I've been lurking around here for some time. I thought it was time to post my "big questions" since I've gleaned lots of great info but I still don't have a comprehensive picture of what I need to to. Here goes...
I have a 3 year old, very tightly insulated three level home in Minnesota. We have high Radon in the area although tests here have been clean.
The majority of the home is heated via a 2-zone forced air furnace air conditioner unit. The basement uses in-floor heat and is ducted to the forced air but most of the ducts are kept closed (yes, I know the basement is where the Radon builds up, more on that later).
There is a ducted Carrier HRV installed but it was installed into the existing HVAC ductwork and does not have it's own ducting beyond that. The installer did not put in an HVAC / HRV fan interlock. The controller is a Carrier comfort controller with humidity control and interval timer.
There is also a pad based humidifier attached to the HVAC output venting that is controlled by a mechanical humidistat on the HVAC intake venting.
There are at least 6 exhaust-only vents in the house including a high-flow indoor grill/griddle vent on the stove.
When I think about the discussions that have gone on here and look at what the HVAC contractor installed in the house, I see at least 5 things wrong with the setup. This house was built before we purchased so I did not have any input.
My biggest initial problem is humidity control. The A/C system does well keeping the summer time humidity down. In the early fall and late spring I do get some increased humidity when the A/C doesn't need to run. My *big* problem is humidity control in the winter time. We can get massive temperature swings over a period of a few days. Even though we have pretty energy efficient windows they will still freeze up and the window frames are painted enamel on wood. The moisture pops the paint right off. We also have fairly soft wood floors that shrink considerably if they get too dry for too long.
Every day I have to run downstairs and try to guess where I should set the humidistat based on where the temp will be over the next few days. Then I have to adjust the HRV to make sure that it won't try to fight against the humidifier. If I do it just right I can keep the windows pretty dry, our sinuses from hurting, and our floors happy. If I don't do it for a few days then everything goes to heck.
On to the questions:
1) Isn't there a controller out there that has an external temp sensor and can run the HRV *AND* humidifier as a single system? A smart controller should be able to do a way better job than me (and it won't forget when its busy).
2) Since the HRV doesn't have its own ducts, wouldn't it need to be interlocked to the HVAC fan? The shortest path between inside fresh and inside exhaust seems to me to be straight through the furnace unless the HVAC fan is running, which doesn't accomplish anything for the house.
3) Would it make sense to commandeer one or two of the basement ceiling HVAC vents and hook them directly to the HRV ducts to enable basement air recirculation? The vents are currently closed because the basement gets too hot/cold when the HVAC is sent in. There is no HVAC thermostat in the basement, only a water circulation controller.
Thanks for your time