SHR 1504 Installation Manual
3
Example for maximum airflow normally required.
HRVs are typically sized to ventilate the whole house at a minimum of 0.35 air changes per hour.
To calculate, simply take the square footage of the house (including basement) and multiply by the
height of the ceiling to get the cubic volume. Then, divide by 60 and multiply by 0.35.
Example: SQFT of House 1100
Basement 1100
Total SQFT 2200
Height of ceiling x 8
Cubic volume 17600
Minutes per hour / 60
Maximum airflow required (CFM) 293
Minimum air changes per hour x 0.35
Minimum airflow required (CFM) 103
* Always consult your local building codes for sizing requirements in your area.
i.e. Local building codes may require more or less air change per hour.
Room classification Number of rooms CFM (L/s)
CFM Required
Master bedroom x 10 L/s (20 CFM) =
Basement yes or no =
Bedrooms x 5 L/s (10 CFM) =
Living room x 5 L/s (10 CFM) =
Others x 5 L/s (10 CFM) =
Kitchen x 5 L/s (10 CFM) =
Bathroom x 5 L/s (10 CFM) =
Laundry room x 5 L/s (10 CFM) =
Utility room x 5 L/s (10 CFM) =
Total Ventilation Requirements (add last column ) =
if yes add 10 L/s (20 CFM)
if no = 0
1 cfm = 0.47189 L/s
1 L/s = 3.6 m
3
/hr
Alternate Method
DETERMINING YOUR AIRFLOW REQUIREMENT