Compensating
Hood Engineering
Manual
___________________________
Spring Air Systems Inc., Oakville, Ontario
Phone (905) 338-2999, Fax (905) 338-0179, info@springairsystems.com
www.springairsystems.com
Compensating Hood Engineering Manual
Table of Contents
Introduction
What is a Compensating Hood?
Benefits
Model Number Designation
Model B-MI Box Canopy
Model B-S-MI Box Canopy
Model DB-MI Double Box Canopy
Exhaust and Supply Air Calculations
Compensating Dry Hood Model Numbers
Compensating Water Wash Hood Model Numbers
Hood Type vs. Exhaust Flow Rate and Static Pressure
Net Exhaust Air Volume Chart
Supply Volume vs. Supply Duct Size (All Ventilators)
Exhaust Volume vs. Exhaust Duct Size (All Ventilators)
Determining Hood Dimensions
The Systems Approach
Heating Capacity
Compensating Hood Controllers
Motor Control Panels
Specification
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May05
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Compensating Hood Engineering Manual
Introduction
Spring Air Systems Inc. commercial compensation type hoods have been designed and
constructed in accordance with the Canadian Building Code, the National Fire Protection
Association (NFPA-96) and listed by Underwriters Laboratories of Canada. In addition the Spring
Air Systems Compensating Hoods meet all provincial and municipal code requirements.
The Spring Air Systems Compensating Hood is fabricated from stainless steel with No. 4 finish
on all exposed surfaces. All edges are ground and polished. All hoods are manufactured to
stringent quality standards and are guaranteed to enhance the appearance of any commercial
kitchen.
What is a compensating hood?
The Compensating Hood is a commercial kitchen hood that introduces fresh unheated air directly
into the canopy uniformly along the length of the hood. The fresh air (supply air) discharges
through a stainless steel perforated plate into the canopy forming a blanket of air across the roof
of the hood. Both the rising vapours from the cooking surface and the dilution air from the
kitchen area are entrained into this blanket of fresh air. This blended air mixture is then
exhausted outside.
In accordance with the NFPA-96 and the ULC listing, a fusible link fire damper is located at each
supply air inlet duct collar.
To assist in site balancing of the Compensating Hood an opposed blade balancing damper with
locking quadrant is installed in each supply air inlet duct collar. The install contractor must supply
an access door above the balancing damper to access the fusible link of the supply fire damper.
The access door should be no smaller than 12” x 6” (305 mm x 150 mm) located about 6” (305
mm ) above the balancing damper. All supply air plenums have 1” (25 mm) of foam insulation for
sound attenuation and insulation.
The Compensating Hood Model CD-B-MI
Figure 1
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The introduction of unheated air into the canopy
minimizes the NET EXHAUST (NEX) from the kitchen,
reducing the requirements for heated makeup air. The
NEX is the difference between the TOTAL EXHAUST
(TEX) and the TOTAL SUPPLY (TSU). A properly
balanced Compensating Hood will exhaust the absolute
minimum necessary to properly ventilate the cooking
appliances.
Benefits
A Spring Air Systems Inc. Compensating Hood supply
and exhaust systems provides numerous benefits to the
owners of a commercial restaurant.
1. More comfortable kitchen environment.
2. Lower annual heating cost with little or no capital
cost increase.
3. Lower annual air conditioning costs and possible
reduced capital cost for air conditioning equipment.
Compensating Hood Figure FDBSMI
Figure 2
More Comfortable Kitchen Environment
The Spring Air Compensating Hood System provides excellent smoke capture using minimum
net exhaust air from the store. The system is interlocked with the building air conditioning units to
energize the economizer and provide a balanced supply and exhaust system. Reduced drafts
will provide more comfortable temperatures throughout the kitchen.
Low Heating Costs
The Spring Air Compensating Hood System is designed to minimize the net exhaust air from the
building. Less net exhaust means less heating of fresh air or supply air into the building.
Lower Air Conditioning Costs
The Spring Air Compensating Hood System is designed to minimize the amount of conditioned
supply air required in the store. By reducing the conditioned air into the store, the required air
conditioning load is reduced and the air conditioning operating cost will consequently decline.
