Heatcraft Refrigeration Products H-ENGM0806, H-ENGM0408 User Manual
H-ENGM0408, April 2008
(Replaces H-ENGM0806, August 2006)
Engineering Manual
Commercial Refrigeration
Cooling and Freezing
Load Calculations and Reference Guide
Expansion
Valve
Suction
Filter
Suction
Accumulator
Evaporator
Compressor
Liquid Line
Solenoid Valve
Separator
Heat
Exchanger
Oil
Filter-
Drier
Liquid Line
Sight Glass
Head Pressure
Control Valve
Receiver
Condenser
Forward
This edition of Heatcraft Refrigeration Products LLC’s, Engineering
Manual covering Commercial Refrigeration Cooling and Freezing
Load Calculations has been prepared in the form of a condensed
text and reference book.
The theory and principle of modern refrigeration has been
omitted due to the many excellent publications currently available
on these subjects. The purpose of this reference book is to furnish
the engineering, selling and servicing organizations with accurate
and useful data to simplify load calculations.
No attempt has been made to specify a particular make of
equipment. We sincerely hope that our eorts will be a tangible
contribution to our rapidly growing industry.
Table of Contents
Job Survey 4
Refrigeration Load Calculations 4-6
Sample Calculations:
Above 32ºF. (0ºC.) 7-9
Sample Calculations:
Rooms Below 32ºF. (0ºC.) 10-12
Refrigeration Equipment Selection 21
Type of Operation and Air Flow 22
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choice for meeting the demanding needs of this industry
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Refrigeration Equipment References on the World Wide Web
History of Leadership, Service
and Innovation
Bohn has been the
Supermarket Industry’s leading
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since 1946. With an emphasis
on innovation and the
environment, Bohn is the clear
Derating Factors 22
General Guidelines 23
Unit Cooler Coil Placement 24
Sizing of Refrigerant Lines 25-32
Psychrometric Chart 37-39
Glossary of Refrigeration Terms 40
Quick Selection Guide 41
Rapid Load Calculator for Large Coolers & Freezers 43
History of High Performance,
Innovation and Product Selection
Larkin has been the most trusted
brand of refrigeration products for
clean environments since 1928. With
its innovative products, it is uniquely
qualied to meet the needs of
foodservice applications as well as
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data centers.
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History of Dependability,
Technical Support and
Product Choice
Climate Control is the
brand that revolutionized
convenience store refrigeration in the 1970’s. Its reputation
of dependability and products designed to reduce
installation and operation costs still make it the number one
choice of convenience store owners everywhere.
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Serving the Cold
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Chandler has been a
leading commercial refrigeration brand since 1933. Its
emphasis on partnership allows customers to give input
during the system design process, resulting in customized
solutions that are precisely engineered to order.
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© 2008 Heatcraft Refrigeration Products LLC
2
Tables
Table
No.
1. Wall heat loads 13
2. Insulated block K factors 13
3. Allowance for sun eect ............................................................................13
4. Average air changes per 24 hours for storage
rooms above 32ºF. (0ºC.) due to door
openings and inltration 14
5. Average air changes per 24 hours for storage
rooms below 32ºF. (0ºC.) due to door
openings and inltration 14
6. Heat removed in cooling air to storage
room conditions (BTU per Cu. Ft.) 14
7. Storage requirements and properties of
perishable products 15-16
8. Heat of respiration 17
9. Heat loads of keg and bottled beer 18
10. Carcass weights 18
11. Heat equivalent of electric motors 18
12. Heat equivalent of occupancy 18
13. General standards for insulation
thickness in storage rooms 18
14. Heat gain due to operation of battery lift trucks 18
15. Specic heats of various liquids and solids 18
16. Banana room
refrigeration requirement 19
17. Meat cutting or preparation room 19
page
No.
Table
No.
18. Rapid load selection for back bars 19
19. Refrigeration requirements for hardening
ice cream 19
20. Glass door load 19
21. Summer outside air and ground
temperature design conditions 20
22. Suction and liquid line sizes for R-134A 25, 26
23. Suction and liquid line sizes for R-22 27, 28
24. Suction & liquid line sizes for R-404A, R-507/AZ50 29, 30
25. Pressure drop of liquid refrigerants in
vertical risers 31
26. Equivalent feet of pipe for
valves and ttings 31
27. Remote condenser line sizes for
R-134A, R-22, R-507/AZ50 and R-404A 32
28. L-type tubing– weight of refrigerants in copper
lines of operating systems 33
29. Fahrenheit-Celsius temperature
conversion chart 34
30. Conversion factors 35
31. Electrical formulas 35
32. English conversion factors and data 36
33. English to metric conversion factors 36
page
No.
3
Job Survey
The person involved in a heat transfer calculation needs
information in order to predict accurately the heat load on a
refrigerated structure. The more complete the information, the
better the calculation. Good calculations are the rst step in
assuring adequate refrigeration equipment is selected for the
project.
The initial job survey should be as complete as possible and
include the following:
Design Ambient Temperature
This is the ambient surrounding the box necessary for the load
calculations. Another ambient to be considered on air cooled
projects is the one surrounding the condensing unit which will
aect equipment selection.
Storage Temperature and Humidity Requirements
Refrigeration equipment by its nature is a dehumidication
process. We try to minimize or maximize the drying eect of the
equipment by selecting the appropriate Temperature Dierence
(T.D.) between the saturated suction temperature of the
evaporator and the room air. The T.D. selected approximates the
desired relative humidity (see page 21).
