General question before deciding on furnace contractor

esgaNovember 25, 2011

Is is possible that some houses are so small that contractors don't bother with Manual J when recommending furnaces? I ask because I've just had two very different companies come out, and I would have expected at least one of them to use correct procedures, based on their profile. Maybe my house is so small any unit is going to big enough? Or it's because it's both small and in the south?

I live in a 1350 sf, one story house outside Atlanta. I haven't seen written proposals from either one yet, but one told me he's going to give me a proposal including a good - better and best option, and he'll also include package deals for replacing the 13-year-old A/C at the same time as the furnace which just stopped working. THought this makes some sense, I am leery of a "deal" I didn't ask for - there are also rebates that expire in a week. This is one of the biggest contractors in the metro area.

The other is a small local outfit that does a lot of work around here and is well liked. The guy who came out told me he was only going to recommend one system, a Goodman Amana high-efficiency. The reason for this is that my crawl space requires some very awkward venting for which PVC is better than metal (but he is going to consult someone else before writing up the proposal). For other guy told me that it's hard to recover costs on high efficiency here due to our rather mild weather.

In the meantime, I have contacted a third company with a very good reputation.

I don't yet have the kind of specifics that others have posted here, but I am curious as to why the large, well-thought-of company seemed to eyeball it.


Thank you for reporting this comment. Undo


What size and efficiency is existing furnace and AC?

How would you describe the insulation properties of your home? Have you made any substantial improvements to your home in this area?

Any specific problems relating to existing equipment? Are there any
hot/cold spots in your home.

I don't think a load calculation is required in every situation unless there have been problems heating and/or cooling one's home or there have been improvements which may have lowered the load requirements for the home.

However there are three reasons why an HVAC dealer will not perform a load calculation.

1. The dealer is ignorant and does not know how.
2. The dealer is lazy
3. The dealer just not give a damn nor is he concerned about the interests of his customer.

Probably the most overlooked aspect of a successful new installation is a thorough inspection of the ductwork system.

I generally think when choosing an HVAc dealer that a homeowner is best served by a small shop that has been in business for 10+ years, has a track record, history, and reputation in the market that he serves, and where the owner is still actively involved in the business and that does not mean sitting behind a desk. It means getting out in the field on sales calls, service calls, and new installs. And while not always necessary, I think a homeowner gets some measure of protection where dealer is an authorized dealer for the product they sell.


    Bookmark   November 26, 2011 at 7:40AM
Thank you for reporting this comment. Undo

Good advice above.

My personal opinion after reading your account, is that #1 is thinking about what to sell you. Doing a fine job, but not necessarily custom tailored to you. And #2 is thinking about the job, what is going to be needed to physically have a good install given the situation in your house. If there is no significant difference between cost and warranty I would favor #2 because of that.

    Bookmark   November 26, 2011 at 8:55AM
Thank you for reporting this comment. Undo

A small house is likely not to need a load calculation since the smallest equipment will be larger than needed. However a contractor who does load calculations on a routine basis should be able to do one quickly on your house. You may have a lot of windows which may skew the results. You cannot calculate the heating load accurately by the square footage area.

    Bookmark   November 26, 2011 at 10:02AM
Thank you for reporting this comment. Undo

Thanks, all. I need to see if I can find paperwork on the existing furnace with the info tigerdunes asked about. It was here when I bought the house 13 years ago, and it's in an (inaccessible to me) crawlspace. Mike, you've said exactly what I wondered - I've heard it's wise to not get too large a system, but maybe they are all larger than I really need.

Julie, that's a really good point. I just think it's bizarre to buy a high efficiency furnace just to solve a venting problem. And that guy made no comments about general ductwork, which is old and well, dubious, to be polite. The other guy did bring it up and is including $800 to replace the parts that will have to be taken replaced to interface with the new furnace.

I am trying to get 2 more estimates because their approaches are so different. However, it is going to get a lot colder here over the next few days. I can stay with my partner, who lives a couple blocks away, and I have some good space heaters, but I want this resolved ASAP.

Tigerdunes, my kitchen is usually too hot or too cold - but it's a lot of old, poorly insulated windows - I think that' s the problem there, more than the ductwork. Also, in this house, the vents are generally placed in the stupidest possible places. For example, in the kitchen, it's in the furthest corner from the core of the house, under a counter between 2 cabinets. The counter isn't very deep, maybe 10", but still . . . This house began to be built in 1938, has 3 separate foundations and 2 slabs - very typical of my neighborhood. Very quaint, very inconvenient.

    Bookmark   November 26, 2011 at 9:35PM
Sign Up to comment
More Discussions
What in the world is this thing? (Water furnace) And I need a new one?
Hi. So my new condo has an ancient thing I've been...
Manual J -> S ->D
JSHR: 0.81 MJ8 Tons: 3.03 SqFt/Ton: 1667 CFM/SqFt:...
Brian S
can people share their weekly propane use and square footage, please?
With the coldest weather in roughly 20 years here,...
davidrt28 (zone 7)
carrier infinity with greenspeed service settings
We just built a new home in central Kansas this year,...
Nozzle size for Oil Burner ??
I have a Slant fin oil furnace that heats my water...
People viewed this after searching for:
© 2015 Houzz Inc. Houzz® The new way to design your home™