Furnace shopping - Looking for input

[Pat Barry]

Sadly its time to replace my 40 yr old gas furnace (and A/C) with something modern. I'm considering the following options which are being quoted by 3 different installers. I don't have all the pricing info yet but the furnace models are 1) Rheem 80% efficient, single stage, and single speed blower; 2) Lennox 80% efficient, two stage with variable speed blower; 3) Lennox 96% efficient, two stage, variable speed blower; also, 4) more info coming on a model from Day and Night and 5) American Standard. Anyway, what I think I have learned is that a two stage furnace is the way to go (basically two power settings so that the high power setting is used only on the coldest days). ALso, a variable speed blower is a good thing to have, especially when including A/C. What I'm really wondering if the extra efficiency of a 95+% unit makes sense as compared to a modern 80% efficiency unit. The 80% units will be less expensive to install since they can use the existing chimney flue whereas the high efficiency units vent thru PVC pipe and a sidewall. I'd appreciate hearing from others who recently when thru this process of replacing a worn out furnace. Thank you

[Charles Wiggins]

I don't have all the data at hand, but we replaced our system about 18 months ago. We went with a dual-fuel system from Trane. It's a heat pump with a gas furnace on backup that kicks in when outdoor temps get down to about freezing. Both the heat pump and furnace are much more efficient than the units they replaced, but neither was the top of the scale on efficiency. We looked at the extra initial cost versus the energy savings, and in our area it did not seem to make sense because we don't have a lot of days of extreme temperatures, hot or cold. Plus we started burning wood about the same time, so that reduced our need for the furnace even more. Between the two, we went from a $500 energy bill in February 2011 to just under $200 last February.

I don't think this will be very helpful to you, given the differences in climate, but I hope it is.

Cheers,
Charles

[Mark Paavola]

I would definitely go with a 2 stage furnace. The comfort level is better and the reduce noise from the equipment is nice. Pretty much all of them will come with the variable speed blower. The variable speed is not a critical item to have. As far as 80% vs the 96% you need to compare fuel costs and see what the payback time is. The problems with the 96% is more parts and more expense to repair. I have a dual fuel system but that is primarily due to the lack of natural gas where I live.

[George Bokros]

We replaced our HVAC last November wtih a 97 % efficient Trane unit with a variable speed blower. We were told at that time that 80% efficient units could not be sold in our part of the country (north east Ohio) after May of 2013 by federal regulation. This regulation has since been rescinded by the federal government.

We have been completely satisfied with the new unit. We did the upgrade because our 15 yo unit had an issue with the ignitor not shutting down after it lit the pilot. This was estimated to be $850 to $1,000 repair. I would not put that much money into a 15 yo unit that was 80% efficient. Upgrade then we get the benefit of the more efficient unit.

In the part of the country you are located I would go as efficient as you can on the heat side.

George

[David Weaver]

Is anyone here an HVAC guy? I have the same dilemma coming up, an old 80% efficient furnace that's 30 years old, but I haven't heard great things about heat exchanger life and reliability of the ultra efficient furnaces, presumably due to condensation.

At this point, gas is cheap and my furnace is running well, and I figure the heat that goes up the chimney is insurance that the condensation occurs somewhere other than where it can end up back in the furnace.

Will the new ultra efficient furnaces last like the old ones? Where does the condensation go from the cooled flue gas, do they have a condensation pump like a sub-mounted heat pump would have?

[Joe Tilson]

Dave, I was in the HVAC business for some twenty one years as a parts distributor and in sales. We have owned Carrier and Trane over the past thirty years and find they really are the most reliable. We had a ten SEER Carrier for twenty years and now we have a Trane fourteen SEER, both being heat pumps. The Trane has kept our home a little warmer in winter(if you can call it that in SC). If your gas furnace is vented properly and is maintained properly you should have no real problems with either one of these brands. I really am not up to date on the newest equipment out there, as I have been away from it for several years. Other brands have made great strides over the years, but stick with tried and true brands.