The Spring Air Systems Compensating Hood is available in five basic types
1. Continuous cold water spray/hot water wash - “C”
2. Hot water wash - “H”
3. Dry Ventilator - “D”
4. Filter Hood with exhaust fire damper - “FD”
5. Filter Hood without exhaust fire damper - “FN”
For a more detailed description of the types of hoods refer to the Spring Air Systems “Ventilator
Engineering Manual”. Each type of hood provides varying degrees of grease extraction
efficiency, automatic/manual wash, and second line fire suppression.
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Model Number Designation
H
C
H
D
F
Cold Water Spray/Hot water wash
Hot water wash
Dry Grease Extractor/No wash
Filter Hood/No wash
T
F
D
N
Thermostatic Fire Damper
Fusible Link fire damper spring loaded
Fusible Link fire damper dead weight
No Fire damper
B
BS
DB
Box type canopy
Box Shelf type canopy
Double box canopy
MI
Make up air internally in canopy
10
4
T
B
MI
10/4
The length of the ventilator in feet
The width of the ventilator in feet
Typical Water Wash Application
Figure 3
The type “H” and “C” ventilators require a water wash control panel. Consult the “Ventilator
Engineering Manual” for the proper water wash control panel. The water wash control panel is
supplied to provide operation of the exhaust fan, supply unit (Spring Air SFA series), time wash
cycle, fire suppression system.
Model B-MI Box Canopy
Used on all cooking equipment. Wall hung with a recommended mounting height of 6’6” (1980
mm) from the lower front edge of the hood to finished floor. Finished with a No.4 finish on three
sides. The box canopy can be tapered to fit into kitchens with ceilings as low as 7’6” (2290 mm).
Available with fluorescent or incandescent lights.
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Model B-MI Box Canopy
Figure 4
Model B-S-MI Box Canopy
Used on fryers, ranges, griddles, gas or electric. Wall hung with a recommended mounting
height of 5’6” (1680 mm) from the lower front edge of the hood to the finished floor. Finished with
a No.4 finish on three sides. The box canopy is 33” (840 mm) deep from front to back and
excellent selection for locations with low head room.
Model B-S-MI Box Canopy
Figure 5
Model DB-MI Double Box Canopy
Used on all cooking equipment in double row island arrangement. Water wash and dry grease
extractor type have single grease extractor with double slot. Filter hood type has center V bank
filter arrangement. Specifically designed for applications with a heavy side such as fryers, hot
tops and broilers and a light side such as ovens, kettles, and ranges. Finished on all four sides
with a No. 4 finish, double box canopy can be tapered to fit a kitchen ceiling height as low as 7’6”
(2290 mm).
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Model DB-MI Double Box Canopy
Figure 6
Exhaust and Supply Air Calculations
The Compensating Hood air formula is as follows:
TOTAL SUPPLY (TSU) = TOTAL EXHAUST (TEX) - NET EXHAUST (NEX)
The TOTAL EXHAUST (TEX) for each hood varies depending on the type of hood.
TEX = Length of hood x EXHAUST FLOW RATE (EFR)
Refer to Chart No. 2 for EXHAUST FLOW RATE (EFR) for the various types of Spring Air
Systems hoods available.
Compensating Dry Hood Model Numbers
Model No.
Description
DD-B-MI
FD-B-MI
FN-B-MI
DD-BS-MI
FD-BS-MI
FN-BS-MI
DD-DB-MI
FD-DB-MI
FN-DB-MI
Single row box canopy, dry grease extractor with fusible link dead weight fire damper
Single row box canopy, filter hood with fusible link dead weight fire damper
Single row box canopy, filter hood with no fire damper
Single row box-shelf canopy, dry grease extractor with fusible link dead weight fire damper
Single row box-shelf canopy, filter hood with fusible link dead weight fire damper
Single row box-shelf canopy, filter hood with no fire damper
Double row box canopy, dry grease extractor with fusible link dead weight fire damper
Double row box canopy, filter hood with fusible link dead weight fire damper
Double row box canopy, filter hood with no fire damper
Chart No. 1a
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6
Compensating Water Wash Hood Model Numbers
Model No.
