Saskatchewan's Green Directory Helping Saskatchewan choose a better environment

Good ventilation characteristics are important to maintaining a healthy building. Excessive ventilation results in unnecessary heat losses and higher greenhouse gas emissions; inadequate or poorly balanced ventilation can result in poor air quality and a higher risk of condensation and mould growth. Having optimised ventilation rates, it is then possible to make further savings by means of heat recovery ventilation: in winter, warm extract air is used to preheat incoming ventilation or furnace input air. [Typically, an HRV recovers only sensible heat, and an ERV also collects latent heat from condensed water vapour.]

It is important that your house be as well-sealed as possible before installation of one of these units.

What to look for:

Consider the following when selecting an HRV or ERV:

• Proper Sizing

  Make sure that the unit you choose is appropriately sized for your house. You should aim for about 0.5 air changes per hour (a.c.h.). [Manufacturers often express this in cubic feet per minute (cfm): to convert 0.5 a.c.h. to cfm for your house, calculate the internal volume of your house, including basement, and multiply by 30.]

• Effectiveness Ratio

  Your supplier should be able to give you a percentage figure for the proportion of outgoing heat recovered. A good unit achieves better than 80%.

• Government Grants

  Grants are available, both for air sealing of your house and for HRVs/ERVs, from two government programmes: EnerGuide for Houses (Saskatchewan) and ecoEnergy Retrofit (federal).

Criteria