Dimensions, Insulation, Type of Construction,
Exposure
This criterion lends itself to well established, straight forward
calculations, but the information while elementary, is often
omitted from the initial job survey. Transmission load for 4”
Styrofoam is double the transmission load for 4” formed in place
urethane.
Inltration or Air Changed Load
Heat, both sensible and latent, enters an enclosure through door
openings whenever the air surrounding the enclosure is warmer
than the box temperature. Knowing the location, size and
number of the door openings and the temperature to which they
are exposed will greatly aid in determining the heat load of the
inltration air.
Product
1. Type - storage requirements
2. Weight
3. Entering temperature
4. Pull down time
Miscellaneous Loads
1. Lights
2. Motors including fan motors, fork lifts, conveyers
3. People
4. Glass doors
Operations
1. Holding cooler or freezer
2. Blast cooling or freezing
3. Preparation, processing or cutting rooms
4. Distribution warehouses
5. Reach-in or walk-in boxes
Unusual Conditions
Electrical Service and Type of Equipment Desired
While not directly aecting refrigeration load calculations,
this is essential in the job survey to select the proper equipment.
4
Refrigeration Load Calculations
With the initial survey complete, the heat load calculation is
separated into the following main sources of heat for a given 24
hour period:
1. Transmission load
2. Air change load
3. Miscellaneous load
4. Product load
Accuracy
Accuracy in calculation is the rst step in having a satised
customer. There are short cuts, based on averages, that may
be taken and which must be used when the product load is
indenite or unknown (see Quick Selection Guide on page 41
and the Rapid Load Calculator on page 43). But when all the data
necessary to calculate the four main sources of heat gain are
available, the complete calculation should be made.
Quick Selection Chart for Small
and Medium Coolers and Freezers
The Quick Selection Guide on page 41 may be used for a quick
comparison of heat load gured on Bulletins Above32-05 or
Below32-05 or to obtain approximate heat loads for small and
medium sized boxes. The loads are shown for a 95ºF. outside
temperature.
Rapid Load Calculator for Large Coolers and Freezers
The Rapid Load Calculator on page 43 may be used for quick
approximations of the heat load in large boxes and for a
reasonable comparison of heat loads gured on Bulletins
Above32-05 or Below32-05. The Calculator graph on page 43 is
based on the following average daily product loadings for coolers
and freezers:
Average Daily Average Daily
Volume- Product Loads (lbs.) Product Loads (lbs.)
Cu. Ft. for Coolers for Freezers
500 - 3,000 6,200 - 8,000 1,600 - 2,000
3,000 - 4,600 8,000 - 11,000 2,000 - 2,500
4,600 - 8,100 11,000 - 17,000 2,500 - 4,000
8,100 - 12,800 17,000 - 26,000 4,000 - 6,200
12,800 - 16,000 26,000 - 33,000 6,200 - 7,500
16,000 - 20,000 33,000 - 40,000 7,500 - 9,500
20,000 - 28,000 40,000 - 56,000 9,500 - 13,000
28,000 - 40,000 56,000 - 66,000 13,000 - 17,000
40,000 - 60,000 66,000 - 110,000 17,000 - 25,000
60,000 - 80,000 110,000 - 150,000 25,000 - 34,000
80,000 - up 150,000 - up 34,000 - up
1. Transmission Load
Methods of determining the amount of heat ow through walls,
oor and ceiling are well established. This heat gain is directly
proportional to the Temperature Dierence (T.D.) between the
two sides of the wall. The type and thickness of insulation used
in the wall construction, the outside area of the wall and the
T.D. between the two sides of the wall are the three factors
that establish the wall load. Tables are provided to simplify
the calculations (see Table 1, page 13). Some coolers for above
freezing temperatures have been constructed with only a oor
slab (no oor insulation). The factors shown in the wall heat gain
(Table 1) are based on a concrete oor slab and the T.D. between
the local ground temperature and the storage room temperature.
For freezers it becomes necessary to provide heat in the base slab
to avoid freezing of the ground water and heaving of the oor.
Minimum slab temperature should be at least 40ºF. Normally, 55ºF.
should be used for freezer applications.
cooler and one HP for each 12,500 C.F. in a storage freezer
which allows for fan motors and some forklift operations.
These gures can be higher in a heavily used area, i.e. loading
dock or distribution warehouse.
2. Air Change Load
(a) Average Air Change- when the door to a refrigerated room is
opened, warm outside air will enter the room. This air must be
cooled to the refrigerated room temperature, resulting in an
appreciable source of heat gain. This load is sometimes called
the inltration load. The probable number of air changes per
day and the heat that must be removed from each cubic foot
of the inltrated air, are given in tables based on experience
(see Table 4, 5 & 6, page 14). For heavy usage, the inltration
may be doubled or more.
(b) Inltration Through a Fixed Opening- As an alternate to the
average air change method using the Psychrometric Chart
(page 37), the following formulas may be used to calculate
the inltration resulting from natural ventilation (no wind)
through external door openings.
[ (4.88) ( door height) (area/2) (minutes open) ( temp. di. ºF.)
(enthalpy incoming air – enthaply warehouse air) ] [ (1–X)]
Specic Volume of Incoming Air
Where X = % of heat transmission blocked by thermal barrier.
The air change load can be substantial and every means
should be taken to reduce the amount of inltration entering
the box. Some eective means of minimizing this load are:
• Automatic closing refrigerator doors
• Vestibules or refrigerated anterooms
• Plastic strip curtains
• Air Curtains
• Inated bumpers on outside loading doors.
3. Miscellaneous Loads
Although most of the heat load in a refrigerated room
or freezer is caused by wall heat leakage, air changes and
product cooling or freezing, there are three other heat
sources that should not be overlooked prior to the selection
of the refrigeration equipment. Since the equipment has to
maintain temperature under design conditions, these loads are
generally averaged to a 24 hour period to provide for capacity
during these times.
