6
2.0 Sizing
These are the two most common methods used to evaluate the ventilation needs of a house:
CSA F326 and Canadian Building Code:
• High speed: 10 cfm per room
20 cfm for the master bedroom and the basement
• Low speed: 40-60% of high speed
ASHRAE Standard 62-2001:
• 0.35 air change per hour
Refer to ventilation code of your area to determine which method to use.
Example:
Master
Bedroom
Bedroom #1
Kitchen
Basement
Bedroom
#2
Bedroom
#3
Living room
Bathroom
#3
Dining room
VH0021A
Family room
Bathroom
#1
Bathroom
#2
Laundry
room
1320 ft2
1320 ft2
CSA F326
Kitchen (10 cfm)
Dining room (10 cfm)
Living room (10 cfm)
Family room (10 cfm)
Master bedroom (20 cfm)
Bedroom #1 (10 cfm)
Bedroom #2 (10 cfm)
Bedroom #3 (10 cfm)
Bathroom #1 (10 cfm)
Bathroom #2 (10 cfm)
Bathroom #3 (10 cfm)
Laundry room (10 cfm)
Basement (20 cfm)
Total 150 cfm
(high speed)
ASHRAE Standard 62-2001
Volume of basement 10560 ft3
Volume of main floor 10560 ft3
Volume of second floor 10560 ft3
Total volume 31680 ft3
x .35/h
11090 ft3/h
÷ 60 (min/h)
Total 185 cfm
(high speed)
1320 ft2
Second floor Main floor
Basement