ 90° rise: 400 gal. tank ÷ 255 GPH @ 90° rise = 1.56 x 60 min. = 93.6 min.
*Example recovery rate for 399VWH @ 90° rise: 400 gal. tank ÷ 510 GPH @ 90° rise = .78 x 60 min. = 46.8 min.
6
GENERAL INFORMATION
DIMENSIONS
Figure 1-2
GENERAL INFORMATION
7
GENERAL
1. Munchkin VWH is supplied completely assembled as a packaged boiler. The package should
be inspected for damage upon receipt and any
damage to the unit should be reported to the
shipping company and wholesaler. This boiler
should be stored in a clean, dry area.
2. Carefully read these instructions and be sure
to understand the function of all connections
prior to beginning installation. Contact your
Heat Transfer Products, Inc. Representative or
the Heat Transfer Products, Inc. Customer
Service Department for help in answering
questions.
3. This boiler must be installed by a qualified
contractor. The boiler warranty may be voided
if the boiler is not installed correctly.
CODES & REGULATIONS
Installation and repairs are to be performed in strict
accordance with the requirements of state and local
regulating agencies and codes dealing with boiler
and gas appliance installation.
ACCESSIBILITY CLEARANCES
1. The Munchkin VWH is certified for closet
installations with zero clearance to com-
bustible construction. In addition, it is design
certified for use on combustible floors.
2. Refer to Figure 1.1 for the recommended clearance to allow for reasonable access to the boiler. Local codes or special conditions may
require greater clearances.
COMBUSTION AND VENTILATION AIR
1. The Munchkin VWH is designed only for operation with combustion air piped from outside
(sealed combustion). PVC pipe must be supplied between the air inlet connection at the
rear of the boiler through an outside wall.
2. No additional combustion or ventilation air is
required for this appliance.
3. Refer to Section 4 of this manual, Venting, for
specific instructions for piping combustion air.
PLANNING THE LAYOUT
1. Prepare sketches and notes showing the layout of the boiler installation to minimize the
possibility of interferences with new or existing equipment, piping, venting and wiring.
2. The following sections of this manual should
be reviewed for consideration of limitations
with respect to:
a. Electrical Wiring: Part 2
b. Gas Connection: Part 3
c. Venting: Part 4
f. Piping the Munchkin VWH to the
Storage Tank: Part 5
WARNING
Liquefied Petroleum (LP) Gas or Propane is
heavier than air and, in the event of a leak, may
collect in low areas such as basements or floor
drains. The gas may then ignite resulting in a
fire or explosion.
CAUTION
Do not install this boiler on carpeting.
Figure 1-3
C. PRE-INSTALLATION REQUIREMENTS
8
If the Munchkin is set up for liquefied petroleum (LP) gas, some geographic areas follow the Uniform
Mechanical Code, section 304.6, “Liquefied petroleum gas burning appliances shall not be installed in
a pit, basement or similar location where heavier-than-air gas might collect. Appliances so fueled, shall
not be installed in a below grade under-floor space or basement unless such location is provided with
an approved means for removal of unburned gas.”
D. PRESSURE RELIEF VALVE
A pressure relief valve is installed into the right front side of the manifold. It is required that it meets
the requirements of ANSI/ASME Boiler and Pressure Vessel Code, Section IV or CSA B51: Boiler
Pressure Vessel and Piping Code as applicable for heating boilers. A ¾” pipe connected to the pressure
relief valve must be directed to a floor drain or suitable location within 6” of a drain or floor. To protect
the valve from freezing, do not plug or cap the pressure relief valve.
GENERAL INFORMATION
NOTICE
Service clearance of the Munchkin
1. The front of the appliance needs 24" of clearance for service minimum. It may have
a non-rated or combustible door or access panel and must have a minimum of 24"
clearance.
2. The left side of the heater is 12" clearance
3. The right side of the heater is 12" clearance
4. The top of the heater is 15" clearance.
WARNING
The Munchkin is certified as an indoor appliance. Do not install the Munchkin
outdoors or locate where it will be exposed to freezing temperature. This includes all
related piping and components. If the Munchkin is subjected to flood water or
submersed in water, the Munchkin must be replaced.
NOTICE
Condensation removal: This is a condensing, high efficiency appliance, therefore
condensation removal must be addressed to avoid damage to surrounding area or
appliance. See Part (4) for Condensate Requirements.
DANGER
Serious explosion causing property damage and/or loss of life could result. Under no
circumstances should the relief valve be eliminated, capped or plugged.
