Required Ventilation
ASHRAE
• ASHRAE 62.2-2019 is a national standard that provides methods for achieving acceptable indoor air quality in typical
residences. It was developed and is maintained by the American Society of Heating and Air-Conditioning Engineers (ASHRAE).
• This standard recommends Dwelling-Unit Ventilation, which is a mechanical exhaust system, supply system, or combination
thereof.
Formula Method
The Building Ventilation rate is determined based on the floor area and the number of bedrooms, as defined in Section 4.1.1 equation
4-1a.
Formula:
(Square feet x 0.03) + (be 1) x 7.5 = 97.5
(2000 X 0.03) + (4+1) X 7.5 = 97.5
Table Method
Example: a 2000 square foot building with 4 bedrooms from Section 4.1.1 Table 4-1a, a quick reference table predicts 98 cfm. The
following table complies with ASHRAE Standard 62.2-2019, Section 4.1.1 Table 4-1a, Continuous Whole-Building Ventilation rate in
cfm.
Table 5. Whole Building Ventilation Air Requirements
Floor Area
(Square Feet)
Number of Bedrooms
1
2
3
4
5
CFM
CFM
CFM
CFM
CFM
<500
30
38
45
53
60
501 - 1000
45
53
60
68
75
1001 - 1500
60
68
75
83
90
1501 - 2000
75
83
90
98
105
2001 - 2500
90
98
105
113
120
2501 - 3000
105
113
120
128
135
3001 - 3500
120
128
135
143
150
3501 - 4000
135
143
150
158
165
4001 - 4500
150
158
165
173
180
4501 - 5000
165
173
180
188
195
For more information about ASHRAE, go to: https://www.ashrae.org.
Residential Energy Recovery Ventilators
9
®
