Balanced Ventilation
Balanced Ventilation Is Appropriate for All Climates
Read the full article by subscribing to GBA Pro for valuable how-to information and insights about
Balanced Ventilation, including:
- Design and build strategies
- Necessary codes
- Application how-tos
- Using materials
Supply and exhaust fans working in cooperation
Supplying fresh air while exhausting stale air
A balanced ventilationMechanical ventilation system in which separate, balanced fans exhaust stale indoor air and bring in fresh outdoor air in equal amounts; often includes heat recovery or heat and moisture recovery (see heat-recovery ventilator and energy-recovery ventilator).
system uses a supply fan to introduce the same volume of fresh outdoor air that is being simultaneously removed from the house by an exhaust fan. These systems are more complex than supply-only or exhaust-only ventilationMechanical ventilation system in which one or more fans are used to exhaust air from a house and make-up air is supplied passively. Exhaust-only ventilation creates slight depressurization of the home; its impact on vented gas appliances should be considered. systems, but provide better fresh air distribution and in some cases lower ...
Green Basics Index
Related Topics in the Green Building Encyclopedia
4.
Mon, 11/14/2011 - 16:29
Mon, 11/14/2011 - 16:29
Response to David Mackenzie
by Martin Holladay, GBA Advisor
David,
An HRV provides balanced ventilation, as you point out, not makeup air. If you want to have a 600-cfm range hood, you need to install a source of makeup air -- and an HRV can't do that.
Here's more information: Makeup Air for Range Hoods.
3.
Mon, 11/14/2011 - 16:10
Mon, 11/14/2011 - 16:10
600 cm/h range hood fan
by David Mackenzie
In a well sealed house with minimised air infiltration and HRV system provides for air exchange and heat recovery. My concern is when a commercial rated kitchen range hood is operating - this removes a significant volume of air (say 600 cu m per hour). If there is a wood fire in operation, is it possible to create a negative pressure inside the house which might draw CO gases down the fireplace flue and into the house. How can the system be set up to ensure a balanced ventilation when the fireplace and range-hood are operating?
2.
Tue, 05/03/2011 - 03:39
Tue, 05/03/2011 - 03:39
Edited Tue, 05/03/2011 - 03:56.
Response to Sean Wiens
by Martin Holladay, GBA Advisor
Sean,
I agree that exhaust ducts should not terminate at soffits. Fortunately, this article neither recommends nor illustrates that practice.
The HRV ducting illustration was pulled from a different source; I agree that connecting an HRV to forced-air ductwork is an inferior installation compared to an HRV with dedicated ventilation ductwork.
Here is a simplified drawing showing dedicated HRV ductwork; the illustration appeared on a Web site maintained by the Office of Energy Efficiency of Natural Resources Canada (http://www.oee.nrcan.gc.ca/Publications/infosource/Pub/hrv/hrvsystem.cfm...):
1.
Tue, 05/03/2011 - 00:28
Tue, 05/03/2011 - 00:28
Edited Tue, 05/03/2011 - 00:29.
Balanced Ventilation
by Sean Wiens
Hi Martin,
Kind of surprised your graphic does not show independently ducted system considering your recommendations on this regard.
Can you also caution your readers against terminating any type of interior air flow to soffit areas (especially when soffits are perforated like here in the Pacific North-West). The warm moist air is just sucked back into the attic cavities where it condenses on the cold surfaces and causes moisture problems including mould.
Comments