Folks,

We have been living in a 10-year old 2150 SFT home (with full walkout basement) in east-central Illinois with the following features:

1. Exterior walls are ICF (Insulated Concrete Form) with EIFS siding.
2. No gas/oil connection to home (all electric appliances/furnace).
3. Regular Air Conditioning with an exterior condenser unit (3-ton).
4. Regular exhaust-only fans for the bathrooms
5. Windows are double-paned but not good and there’s a draft thru the sills during winter that I try to block using foam stoppers.

We have had very reasonable heating/cooling bills ($2000 for the the last 12 months combined and $2400 for the previous 12 months combined). But we have had to contend with high humidity even in winter (symptomotized by condensation on the big windows facing the pond as well as moisture on the inside perimeter of the ceiling). I suspect part of the reason for it might be that we do steam/rice cooking and such generating perhaps more than usual moisture.

Now the exterior condenser unit has quit. Since it uses old R-22, replacement is expensive and won’t be as green as the newer R410A so we are planning to replace it with a 3-ton geothermal system (another option we looked at is the Lennox Air source Heat Pump XP21).

Now in conjunction with the new system, we plan to install a dehumidifier (Lennox 65-pint) and the Lennox HRV. Because the exterior walls are concrete, the only breathing if any is currently via the leaks in the doors/windows and the ceiling. This is what I am planning to do:

1. Install new ducting from the 3 bathrooms to the HRV. The ducting will have to go thru closets and such.
2. Install a duct from a spot on the ceiling in the kitchen to the HRV. The kitchen hood is currently a GE Profile Microwave that simply recirculates the air. Currently there’s no exhaust to the outside for the kitchen.
3. Connect the 14-year-old dryer’s output to the HRV as well.
4. That will leave out the central-vac which I am planning to leave alone.

Now I have the following questions:

1. Does anyone see any issues with the above?

2. Is there a high-efficiency Microwave hood that’s known to effectively clear out the grease and such? This is so as to prevent risking damage to the HRV from grease and such.

3. In regard to the dryer, what’s the best way to clean out the lint? The lint screen on the current unit isn’t good at all. Are there standalone units I can connect to the exhaust that are good at catching the lint that I can periodically clear out?

4. I suspect we have negative pressure during winter particularly when the dryer and the bath exhausts run. Is there an HRV that will also act like a passive air inlet, basically sensing the negative pressure and lets air in or lets more air in than it sends out via some setting?

5. Should the fresh air from the HRV go into the return air plenum of the Air Handler, so the air is conditioned or bypass the HVAC and connect directly to the supply side?

Many thanks for your help.