My ground loops are in, tie-in complete and capped ends are patiently awaiting for my Waterfurnace ND049 to get installed.  Contractor told me he'll start the week of February 2nd.

So my question is, "What filter / air quality system would you install?"  Indoor air quality is a high priority since 3 of the 4 family members do have seasonal allergies and I'd like to keep the dust levels down as much as possible as well.

My former house had a Honeywell electronic air cleaner which we liked but ozone concerns are starting to put a damper on that technology.

We have also opted to upgrade our whole-house humidification from a manually controlled April-Aire (with the pad) to a fully automatic (humidistat?) controlled Honeywell steam unit.

I'm a bit old school on this question.

If the great big (I think it is 30x36x2) MERV 11 filter that comes with the unit won't meet your needs, consider separate equipment. Your new geo system needs to move a great deal of air at relatively low static pressure loss. It is designed to heat and cool your home efficiently, but not to handle the high static pressure loss across an overly restrictive filter.

Given the acreage of the Envision filter, you may be able to bump the MERV number up a couple notches if your ductwork is good and the total static pressure stays within limits. Installing contractor should confirm via manometer measurements.

Given your households' allergy issues, you may want to consult an expert on what IAQ steps should be taken to combat the specific issues at hand. Broaden your lines of inquiry to consider what products (carpets, upholstery, cleaning chemicals, pets) may be inappropriate for your home.

I personally like April air 220 , Everything Engineer said is correct ,But excuse me if Im wrong any good filter is restrictive so combat that with increased surface area 6inch pleated will much less restrictive .
What allergies ?

My favorite is the Aprilaire 5000. Best ofboth worlds with old electronic air cleaner numbers and 2200 kind of maintenence.
J

Agree with going to 4" or 6" if unit will take it - more surface area in deeper pleats will stave off restriction and loss of ESP for awhile longer.

When my unit was installed, the installer recommended putting a UV light in the duct. It supposedly kills any living allergens/ viruses in the air. Does anyone have experience with this or did I just have a good saleman? The light works along side the 2" filter in the Envision.

Greg

My only compaint with electonic filters is how do you know it is working? At some point my old electonic filter quit working and dust began to clog the heat exchanger. I believe it lead the the permature death of my Geothermal system.

I like any good 4 inch thick filter one that has lots of folds in it to increase surface area to trap dust. Stay away from anything less then 2 inches thick, change them ever 3 to 4 months, depending on how dusty your house gets, Change them after any contruction project where dust could have been sucked into the system. For example painting which involves patching and sanding.    

The neat part about the Aprilaire 5000 is the combination of the 6" according media with electrostatic components, so it works with or without the power on.
Re the germ lamp, I have heard good reviews and no complaints, but have polled <12 people.
J

2 points if you have a bypass humidifier placing it in front of the pad will be a good security blanket against the funk
and remember mold only grows on the north side of the airhandler position correctly jk
if no humidifier get the light to shine on the evap coil , second mold source