CD-B-MI
CF-B-MI
CT-B-MI
HD-B-MI
HF-B-MI
HT-B-MI
CD-BS-MI
CF-BS-MI
CT-BS-MI
HD-BS-MI
HF-BS-MI
HT-BS-MI
CD-DB-MI
CF-DB-MI
CT-DB-MI
HD-DB-MI
HF-DB-MI
HT-DB-MI
Description
Single row box canopy, continuous cold water spray/hot water wash ventilator with fusible
link dead weight fire damper
Single row box canopy, continuous cold water spray/hot water wash ventilator with fusible
link spring loaded fire damper
Single row box canopy, continuous cold water spray/hot water wash ventilator with
thermostatic activated spring loaded fire damper
Single row box canopy, hot water wash ventilator with fusible link dead weight fire damper
Single row box canopy, hot water wash ventilator with fusible link spring loaded fire damper
Single row box canopy, hot water wash ventilator with thermostatic activated spring loaded
fire damper
Single row box-shelf canopy, continuous cold water spray/hot water wash ventilator with
fusible link dead weight fire damper
Single row box-shelf canopy, continuous cold water spray/hot water wash ventilator with
fusible link spring loaded fire damper
Single row box-shelf canopy, continuous cold water spray/hot water wash ventilator with
thermostatic activated spring loaded fire damper
Single row box-shelf canopy, hot water wash ventilator with fusible link dead weight fire
damper
Single row box-shelf canopy, hot water wash ventilator with fusible link spring loaded fire
damper
Single row box-shelf canopy, hot water wash ventilator with thermostatic activated spring
loaded fire damper
Double row box canopy, continuous cold water spray/hot water wash ventilator with fusible
link dead weight fire damper
Double row box canopy, continuous cold water spray/hot water wash ventilator with fusible
link spring loaded fire damper
Double row box canopy, continuous cold water spray/hot water wash ventilator with
thermostatic activated spring loaded fire damper
Double row box canopy, hot water wash ventilator with fusible link dead weight fire damper
Double row box canopy, hot water wash ventilator with fusible link spring loaded fire damper
Double row box canopy, hot water wash ventilator with thermostatic activated spring loaded
fire damper
Chart No. 1b
Hood Type Vs EXHAUST FLOW RATE (EFR) and Static Pressure
Description
EFR
CFM/ft
Water wash & Dry Grease Extractors
All single row hoods light to medium cooking
All single row hoods heavy cooking
All double row, island hoods one single row appliance
All double row, island hoods light to medium cooking
All double row, island hoods heavy cooking
Filter hoods with exhaust fire damper
All single row hoods light cooking
All single row hoods medium cooking
All single row hoods heavy cooking
All double row, island hoods light to medium cooking
All double row, island hoods heavy cooking
Filter hood without exhaust fire damper
All single row hoods light cooking
All single row hoods medium cooking
All single row hoods heavy cooking
All double row, island hoods with one single row appliance
All double row, island hoods light to medium cooking
All double row, island hoods heavy cooking
l/s/m
Static Pressure
in. W.C.
