load-calc

QUICK CALCULATIONSfor

WALK-IN COOLERSand

FREEZERS

HRPQC-03 (7/03)

Based on 95F. Ambient

BTUH LOADS for:6 x 6 to 40 x 40 Rooms

with 8 Ceilingsat -20F. to +35F.

APPLICATIONS NOTE

Quick Calculations Tables give typical and heavy load estimatesbased on the conditions in each room temperature table. Condi-tions include construction, loading, and room surroundings.

If your conditions are very different from the typical or heavyconditions, then figure a load estimate specifically for your job.Here are three suggestions to help you get an accurate loadestimate for your application:

a. You can use the paper and pencil calculation inHeatcraft Refrigeration Products Engineering Manual(H-ENG-1)

b. You can use the box load software, in the Calculation Toolboxof the Cold Solutions Program provided by a Sales Rep

c. Or you can call your Sales Representative for assistance

Before you do a, b, or c, get this information about your job:1. Room information:

Length, width, and height of the box in feetTemperature of the refrigerated room (F)Relative humidity in the refrigerated room (if specified)Summertime design ambient temperature (F). This isusually the temperature expected at the location of an aircooled condensing unit which cools the room

2. Insulation information:Type of insulation, insulation thickness (inches), and externaltemperatures on walls, ceiling, floor

3. Infiltration load information:The temperature (F) of the entering air and the relativehumidity of the entering air. Also, an estimate of the doorusage - average, heavy, etc.Does the box have glass doors? Dock doors? How many?

4. Product load information:What is the product or product mix?How many pounds of product entering at what temperature?How long (hours) does it take to load the product into room?How quickly (hours) should the room pull the product downto what temperature?How many pounds of fruit and vegetables are in the room?(respiration load)

5. Miscellaneous loads information:How many people work in the room?What is the lighting (watts)?How many motors (HP) do work in the room?

6 6 8 36 288 4522 65706 8 8 48 384 5296 73906 10 8 60 480 6020 81708 8 8 64 512 6193 83608 10 8 80 640 7032 92708 12 8 96 768 7830 101408 14 8 112 896 8597 109808 16 8 128 1024 9341 117908 18 8 144 1152 10065 125808 20 8 160 1280 11402 138008 22 8 176 1408 12097 145708 24 8 192 1536 12779 153208 26 8 208 1664 13451 160608 28 8 224 1792 14115 168008 30 8 240 1920 14770 175208 32 8 256 2048 15417 1824010 10 8 100 800 7980 1031010 12 8 120 960 8883 1130010 14 8 140 1120 9752 1225010 16 8 160 1280 11224 1363010 18 8 180 1440 12045 1453010 20 8 200 1600 12849 1543010 24 8 240 1920 14413 1717010 28 8 280 2240 15931 1886012 12 8 144 1152 9887 1241012 14 8 168 1344 11483 1392012 16 8 192 1536 12423 1497012 18 8 216 1728 13338 1599012 20 8 240 1920 14235 1699012 22 8 264 2112 15115 1797014 14 8 196 1568 12547 1511014 16 8 224 1792 13580 1626014 20 8 280 2240 14587 1752014 24 8 336 2688 15574 1875016 16 8 256 2048 14704 1753016 20 8 320 2560 17318 2042016 24 8 384 3072 19416 2280018 18 8 324 2592 17429 2055018 20 8 360 2880 18592 2187018 24 8 432 3456 20863 2446020 20 8 400 3200 19842 2330020 24 8 480 3840 22911 2653020 28 8 560 4480 25289 2926020 32 8 640 5120 28058 3238020 36 8 720 5760 30347 3502020 40 8 800 6400 33231 3807040 24 8 960 7680 37745 4329040 28 8 1120 8960 42361 4842040 32 8 1280 10240 46722 5349040 36 8 1440 11520 51218 5850040 40 8 1600 12800 55479 63460

Typical Load Conditions:The Cold Solutions Programautomatically figures typical loads.Here are the typical conditions:

