Published on September 5th, 2013 | by Henri0
Ventilation needed for healthful indoor air
Q. In a recent article about installation of a housewrap in combination with Styrofoam, you said that houses should breathe through ventilation. What do you mean by that?
A. Many houses built since the energy crisis of the early 1970s (especially in the last couple decades) are built to be very tight to conserve energy. This is a noble goal but it has resulted in some unhealthy indoor air. Dust, mites, outgassing of manufacturing processes in furniture, building materials, carpeting, etc. contribute to this unhealthy atmosphere. The result may be allergic reactions in sensitive people, increased relative humidity, mold build-up, etc.
A well-ventilated attic is helpful in dissipating moisture that migrates from the living space but it may also be necessary to ventilate the conditioned space as well. This can be done in a low-tech fashion by the judicious opening of windows, or by the use of fans exhausting to the outside as long as there is an adequate supply of make-up air. (Otherwise, the heating system may back-draft — a serious and potentially lethal issue.) Or a whole-house air-to-air heat exchanger can be installed.by