kpa
300
350
400
600
700
465
545
622
930
1090
1.26
1.50
1.25
1.46
1.74
0.31
0.37
0.31
0.33
0.43
250
300
350
600
700
385
465
545
930
1090
0.45
0.55
0.65
0.55
0.65
0.11
0.14
0.16
0.14
0.16
250
300
350
400
600
700
385
465
545
622
930
1090
0.35
0.35
0.45
0.45
0.55
0.65
0.09
0.09
0.11
0.14
0.14
0.16
Chart No. 2
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Net Exhaust Air (NEV)Volume Chart
Cooking Appliances
Description
Length (in)
Charbroiler 24
Charbroiler 30
Charbroiler 34
Charbroiler 36
Charbroiler 48
Charbroiler 60
Charbroiler 72
Chicken broaster 20
Chicken broaster 30
Conveyor Oven one deck 90
Conveyor Oven two deck 90
Comb. Wood/Gas Brick Oven 48
Donut Fryer 32
Donut Fryer 72
Fry Top 36
Fryer Pitco model 14
Fryer 15
Fryer 16
Fryer 18
Fryer 24
Griddle 24
Griddle 36
Gyro 18
Hot Top Range 48
Kettle one with stand 28
Kettle Single 45
Microwave 24
Oven 38
Pasta Cooker 18
Pizza Oven 60
Rotisserie Oven 42
Rotisserie Oven 66
Range stock pot 24
Range two burner regular duty 12
Range four burner regular duty 24
Range six burner regular duty 36
Salamander Broiler 36
Spreader 12
Steamer 30
Solid Fuel 36”
Solid Fuel – 60”
Tilting Skillet 42
Toaster 18
Wok – one hole 30
Wok – two hole 60
Wok –three hole 90
Woodstone Oven 64
Upright Broiler 2 shelf 36
Upright Broiler 3 shelf 36
Warming Lamp 18
24
30
34
36
48
60
72
20
30
90
90
48
32
72
36
17
15
16
18
24
24
36
18
48
28
45
24
38
18
60
42
66
24
12
24
36
36
12
30
36
60
42
18
30
60
90
64
36
36
18
Net Exhaust Volume
Electric CFM
Gas CFM
900
1100
1300
1440
1600
1800
2250
200
300
325
430
285
320
300
100
125
150
200
250
700
130
250
30
180
150
260
550
960
255
180
275
415
270
10
150
370
50
540
810
30
1125
1325
1600
1800
2000
2250
2800
200
300
430
575
1200
430
480
340
150
190
200
250
300
225
275
175
880
130
250
225
150
325
750
1250
300
225
315
475
350
10
1800
2400
500
50
500
850
1400
400
700
1050
30
Chart No. 3
The NET EXHAUST (NEX) is determined by adding the NET EXHAUST VOLUME (NEV) CFM
(l/s) for each individual cooking appliance. The NET EXHAUST VOLUME (NEV) for individual
appliances varies depending on the amount of smoke, particulate, and grease generated, the
surface temperature and whether the appliance is gas or electric. Gas appliances require higher
NEV because of the high flue gas temperatures. Chart No. 3 includes typical NEV values for
most cooking applications. Consult the factory if an appliance is not listed.
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It is important to know the dimensions of each appliance. The NET EXHAUST VOLUME (NEV)
decreases and increases proportionally to the length of some appliances. These appliances are
indicated in Chart No. 3 with length dimensions. For lengths other than indicated prorate the
value in the chart.
Once the cooking line up has been established, the NET EXHAUST (NEX) is calculated by
adding each individual NEV valve.
NEX = (NEV of appliance No. 1 + NEV of appliance No. 2 + NEV of appliance No. 3 +....)
The TOTAL SUPPLY (TSU) is determined by subtracting the NEX calculated above from the
TOTAL EXHAUST (TEX) calculated earlier.
Supply volume Vs Supply Duct Size
All Ventilators
Supply Volume
Duct Collar Size
CFM
l/s
WxL
10 in x in
350
400
450
500
550
600
650
700
750
800
850
900
950
1000
1050
1100
1150
1250
1200
165
189
212
236
260
283
307
330
354
378
401
425
448
472
796
519
543
590
560
6
7
7.5
8.5
9.5
10
11
12
13
13.5
14.5
15
16
17
18
18.5
19.5
21
20.5
WxL
254 mm x
mm
152
178
191
216
241
254
279
305
330
343
368
381
406
432
457
470
495
533
521
Supply Volume
Duct Collar Size
CFM
l/s
WxL
10 in x in
1300
1350
1400
1450
1500
1550
1600
1650
1700
1750
1800
1850
1900
1950
2000
2050
2100
2150
613
637
661
684
708
731
755
779
802
826
849
873
897
920
944
968
991
1015
22
23
24
24.5
25.5
26.5
27
28
29
29.5
30.5
31.5
32
33
34
35
35.5
36.5
WxL
254 mm x
mm
559
584
610
622
648
673
686
711
737
749
775
800
813
838
864
889
902
927
1. The static pressure at the supply duct collar is 0.45” W.C.
(0.11kpa) for all supply duct collars.