(a) Lights- typically storage requirements are 1 to 1-1/2 watt per
square foot. Cutting or processing rooms can be double the
wattage. Each watt is multiplied by 3.42 BTU/watt to obtain a
BTUH gure. This is then multiplied by 24 to obtain a
daily gure.
(b) Motors- smaller motors are usually less ecient and tend to
generate more heat per horsepower as compared to larger
motors. For this reason Table 11, on page 18, is broken down
in to H.P. groups. Also, motors inside the refrigerated area will
reject all of their heat losses as shown in Table 11. However,
motors that are located outside but do the work inside, like
a conveyor, will reject less heat into the refrigerated space. If
powered material handling equipment is used, such as forklift
trucks, this must be included under Motor Heat Loads.
Generally only battery operated lift trucks are used in
refrigerated rooms, which represent a heat gain of 8,000 to
15,000 BTU/hr. or more over the period of operation. If motor
or loading conditions are not known, then calculate one
motor horsepower for each 16,000 cubic foot box in a storage
(c) Occupancy- People working in the refrigerated storage area
dissipate heat at a rate depending on the room temperature
(Table 12, page 18). Multiple occupancies for short periods
should be averaged over a 24 hour period. If occupancy load
is not known, allow one person per 24 hour for each 25,000
cubic foot space.
4. Product Load
Whenever a product having a higher temperature is placed
in a refrigerator or freezer room, the product will lose its
heat until it reaches the storage temperature. This heat load
consists of three separate components: (see Table 7, page 15-
16).
(a) Specic Heat- The amount of heat that must be removed
from one pound of product to reduce the temperature of this
pound by 1ºF., is called its specic heat. It has two values: one
applies when the product is above freezing; the second is
applicable after the product has reached its freezing point.
(b) Latent Heat- The amount of heat that must be removed from
one pound of product to freeze this pound is called the latent
heat of fusion.
Most products have a freezing point in the range of 26ºF. to
31ºF. If the exact temperature is unknown, it may be
assumed to be 28ºF.
There is a denite relationship between the latent heat of
fusion and the water content of the product and its specic
and latent heats.
Estimating specic and latent heats:
Sp. Ht. above freezing = 0.20 + (0.008 X % water)
Sp. Ht. below freezing = 0.20 + (0.008 X % water)
Latent Heat = 143.3 X % water
(c) Respiration- Fresh fruits and vegetables are alive. Even in
refrigerated storage they generate heat which is called the
heat of respiration. They continually undergo a change in
which energy is released in the form of heat, which varies with
the type and temperature of the product. Tabulated values are
usually in BTU/lb./24 hours (Table 8, page 17), and are applied
to the total weight of product being stored and not just the
daily turnover.
(d) Pull down Time- When a product load is to be calculated at
other than a 24 hour pull down, a correction factor must be
multiplied to the product load.
24 hours
Pull down Time
Note: While product pull down can be calculated, no
guarantee should be made regarding nal product
temperature due to many uncontrollable factors (i.e., type of
packaging, position in the box, method of stacking, etc.)
5. Safety Factor
When all four of the main sources of heat are calculated,
a safety factor of 10% is normally added to the total
refrigeration load to allow for minor omissions and
inaccuracies (additional safety or reserve may be available
from the compressor running time and average loading).
5
6. Hourly Heat Load
The hourly heat load serves as the guide in selecting
equipment. It is found by dividing the nal BTU/24 hour load
by the desired condensing unit run time.
35ºF. rooms with no timer 16 hr.
35ºF. rooms with timer 18 hr.
Blast coolers/Freezers with
positive defrost 18 hr.
Storage Freezers 18-20 hr.
25ºF. - 34ºF. coolers with hot gas
or electric defrost 20-22 hr.
50ºF. rooms and higher with coil
temperature above 32ºF. 20-22 hr.
7. Load Calculation Forms
To simplify the calculation and tabulation of refrigeration
loads, there are two forms available:
Bulletin Above32-05 is used for all rooms above 32ºF. (0ºC.)
Bulletin Below32-05 is used for all rooms below 32ºF. (0ºC.)
All data and tables necessary to ll in the Load Calculation
Forms can be found in this manual.
A Word of Caution: The refrigeration load calculation
methods presented in this manual are intended for use
in selecting refrigeration equipment for rooms used for
holding and sometimes pulling product temperature down.
For process or unusual applications such as blast freezing or
food processing situations, please contact our Application
Engineering Department.
6
Refrigeration Load Estimate Form
(for rooms above 32ºF) Bulletin Above32-05
Estimate for: Estimate by: Date:
Example: 35ºF Convenience Store Cooler With Glass Doors
Basis for Estimate
8 28 8
Room Dimensions: Width ft. x Length f t. x Height ft.
28 8 8 1792
Volume: (L) x (W) x (H) = cu. ft.
85 35 50
Ambient Temp ºF. (Corrected for sun load) — Room Temp ºF. = ºF. T.D.
Inches
Ceiling
Walls
Floor
Product Load
2000 Beer
(a) lbs./day of to be reduced from entering
85 35 50
temp. of ºF. to ºF. Temp. Drop ºF.
200 Milk
(b) lbs./day of to be reduced from entering
40 35 5
temp. of ºF. to ºF. Temp. Drop ºF.