Product - In at +10a) Specific heat of product is 0.45

BTU per poundb) Product loaded in a 24 hour periodc) Freezing point of product is 27d) Reduce product to 0 in 24 hourse) Pounds of +10 product EQUALS

room volume (cu. ft.)External Temperaturesa) 95 on all four wallsb) 115 on the ceiling (solar effect)c) 55 on the floorInsulation - 4" Urethane4" urethane on the walls, ceiling,and floor with R = 25 and k = 0.16Infiltration - 2 times Averagea) 95 air enters room through the

door at 50% relative humidityb) The door openings cause TWICE

the number of air changes listed inAVERAGE AIR CHANGES FORSTORAGE ROOMS table

Miscellaneousa) Lighting - One watt per square

foot of floor areab) People Load - charged at 1person

per 25000 cu. ft. of room volumec) Motors - charged at 1 HP per

12500 cu. ft. of room volumeHeavy Load Conditions:Same as Typical except:a) Pounds of product is 3 times cu. ft.b) People load is 1 person Safety Factor - 10%10% safety factor is added to theproduct, transmission, infiltration,and miscellaneous loads describedabove. Run time - 18 hrs, electric defrost18 hour condensing unit run time.The BTU load for 24 hours isdivided by 18 to yield the hourlyheat load reported in this table.

DIMENSIONS ROOM ROOM BTUH BTUH(FEET) AREA VOLUME TYPICAL HEAVY

W L H SQ. FT. CU. FT LOAD LOAD

0F. ROOM(add 15% to loads for 10' height)

QUICK CALCULATIONS forFREEZERS


Product - In at 0a) Specific heat of product is 0.45

BTU per poundb) Product loaded in a 24 hour periodc) Freezing point of product is 27d) Reduce product to -10 in 24 hourse) Pounds of 0 product EQUALS










-10F. ROOM(add 15% to loads for 10' height)

6 6 8 36 288 4859 70706 8 8 48 384 5692 79606 10 8 60 480 8573 108908 8 8 64 512 6654 89908 10 8 80 640 7555 99608 12 8 96 768 8413 108908 14 8 112 896 9239 117908 16 8 128 1024 10039 126608 18 8 144 1152 10818 135108 20 8 160 1280 12225 147808 22 8 176 1408 12973 156008 24 8 192 1536 13708 164008 26 8 208 1664 14432 172008 28 8 224 1792 15146 179808 30 8 240 1920 15851 187608 32 8 256 2048 16549 19520

10 10 8 100 800 8573 1107010 12 8 120 960 9543 1213010 14 8 140 1120 10477 1315010 16 8 160 1280 12028 1458010 18 8 180 1440 12911 1555010 20 8 200 1600 13775 1650010 24 8 240 1920 15457 1836010 28 8 280 2240 17090 2017012 12 8 144 1152 10621 1331012 14 8 168 1344 12305 1489012 16 8 192 1536 13314 1601012 18 8 216 1728 14297 1710012 20 8 240 1920 15260 1816012 22 8 264 2112 16206 1922014 14 8 196 1568 13446 1616014 16 8 224 1792 14554 1739014 20 8 280 2240 16696 1978014 24 8 336 2688 19202 2253016 16 8 256 2048 15761 1874016 20 8 320 2560 18533 2179016 24 8 384 3072 20786 2432018 18 8 324 2592 18652 2193018 20 8 360 2880 19900 2333018 24 8 432 3456 22336 2609020 20 8 400 3200 21240 2485020 24 8 480 3840 24503 2826020 28 8 560 4480 27054 3116020 32 8 640 5120 29993 3445020 36 8 720 5760 32449 3726020 40 8 800 6400 35515 4047040 24 8 960 7680 40316 4598040 28 8 1120 8960 45232 5139040 32 8 1280 10240 49870 5673040 36 8 1440 11520 54656 6202040 40 8 1600 12800 59186 67250



W L H SQ. FT. CU. FT LOAD LOADTypical Load Conditions:The Cold Solutions Programautomatically figures typical loads.Here are the typical conditions:

Product - In at -10a) Specific heat of product is 0.45

BTU per poundb) Product loaded in a 24 hour periodc) Freezing point of product is 27d) Reduce product to -20 in 24 hourse) Pounds of -10 product EQUALS








