Your house may not be coughing but it may be sick...

In this blog post I would like to discuss something that not many people realize.  Your home or office could get sick. Not literally sick, but there is something called "sick building syndrome".  Indoor air quality is most times worse than outdoor air quality. With construction of new homes and buildings becoming more and more tight, we may see that not enough infiltration and ventilation is happening.

I had done a little bit of light research in preparation for this post and found some facts that I think are worth mentioning from the EPA. In the document that I had come across it states that in 1973 there was an oil embargo and, to save energy, building specs were changed from 15 cubic feet per minute of ventilation to only 5. ASHRAE is a group that I am a student member of and they set the standards for building ventilation in our industry. ASHRAE has revised these standards recently to a minimum of 15 cfm per person (20 cfm in office environments. The amount of ventilation varies on the types of contaminants that could be found and spaces to be ventilated. I find it interesting that in 2012 a decorative fountain in the Chicago Marriot downtown caused an outbreak of legionnaires. This building was built in 1978. This was during the time of the 5 cfm mandate. Legionnaires is a bacteria and is not caused by poor ventilation, but is an indoor contaminant that may occur.

How do we get better ventilation on homes and other buildings?  We could all open our windows and vent that way or just leave an opening to the outside. Those are both options but inefficient ones. I would recommend an ERV, or Energy Recovery Ventilator. This special box that runs in your duct work brings in air from the outside, but does it differently.

ERV units bring air in from the outside and exhaust air from the inside at a given percentage. In the summer the air is dehumidified and pre-cooled and in the winter the air is humidified and pre-heated. It uses the warm or cool air being exhausted to warm or cool the incoming air to make an ventilation with the outside much more efficient. They are more common in commercial applications but residential versions are readily available. In areas where climates will have extreme cooling or heating requirements, such as Michigan for example, the ERV's would be an excellent addition.

The cases where people forget about indoor air quality such as the case in Chicago last year bother me. I have a friend who has a house near Lansing with a hole going out the wall in the lower level with some dampers in it to control the flow of air and provide an outlet to outside air. Remember our parents saying "Shut the door. You are heating the outside."?  This is the same premise.  ERV's would keep us healthy and conserve energy that we have used to heat or cool the air inside the conditioned space.

How much energy can we conserve? What are the costs? Also excellent questions. In the January 2013 issue of the ASHRAE journal a group of fellow members set out to find just that. They did an experiment with the Turtle River Montessori School located in Florida. A climate extreme, like mentioned above, that would have quite a cooling load. Since the school opened in 2009 the cost has been reduced by 70%! If you could lower your costs by 70% you would be using less energy to the point where you could downsize the equipment. In reducing the size of the equipment needed you could pay for the ERV's and still have a lower first cost than using the larger unit. Not to mention the benefits over time that you would see.  ERV's are still an up-and-coming technology. I hope to see a lot more of them used in residential and commercial applications.