9
ELECTRICAL
PART 2. ELECTRICAL
A. ELECTRICAL CONNECTION
The electrical connection for the Munchkin is on the left hand side of the unit. There is a ½” knockout
location for an electrical connection for both the incoming power and the circulator connection. All
electrical wiring must be performed by a qualified licensed electrician in accordance with National
Electrical Code ANSI/NEPA to and/or the Canadian Electrical Code, Part 1 CSA C22.1, or to the
applicable codes and standards. For your convenience, we have labeled all the wires that need to be
connected to operate the Munchkin.
The electrical requirements are for standard 120 volts, 60 Hz 15 Amp service. This unit is wired with
#18 awg and fused for no more than 15 Amps.
There are two ground points in the electrical compartment that must be connected to the building
ground system. Connect the building ground to the green ground screw and the green ground wire
inside electrical box provided.
The Incoming power supply is connected to the Black (Hot) and the White (Neutral).The Munchkin
Control board is polarity sensitive. If the polarity is reversed, the Munchkin control will not sense a
flame and lock out the system.
It is important that the electrical power is not turned on at this time. Double check all connections and then
turn the power on. The display that is provided with the Munchkin should now be reading the outlet
temperature. Note: see Part 6/Startup Procedure section in the manual to change the temperature setting
or run the heater.
DANGER
IT IS VERY IMPORTANT THAT THE BUILDING GROUND IS INSPECTED BY A
QUALIFIED ELECTRICIAN PRIOR TO MAKING THIS CONNECTION!
DANGER
IT IS EXTREMELY IMPORTANT THAT THIS UNIT BE PROPERLY GROUNDED!
10
GAS CONNECTION
PART 3. GAS CONNECTION
A. GAS CONNECTION
The gas supply shall have a maximum inlet pressure of less than 14” water column (350 mm), ½ pound
pressure (3.5 kPa), and a minimum of 3.5” water column. The entire piping system, gas meter and
regulator must be sized properly to prevent pressure drop greater than 0.5” as stated in the National
Fuel Gas Code. This information is listed on the rating plate. It is very important that you are
connected to the type of gas as noted on the rating plate. “LP” for liquefied petroleum, propane gas
or, “Nat” natural or city gas. All gas connections must be approved by the local gas supplier, or utility
in addition to the governing authority, prior to turning the gas supply on. The nipple provided for the
399VWH is 1
1
/
4” with a mandatory 1 x 1
1
/
4 reducing coupling (provided). Threaded into the branch of
a 1
1
/4” tee and a drip leg fabricated as per the national fuel gas code. The 199VWH has a 3/4” gas supply
nipple with a
1
/2 x 3/4 reducing coupling (provided) which is to be threaded into the branch of a 3/4” tee.
You must ensure that the entire gas line to the connection at the Munchkin is no smaller than 1
1
/
4”
for the 399VWH and
3
/
4” for the 199VWH. Once all the inspections have been performed, the piping
must be leak tested. If the leak test requirement is a higher test pressure than the maximum inlet
pressure, you must isolate the Munchkin from the gas line. In order to do this, you must shut the gas
off using factory and field-installed gas cocks (following the lighting instructions in Part 6 Section B.)
This will prevent high pressure. Failure to do so may damage the gas valve. In the event the gas valve
is exposed to a pressure greater than
1
/2 PSI, 14” water column, the gas valve must be replaced. Never
use an open flame (match, lighter, etc.) to check gas connections.
B. GAS PIPING
1. Run the gas supply line in accordance with all applicable codes.
2. Locate and install manual shutoff valves in accordance with state and local requirements.
C. GAS TABLE
Refer to Table (1) to size the supply piping to minimize pressure drop between meter or regulator
and unit.
Maximum Capacity of Pipe in Cubic Feet of Gas per Hour for Gas Pressures of 0.5 psi or Less and a
Pressure Drop of 0.3 Inch water Column
(TABLE 1) (Based on a 0.60 Specific Gravity Gas)
WARNING
Failure to follow all precautions could result in fire, explosion or death!
Nominal
Iron Pipe Internal Length of Pipe (Feet)
Size Diameter
(inches) (inches) 10 20 30 40 50 60 70 80 90 100 125 150 175 200.