6 6 8 36 288 5187 75706 8 8 48 384 6076 85106 10 8 60 480 6908 93908 8 8 64 512 7104 96108 10 8 80 640 8066 106408 12 8 96 768 8982 116208 14 8 112 896 9865 125808 16 8 128 1024 10720 135008 18 8 144 1152 11553 144108 20 8 160 1280 13031 157308 22 8 176 1408 13830 166008 24 8 192 1536 14617 174608 26 8 208 1664 15392 183108 28 8 224 1792 16156 191408 30 8 240 1920 16912 199708 32 8 256 2048 17659 2078010 10 8 100 800 9152 1181010 12 8 120 960 10187 1294010 14 8 140 1120 11185 1402010 16 8 160 1280 12815 1552010 18 8 180 1440 13758 1655010 20 8 200 1600 14682 1756010 24 8 240 1920 16480 1953010 28 8 280 2240 18227 2146012 12 8 144 1152 11338 1419012 14 8 168 1344 13108 1585012 16 8 192 1536 14185 1703012 18 8 216 1728 15236 1818012 20 8 240 1920 16246 1930012 22 8 264 2112 17274 2043014 14 8 196 1568 14326 1719014 16 8 224 1792 15509 1849014 20 8 280 2240 17795 2103014 24 8 336 2688 20441 2392016 16 8 256 2048 16795 1992016 20 8 320 2560 29124 3253016 24 8 384 3072 22129 2582018 18 8 324 2592 19850 2327018 20 8 360 2880 21182 2476018 24 8 432 3456 23781 2768020 20 8 400 3200 22611 2637020 24 8 480 3840 26066 2995020 28 8 560 4480 28788 3303020 32 8 640 5120 31894 3649020 36 8 720 5760 34516 3946020 40 8 800 6400 37762 4284040 24 8 960 7680 42487 4827040 28 8 1120 8960 48059 5432040 32 8 1280 10240 52973 5994040 36 8 1440 11520 58047 6549040 40 8 1600 12800 62848 71000

-20F. ROOM(add 15% to loads for 10' height)


2003, Heatcraft Refrigeration Products LLC

Electrical Formulas(Heaters, Resistive Loads)

Single Phase Loads:Watts = Amps times Volts [P = I x E]Amps = Watts divided by Volts [I = P / E]Volts = Amps divided by Watts [E = P / I]

Three Phase Loads: (where the loads on each phase are equal)Watts = 1.732 times Amps times Volts [P = 1.732 x I x E]Amps = Watts divided by Volts [I = P / (1.732 x E)]Volts = Amps divided by Watts (E = P / (1.732 x I)]

Based on a minimum 1-1/2 inchurethane foam insulated fixture,18 hours per day compressor

run time.

Based on a minimum 1 inchurethane foam insulated fixture,16 hours per day compressor

run time.

-10F. to 0F. Reach-Ins 35F. to 40F. Reach-Ins

Room VolumeCubic Feet

ApproximateBTUH

Room VolumeCubic Feet

ApproximateBTUH

4 - 1011 - 1819 - 35

4 - 1011 - 1819 - 28

36 - 5556 - 75

76 - 100

100013501900

290042005500

950 - 11501100 - 1300

2100

260035005700

29 - 3839 - 68

69 - 100

Use motor inside when BOTHthe motor and the work doneby the motor are inside the

refrigerated room.

Use motor outside when thework done by the motor is

inside the refrigerated room,but the motor is outside of the

refrigerated room.

If occupancy is unknownallow one person per 24

hours for each 25,000 cubicfeet of space.

HEAT EQUIVALENTin BTUH per HP of Electric

Motors Openings & Infiltration

MotorHP

InsideRefrigeration

Space

RoomTemperature

Heat Equivalentper person

BTU / 24 Hours

1/8 to 1/21/2 to 33 to 20

50F.40F.30F.

425037002950

172802016022800

HEAT EQUIVALENTof Occupancy

OutsideRefrigeration

Space

254525452545

20F.10F.0F.

-10F.

25200288003120033600

LIGHTSTypically 1 to 1-1/2 watts per square foot. Cutting or storage rooms

can be double the storage figure.

Each watt is multiplied by 3.42 BTU per watt to get BTUH and thenmultiplied by 24 to get the daily load.