[Brian Elfert]

The 90%+ furnaces seem to be lasting pretty long these days. The one in my house is 12 years old now and still going strong. I have it checked every few years and no issues yet. No, you may not get 30 years out of them, but I never planned on getting 30 years out of mine. Natural gas is cheap today, but how much is it going to cost in a few years as demand increases due to vehicles switching over and more and more electricity generated from natural gas?

My parents bought a 90% furnace when they still pretty new and they ended up having to get a new one after 12 years. I believe by now that the manufacturers have fixed the initial issues. My parents replaced their 80% furnace when it was about 16 years old, but there was nothing wrong with it. They needed a new air conditioner and decided to get a new furnace at the same time.

[Jerome Stanek]

I heat my house with a 99% gas unvented heater. My furnace is a 80% 25 year old unit that only ones when it is below 0

[Dan Hintz]

When we replaced our ancient system a few years back, we went with the most efficient we could get. For a couple of hundred $s more, I could upgrade the heating coils another 50% in capacity, so I went ahead and did it. Shortly thereafter, however, I had a pellet stove installed and that has significantly reduced the amount the heater comes on. I don't believe the heater fan ever runs more than at the lowest speed, and I know the secondary coils have never activated. The pellet stove is 93% efficient, and I go through roughly 2 tons of pellets a year (the wife likes it hot, but I convinced her that 77 is a good temp to avoid boiling me out of the house). Even without the stove, however, we saw our electricity bills drop by over half ($400-450 down to $200+) just moving to a more efficient system.

[Shawn Pixley]

We replaced our furnace a little over a year ago. The previous one was a high efficiency unit from 1989. The firebox rusted due to the ocean air. We replaced it with an Amana 98% efficient unit with a stainless steel firebox. I calculated the return on the eficiency. The payback was a little under 7 years assuming no increase in rate. If one were to get real sophisticated, you would monte carlo the scenarios with assumptions on rates / increases, repair, and replacement timeframes. Energy is expensive in California. Since we are planning to stay in the house for the rest of our life, we are opting to buy down future expense for near-term capital.

As an admitted environmental "greener," I would recommend that you go for the higher efficiency unit.

Our unit works well and it is almost silent. The exhaust and intake are through the sidewall of the house. The furnace closet is weather stripped to the interior and is unconditioned. We turn the furnace on around Thanksgiving and it is turned off in February. We also have a high end programable thermostat.

[Ralph Butts]

I just upgraded an older electric forced air furnace to a Trane two stage, two compressor heat pump. My electric bill is less than half what it was the previous year. I would go with the more efficient models, I think you will see significant savings on your energy bill.

[Raymond Fries]

We have a 96 percent Lennox and are very happy with it.

Just as an FYI - We purchased a power inverter instead of a backup generator for those emergency situations with no electricity. In researching what we could connect to it, our heating contractor tols us that the modern furnaces with the circuit boards cannot be ran from power inverters or backup generators and that only whole house systems are acceptable. So we plan on using it for our refrigerator and lights. We have a fireplace that can suffice for heat as we made it 5 days with no electricity when we had a bad ice storm some years back. Our heating contractor told us that they repaired numerour furnaces that were connected to generators during that storm.

Good Luck on your decision and stay warm this winter...

[Dan Hintz]

We purchased a power inverter instead of a backup generator for those emergency situations with no electricity.

What does the power inverter run off of if you have no generator? The car?

[Raymond Fries]

Dan

Yes it is the car. My brother recommended this option to avoid perodic generator starting, maintenance, etc.
You can connect it to the battery and start the car periodically to keep the battery changed. There are options to connect it to stand alone batteries as well but this option looks like it will work well for our needs.

Here is the one I bought:

http://www.amazon.com/Whistler-Pro-1600W-Watt-Power-Inverter/dp/B003R7AJ4K/ref=sr_1_1?ie=UTF8&qid=1381259900&sr=8-1&keywords=whistler+1600+power+inverter

There are bigger and smaller ones depending on your needs.

