How to destroy your homeís air quality...
I bought a mid 70ís ranch in 2003 which was not in a great state of repair. The first winter was brutal; windows leaked, doors leaked and the heat pumps would run continuously to maintain 67 degrees. Humidity would drop to 5-10% in the winter and run as high as 50-55% in the summer.
I did what any good homeowner would: over the next two years I replaced all the windows, installed new heat pumps, sealed and replaced ductwork, put weather stripping on doors, put gaskets behind electrical plugs and used about 30+ tubes of caulk.
About a year after doing these things we noticed that odors seemed to accumulate in the house and at about that same time my daughter had an increase in her asthma. Humidity is now well controlled in the winter but seems to rise rapidly if the house is not ventilated during the non-cooling/heating season.
In 2011 I installed wood flooring in about one third of the house (1000 square feet of flooring). Ever since then we have experienced a series of chemical smells. I have had eye and sinus irritation ever since. I suspect outgassing from the flooring or cement used to install it.
I hired a guy to perform a blower door test because I suspected the house was too airtight. At 50 pascals my air change rate was 3.43 with a calculated Ďnaturalí air change rate of about 0.17 which is about one half of the ASHRAE recommended minimum. Yes, itís way too tight! I never dreamed that so little work was going to result in that level of air tightness in a mid 70ís home!
I am now looking at the requirement to add an energy recovery ventilator to provide a decent ventilation rate in the house with a self-installed cost of about $1200 plus the electricity to run the thing at about $15 per month. This is going to pretty well offset any energy savings my improvements gave me.
Now I wish I had just kept my old leaky windows so none of this would be an issue!
So, before you go off into any energy retrofits I highly recommend you obtain an air change rate from a blower door test first to prevent the creation of an indoor air quality issue.