Saturday, 23 March 2019

Ventilation Strategies for the Whole House

Most good builders follow a simple but effective construction strategy. They construct homes that are extremely tight, with a well-designed ventilation system. The truth is, you can save more cooling and heating energy by living in a tight house than with a ventilated one. There are three ways of achieving mechanical ventilation: exhaust-only supply-only, and balanced.

Image Courtesy: Pixabay

  1. Exhaust-Only
Exhaust fans (bathroom, whole-house fans or kitchen fans) “depressurize” the area, leading to infiltration from the air outside through different openings and cracks. Places where winters are intense, exhaust-only ventilation is enough as they do not cause damage that may happen because of moisture. As summers are shorter and relatively moderate in places with cold climates, the building is very unlikely to get marred by drawing hot and humid air. On the contrary, exhaust-only strategies are not the best option for places with hot weather conditions.

  1. Supply-Only
Supply-only systems pull clean outer air inside the interior space, normally from a supply vent. Benefits of supply-only system include the option of controlling the incoming air, treating the incoming air, and reducing humid air pulled within the living area. Controlled supply can also reduce the possibility of back drafting of combustion appliance, a risky uncontrolled infiltration which is common in poorly vented basements.

  1. Balanced
In a balanced ventilation exhaust, the interior space pressure remains relatively persistent. Basically, balanced ventilation is a combination of the supply and exhaust strategies. Normally, a balanced system comes with a powered energy recovery or heat recovery ventilator that enhances pressure and efficiency balance by exchanging energy between the incoming and outgoing airstreams. Heat recovery ventilators only transfer sensible heat while energy recovery ventilators also transfer moisture. The comparatively large electric power use of HRVs and ERVs normally make them an expensive option.


Local Exhaust

In case you reside in a climate that is hot and humid, ventilation which is exhaust-only can end up depressurizing the area. This may pull in outdoor, humid air within the cavities of the wall, condensing and creating several issues. It is best to deliberately introduce the outer air within the building than having it penetrate through the walls. You are less likely to face trouble by making use of exhaust fans, or by keeping the windows open occasionally when you feel a little stuffy or in case the exhaust fans have stayed on for too long.
            Natural Ventilation

This is normally employed as one of the strategies of cooling, but principally, the design is of replacing stuffy inside air with cool air from the outside. For natural ventilation to be effective, incoming air has to be dryer and cooler from the air inside. Therefore, this strategy works best in places with milder climates, or on drier, cooler days. Make sure the house remains closed when the days are hot and try to reduce unwanted gains in the heat and then try to ventilate the space during nights. In locations that are breezy, natural ventilation is offered by simply opening up windows.

With these strategies, any house can stay ventilated with healthy air to breathe for all family members. It is best to call HVAC experts to know the right system for your house.