3/4 .824 278 190 152 130 115 105 96 90 84 79 72 64 59 55} BTU'S
1 1.049 520 350 285 245 215 195 180 170 160 150 130 120 110 100} PER
1 1/4 1.380 1,050 730 590 500 440 400 370 350 320 305 275 250 225 210} HOUR
1 1/2 1.610 1,600 1,100 890 760 670 610 560 530 490 460 410 380 350 320} X 1,000
11
GAS CONNECTION
It is recommended that a soapy solution be used to detect leaks. Bubbles will appear on the pipe to
indicate a leak is present. The gas piping must be sized for the proper flow and length of pipe, to
avoid pressure drop. Both the gas meter and the gas regulator must be properly sized for the total
gas load. If you experience a pressure drop greater than 1" WC, the meter, regulator or gas line is
undersized or in need of service. You can attach a manometer to the incoming gas drip leg, by
removing the cap and installing the manometer. The gas pressure must remain between 3.5" and 14"
during stand-by (static) mode and while in operating (dynamic) mode. If an in-line regulator is used,
it must be a minimum of 10 feet from the Munchkin. It is very important that the gas line is properly purged by the gas supplier or utility. Failure to properly purge the lines or improper line sizing, will result in ignition failure. This problem is especially noticeable in NEW LP installations and
also in empty tank situations. This can also occur when a utility company shuts off service to an area
to provide maintenance to their lines. This gas valve must not be replaced with a conventional gas
valve under any circumstances. As an additional safety feature, this gas valve has a flanged connection to the Venturi and blower.
WARNING
Failure to follow all precautions could result in fire, explosion or death!
12
VENTING
PART 4. VENTING
A. APPROVED VENTING MATERIALS
EXHAUST VENT
Use Plastic 3” and 4” and 6” Pipe Schedule 40 or 80.
1. Non-Foam Core PVC Pipe
2. Non-Foam Core CPVC Pipe
3. Non-Foam Core ABS Pipe
Vent Piping must conform to following
1. PVC Non Foam Core Pipe (Polyvinyl Chloride) to ASTM D-1784 Class 12454-B, Formerly designated Type 1, Grade 1.
2. CPVC (Chlorinated Polyvinyl Chloride) Class 23447-B, Formerly designated Type IV, Grade 1 conforming to ASTM D-1784.
3. ABS (Acrylonitrile-Butadiene-Styrene) Class 3-2-2-2-2 conforming to ASTM D3965.
The Munchkin is a direct vent appliance. The Munchkin is listed as a Category
IV Condensing Appliance. (The Munchkin Venting is rated at Zero Clearance
to combustibles.)
Note: For Concrete construction or to meet certain fire codes, exhaust and inlet piping at the wall
penetration to the Munchkin must be CPVC Schedule 40 or 80 to meet local fire codes. The balance
from the penetrated wall to the outside, may be PVC Schedule 40 or 80.
INTAKE VENT
Use the same material as used for exhaust. Plastic Pipe or Cellular Foam Core Pipe may be used for
the inlet only, NEVER ON EXHAUST PIPING!
B. VENTING THE MUNCHKIN VWH IN 3”, 4” OR 6” PLASTIC PIPE
DANGER
Foam Core Pipe is not to be used in connecting the exhaust pipe.
DANGER
It is extremely important to follow these venting instructions carefully. Failure to do
so can cause severe personal injury, death or substantial property damage.
WARNING
This vent system will operate with a positive pressure in the vent pipe. Do not
connect vent connectors serving appliances by natural draft into any portion of
mechanical draft systems.
DANGER
It is extremely important to follow these venting instructions exactly. Failure to do so
can cause severe personal injury, death or substantial property damage.
13
VENTING
The inlet pipe on the back of the cabinet is 3" for the 199 VWH and 4" for the 399 VWH. It is very
important that you plan the location properly to eliminate long pipe runs and excessive fittings. Inlet
pipe size must not be reduced. Do not combine the inlet air with any other inlet pipe including an
inlet to an additional similar appliance. The joints must be properly cleaned, primed and cemented.
The piping must also be properly supported as per Local and National Standard Plumbing Codes. It
is important that the piping must be clean and free from burrs, debris, ragged ends and particles of
PVC.
Exhaust piping should be sloped back to the connection on the Munchkin, at least ¼" per foot to
remove additional condensate that forms within the pipe. The total combined length of pipe (intake
piping plus exhaust piping added together) including elbow allowances for intake and exhaust (each
elbow = 5' of pipe) should not exceed 85'. The combined vent length should not be less than a combined length of 6' plus two 90 degree elbows. Choose your vent termination locations carefully. You
must also make certain that exhaust gas does not re-circulate back into the intake pipe. You must
place them in an open area and follow the guidelines below.