2. All ventilators and hoods over 8’0” (2440 mm) require two
supply duct collars. The static pressure at the supply duct
collar is 0.45” W.C. ( 0.11kpa).
Chart No. 4
For a double row island arrangement calculate, the NEX for both sides of the cooking line up.
Determine the TOTAL SUPPLY (TSU) for each side by subtracting the NEX for each side from
one-half of the TOTAL EXHAUST (TEX). Refer to the example for a more detailed description.
Using Chart No. 4 select the supply duct collar size based on the TSU. Using Chart No. 5 select
the exhaust duct collar sized based on the TEX.
WARNING
This method is an excellent guide to assist in calculating the TOTAL EXHAUST (TEX) and the
TOTAL SUPPLY (TSU) volumes, but consideration must be made for the conditions within the
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kitchen. i.e. location of the hood to doors, windows, and pass through which might create a draft.
Consult the factory when unusual site conditions exist. As described earlier the supply air is
discharged directly into the ventilator or hood canopy. The supply air (fresh air) is unheated and
should not exceed 70% of total exhaust air without consulting factory. In addition caution is
advised when the outside winter design for the location is below -5F as the fresh air may
requiring tempering to prevent possible frost or condensation. Again consult factory before
proceeding.
Exhaust Volume Vs Exhaust Duct Size
All Ventilators
Exhaust
Volume
CFM l/s
Duct Collar Size
Exhaust
Volume
CFM l/s
Duct Collar Size
WxL
WxL
WxL
WxL
in x in
mm x mm
in x in
mm x mm
450
212
10 x 4
254 x 102
4000 1888 10 x 36
254 x 914
500
236
10 x 4.5
254 x 114
4125 1947 10 x37
254 x 940
625
295
10 x 5.5
254 x 140
4250 2006 10 x38
254 x 965
750
354
10 x 7
254 x 178
4375 2065 10 x39
254 x 991
875
413
10 x 8
254 x 203
4500 2124 10 x 40.5
254 x 1029
1000 472
10 x 9
254 x 229
4625 2183 14 x 29.5
356 x 749
1125 531
10 x 10
254 x 254
4750 2242 14 x 30.5
356 x 775
1250 590
10 x 11
254 x 279
4875 2301 14 x 31.5
356 x 800
1375 649
10 x 12.5
254 x 318
5000 2360 14 x 32
356 x 813
1500 708
10 x 13.5
254 x 343
5125 2419 14 x 33
356 x 838
1625 767
10 x 14.5
254 x 368
5250 2475 14 x 33.5
356 x 851
1750 826
10 x 16
254 x 406
5375 2537 14 x 34.5
356 x 876
1875 885
10 x 17
254 x 432
5500 2596 14 x 35.5
356 x 902
2000 944
10 x 18
254 x 457
5625 2655 14 x 36
356 x 914
2125 1003 10 x 19
254 x 483
5750 2714 14 x 37
356 x 940
2250 1062 10 x 20
254 x 508
5875 2773 14 x 38
356 x 965
2375 1121 10 x 21.5
254 x 546
6000 2832 14 x 38.5
356 x 978
2500 1180 10 x 22.5
254 x 572
6125 2891 14 x 39
356 x 991
2625 1239 10 x 23.5
254 x 597
6250 2950 14 x 40
356 x 1016
2750 1298 10 x 25
254 x 635
6375 3008 16 x 36
406 x 914
2875 1357 10 x 26
254 x 660
6500 3067 16 x 36.5
406 x 927
3000 1416 10 x 27
254 x 686
6625 3125 16 x 37
406 x 940
3125 1475 10 x 28
254 x 711
6750 3185 16 x 38
406 x 965
3250 1534 10 x 29
254 x 737
6875 3244 16 x 38.5
406 x 978
3375 1593 10 x 30.5
254 x 775
7000 3303 16 x 39.5
406 x 1003
3500 1652 10 x 31.5
254 x 800
7125 3362 16 x 40
406 x 1016
3625 1711 10 x 32.5
254 x 826
7250 3421 16 x 41
406 x 1041
3750 1770 10 x 34
254 x 864
7375 3480 16 x 41.5
406 x 1054
3875 1829 10 x 35
254 x 889
7500 3539 16 x 42
406 x 1067
1. If exact exhaust volume is not indicated use duct size closest to required exhaust.
2. Model S, B, & B-S water wash hoods and dry grease extractors have 1.0” W.C. (0.25
kPa) for exhaust flow rates from 300 to 450 CFM/ft (466 to 700 l/s/m)
3. Model DB water wash hoods and dry grease extractors have 1.13” W.C. (0.28 KPa) for
