Honeywell VNT5200E1000 User 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.
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
Floor Area (ft
2
)
Number of Bedrooms / CFM
0-1
0-1
2-3
4-5
6-7
>7
< 1500
30
45
60
75
90
1501 - 3000
45
60
75
90
105
3001 - 4500
60
75
90
105
120
4501 - 6000
75
90
105
120
135
6001 - 7500
90
105
120
135
150
> 7500
105
120
135
150
165
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
Number of Rooms
x CFM (or L/s)
=
CFM Required
Master Bedroom
x 20 cfm (or 10 L/s)
=
Basement
x 20 cfm (or 10 L/s)
=
Single bedroom
x 10 cfm (or 5 L/s)
=
Living Room
x 10 cfm (or 5 L/s)
=
Dining Room
x 10 cfm (or 5 L/s)
=
Family Room
x 10 cfm (or 5 L/s)
=
Recreation Room
x 10 cfm (or 5 L/s)
=
Other
x 10 cfm (or 5 L/s)
=
Kitchen
x 10 cfm (or 5 L/s)
=
Bathroom
x 10 cfm (or 5 L/s)
=
Laundry Room
x 10 cfm (or 5 L/s)
=
Utility Room
x 10 cfm (or 5 L/s)
=
Total Ventilation Requirement
=
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
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
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
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