Miscellaneous
0.2 60
Motors (including all blower motors) HP Ground Temp. (Table 21)
224
Lights (assume 1 watt/sq.ft.) Watts
No. of people
0
1. Transmission Loads
28 8 72 16128
Ceiling: (L) x (W) x Heat Load (Table 1) =
28 8 72 16128
North Wall: (L) x (W) x Heat Load (Table 1) =
28 8 72 16128
South Wall: (L) x (W) x Heat Load (Table 1) =
East Wall: (L) x (W) x Heat Load (Table 1) =
8 8 72 4608
West Wall: (L) x (W) x Heat Load (Table 1) =
8 8 72 4608
Floor: (L) x (W) x Heat Load (Table 1) =
28 8 125 28000
(W)
(W)
(H)
(H)
(H)
(H)
4 Styrene
4 Styrene
6 Concrete
Note: Tables can be found in
Engineering Manual, H-ENG-2
Insulation
Type
2. Air Change Load
Volume: cu. ft. x Factor (Table 4) x Factor (Table 6) =
1792 13 1.86 43331
3. Additional Loads
0.2 15000
Electrical Motors: HP x 75000 BTU/HP/24 hr. =
224 18368
Electrical Lights: Watts x 82 =
0 —
People Load: People x BTU/24 hrs. (Table 12) =
10 192000
Glass Door Load: Doors x 19200 BTU/Door/24 hr. =
4. Product Load: Sensible (Product Load Figured @ 24 hr. Pulldown*)
2000 0.92 50 92000
(a) lbs./day x Spec. Heat (Table 7) x ºF. Temp Drop =
200 0.93 5 930
(b) lbs./day x Spec. Heat (Table 7) x ºF. Temp Drop =
*For product pulldown time other than 24 hrs. fi
5. Product Load: Respiration*
(a) lbs. stored x BTU/lbs./24 hrs. (Table 8) =
— — —
(b) lbs. stored x BTU/lbs./24 hrs. (Table 8) =
— — —
*For consideration of previously loaded product, a multiplier of (5) is normally applied to the daily
product load (Line #4)
447229
Total Refrigeration Load (1+2+3+4+5) BTU/24 hrs.
44723
Add 10% Safety Factor
491952
Total with Safety/Factor BTU/24 hrs.
Divide by No. of Operating Hrs. (16) to obtain BTUH Cooling Requirement
30747
Equipment Selection
Condensing Unit Unit Cooler System Capacity
Qty. Model No. Qty. Model No. BTU/hr.
gure 24 hr. load x (24/Pulldown Time)
2175 West Park Place Blvd. • Stone Mountain, GA 30087 • 770.465.5600 • Fax: 770.465.5990 • www.heatcraftrpd.com
7
Refrigeration Load Estimate Form
(for rooms above 32ºF) Bulletin Above32-05
Estimate for: Estimate by: Date:
Example: 35ºF Beef Cooler
Basis for Estimate
14 16 8
Room Dimensions: Width ft. x Length f t. x Height ft.
16 14 8 1792
Volume: (L) x (W) x (H) = cu. ft.
95 35 60
Ambient Temp ºF. (Corrected for sun load) — Room Temp ºF. = ºF. T.D.
Inches
Ceiling
Walls
Floor
Product Load
1000 Beef
(a) lbs./day of to be reduced from entering
50 35 15
temp. of ºF. to ºF. Temp. Drop ºF.
— —
(b) lbs./day of to be reduced from entering
— — —
temp. of ºF. to ºF. Temp. Drop ºF.
Miscellaneous
0.1 60
Motors (including all blower motors) HP Ground Temp. (Table 21)
224
Lights (assume 1 watt/sq.ft.) Watts
No. of people
0
1. Transmission Loads
16 14 87 19488
Ceiling: (L) x (W) x Heat Load (Table 1) =
16 8 87 11136
North Wall: (L) x (W) x Heat Load (Table 1) =
16 8 87 11136
South Wall: (L) x (W) x Heat Load (Table 1) =
East Wall: (L) x (W) x Heat Load (Table 1) =
14 8 87 9744
West Wall: (L) x (W) x Heat Load (Table 1) =
14 8 87 9744
Floor: (L) x (W) x Heat Load (Table 1) =
16 14 125 28000
(W)
(W)
(H)
(H)
(H)
(H)
4 Styrene
4 Styrene
6 Concrete
Note: Tables can be found in
Engineering Manual, H-ENG-2
Insulation
Type
2. Air Change Load
1792 13 2.49 58007
Volume: cu. ft. x Factor (Table 4) x Factor (Table 6) =
3. Additional Loads
0.1 7500
Electrical Motors: HP x 75000 BTU/HP/24 hr. =
224 18368
Electrical Lights: Watts x 82 =
0 — —
People Load: People x BTU/24 hrs. (Table 12) =
0 —
Glass Door Load: Doors x 19200 BTU/Door/24 hr. =
4. Product Load: Sensible (Product Load Figured @ 24 hr. Pulldown*)
1000 0.77 15 11550
(a) lbs./day x Spec. Heat (Table 7) x ºF. Temp Drop =
— — — —
(b) lbs./day x Spec. Heat (Table 7) x ºF. Temp Drop =
*For product pulldown time other than 24 hrs. fi
5. Product Load: Respiration*
— — —
(a) lbs. stored x BTU/lbs./24 hrs. (Table 8) =
— — —
(b) lbs. stored x BTU/lbs./24 hrs. (Table 8) =
*For consideration of previously loaded product, a multiplier of (5) is normally applied to the daily
product load (Line #4)
184673
Total Refrigeration Load (1+2+3+4+5) BTU/24 hrs.
18467
Add 10% Safety Factor
203140
Total with Safety/Factor BTU/24 hrs.
