Dr-Fix-It! Notebook Archive:
|Happy Birthday HVAC?
This weekend, the Associated Press is reporting the 100th anniversary of the invention of air conditioning. The AP articles laud the advancement as one of the most important developments of the 20 century having considerable effects on how and where we live today. From industrial cooling to frozen foods to air conditioned high-rise buildings to automobiles, HVAC/R has grown from a dream to indispensability in 100 years.
But, some changes in construction techniques intended to maximize air conditioning efficiency have now caused another problem. Concern about mold has been increasing as the public becomes more aware that exposure to mold can cause a variety of health concerns including chronic allergic reactions. Molds can produce allergens that can trigger allergic reactions or even asthma attacks. Other molds are known to produce potent toxins and irritants.
Of course, moisture may stem from roof leaks, plumbing leaks, poor housekeeping, improper landscape design or gutters but some dampness in buildings has been linked to changes in building construction that have made buildings too tightly sealed and lacking sufficient fresh air ventilation. 100 years ago, buildings were cooled by cross ventilation, open verandas, large shady porches, and plenty of fresh air.
It is probably impossible to eliminate all mold and mold spores. Molds reproduce by releasing microscopic spores to be carried off by air currents. Mold spores continuously drift on air currents both indoors and out. Once they land on a damp spot, mold spores can grow on virtually any construction material. Molds can thrive on the scarce nutrients found in wood, paper, carpet, drywall and insulation, gradually digesting and destroying the material as it grows.
Usually, indoor mold growth can be controlled by simply controlling moisture. Since mold requires water to grow, it is important to prevent dampness in buildings. But once mold has taken root, the problem is much more difficult to resolve. Clean-up crews must be cautious to avoid exposing themselves and others to mold-laden dusts. Extreme care must be taken to prevent mold and mold spores from being released into the air where they can be inhaled by building occupants or cause the mold to spread.
Insurance companies are running for cover as mold claims threaten to bankrupt them. Mold abatement companies are springing up faster than clover on compost. Lowly mold is creating an industry that mirrors the development of asbestos abatement industry.
So, the benefits of a hundred year old technology are being offset by the will of a billion year old life form. As for me, I am going to let the lawyers and the engineers duke this one out . . . On the personal level, we might all take a tip from our grandfathers who never considered mold to be a threat. Perhaps you will join me as I grab a straw hat, open all of the windows and retire to the rocker on the back porch to get a little fresh air and sip a julep. If you listen carefully you might hear the band down at the town square practicing the latest Sousa March. I'm told it's a dandy !