Thank you mike_home. Any suggestions on the HRV brand? I have come across Lifebreath and Zehnder. Also, if I have an HRV, do I need an air purifier also, or will the HRV take care of that?

I am not familiar with HRV brands, perhaps others can comment.

I am not sure exactly what you mean by an air purifier. If you are talking about something that sits on a table or floor and sells you can buy on Amazon then I have no experience. I question how well these work and if they are necessary.

I do recommend getting a 4 inch media filter installed with the furnace. The 4 inch thick filters are much better and last longer than the cheap 1 inch thick type. In my opinion a Merv 8 filter is fine. Going to a higher rating may become too restrictive.

Some people have have allergies invest in an electrostatic filter. They may work better but they have to be maintained on a regular basis. I am not sure if they are worth the extra money and hassle.

Thanks mike_home. This is the filter they are talking about: Heil Electronic Air Purifier

I did tell my builder that we want a 4 or 5 inch media filter - maybe this is that?

This is an electrostatic type filter. The idea is that elements are charged to a high voltage in order to attract very small particles. The problem is the cleaning. Supposedly you can put the parts inside a dishwasher, or you can put them in a bath tube. Once you wash the parts then you have to make sure they are completely dry before reinstalling them. You may have to do this once a month. This is no fun in my opinion.

The alternative is to put a good quality paper filter. A 4 or 5 inch will last 8 - 12 months. When it gets dirty you replace it.

thank you mike_home.. that is what we have now... and we do get a new one 2x a year to replace, easy breezy :)

The last time I looked at any information, air purifiers don't do much. I think that the problem is that the HVAC system does not usually pick up the allergens and move them around. Have a whole-house vacuum cleaner system installed and keep the place clean. Echo mike_home's advice on humidity control. Although you don't like carrying water, the portable humidifiers seem like a much healthier alternative since they can be broken down daily and cleaned out. Having your ducts inside the building envelope is very important. Duct leaks increase air exchange with the outdoors by pressurizing or depressurizing the living space. Outdoor (attic and crawl space) duct leaks turn your air handler into a power vent so what good is keeping the windows closed?

Pressure differentials between rooms will also such in outside air in random places and that can deteriorate air quality. Your return air must be well planned (balanced) A return in each room is best. If your HRV or ERV is set to pressurize the home, and it should be, it will help with that but you should still start with indoor ducts.

Have you read "My House is Killing Me" (Jeffery C. May)?