Divide by No. of Operating Hrs. (16) to obtain BTUH Cooling Requirement
12696
Equipment Selection
Condensing Unit Unit Cooler System Capacity
Qty. Model No. Qty. Model No. BTU/hr.
gure 24 hr. load x (24/Pulldown Time)
2175 West Park Place Blvd. • Stone Mountain, GA 30087 • 770.465.5600 • Fax: 770.465.5990 • www.heatcraftrpd.com
8
Refrigeration Load Estimate Form
(for rooms above 32ºF) Bulletin Above32-05
Estimate for: Estimate by: Date:
Basis for Estimate
Room Dimensions: Width ft. x Length ft. x Height ft.
Volume: (L) x (W) x (H) = cu. ft.
Ambient Temp ºF. (Corrected for sun load) — Room Temp ºF. = ºF. T.D.
Note: Tables can be found in
Engineering Manual, H-ENG-2
Insulation
Inches
Type
Ceiling
Walls
Floor
Product Load
(a) lbs./day of to be reduced from entering
temp. of ºF. to ºF. Temp. Drop ºF.
(b) lbs./day of to be reduced from entering
temp. of ºF. to ºF. Temp. Drop ºF.
Miscellaneous
Motors (including all blower motors) HP Ground Temp. (Table 21)
Lights (assume 1 watt/sq.ft.) Watts
No. of people
1. Transmission Loads
Ceiling: (L) x (W) x Heat Load (Table 1) =
North Wall: (L) x (W) x Heat Load (Table 1) =
South Wall: (L) x (W) x Heat Load (Table 1) =
East Wall: (L) x (W) x Heat Load (Table 1) =
West Wall: (L) x (W) x Heat Load (Table 1) =
Floor: (L) x (W) x Heat Load (Table 1) =
(W)
(W)
(H)
(H)
(H)
(H)
2. Air Change Load
Volume: cu. ft. x Factor (Table 4) x Factor (Table 6) =
3. Additional Loads
Electrical Motors: HP x 75000 BTU/HP/24 hr. =
Electrical Lights: Watts x 82 =
People Load: People x BTU/24 hrs. (Table 12) =
Glass Door Load: Doors x 19200 BTU/Door/24 hr. =
4. Product Load: Sensible (Product Load Figured @ 24 hr. Pulldown*)
(a) lbs./day x Spec. Heat (Table 7) x ºF. Temp Drop =
(b) lbs./day x Spec. Heat (Table 7) x ºF. Temp Drop =
*For product pulldown time other than 24 hrs. fi
5. Product Load: Respiration*
(a) lbs. stored x BTU/lbs./24 hrs. (Table 8) =
(b) lbs. stored x BTU/lbs./24 hrs. (Table 8) =
*For consideration of previously loaded product, a multiplier of (5) is normally applied to the daily
product load (Line #4)
Total Refrigeration Load (1+2+3+4+5) BTU/24 hrs.
Add 10% Safety Factor
Total with Safety/Factor BTU/24 hrs.
Divide by No. of Operating Hrs. (16) to obtain BTUH Cooling Requirement
Equipment Selection
Condensing Unit Unit Cooler System Capacity
Qty. Model No. Qty. Model No. BTU/hr.
gure 24 hr. load x (24/Pulldown Time)
2175 West Park Place Blvd. • Stone Mountain, GA 30087 • 770.465.5600 • Fax: 770.465.5990 • www.heatcraftrpd.com
9
Refrigeration Load Estimate Form
(for rooms below 32ºF) Bulletin Below32-05
Estimate for:
Estimate by: Date:
Example: -20ºF Ice Cream Hardening Freezer
Basis for Estimate
12 14 8
Room Dimensions: Width ft. x Length f t. x Height ft.
14 12 8 1344
Volume: (L) x (W) x (H) = cu. ft.
85 -20 105
Ambient Temp ºF. (Corrected for sun load) — Room Temp. ºF. = ºF. T.D.
Inches
Ceiling
Walls
Floor
Product Load
— — —
(a) lbs./day of to be reduced from entering temp. of ºF.
— —
to freezing point of ºF. (Table 7) = ºF. Initial temp. drop
— —
and then reduced from freezing point to storage Temp. of ºF. = (Table 7) ºF. Final temp. drop.
100 100%
(b) gallons of ice cream @ overrun
Miscellaneous
0.2 60
Motors (including all blower motors) HP Ground Temp. (Table 21)
168
Lights (assume 1 watt/sq.ft.) Watts
0
No. of People
1. Transmission Loads
14 12 76 12768
Ceiling: (L) x (W) x Heat Load (Table 1) =
14 8 76 8512
North Wall: (L) x (W) x Heat Load (Table 1) =
14 8 76 8512
South Wall: (L) x (W) x Heat Load (Table 1) =
East Wall: (L) x (W) x Heat Load (Table 1) =
12 8 76 7296
West Wall: (L) x (W) x Heat Load (Table 1) =
12 8 76 7296
Floor: (L) x (W) x Heat Load (Table 1) =
14 12 58 9744
(W)
(W)
(H)
(H)
(H)
(H)
4 Foamed In place Ure
4 Foamed In place Ure
4 Foamed In place Ure
Note: Tables can be found in
Engineering Manual, H-ENG-2
Insulation
Type
2. Air Change Load
1344 12 3.49 56287
Volume: cu. ft. x Factor (Table 5) x Factor (Table 6) =
3. Additional Loads
0.2 15000
Electrical Motors: HP x 75000 BTU/HP/24 hr. =
168 13776
Electrical Lights: Watts x 82 =
0 — —
People Load: People x BTU/24 hrs. (Table 12) =
10 —
Glass Door Load: Doors x 31200 BTU/Door/24 hr. =
4. Product Load: (Table 7) (Product Load Figured @ 24 hr. Pulldown*)
— — —
(a) lbs./day x Spec. Heat above freezing x ºF. Intial Te
— — —
lbs./day x Latent Heat Fusion =
lbs./day x Spec. Heat below freezing x ºF. Intial Temp. Drop =
— — —
100 425 X 2.4 (10 hr. Pull down)* 102000
(b) gallons of ice cream/day x BTU/gal (Table 19) =
*For product pulldown time other than 24 hrs. figure 24 hr. load x (24/Pulldown Time)
241191
Total Refrigeration Load (1+2+3+4+5) BTU/24 hrs.
