Has anyone here switched to a high efficiency furnace in the last few years? my gas furnace is now outdated and was wondering how much of a difference switching to a high efficiency would make....sales guy showed me a chart which said I'd save about $600-700 a year, but I'm skep-tee-kal. Anyone switch over?

Shawn (real80sman) is an expert. My oversimplification of what he told me is that it depends upon how long you plan to stay in your house. The longer you stay, the more easily you can justify upgrades, including increased efficiency. I'd send Shawn a PM.

I'm on my second super-duper-high-efficiency furnace. My impression is that you are better off spending the extra $$ on insulation and drapes, unless you want the super-quiet super-electricity-efficient servo fan that some of them come with.

My first was a Lennox which was too expensive but worked really well (even though I ended up getting one size larger than I needed, my fault, long story), the second was a (Bryant ? something starting with B) which has worked well but which seems to have a less efficient & louder fan.

My recollection is that there are basically 3 levels - 80% efficiency, ~90% efficiency, and ~95% efficiency. If that's still the case, the 90%'ers seemed like a good deal if your furnace runs a lot during winter, but I wouldn't bother with the 95%'er (despite buying 2 of them ;)).

If your winters are moderate then it's hard to justify spending a lot more money on efficiency. You're going to save maybe 12% of your annual heating bill going from an 80 to a 90, so saving 600/yr implies that your heating bill is 5000/yr (which sounds high to say the least).

One other obvious point -- smaller furnaces running longer tend to make for more comfortable houses and lower fuel bills. If you size the furnace to keep your house toasty on the "coldest day in 5 years" that's probably bigger than you need... next time I would go with something sized to "keep the house comfortable on the colder days running most of the time" and put on a sweater or light a fire on the occasional freeze-ups. I guess having the furnace burning relatively more of the time would translate into a shorter heat-exchanger life but I've never actually heard that discussed.

Ten years ago, I switched from a standard furnace ($1800) to a high efficiency one ($2500) and it was well worth it.

My house was so hard to heat, that I employed a kerosene heater at a lower level to help heat it. Gas bill was running around $200 a month in the winter plus about $80 for kerosene.

After switching furnaces, I no longer need to run the kerosene heater and my gas bill was cut in half. Since then gas has climbed, but the new furnace was well worth it.

Thanks guys. My gas bill in recent years has been around $1200 to $1500 annually(also runs hot water heater), so I can't really see how getting a high efficiency furnace is going to nearly cut that in half. I've been told that the high efficiency furnaces are more troublesome than many of the older units on top of that so I'm leaning towards keeping what I've got, despite it being "outdated".

Hmmm....now I just read Brian's post.....

So far, in (9 years, not 10), I've never experienced any problems with the furnace. I've never had it serviced, but probably wouldn't hurt.

I purchased the Trane XV90 a couple years ago, along with a Lifebreath HRV. If you have the finances, Adrian, I'd really consider a HRV; pretty sure they're code in all new homes now.

If I was purchasing a new furnace or HRV, I'd get the more efficient ECM motor.

Yep, same here, absolutely no problems in probably 5 years (not a couple I guess). My furnace cost $5000, but I didn't care about the savings over time and whether I'd gain it back, it was solely based on lessening my footprint.

It's been a while since I had a furnace put in but back then the cost of the unit was far to high to make up the difference in savings. I went with the 80% efficiency unit.

I think I would spend some money on a house evaluation and see what they say about the efficiency of your insulation, heating etc. and go from there.

http://www.homeperformance.com/energy-audit-home-eco-energy-auditors-ontario-bc-canada

What in the heck is a furnace?

The opposite of an air conditioner

What we *really* need is something that could, for example, pump some of the heat out of Rick's house and into my house.

Adrian, if your current furnace is *really* old it could be considerably lower than 80% efficiency (I think the norm was about 60%), in which case the savings could be higher... but the savings from even a basic new furnace (80% efficiency is the lowest I have seen for a while) would be proportionally higher as well.

There seem to be two levels of "troublesomeness" - first level is from replacing the pilot light with electronic ignition, adding a blower (to the air intake, I think), and that's pretty much it. That seems to be enough to get you to the high 80s in efficiency.

Next level of complexity is extra heat exchanger capacity, enough to cool the exhaust air low enough that water condenses out, mixes with the flue gases to get a bit acidic, and drips down to the bottom of your furnace and out a hose. You also end up replacing your current chimney with a plastic pipe, and typically add another pipe for intake air. That was what made me think my furnace was just too damn fancy.

As a starting point I would try to get an estimate for how efficient your current furnace is. That will let you make some reasonable estimates for how much you can save at each efficiency level / price point.

What's an air conditioner?

Nice avatar Cam.

I guess the main question is, how efficient is my existing furnace? if it's 80% I won't bother, but it's possible it's not as good as that, in which case it may be worth the change. I'd like to sell the house in a year or so....on the one hand, a new furnace might be an unnecessary expense, but on the other it may be a selling feature.

Thanks for all the feedback, everyone.

AFAIK the big selling feature is "new" furnace, not "fancy" furnace.

Only people like us care about furnace technology or look at the efficiency specs

Whadya mean people like us?

