Results 1 to 3 of 3
  1. #1
    Join Date
    Jul 2006
    Post Likes



    The heating/air conditioner system in our new house is about to be installed in the next few days. The heating/air conditioner tech mentioned that the price of our home includes a Maytag 100k BTU furnace and a 14 SEER air conditioner (forget the brand), both with 10/10
    warranties. The other HVAC systems being installed in our house are a Fantech(?) air-to-air exchange system and AprilAire humidifier.

    a) Is the Maytag 100k BTU, 92.5% AFUE efficiency furnace the right capacity furnace for our house? Our house is a three level (Two finished floors and unfinished walk-out basement) 3300 sqft house in Minnesota.

    b) As I understand from my builder and heating technician, they will also be extending 6 heating ducts to the basement floor to provide heat runs as an alternative way to heat the basement instead of spending extra money on heated floors. How well does this method of heating the basement compare to the traditional heated floors? Is it effective?

    The heating tech suggested adding a couple items:
    c) A variable speed motor - He mentioned this is an ECM motor (invented by GE when they owned Trane) and said it would be lot more quiet compared to the standard A/C motor, especially in the "continuous mode" and more efficient. He said they already build the ducts in the house big enough to make the most efficient use of the ECM motor. I did some
    research on the internet and his claims about the
    advantages of ECM motor seem to be valid. A lot of other heating techs on the net seem to highly recommend these, especially for new and replacement furnaces. I wonder, however, what would be a reasonable upgrade price for this motor for our furnace? I've seen prices for new/replacement ECM motors on the Internet of xxxx. The furnace tech has quoted us additional cost of xxxx to go with the ECM motor -however, if we are "exchanging" the regular A/C motor with the D/C motor, shouldn't we be getting some credit for the cost of the A/C motor? Does the upgrade price for the ECM motor seem reasonable?

    d) Finally, I do tend to get allergies, especially during the spring and fall seasons. So the heating tech suggested putting a Trion Media filter system with 5" media filter instead of the standard 1" filter system normally installed by the builder. He said these are quite cost effective compared to the standard filter system and we would recover the additional cost xxxx in a few years by the savings in the replacement filter costs. Does the upgrade price for the filter system seem reasonable? Would it help with the allergies?

    Would appreciate any feedback on these four questions from experts on this forum.


    >>> Edit: No Pricing. Please review the site rules before further posting. <<<

    [Edited by Senior Tech on 07-30-2006 at 11:18 PM]

  2. #2
    Join Date
    May 2006
    Philadelphia, PA
    Post Likes
    a) the only way to know if the size is correct is to compare the manual j calculations with the size selected.

    b) not sure what you mean by heated floors. Extending the supply ducts down to the floor is more effective than having warm air supplied at the ceiling level since warm air rises.

    c) variable speed motor is a fantastic option especially considering your allergy situation the the desire to filter the air even when there is no need for heat or cooling. I cannot comment on the price, but the upgrade would be a different furnace that is designed with the ECM motor.

    d) another great option considering your allergies. You will probably only need to replace the 5" media 4 times a year as opposed to monthly.

  3. #3
    Join Date
    Jul 2006
    Post Likes
    You will only know if a 92.5% 100k btu furnace is the right compacity by checking the load calculations. It sounds as though you have concerns and needs, and it sounds as though your HVAC contractor has made an honest attempt to address them. You being there, need to evaluate him, the company, reputation and the "word of mouth" in the locality.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts

Related Forums

Plumbing Talks | Contractor MagazineThe place where Electrical professionals meet.