Six years ago we spray-foamed the inside roof of our home and it has worked wonders in reducing our electricity heating and cooling bills. It is a completely closed system, meaning that all the soffits and ridge vents were foamed over. I always air out the attic out 2-3 times a year and we have not had any problems with mold, mildew or any respiratory issues (that we know of). We change our Filtrete 4" filters on a regular basis.

I am in the process of replacing one of my AC units and air handlers, and the company reps have recommended installing a Fresh Air Ventilation/Return Air system to this unit as well as retrofitting one to the other AC unit. Their pitch is that due to our house being so tight, we are breathing the same old air without enough turnover which has health implications. They recommend the air should be "turned over" inside the home utilizing this Fresh Air Ventilation system at the rate of 80CFM. I've done my homework on the internet and understand the theory of how the system works and why we should have one, but the info is only available from online HVAC companies, not medical experts. So my questions to the HVAC gurus on Sig Forum are:

1. Is the addition of a Fresh Air system something you recommend to your customers when you see they have a "tight" home, or is this just something extra I don't need that they are trying to sell me?

2. I found the formula online that determines additional BTU requirements (Inside/Outside temp differential x planned CFM x 1.08 constant) and have determined that worst case I'm looking at 4000 BTUs (per minute?) that must be overcome during the winter and 3000 BTUs in the summer. Do you use this formula to determine increased heating/cooling requirements, and therefore recommend a unit with higher ton capacity?

3. My research indicates there are passive systems (air handler draws the outside air into the system) and active systems with a separate electric fan than can be adjusted to change the CFM entering the system. My installer wants to install the latter for $866 each. This includes digging through the foam to use a soffit vent, running ducting and re-foaming as necessary to maintain the integrity of the attic seal. Is this in the ballpark of "reasonable" or am I being taken to the cleaners?

4. Speaking of cleaners, my installers also recommend retrofitting Reme Halo LED bulb air cleaning systems to my air handlers. Is this something your recommend to your customers or is this an extra $950/unit that I don't need? And how long do the LED bulbs last in your experience? (They are not cheap to replace.)

My appreciation up front for any information and recommendations you're willing to provide. I would also like to hear from anyone who has one of these Fresh Air Ventilation systems and/or Reme Halo systems installed. Cheers!

Getting this thread back on Page 1 so it doesn't get lost. Thanks.

Once more back to the top. Thanks.