[Pat Barry]

So I did some calculations based on Natural gas energy charges over the past two years. I spent a total of $1822 over the two year period. Some of the gas goes to the water heater and gas range. I figure this is $25 per month so that leaves $1164 for the furnace. I figure the old one is 60% efficient (the heating guys said I would be lucky if it was 55% for a 40 yr old monster that was oversized to begin with) so that's a total wasted gas charge of $465 over the two year period - actually lower than I would have guessed from what I thought I was paying. SO a new 80% efficient furnace could save me only $163 per year. A 95% efficient model would save $215 per year. SO the 95% model will save an additional $50 per year. I would get a $400 rebate from Xcel energy for the high efficiency unit compared 21 year payback. I need to verify the prices and rebates but the numbers don't seem to be in favor of a high efficiency unit. Who knows what will happen in the future but it might have to be dramatic to make the savings picture a whole lot more in favor of the high efficiency model.
Thoughts?

[David Weaver]

Gas is cheap here, which means it probably will be there. We'll be looking to pipe it out of this area as fast as we can for quite some time unless there's a legislative change as we've got tons of speced well sites that never were drilled put could easily produce.

I'm going to ride my old furnace until it quits, but I may be in the same boat as you are, with a large part of the bill coming from customer charges, etc, in reality, my incremental spend on gas each year for the furnace is about $700 (it's a bit warmer here, I guess) and moving up to a 95% unit won't do me much good cost wise - especially if it's problematic and costs a lot more up front. If I could, I would buy another furnace identical to the one I have already, it's simple, and efficient enough, but that's not an option.

Ten years from now, you can always get another high efficiency unit if we turn out to guess wrong on the price of gas. It's very unlikely here, though, we have people just itching to put more production online and pipeline building is going at a mad pace.

The A/C of the same vintage is another story.

[Pat Barry]

Calculations:
waste at 60% efficiency = $1164(100-60)/100 = $465
useful at 60% efficiency = $1164(60/100) = $698
assuming the useful is correct, then with 80% efficiency, the waste would be
$698(100-80)/100= $139. Add that to the $698 useful amount and the estimated cost is $838
and at 95%
$698(100-95)/100= $35. Add that to the $698 useful amount and the estimated cost is $733
All these are two year numbers

Anyway, those are my calculations for the math fans. Please let me know if the numbers don't make sense

[Pat Barry]

Gas is cheap here, which means it probably will be there. We'll be looking to pipe it out of this area as fast as we can for quite some time unless there's a legislative change as we've got tons of speced well sites that never were drilled put could easily produce.

I'm going to ride my old furnace until it quits, but I may be in the same boat as you are, with a large part of the bill coming from customer charges, etc, in reality, my incremental spend on gas each year for the furnace is about $700 (it's a bit warmer here, I guess) and moving up to a 95% unit won't do me much good cost wise - especially if it's problematic and costs a lot more up front. If I could, I would buy another furnace identical to the one I have already, it's simple, and efficient enough, but that's not an option.

Ten years from now, you can always get another high efficiency unit if we turn out to guess wrong on the price of gas. It's very unlikely here, though, we have people just itching to put more production online and pipeline building is going at a mad pace.

The A/C of the same vintage is another story.

My biggest problem is that my furnace is apparently not safe to operate due the heat exchanger leaking and creating a potential CO issue

[Brian Elfert]

I'm curious what the price difference between the 80% furnace and 95% is? I've heard that 95% furnaces are pretty expensive. Is 90% or 92% an option for lower cost?

My furnace is 90% or 92% because Minnesota energy codes required 90% or better when the house was built. I don't know if it would be legal for me to install an 80%, but it wouldn't make sense as my house has no venting for an 80% furnace.

[Matt Meiser]

I would look at heat pumps if you have ancient AC. Heat pump technology has come a long way and if installed with a high efficiency gas furnace are very cost effective to run--efficient heat pump heat until down around freezing, below that you use gas. According to my HVAC guy, the best systems are "within spitting distance" efficiency-wise of geothermal. We learned of heat pumps 2 years after having our furnace replaced with a 93% furnace by another contractor. Knowing what I know now I'll never use that other contractor again. The new guy was able to pair a decent unit with our furnace, but if we'd known up front, we could have spend a couple $K more overall and gotten a good jump in efficiency.