1) Never vent into a walkway, patio area, alley or otherwise public area less than 7' from the
ground. (See detail below references Fig. A.10.8 in the National Fuel Gas Code 2002 “Exit
Terminals of Mechanical Draft and Direct-Venting Systems”.)
2) Never vent over or under a window or over a doorway where the exhaust plume or condensation liquid will cause obtrusive or dangerous conditions. (Or refer to National Fuel Gas
Code, CAN B149)
3) Never install a heat saver or similar product to capture waste heat from exhaust.
4) Always have a vent location at least 1' above maximum snow level.
5) Always have vent 1' above ground level, away from shrubs and bushes.
6) Follow local gas codes in your region or refer to National Fuel Gas Code, Can B149.
7) Always have at least 3' from an inside corner of outside walls, including roof overhang.
8) Maintain at least 4’ clearance to electric, gas meters, windows, exhaust fans, chimneys, inlets
or mechanical vents.
9) Very Important! The inlet air connection must be connected to outside air and should be
located no closer than 8” to the exhaust and no further than 36”.
10) Always place screens in all openings in intake and exhaust to prevent foreign matter from
entering the Munchkin.
11) The vent intake and exhaust must be properly cleaned and glued for a pressure tight joint.
Several methods for venting the Munchkin can be found in Figures 4-1 thru 4-6 in this section. Use these layouts as guidelines: certain site conditions such as multiple roof lines/pitches may require venting modifications (consult factory). The air inlet must be a minimum of 1’
vertically above the maximum snow level. It is very important that there are no other vents,
chimneys or air inlets in any direction for at least 4’.
NOTICE
The following are code restrictions for the location of the flue gas vent terminal.
Compliance to these requirements doesn’t insure a satisfactory installation; good
common sense must also be applied. It is important to make sure that exhaust gases
are not recirculated into the inlet air of the Munchkin VWH.
14
VENTING
RECOMMENDED VENTING CLEARANCES PER THE NATIONAL FUEL GAS CODE*
All venting must be properly supported. The Munchkin is not intended to support any venting
whatsoever. All piping, glue, solvents, cleaners, fittings and components, must conform to ASTM
(American Society for Testing and Materials), and ANSI (American National Standards Institute). It is
recommended that you use one of the optional vent kits specifically designed for Munchkin installations, available from Heat Transfer Products, Inc.
Example: Installation requires the following material for both inlet and exhaust piping for the
Munchkin 199VWH and the 399VWH.
Required: 4 Pcs. 90 degree elbow (4 x 5 = 20 Equivalent Feet) = 20 Equivalent Feet
Required: 20' of Plastic PVC Pipe (20 x 1 = 20 Equivalent Feet) = 20 Equivalent Feet
Total Friction Loss in Equivalent Feet (20 + 20 = 40 Equivalent Feet) = 40 Equivalent Feet
C. LONGER VENT RUNS
CAUTION
Flue Gas will condense as it exits the vent termination. This condensate can freeze on
exterior building surfaces which may cause discoloration of these surfaces.
Consideration should be given to the plume of condensation that exits the exhaust
which may affect the cosmetic appearance of the building.
EXIT TERMINALS OF MECHANICAL DRAFT AND DIRECT-VENT VENTING SYSTEM
* REFERENCE: THE NATIONAL FUEL GAS CODE 2002 EDITION
*IMPORTANT NOTE
HEAT TRANSFER
PRODUCTS
RECOMMENDS A
MINIMUM
CLEARANCE OF 4
FEET WHERE THE
PLUME CAUSED BY
THE UNIT MAY
OBSTRUCT VIEWS
OR AFFECT THE
COSMETIC LOOK OF
THE BUILDING.
NOTICE
Do not exceed the 125 foot maximum requirement for (intake plus exhaust piping
added together). Consider fitting allowance shown in friction loss equivalent table on
the following page.
echan
M
raft vent
d
term
(se
ical draft
echan
M
inal
C
um
inim
12 in.minimum
Direct vent terminal clearance
Minimum clearance, C
Input (Btu/hr)
10,000 or less
10,001 to 50,000
Over 50,000
(see 10.8.3)*
For SI units: 1 ft = 0.305 m; 1 in. = 25.4 mm;
1 Btu/hr = 0.293 W
Clearance (in.)
4 ft.m
4 ft.
minimum
12 in.minimum
6
9
12
12 in.m
vent term
(see 10.8
inim
.2)*
ss
Le
um
than 10 ft.
3 ft.minim
Fo
inlet
um
rad
G
rced air
e
e 10
l
ica
al
in
.8.1)*
Loading...