Installation Template - Aprilaire 8120 Safety & Installation Instructions

STEP 7: CALCULATE THE VENTILATION REQUIREMENT
A. The MINIMUM ventilation requirement is calculated using ASHRAE 62.2-2004.
ASHRAE Airfl ow In CFM = [House Area in Sq Ft x 0.01] + [No. Bedrooms +1 x 7.5]
Use the Number of Bedrooms (Plus 1) or the Number of Occupants, Whichever Is Larger
Additional ventilation may be required for pets, hobbies,
fi replaces and attached garage, etc. Use your judgement.
B. This Table shows calculated airfl ow values at the nearest 5 CFM.
If more outdoor air is required than the Vent Control can deliver,
a 2nd device is advised. Consult with the homeowner.
C. Indicate the required CFM below.
STEP 8: DETERMINE THE VENT CONTROL'S FRESH AIR DELIVERY RATE
AIRFLOW DELIVERY VS NEGATIVE STATIC PRESSURE AS MEASURED FOR RETURN DUCT OR PLENUM (IN WC)
0.05
DUCT
LENGTH
FLEX PIPE
10 FT 60 65
20 FT 55 60
30 FT 50 55
A. Measure the negative static pressure of the return system and consult table above for approximate inlet airfl ow. But these values are
estimates. An airfl ow measuring device (Nailor-Hart, etc.) will give the Vent Control's airfl ow exactly.
B. For the Table above the fl ex duct is laid loose with 2 wide 90° bends, and the damper is full open. For the rigid pipe the values are
based on two 90° elbows, and the damper is open. For both cases the air intake is through a metal vent hood with a bird screen.
Adjust airfl ow up or down for variations, including one elbow or bend, or the length of duct you're using isn't listed, etc.
C. Measure the delivered airfl ow or determine from above chart and record below.

INSTALLATION TEMPLATE

4-11/16" x 2-15/16" cutout
0.10 0.15
FLEX PIPE FLEX
85 90 105
80 85 100
75 80 95
Sharp edges can cause injury from cuts. Use gloves when cutting plenum
openings or handling ductwork.
1. Do not mount Vent Control on supply side. The unit will malfunction at
heated temperatures.
2. When installing the Vent Control on downfl ow furnaces make sure
blower continues to run after burner shuts off to prevent high heat
damage to the Control
3. Do not mount the Vent Control downstream of the fresh air intake, or a
humidifi er or bypass outlet. False humidity levels can cause the Control
to malfunction.
Minimum CFM Per Number Bedrooms
HOUSE
SQ FT
2
1000 35
1500
40
2000 45
2500 50
3000 55
3500 - - -
0.20
PIPE FLEX PIPE
110 120 125
105 115 120
100 110 115
WARNING
CAUTION
4
3 4 5
40 50 - - -
45 55 60
50 60 65
55 65 70
60 70 75
- - - 75 80
0.25 0.30
FLEX PIPE FLEX
135 140 150
130 135 140
125 130 130
6
- - -
70
75
80
85
90
PIPE
160
150
140