Furnace brands

[WM]

Our 40-yr-old furnace died this past winter, and we're finally getting around to replacing it. I've had 4 people out to give estimates, and they all said the same thing - small house, so 40K BTU is fine, and the biggest challenge is finding something that will fit in the very narrow closet that was built to house the old one.

There are a couple of Tranes that will work (single or two-stage), or if I go with Day and Night brand, I can get a variable-speed. Price is close enough that isn't not an issue.

I'm familiar with Trane as a good brand, but wonder how much nicer (quieter) the variable-speed would be.

Anyone that's converted from single stage to something else, are you glad you upgraded?

And does anyone have experience with Day and Night brand furnaces?

 

[BTravlin]

We upgraded our heat pump system a couple of years ago and spent a little extra for the variable speed and it was well worth the extra money. System comes on at very low speed such that you barely notice it at all. A few minutes later and it is running full speed. No more sudden blasts of noise and air. Can't be of much help on furnace brands but definitely get the variable speed option.

 

[travelover]

I upgraded a 40 year old 200,000 BTU monster to a two stage variable speed Lennox in March 2009. The ECM blower is much quieter and uses less electricity, though I know that repairs or replacement costs are higher.

There a good thread on here with a comprehensive post from Cute Fuzzy Bunny on choosing a furnace. My experience was that choosing a competent installation crew was more important than the furnace brand. Also it is important to size the furnace right and few companies are willing to do an actual Manual J calculation, preferring to oversize instead. A smaller furnace running longer gives more even heat and is more efficient. Some Federal tax credits may still be available to offset a higher efficiency model's cost.

 

[valsdad]

Is your ductwork also 40 years old? Make sure it is checked and sized properly. Travelover is correct when he says installation is very important. Here is a forum where you can get some valuable info.
Heating and Air Conditioning Forum - GardenWeb

 

[samclem]

It would be best to have the contractor do a Manual J calculation to determine the needed furnace size (rather than just use a rule of thumb or guess). You can do a very good approximation yourself at this site. Many contractors will deliberately oversize units "to be safe." but it just results in a slightly higher sale for them (more expensive equipment) and buys them insurance that even if the installation is poor (e.g. leaky ducts, etc) they might not get a call-back, since the house still gets warm enough. As travelover mentioned, the heat is more comfortable if the unit is sized right. If you've also got central AC the furnace size is especially important, since the same fan probably pushes the air for both heating and cooling, and an improperly-sized unit can lead to problems.

We do have some good threads here on furnaces--a search might turn up useful info.

You'll also need to figure out if you want to get the 30% federal tax credit by buying a unit that meets the requirements. Furnaces that meet the requirements are highly efficient and are also more expensive.

Carrier corporation manufactures Day & Night furnaces (as well as many others, including Payne and Bryant). I don't know about the relative quality of their various brands.

Look for a long warranty on the heat exchanger--that's the heart of the furnace and usually the life-limiter.

 

[Telly]

Our 40-yr-old furnace died this past winter, and we're finally getting around to replacing it. I've had 4 people out to give estimates, and they all said the same thing - small house, so 40K BTU is fine, and the biggest challenge is finding something that will fit in the very narrow closet that was built to house the old one.

40K BTU is the standard lower end of furnace sizing. Standing upright, it is the narrowest standard furnace. Hopefully, your distribution ducting is overhead, so a standard upflow furnace works. If your distribution ductwork is underfloor, then a downflow furnace is needed, very few of those are built.

With today's high efficiencies, a 40k BTU input furnace yields close to 40k BTU output. Back in the days of simple atmospheric burners, efficiencies were only 50% or so, and to see a 40k furnace was rare, as it would only deliver ~20k BTU. Times have changed!

If in a major air-conditioning climate, one would have to watch the downsizing of furnaces to be sure that the airflow requirements for good cooling were still maintained, and that the needed evap coil case will fit without making it a hack job. Because of that, some furnace BTU sizes have two different physical widths available, a narrow and a wide, with different blower motors and different airflow ratings. The wide would be used if needed to keep airflow up for A/C.

 

[WM]

Thanks for the replies.

Travelover, is yours two stage or variable speed? Those are two different choices. From what BTravlin said, it sounds like variable speed would be nice. I'll look for the CFB thread.

Yes, the ductwork is also 40 years old, and awful, so everyone wants to replace it, which seems right. And they are all going to increase the size of the ductwork to ensure proper airflow, because there is very little of it.

No air conditioning, so no worries there.

Yes, my impression was that 40K BTU is the lowest readily available, and the ductwork does go up rather than down so these are standard (if small) units. Samclem, thanks for the info on Carrier, maybe that will help me find more info. I'll try the heating and air forum...

 

[travelover]

Thanks for the replies.

Travelover, is yours two stage or variable speed? Those are two different choices. From what BTravlin said, it sounds like variable speed would be nice. I'll look for the CFB thread.......................

It has a two stage burner with a variable speed blower. This was the thread that I was referring to:

http://www.early-retirement.org/forums/f27/high-efficiency-furnace-35473.html

 

[samclem]

Yes, the ductwork is also 40 years old, and awful, so everyone wants to replace it, which seems right. And they are all going to increase the size of the ductwork to ensure proper airflow, because there is very little of it.

That should help. Be aware that "flexduct" is very popular now, especially in new construction. It looks like a big slinky and is very easy to install if there's enough room (in an open attic, etc). Contractors (especially builders) love it because it is cheap and easy. It does have problems and limitations: It is corrugated on the inside, so it has considerably higher resistance to airflow than does a metal duct or a "ductboard" duct (which resultys in your fan motor working harder and less warm air being delivered than with a similar-sized smooth duct). It can also get crushed or kinked, blocking airflow. Finally, if it is not carefully installed (using the right kind of adhesives and supports, etc) then the couplings can develop leaks that are more serious than the smaller leaks than can develop with metal or ductboard ducts. It's very common to find these flexduct connections coming apart after only a few years. Anyway--before your contractors start to tell you about why this or that duct material is better, do a little research online so you'll be equipped to make an informed choice.

 

[WM]

Thanks for the additional info. That's quite a thorough post! Overall I'm inclined to go with the Day and Night variable system.

That is very good to know about the ducts, at least one guy did mention that the new ones would be flexible, but I don't remember which guy...I'll have to ask about that.