24119
Add 10% Safety Factor
265310
Total with Safety/Factor BTU/24 hrs.
Divide by No. of Operating Hrs. (18) to obtain BTUH Cooling Requirement
14739
Equipment Selection
Condensing Unit Unit Cooler System Capacity
Qty. Model No. Qty. Model No. BTU/hr.
mp. Drop =
2175 West Park Place Blvd. • Stone Mountain, GA 30087 • 770.465.5600 • Fax: 770.465.5990 • www.heatcraftrpd.com
10
Refrigeration Load Estimate Form
(for rooms below 32ºF) Bulletin Below32-05
Estimate for:
Estimate by: Date:
Example: -10ºF Beef Freezer
Basis for Estimate
20 24 12
Room Dimensions: Width ft. x Length f t. x Height ft.
24 20 12 5760
Volume: (L) x (W) x (H) = cu. ft.
90 -10 100
Ambient Temp ºF. (Corrected for sun load) — Room Temp. ºF. = ºF. T.D.
Inches
Ceiling
Walls
Floor
Product Load
3000 Beef 35
(a) lbs./day of to be reduced from entering temp. of ºF.
28 7
to freezing point of ºF. (Table 7) = ºF. Initial temp. drop
-10 38
and then reduced from freezing point to storage Temp. of ºF. = (Table 7) ºF. Final temp. drop.
— —
(b) gallons of ice cream @ overrun
Miscellaneous
0.5 60
Motors (including all blower motors) HP Ground Temp. (Table 21)
480
Lights (assume 1 watt/sq.ft.) Watts
0
No. of People
1. Transmission Loads
24 20 72 34560
Ceiling: (L) x (W) x Heat Load (Table 1) =
24 12 72 20736
North Wall: (L) x (W) x Heat Load (Table 1) =
South Wall: (L) x (W) x Heat Load (Table 1) =
24 12 72 20736
East Wall: (L) x (W) x Heat Load (Table 1) =
20 12 72 17280
West Wall: (L) x (W) x Heat Load (Table 1) =
20 12 72 17280
Floor: (L) x (W) x Heat Load (Table 1) =
24 20 50 24000
(W)
(W)
(H)
(H)
(H)
(H)
4 Foamed In place Ure
4 Foamed In place Ure
4 Foamed In place Ure
Note: Tables can be found in
Engineering Manual, H-ENG-2
Insulation
Type
2. Air Change Load
5760 5.2 3.56 106629
Volume: cu. ft. x Factor (Table 5) x Factor (Table 6) =
3. Additional Loads
0.5 37500
Electrical Motors: HP x 75000 BTU/HP/24 hr. =
480 39360
Electrical Lights: Watts x 82 =
0 — —
People Load: People x BTU/24 hrs. (Table 12) =
0 —
Glass Door Load: Doors x 31200 BTU/Door/24 hr. =
4. Product Load: (Table 7) (Product Load Figured @ 24 hr. Pulldown*)
3000 0.77 7 16170
(a) lbs./day x Spec. Heat above freezing x ºF. Intial Te
3000 100 300000
lbs./day x Latent Heat Fusion =
3000 0.4 38 45600
lbs./day x Spec. Heat below freezing x ºF. Intial Temp. Drop =
(b) gallons of ice cream/day x BTU/gal (Table 19) =
— X 2.4 (10 hr. Pull down)* —
*For product pulldown time other than 24 hrs. figure 24 hr. load x (24/Pulldown Time)
679851
Total Refrigeration Load (1+2+3+4+5) BTU/24 hrs.
67985
Add 10% Safety Factor
747836
Total with Safety/Factor BTU/24 hrs.
Divide by No. of Operating Hrs. (18) to obtain BTUH Cooling Requirement
41546
Equipment Selection
Condensing Unit Unit Cooler System Capacity
Qty. Model No. Qty. Model No. BTU/hr.
mp. Drop =
2175 West Park Place Blvd. • Stone Mountain, GA 30087 • 770.465.5600 • Fax: 770.465.5990 • www.heatcraftrpd.com
11
Refrigeration Load Estimate Form
(for rooms below 32ºF) Bulletin Below32-05
Estimate for:
Basis for Estimate
Room Dimensions: Width ft. x Length ft. x Height ft.
Volume: (L) x (W) x (H) = cu. ft.
Ambient Temp ºF. (Corrected for sun load) — Room Temp. ºF. = ºF. T.D.
Product Load
(a) lbs./day of to be reduced from entering temp. of ºF.
to freezing point of ºF. (Table 7) = ºF. Initial temp. drop
and then reduced from freezing point to storage Temp. of ºF. = (Table 7) ºF. Final temp. drop.