Most of my experience is with oil fired units but I have replaced a few gas units and all were replaced due to heat exchanger failure. How old is the unit you have now? Gas / LP fired furnaces are not typically designed with much of a life expectancy. The heat exchangers fail over time and flue gasses start to mix with the air supply that is routed through the home. There’s also not a great deal of adjustability with the burner on gas units either. With some units, you can’t adjust anything. If you are serious about replacing your furnace, take a look at Lochinvar. They make some extremely efficient units approaching 100%. Their gas fired Knight Boilers are amazing. Their water heaters are pretty slick too.

Hi, Michael. The unit(Lennox) is a good 18 yrs old now and has been extremely reliable though perhaps not overly efficient... I recently installed a new water heater btw.

It's a heat pump.

Wow, this thread almost slipped me by! Better late than never, I guess. Excellent posts by all. There are only a couple of points I can add:

- In Ontario, you can no longer buy a forced-air gas furnace under 90% AFUE.
- There are rebates available from the Provincial Government and the Ontario Power Authority (OPA) to upgrade your furnace. A home energy audit is required, (which will cost you ~$350.00), but you could qualify for up to $940.00 in rebates.
- Most manufacturers also have rebates available.
- If you are truly moving within the next couple of years listen to John: Excellent advise.
Conversely, if you are staying in the house, the multi-stage gas valves and ECM motors are WELL worth the extra money.

With regard to the quoted "Savings" on fuel costs, it really depends on the age and efficiency of the existing furnace. I have seen consumption cut in half in a number of installs, but it is not common.

Also, since you are moving, don't get talked into spending more on one of the higher end name brands. Even a cheap-o builder furnace will be relatively trouble free for the first 5 years if installed correctly. Please note that I will give the exact opposite advise if you are staying in the house long term.

Spot on, John. That's why there are multi-stage furnaces that will match their firing rate to what the house needs. Far more efficient heat delivery and comfort than a single stage unit.


Actually, just the opposite. The thermal expansion & contraction from repeated short heating cycles, causes more wear and aging than fewer, longer, heating cycles. Similar to a car with mostly "highway miles" vs "city miles"

New high efficiency furnace getting installed tomorrow. It's an American Standard which apparently is the same as the Trane units sold in the B&M stores but at a much more reasonable $$.

Interesting, and very good to know. I guess that pretty much eliminates all of the arguments for "oversizing" a furnace. Thanks !!

Just an update on the new high(er) efficiency('bout 92-93%) furnace I had installed back in the fall....I'm definitely seeing a reduction of 25-30% on my gas bills each month, woo-hoo!....should have done this sooner.

That's quite a substantial amount! Congrats!

Adrian, that's great news! Just curious, did you opt for an EMC motor? If so, you should also notice a significant decrease in your hydro bill.

EMC?

Oh. here ya go, bud . Sorry, it's ECM, not EMC.

I got the furnace(Amer. Stdrd) basically at cost + instal/tax in for $2G which was a bargain....a variable speed would have upped that to $3G++ which I didn't think was worth it for the extra 2-3% efficiency.

My neighbour came over a few nights ago to borrow my portable ceramic heater because his Keeprite furnace crapped out(3 yrs new!!). It turned out to be something on the control panel screwed up and had to be replaced($300 under warranty). Also my neighbour's brother's furnace, not sure of make, needed a new motor after only a year!

I hope these new furnaces are reliable, otherwise who cares about saving on gas if they need replacing in half the time. My last furnace was near 20 yrs old and ran fine before I replaced it with a more efficient unit....I've heard of some people getting over 30 yrs out of their old furnaces.

Bump...

Here is a couple of pics of the HVAC system we got this year. It has been absolutely AMAZING. Worth every penny. First summer with AC...and in style.

We have a gas furnace from the original install in 1994.

We've seen a nice decrease in our Natural Gas bills lately due to the fact that bulk gas prices are way down due to the huge supplies that are coming online in North America due to good ole Fracking. As long as this is happening, these advertised monetary savings will not be realized over the short term. Great for us; however, governments don't like this as it cuts into their revenues hence contributing to higher deficits & debt.

A high efficiency furnace might make you feel greener though...

TAM

There's still a significant difference between ~80% and 90%+ especially larger the home is. I'd always pick something at least around 92-95% of course I have a friend that does HVAC and he doesn't over charge me for the actual furnace. The price difference between them really isn't all that significant but it seems the standard is to charge MUCH more for the difference.

Once you get up to the ultra efficiency, there is a large price difference between them and the units below. I have installed two stage heating and two stage cooling. 18 seer AC and 96% AFUE furnace. The energy savings are real especially here in Canada where everything is very expensive. But just as important, the quality of parts are better in the high end models and there is also a MUCH better warranty. Our good friend told us in terms of brand names and their different lines of products, these companies utilize pretty much the same parts, some brands even owned by the same company. He chose to go with the KeepRite because that is what he works a lot with in commercial HVAC and they are easy units to fix.

Congrats on the new furnace, Doc.

I sold the house I had the new furnace installed in, but I was saving $300-450 yr on gas with the higher efficiency unit. Well worth it, should have changed it sooner.