exhaust flow rates from 600 to 700 CFM/ft (933 to 1090 l/s/m)
Chart No. 5
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Determining Hood Dimensions
Hood Length:
The hood length should equal the width of all the cooking appliances to be covered by the hood
plus allow and additional 6” (152 mm) overhang on either end of the cooking line up.
Hood Width: Single Row Wall Mounted
The hood width should be equal the depth of the largest appliance from the wall plus allow for an
additional 12” (305 mm) overhang from the front of the appliance. Generally most single row
compensating hoods fall between 47” (1194 mm) and 66” (1680 mm) wide. The hood should be
a minimum 47” (1194 mm) if fluorescent lights are to be installed. (Exception: The Spring Air
Systems model B-S-MI is only 33” (840 mm) deep).
Hood Width: Double Row Island Style
The hood width should equal the depth of the largest appliance on each side, plus the width of
the service wall and allow an additional 36” (915 mm). Island compensating hoods are generally
between 7’6” (2300 mm) and 8’6” (2600 mm) wide.
The Systems Approach
The Spring Air Systems Compensating Hood does not work alone. A good commercial kitchen
exhaust fan, supply unit, and compensating hood controller are required.
Spring Air Systems Inc. designs a supply unit especially for the compensating hood; the SFA
series. The SFA is available in a vertical or horizontal arrangement, indoor or outdoor and with
gas reheat.
SFA-OV Unheated Makeup Air Unit
The SFA-V unit is designed and constructed
specifically for commercial kitchen applications.
The SFA-V is a vertical supply unit that introduces
unheated fresh air directly into a compensating
kitchen exhaust hood. The vertical arrangement
requires minimum roof space. The roof mounted
SFA-V is complete with filters, supply fan motorized
discharge damper and end switch, fan motor, belts,
drives and perimeter curb. Supply air capacities
range from 500 to 8,000 CFM.
SFA-OV
Figure 7
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Typical Compensating Hood Schematic with electric heating
Figure 8
The kitchen and dining room must be balanced to provide a proper system. The schematic
shows a typical 100% exhaust, with 70% fresh air supply to the hood unheated and 10% directly
to the kitchen through some type of heating unit. This heat can be supplied by a electric duct
heater as shown above or gas, steam or hot water. If the kitchen has an air conditioning unit the
10% could be supplied as fresh through the A/C economizer. The remaining 20% required to
balance the restaurant must be supplied through the dining room air conditioning unit(s)
economizer or through some other makeup air unit. (Such as a Spring Air Systems SFA-IGO
Unit)
SFA-OH Unheated Makeup Air Unit
The SFA-OH unit is designed and constructed
specifically for commercial kitchen applications.
The SFA-OH is a horizontal supply unit that
introduces unheated fresh air directly into a
compensating kitchen exhaust hood. The roof
mounted SFA-OH is complete with filters,
supply fan motorized inlet damper and end
switch, fan motor, belts, drives and perimeter
curb. Supply air capacities range from 500 to
8,000 CFM.
SFA-OH
Figure 9
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SFA-IGOS Unheated and Heated Makeup Air Unit
A Spring Air Systems Inc. SFA-IGOS is available to supply both the unheated fresh air and the
heated supply air to the restaurant. The SFA-IGOS can be sized to supply all the fresh air
requirements for the restaurant eliminating the fresh air load on the roof top air conditioning units.