We have a Trane system. I have mixed feelings. A lot of people really trust them and my HVAC guy who I really trust says they are one of the best. But our house was built in 91 and got a new furnace after a few years due to a Trane recall. We bought the house in 2003 and had trouble with it the first winter to the tune of a few hundred bucks. Then about 5 years ago we had to have it replaced because the heat exchanger, which IIRC has a 20 year transferable warranty, had a hole, Trane had 1 in stock in the entire country, and refused to ship it overnight even at my expense instead offering me a discount on a new furnace. Since it was getting down below zero the coming weekend we had no choice but to replace the whole furnace. Then we installed the heat pump and within 6 months they had to re-braze a connection inside the outdoor unit. Knock on wood they've been good since.

I'm surprised to learn they still make 80% furnaces.

[Brad Adams]

I run a plumbing and heating business. They say it's hard to stop a Trane, but what we say in the heating business is, have you ever tried to get one started. Most high efficiency furnaces are 95 percent efficient now days. I am partial to the Nordyne line of equipment, they are sold under a few different names. I sell the Frigidaire brand name. In the last five years I have had very very few call backs. The best part is they are all made right here in Missouri, not in Mexico like almost still other brands.

[Larry Frank]

I went thru this earlier this year and put in a Lennox 96% Fce, 2 stage AC, and humidity control system. My AC has been 45% less every month and think the furnace will be good. The biggest part of my bill is electricity for AC and the fan with the variable speed fan making a big difference.

I also had some duct work done to balance things out.

I could not be happier.

[Pat Barry]

I'm curious what the price difference between the 80% furnace and 95% is? I've heard that 95% furnaces are pretty expensive. Is 90% or 92% an option for lower cost?

My furnace is 90% or 92% because Minnesota energy codes required 90% or better when the house was built. I don't know if it would be legal for me to install an 80%, but it wouldn't make sense as my house has no venting for an 80% furnace.

Brian, I live in Mn also and have not heard of the regulation you referred to. Of course, that may be a requirement for new construction but doesn't apply to replacement systems. I'll ask about this however, but I think they will tell me its not a problem because every heating contractor I have talked to (5 total) all are quoting 80% furnaces and an alternate high efficiency unit.

[Brad Adams]

The doe was going to make it illegal to install 80 percent efficient furnaces. The rule has been pushed back. In some situations you can't install anything but an 80 percent furnace.

[Shawn Pixley]

Calculations:
waste at 60% efficiency = $1164(100-60)/100 = $465
useful at 60% efficiency = $1164(60/100) = $698
assuming the useful is correct, then with 80% efficiency, the waste would be
$698(100-80)/100= $139. Add that to the $698 useful amount and the estimated cost is $838
and at 95%
$698(100-95)/100= $35. Add that to the $698 useful amount and the estimated cost is $733
All these are two year numbers

Anyway, those are my calculations for the math fans. Please let me know if the numbers don't make sense

The difference (current to 95% eff) is $ 431/year. If the 95% efficient is $ 2,500 more the payback is 5.8 years (simple calc). Factoring the cost of capital, it will pay back in around 7 years (again no assumption on increased energy rates). If I factored in whether I thought I would be living in the house then, I would go with the higher efficiency unit. But it is easy for me to spend your money (tongue firmly in cheek).

Good luck

[David Weaver]

My biggest problem is that my furnace is apparently not safe to operate due the heat exchanger leaking and creating a potential CO issue

Yeah, that's a problem. Your decision is a lot more immediate than mine.

[Brian Elfert]

Brian, I live in Mn also and have not heard of the regulation you referred to. Of course, that may be a requirement for new construction but doesn't apply to replacement systems. I'll ask about this however, but I think they will tell me its not a problem because every heating contractor I have talked to (5 total) all are quoting 80% furnaces and an alternate high efficiency unit.

Minnesota adopted an energy code that took effect in 2000. All new homes built in 2000 or later in Minnesota must be built to meet the new energy code. One requirement of the code is a 90% or higher furnace. My house was built in 2001. It doesn't apply to houses built before 2000. You can put any furnace you want in an older house so far as I know.

[paul cottingham]

Have you considered a heat pump?

[Michael Schneider]

Pat,

I see from your sig you are in MN, pretty chilly in the winter time there :-)

What is your house like? Do you have different areas of the house that you could keep at different temps?