(b) gallons of ice cream @ overrun
Miscellaneous
Motors (including all blower motors) HP Ground Temp. (Table 21)
Lights (assume 1 watt/sq.ft.) Watts
No. of People
2. Air Change Load
Volume: cu. ft. x Factor (Table 5) x Factor (Table 6) =
3. Additional Loads
Electrical Motors: HP x 75000 BTU/HP/24 hr. =
Electrical Lights: Watts x 82 =
People Load: People x BTU/24 hrs. (Table 12) =
Glass Door Load: Doors x 31200 BTU/Door/24 hr. =
4. Product Load: (Table 7) (Product Load Figured @ 24 hr. Pulldown*)
(a) lbs./day x Spec. Heat above freezing x ºF. Intial Te
mp. Drop =
lbs./day x Latent Heat Fusion =
lbs./day x Spec. Heat below freezing x ºF. Intial Temp. Drop =
(b) gallons of ice cream/day x BTU/gal (Table 19) =
*For product pulldown time other than 24 hrs. figure 24 hr. load x (24/Pulldown Time)
Divide by No. of Operating Hrs. (18) to obtain BTUH Cooling Requirement
Equipment Selection
Condensing Unit Unit Cooler System Capacity
Qty. Model No. Qty. Model No. BTU/hr.
Total Refrigeration Load (1+2+3+4+5) BTU/24 hrs.
Add 10% Safety Factor
Total with Safety/Factor BTU/24 hrs.
1. Transmission Loads
Ceiling: (L) x (W) x Heat Load (Table 1) =
North Wall: (L) x (W) x Heat Load (Table 1) =
South Wall: (L) x (W) x Heat Load (Table 1) =
East Wall: (L) x (W) x Heat Load (Table 1) =
West Wall: (L) x (W) x Heat Load (Table 1) =
Floor: (L) x (W) x Heat Load (Table 1) =
Estimate by: Date:
Insulation
Inches
Ceiling
Walls
Floor
Type
Note: Tables can be found in
Engineering Manual, H-ENG-2
2175 West Park Place Blvd. • Stone Mountain, GA 30087 • 770.465.5600 • Fax: 770.465.5990 • www.heatcraftrpd.com
(W)
(W)
(H)
(H)
(H)
(H)
12
Appendix - Tables
Table 1
Wall Heat Loads
Insulation (Inches) Heat Load (BTU Per 24 Hours Per One Square Foot of Outside Surface)
Cork Glass Urethane
or Fiber or Urethane (Foamed Temperature Reduction in ºF.
Mineral Poly- (Sprayed) in R (Outside Air Temperature Minus Room Temperature)
Wool Styrene Place)
k = .30 k = .26 k = .16 k = .12 1 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
1 4 5.10 204 230 255 281 306 332 357 383 408 434 459 485 510 536 561 587 612
2 8 3.40 136 153 170 187 204 221 238 255 272 289 306 323 340 357 374 391 408
4 3 2 12.6 1.80 72 81 90 99 108 117 126 135 144 153 162 171 180 189 198 207 216
5 4 2 16.4 1.44 58 65 72 79 87 94 101 108 115 122 130 137 144 151 159 166 173
6 5 3 19.6 1.20 48 54 60 66 72 78 84 90 96 102 108 114 120 126 132 138 144
8 6 4 3 25 0.90 36 41 45 50 54 59 63 68 72 77 81 86 90 95 99 104 108
10 8 4 33 0.72 29 32 36 40 43 47 50 54 58 61 65 68 72 76 79 83 86
10 6 38.7 0.60 24 27 30 33 36 39 42 45 48 51 54 57 60 63 66 69 72
6 50 0.48 19 22 24 26 29 31 34 36 38 41 43 46 48 51 53 55 58
Single window glass . 9 27 1080 1215 1350 1490 1620 1760 1890 2030 2160 2290 2440 2560 2700 2840 2970 3100 3240
Double Window Glass 2.2 11 440 495 550 610 660 715 770 825 880 936 990 1050 1100 1160 1210 1270 1320
Triple Window Glass 3.4 7 280 315 350 390 420 454 490 525 560 595 630 665 700 740 770 810 840
6” Concrete Floor 4.8 5 200 225 250 275 300 325 350 375 400 425 450 475 500 525 550 575 600
Note: Above insulation “K” Factors [Thermal Conductivity, BTU
per (hour) (square foot) (ºF. per inch of thickness)] and heat
gain factors for Cork and Window Glasses are extracted and
Insulation Values
“K” Factor - Insulating Value of any material is rated by its thermal conductivity
“U” Factor - Overall coecient of heat transfer, BTU per hour/per square foot/per degree F.
“R” Factor - Thermal resistances
“X” = Inches of Insulation
Table 2
Eective K Factor in Block Thickness of Insulation
Insulation Insul. K Factor 6” 8” 10” 12”
Air 4.65 6.94 6.65 6.50 6.40
Vermiculite .47 2.73 2.67 2.64 2.62
Sawdust .45 2.70 2.65 2.62 2.60
Cork .38 2.62 2.57 2.55 2.53
Rock Wool .30 2.52 2.49 2.47 2.45
Mac. Paper .28 2.50 2.46 2.45 2.43
Styrofoam .24 2.45 2.42 2.40 2.40
Polyurethane .16 2.36 2.33 2.33 2.32
reprinted by permission from ASHRAE 1972 HANDBOOK OF
FUNDAMENTALS.
K = UX = X/R
U = K/X = 1/R
R = 1/U = X/K
Note: If blocks have 3 holes, add .75 to all of the values shown. The
above data is being shown for reference purpose only - this is a very
inecient method of construction/insulation due to:
1. Concrete webs are dominant factor in calculating insulating eect.
2. Filling techniques may leave blocks improperly lled.
3. No vapor seal present - moisture inltration decreases insulation
eect.