Typical Compensating Hood Schematic SFA-IGOS
Figure 10
Total Supply Air Volume:
The SFA-IGOS is used in conjunction with a compensating exhaust hood to replace air into a
commercial kitchen. The total exhaust from the kitchen hoods must first be calculated. See the
exhaust air calculation section of this manual. For commercial kitchens, the total supply air
volume into the kitchen should be between 80 and 90 percent of the total exhaust volume from
the kitchen hoods. It s important to maintain a slight negative pressure in the kitchen area.
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Unheated Supply Air Volume:
To calculate the amount of unheated
air to be supplied directly into the
compensating
hoods,
refer
to
unheated supply air calculation
section of this manual.
Heated Supply Air Volume:
The amount of heated supply air
required is equal to the total supply
air volume less the amount of
unheated supply air volume.
Typical SFA-IGOS
Figure 11
For example...
Given a total exhaust air of 4000 CFM exhausted from the compensating hoods, and suppose
80% of the exhaust air is to be supplied into the kitchen as fresh air. Therefore, the total supply
air is 4000 CFM x 0.8 equal to 3200 CFM. If the calculated unheated supply air supplied is 2500
CFM, then the heated supplied air required is 3200 CFM - 2500 CFM equal to 700 CFM. The
SFA-IGOS unit would be selected to provide 3200 CFM total supply with 2500 CFM unheated
supply to the compensating hoods and 700 CFM heated supply to diffusers in the kitchen area.
See Figure 8 for typical layout schematic of this system.
The remaining supply air should be introduced into the building through the dining room air
conditioning and/or heating unit.
Heating Capacity:
The total heating required is equal to the following:
Heating Output (BTU/hr) = Heated Supply Volume (CFM) x 1.09 x (TI - TO) Capacity
Use the chart below to select burner capacity for the application. Note the calculated capacity
above is the output required. The heaters are specified by the input values.
SFA-IGOS BURNER ENGINEERING DATA
HEATER
SIZE
(1)
(2)
(3)
(4)
BTU/HR
GAS PIPE
CONNECTION
(IN)
3/4
3/4
3/4
3/4
3/4
3/4
3/4
NATURAL
GAS FLOW
(SCFH)
100
150
200
250
300
350
400
INPUT
OUTPUT
(1)
80,000
100
100,000
(2)
120,000
150
150,000
(3)
200
200,000
160,000
250
250,000
187,000
300
300,000
225,000
350
350,000
262,500
400
400,000
300,000
Not available with power vent.
112,500 BTU/hr with power vent.
150,000 BTU/hr with power vent.
All units require the following clearances: Front: 48” Bottom: 0” Sides: 24” Rear: 6”
Chart No. 6
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Spring Air Systems Compensating Engineering Manual
14
SFA-IGO Heated Makeup Air Unit
General
The SFA-IGO is an indirect, gas-fired
make-up air unit for commercial
applications. The unit is designed to
introduce 100% fresh air into a
commercial building. When the amount of
heated makeup air required exceed the air
conditioning unit capacity use the SFAIGO. The SFA-IGO is roof-mounted on a
perimeter curb or sleeper with optional
turndown plenum. Supply air capacities
range from 500 to 8000 CFM with burners
from 80,000 to 600,000 BTU/hr output.
pical SFA-IGO
Figure 12
Heating Capacity:
The total heating required is equal to the following:
Heating Capacity (BTU/hr) =
Supply Volume (CFM) x 1.09 x (TI - TO)
Where: TI =
TO =
Supply discharge temperature
Winter design temperature for
required (F)
the area (F)
Use the Chart No. 6 above for selection of burner required.
SFA-IGO BURNER ENGINEERING DATA
HEATER
SIZE
(1)
(2)
(3)
(4)
BTU/HR
GAS PIPE
CONNECTION
(IN)
3/4
3/4
3/4
3/4
3/4
3/4
3/4
NATURAL
GAS FLOW
(SCFH)
100
150
200
250
300
350
400
INPUT
OUTPUT
(1)
80,000
100
100,000
(2)
120,000
150
150,000
(3)
200
200,000
160,000
250
250,000
187,000
300
300,000
225,000
350
350,000
262,500
400
400,000
300,000
Not available with power vent.