For the heat gain from lift truckswith internal combustion engines,

derive the equivalent HP bymultiplying engine HP by daily

hours of operation and dividing by24 (typically 4 - 5 equivalent HP).Multiply the equiv. HP by 75000

for the additional BTU/day.

If motor or loading conditions arenot known then calculate one

motor HP for each 16000 cu. ft. ina storage cooler and 12500 cu. ft.

in a storage freezer. Loadingdocks and high distributionwarehouses are heavier.

HEAT GAINfor battery operated

lift trucks(typically 4 - 5 equivalent HP)Battery

operatedload

capacity,POUNDS

Heat gainper hour

of lift truckoperation,

BTUH

Approx.total

weightof lift truck,POUNDS

2000400060008000

14000210002300026000

60008000

1200014000

AVERAGE AIR CHANGESfor Storage Rooms due to

Door Openings & Infiltration

RoomVolumeCu. Ft.

RoomTemp.

Above 32F.

20025030040050060080010001500200030004000500060008000

1000015000

EQUATIONfor

Heat Conduction

Q Total = U x A x (F. out - F. in)

Legend:Q Total is total heat transfer in BTU

per hour (BTUH)U is coefficient of heat transfer in

BTU / (hour x sq. ft. x F.)x is the symbol for multiplyA is area in square feet(F. out - F. in) is the temperature on

the outside less the temperatureon the inside of the insulation

U = 1 divided by RU = k x (insulation thickness)k = (insulation thickness) / R

Insulation thickness is inches.

RoomTemp.

Below 32F.

REACH-IN GLASS DOOR LOADS

Glass door loads have beenadjusted for run time load.

Multiply number of doors bythe door load listed and add tohourly heat load in the tables.

Meat/Prep. Room loads based oncontinuous operation and includeallowances for average number ofpersonnel, processing equipment,etc., with glass panel in one walland walls and ceilings insulatedwith 3 inches of styrene with boxlocated in air conditioned area.Evaporator should be low outletvelocity type to avoid drafts and

should be selected for continuousoperation and not less than 30F.

evaporator temperature.

MEAT CUTTING / PREP ROOM

FloorSquare

Feet

BTUHper Square Feet of Floor

100200300400500600700800900

10001200

9388858178757269676562

10599959087858178757369

RoomTemperature

BTUHper Door

55F. 50F.

35F.30F.

0F.-10F.-20F.

1060960

173017301730

44.038.034.529.526.023.020.017.514.012.09.58.27.26.55.54.93.9

33.529.026.222.520.018.015.313.511.09.37.46.35.65.04.33.83.0


Product - In at +10a) Specific heat of product is 0.90

BTU per poundb) Product loaded in a 24 hour periodc) Freezing point of product is 27d) Reduce product to 30 in 24 hourse) Pounds of +40 product EQUALS











6 6 8 36 288 3483 51906 8 8 48 384 4095 59106 10 8 60 480 4668 65908 8 8 64 512 4812 67608 10 8 80 640 5485 75808 12 8 96 768 6126 83608 14 8 112 896 6744 91208 16 8 128 1024 7343 98608 18 8 144 1152 7927 105808 20 8 160 1280 9078 117408 22 8 176 1408 9639 124408 24 8 192 1536 10192 131308 26 8 208 1664 10736 138208 28 8 224 1792 11273 144908 30 8 240 1920 11804 151708 32 8 256 2048 12330 1583010 10 8 100 800 6252 852010 12 8 120 960 6984 943010 14 8 140 1120 7691 1031010 16 8 160 1280 8956 1161010 18 8 180 1440 9626 1246010 20 8 200 1600 10282 1329010 24 8 240 1920 11560 1492010 28 8 280 2240 12804 1652012 12 8 144 1152 7805 1046012 14 8 168 1344 9177 1191012 16 8 192 1536 9948 1289012 18 8 216 1728 10700 1385012 20 8 240 1920 11438 1480012 22 8 264 2112 12164 1574014 14 8 196 1568 10054 1303014 16 8 224 1792 10907 1413014 20 8 280 2240 12560 1627014 24 8 336 2688 14597 1880016 16 8 256 2048 11842 1534016 20 8 320 2560 14093 1816016 24 8 384 3072 15846 2048018 18 8 324 2592 14189 1829018 20 8 360 2880 15164 1958018 24 8 432 3456 17071 2212020 20 8 400 3200 16216 2099020 24 8 480 3840 18854 2419020 28 8 560 4480 22108 2815020 32 8 640 5120 23277 3002020 36 8 720 5760 25219 3267020 40 8 800 6400 27714 3573040 24 8 960 7680 31681 4110040 28 8 1120 8960 35721 4641040 32 8 1280 10240 39570 5167040 36 8 1440 11520 43516 5688040 40 8 1600 12800 47289 62060

