Determining Your Ventilation Needs - Honeywell VNT5150H1000 Installation Manual

Determining Your Ventilation Needs
How much fresh air do you need?
Good air quality is based in part on the capacity of the home's ventilation system. Usually, the unit's
capacity is measured in CFM (Cubic Feet per Minute) or L/s (Liters per second) of fresh air being distributed
in the living space. Use the ASHRAE 62.2 Ventilation Standard, the Room Count Calculation Method, or the
Air Change Per Hour (ACH) Method to determine your ventilation needs.
ASHRAE 62.2 Ventilation Standard
ASHRAE 62.2 CFM Sizing Chart
Number of Bedrooms / CFM
2
Floor Area (ft )
0-1
< 1500 30
1501 - 3000 45
3001 - 4500 60
4501 - 6000 75
6001 - 7500 90
> 7500 105
ANSI/ASHRAE STANDARD 62.2-2007 - Ventilation Air Requirements; values in cfm
The above chart outlines the minimum requirements for continuous ventilation.
Room Count Calculation Method
Living Space
Master Bedroom
Basement
Single bedroom
Living Room
Dining Room
Family Room
Recreation Room
Other
Kitchen
Bathroom
Laundry Room
Utility Room
Air Change Per Hour (ACH) Method
TOTAL cubic feet X 0.35 per hour = total cubic feet per hour
Take total and divide by 60 to get cubic feet per minute (CFM)
Example: A 25 ft. x 40 ft. (1,000 sq. ft.) house with basement
1,000 sq. ft. x 8 ft. high x 2 (1st floor + basement) = 16,000 cu. ft.
16,000 cu. ft. x 0.35 ACH = 5,600 cubic feet per hour
5,600 cu. ft. / 60 Minutes = 93 cubic feet per minute (CFM)
93 CFM is your ventilation need
ERV/HRV Ventilation Systems 69-2480EF—01
2-3
45
60
75
90
105
120
Number of Rooms x CFM (or L/s)
x 20 cfm (or 10 L/s)
x 20 cfm (or 10 L/s)
x 10 cfm (or 5 L/s)
x 10 cfm (or 5 L/s)
x 10 cfm (or 5 L/s)
x 10 cfm (or 5 L/s)
x 10 cfm (or 5 L/s)
x 10 cfm (or 5 L/s)
x 10 cfm (or 5 L/s)
x 10 cfm (or 5 L/s)
x 10 cfm (or 5 L/s)
x 10 cfm (or 5 L/s)
Total Ventilation Requirement
4-5 6-7
60 75
75 90
90 105
105 120
120 135
135 150
>7
90
105
120
135
150
165
= CFM Required
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