4. If used for freezers, moisture will freeze inside block and break
out the surface of the block.
5. Blocks are highly subject to setting cracks- more inltration.
Table 3
Allowance for Sun Eect
(Fahrenheit degrees to be added to the normal temperature dierence for heat leakage
calculations to compensate for sun eect- not to be used for air conditioning design.)
Type of East South West Flat
Surface Wall Wall Wall Roof
Dark Colored Surfaces,
Such as:
Slate Roong 8 5 8 20
Tar Roong
Black Paints
Light Colored Surface,
Such as:
White Stone 4 2 4 9
Light Colored Cement
White Paint
Medium Colored Surface,
Such as:
Unpainted Wood
Brick 6 4 6 15
Red Tile
Dark Cement
Red, Gray or Green Paint
13
Table 4
Average air changes per 24 hours for storage rooms
above 32ºF. (0ºC.) due to door openings and inltration.
Table 5
Average air changes per 24 hours for storage rooms
below 32ºF. (0ºC.) due to door openings and inltration.
Air Air Air
Volume Changes Volume Changes Volume Changes
Cu. Ft. Per 24hrs. Cu. Ft. Per 24hrs. Cu. Ft. Per 24hrs.
200 44.0 2,000 12.0 25,000 3.0
250 38.0 3,000 9.5 30,000 2.7
300 34.5 4,000 8.2 40,000 2.3
400 29.5 5,000 7.2 50,000 2.0
500 26.0 6,000 6.5 75,000 1.6
600 23.0 8,000 5.5 100,000 1.4
800 20.0 10,000 4.9 150,000 1.2
1,000 17.5 15,000 3.9 200,000 1.1
1,500 14.0 20,000 3.5 300,000 1.0
Note: For heavy usage multiply the above values by 2.0
For long storage multiply the above values by 0.6
Air Air Air
Volume Changes Volume Changes Volume Changes
Cu. Ft. Per 24hrs. Cu. Ft. Per 24hrs. Cu. Ft. Per 24hrs.
200 33.5 2,000 9.3 25,000 2.3
250 29.0 3,000 7.4 30,000 2.1
300 26.2 4,000 6.3 40,000 1.8
400 22.5 5,000 5.6 50,000 1.6
500 20.0 6,000 5.0 75,000 1.3
600 18.0 8,000 4.3 100,000 1.1
800 15.3 10,000 3.8 150,000 1.0
1,000 13.5 15,000 3.0 200,000 0.9
1,500 11.0 20,000 2.6 300,000 0.85
Table 6
Heat removed in cooling air storage room conditions
(BTU per Cu. Ft.)
Storage Temperature of Outside Air
Room 40ºF. (4.4ºC.) 50ºF. (10ºC.) 85ºF. (29.4ºC.) 90ºF. (32.2ºC.) 95ºF. (35ºC.) 100ºF. (37.8ºC.)
Temp. Relative Humidity of Outside Air, %
ºF. ºC. 70 80 70 80 50 60 50 60 50 60 50 60
55 12.8 – – – – 1.12 1.34 1.41 1.66 1.72 2.01 2.06 2.44
50 10.0 – – – – 1.32 1.54 1.62 1.87 1.93 2.22 2.28 2.65
45 7.2 – – – – 1.50 1.73 1.80 2.06 2.12 2.42 2.47 2.85
40 4.4 – – – – 1.69 1.92 2.00 2.26 2.31 2.62 2.67 3.65
35 1.7 – – 0.36 0.41 1.86 2.09 2.17 2.43 2.49 2.79 2.85 3.24
30 -1.1 0.24 0.29 0.58 0.66 2.00 2.24 2.26 2.53 2.64 2.94 2.95 3.35
25 -3.9 0.41 0.45 0.75 0.83 2.09 2.42 2.44 2.71 2.79 3.16 3.14 3.54
20 -6.7 0.56 0.61 0.91 0.99 2.27 2.61 2.62 2.90 2.97 3.35 3.33 3.73
15 -9.4 0.71 0.75 1.06 1.14 2.45 2.74 2.80 3.07 3.16 3.54 3.51 3.92
10 -12.2 0.85 0.89 1.19 1.27 2.57 2.87 2.93 3.20 3.29 3.66 3.64 4.04
5 -15.0 0.98 1.03 1.34 1.42 2.76 3.07 3.12 3.40 3.48 3.87 3.84 4.27
0 -17.8 1.12 1.17 1.48 1.56 2.92 3.23 3.28 3.56 3.64 4.03 4.01 4.43
-5 -20.6 1.23 1.28 1.59 1.67 3.04 3.36 3.41 3.69 3.78 4.18 4.15 4.57
-10 -23.3 1.35 1.41 1.73 1.81 3.19 3.49 3.56 3.85 3.93 4.33 4.31 4.74
-15 -26.1 1.50 1.53 1.85 1.92 3.29 3.60 3.67 3.96 4.05 4.46 4.42 4.86
-20 -28.9 1.63 1.68 2.01 2.00 3.49 3.72 3.88 4.18 4.27 4.69 4.66 5.10
-25 -31.7 1.77 1.80 2.12 2.21 3.61 3.84 4.00 4.30 4.39 4.80 4.78 5.21
-30 -34.4 1.90 1.95 2.29 2.38 3.86 4.05 4.21 4.51 4.56 5.00 4.90 5.44
Table 3, 4 & 5 extracted and reprinted by permission from ASHRAE 1972 Handbook of Fundamentals.
Table 6 extracted and reprinted by permission from ASHRAE 1967 Handbook of Fundamentals.
14
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