QUICK CALCULATIONS forCOOLERS


Product - In at 40a) Specific heat of product is 0.90

BTU per poundb) Product loaded in a 24 hour periodc) Freezing point of product is 27d) Reduce product to 35 in 24 hours.e) Pounds of 40 product entering the

room is two times room cu. ft.External Temperaturesa) 95 on all four walls,b) 115 on the ceiling (solar effect)c) 55 on the floorInsulation - 4" Styrofoama) 4" Styrofoam on the wall & ceiling,

with R = 16.7 and k = 0.24b) 6 concrete on the floor,

with R = 4.8 and k = 1.25Infiltration - 2 times Averagea) 95 air enters room through the


the number of air changes listed inAVERAGE AIR CHANGES FORSTORAGE ROOMS table.


foot of floor areab) People Load - charged at 1 person


16000 cu. ft. of room volumeHeavy Load Conditions:Same as Typical except:a) Pounds of product is 3 times cu. ft.b) People load is 1 person Safety Factor - 10%10% safety factor is added to theproduct, transmission, infiltration,and miscellaneous loads describedabove. Run time - 16 hrs., air defrost16 hour condensing unit run time.The BTU load for 24 hours isdivided by 16 to yield the hourlyheat load reported in this table.


W L H SQ. FT. CU. FT. LOAD LOAD


6 6 8 36 288 4986 65406 8 8 48 384 5884 74706 10 8 60 480 6729 83508 8 8 64 512 6939 85708 10 8 80 640 7934 96008 12 8 96 768 8887 105908 14 8 112 896 9808 115508 16 8 128 1024 10626 124108 18 8 144 1152 11581 134108 20 8 160 1280 12588 143108 22 8 176 1408 13434 151908 24 8 192 1536 14267 160608 26 8 208 1664 15585 174208 28 8 224 1792 16398 182708 30 8 240 1920 17203 191208 32 8 256 2048 18001 1996010 10 8 100 800 9072 1079010 12 8 120 960 10164 1193010 14 8 140 1120 11221 1304010 16 8 160 1280 12398 1412010 18 8 180 1440 13406 1517010 20 8 200 1600 14890 1671010 24 8 240 1920 16823 1874010 28 8 280 2240 18709 2072012 12 8 144 1152 11391 1322012 14 8 168 1344 12728 1447012 16 8 192 1536 13887 1568012 18 8 216 1728 15518 1737012 20 8 240 1920 16633 1855012 22 8 264 2112 17732 1971014 14 8 196 1568 14046 1585014 16 8 224 1792 15828 1770014 20 8 280 2240 18329 2034014 24 8 336 2688 20756 2291016 16 8 256 2048 17240 1920016 20 8 320 2560 19987 2210016 24 8 384 3072 22656 2493018 18 8 324 2592 20132 2226018 20 8 360 2880 21615 2383018 24 8 432 3456 25018 2741020 20 8 400 3200 23713 2603020 24 8 480 3840 27005 2937020 28 8 560 4480 30084 3265020 32 8 640 5120 33608 3637020 36 8 720 5760 36595 3955020 40 8 800 6400 40190 4320040 24 8 960 7680 45633 4904040 28 8 1120 8960 51628 5528040 32 8 1280 10240 57408 6146040 36 8 1440 11520 63278 6758040 40 8 1600 12800 68954 73650

QUICK CALCULATIONS forCOOLERS

Heatcraft Refrigeration Products LLC2175 West Park Place Boulevard Stone Mountain, GA 30087 USA770-465-5600 Fax: 770-465-5990www.heatcraftrpd.com

Documents

load-calc