112,500 BTU/hr with power vent.
150,000 BTU/hr with power vent.
All units require the following clearances: Front: 48” Bottom: 0” Sides: 24” Rear: 6”
Chart No. 7
14 ______________________________________________________________________
Spring Air Systems Compensating Engineering Manual
15
Typical Compensating Hood Schematic with SFA-OV & SFA-IGO
Figure 13
Compensating Hood Controllers
Spring Air Systems Inc. manufacturers a
Compensating Hood Controller model
RPD20 (For use with no supplemental
heating or a electric duct heater) and
RPD11 (For use with gas duct heater)
for complete single switch operating of
the exhaust/supply system.
The
operator rotates the selector switch to
the occupied position and the exhaust
and supply fans energize, the fresh air
damper opens, and the air conditioning
unit economizers open. In addition, the
panels may be interlocked to the shunt
trip, surface fire suppression system or
building management system. Spring
Air Systems can also supply the motor
starters from stock.
RPD20 & RPD11 Controllers
Figure 14
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Spring Air Systems Compensating Engineering Manual
16
MOTOR CONTROL PANELS
EO-1:
EO-2:
One Exhaust Fan Operation
Two Exhaust Fan Operation
The SPRING AIR SYSTEMS motor control panels EO-1 and EO-2 contain electrical components
to start and stop the exhaust fan(s) and interlock with the surface fire suppression system and
supply air system.
The control panel includes a panel mounted disconnect switch, high voltage fuses, control
transformer, control fuse, motor starter(s) and overloads, control relays, on/off fan switch(es),
pilot lights and optional on/off
switch for the hood lights. To start
the exhaust fan, rotate the fan
selector switch to the “ON”
position. The green “EXH ON”
pilot and the exhaust fan will
activate. In addition the exhaust
fan starter auxiliary contact will
close signaling the supply system
to energize. In the event of a fire
on the cooking surface the contact
between terminals 19 and 20 will
open de-energizing relay R6,
shutting off the exhaust fan(s).
See figures 6 and 7 for electrical
schematics. The EO-1 and EO-2
panels are designed to be
mounted on the kitchen wall. The
EO panels can be supplied for up
to five (5) individual exhaust fans.
E
O
EO-1, Electrical Schematic
Figure 15
16 ______________________________________________________________________
Spring Air Systems Compensating Engineering Manual
17
ES-1:
ES-2:
One Exhaust Fan/One Supply Fan Operation
Two Exhaust Fan/Two Supply Fan Operation
The SPRING AIR SYSTEMS motor
control panels ES-1 and ES-2
contain electrical components to
start and stop the exhaust and
supply fan(s) and interlock with the
surface fire suppression system.
The control panel includes a panel
mounted disconnect switch, high
voltage fuses, control transformers,
control fuses, motor starter(s) and
overloads, control relays, on/off fan
switch(es), pilot lights and optional
on/off switch for the hood lights.
To start the exhaust fan, rotate the
fan selector switch to the “ON”
position. The green “EXH ON”
pilot and the exhaust fan will
activate. To start the supply fan,
rotate the fan selector switch to the
“ON” position. The green “SUP
ON” pilot and the supply fan will
activate.
ES-1 Electrical
Schematic
Figure 16
In the event of a fire on the cooking surface the control between terminals 19 and 20 will open
de-energizing relay R6, shutting off the exhaust and supply fan(s). See figures 8 and 9 for
electrical schematics. The ES-1 and ES-2 panels are designed to be mounted on the kitchen
wall. The ES panels can be supplied for up to four (4) individual exhaust fans.
Specification
Refer to individual specification sheets for the model and type of compensating hood selected.
See Chart No. 1 for a list of the various alternatives available. Refer to the individual specification
sheets for SFA models and Compensating hood controllers available.
compeng.doc
______________________________________________________________________ 17
Spring Air Systems Compensating Engineering Manual
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Phone: 905-338-2999, FAX: 905-338-1079, e-mail info@springairsystems.com
www.springairsystems.com