We are starting to look and have different zones in the house. Think of a zone is a part of the house that you could keep at a different temp. We have a finished basement, couple of areas on the main floor, and an upstairs.

I am looking at a mini-split system.

Have you considered a mini-split? It may be worthwhile to do a little research on them.

Take care,
Michael

[Matt Meiser]

A mini-split is a heat pump. Below mid-30's its not going to heat unless the units have an electric heat $trip ($$$$).

My parents put in a mini split system this summer and its nice. But during the winter it will have to be shut down and their old boiler system will take over.

[Pat Barry]

No, I haven't really looked at a heat pump system but I will make an inquiry. Here in MN I could get a heat pump that might be useful for cooling (is that what you mean?), but for heating this would never work from what I understand. I also have not considered anything with different zones within our home. I could see that might be a nice thing to have but our entire duct system would need to be replaced to accomplish that.. For new construction I think I would go to a multizone radiant heating system.

[Pat Barry]

The difference (current to 95% eff) is $ 431/year. If the 95% efficient is $ 2,500 more the payback is 5.8 years (simple calc). Factoring the cost of capital, it will pay back in around 7 years (again no assumption on increased energy rates). If I factored in whether I thought I would be living in the house then, I would go with the higher efficiency unit. But it is easy for me to spend your money (tongue firmly in cheek).

Good luck
Hi Shawn, All my numbers were for a two year period so the operating cost difference between the current system and the 95% efficient furnace is actually half of $431 on an annual basis or $215 per year. By the same math, the operating cost difference for the 80% furnace compared to the existing furnace is $163 so I see an additional $50 per year to go to the 95% as compared to the 80%. I would get a rebate and some tax credits for the higher efficiency unit, maybe around $600 total. The added cost for the Lennox systems quoted to me was $1100 more for the 95% efficient system so the payback to upgrade to the 95% efficient model would be ($1100-$600)/$50 = 10 yrs

[David Weaver]

No, I haven't really looked at a heat pump system but I will make an inquiry. Here in MN I could get a heat pump that might be useful for cooling (is that what you mean?), but for heating this would never work from what I understand. I also have not considered anything with different zones within our home. I could see that might be a nice thing to have but our entire duct system would need to be replaced to accomplish that.. For new construction I think I would go to a multizone radiant heating system.

In north St Paul, a heat pump probably isn't going to save you much or anything over natural gas for the heating side. The A/C side, I don't know.

I put in a split in an insulated room that's off of my house (and out of the reach of the tinwork in my house, at least without spending huge amounts of money). The split is a 21 seer heat pump/ A/C and the A/C side of the unit is extremely efficient compared to what I already have in the house. The literature that comes with it suggests that when it's cold, it will be cheaper per btu to use gas by a pretty wide margin.

For folks not tied into natural gas, or for folks in fairly warm areas (where the unit will generate a BTU of heat easier against warmer outside temperatures - warmer in a relative basis, like 40 or 45 degrees), the heat pump might make more sense, but for North St. Paul, it would probably be relying on the electric coil - esp. at night, and your money would go pretty quickly with the coil on, no matter the efficiency of the unit.

If my inlaws stay for an extended period of time this winter, I'll find out, as they'll zone out in my outpost and probably shut the door and rely on the heat pump to keep their area warm.

[Brian Elfert]

Here in Minnesota, heat pumps are generally used in conjunction with a natural gas or propane furnace. Below a certain outside temperature the heat pump shuts off and the furnace takes over. I don't know if heat pumps really save any money here in Minnesota, or if HVAC companies simply want to sell them to make more profit.

I have zoning between first and second floors in my house, but the zoning was put in place when the house was built. It could potentially cost a lot of money to zone an existing house depending on how the duct work was run. I have a separate trunk to second floor for the zoning. I don't know if they would have trunked it like that if I didn't have zoning.

[Shawn Pixley]

Pat,


You're right I overlooked the two year note. By my simple revised calcs (based on current energy rate, no cost of money and not indexed to inflation):


Current unit= $ 582/year
The 80% efficient unit est @ $ 418/year (savings delta of $ 164/year against base)
The 95% efficient unit est @ $ 367/year (savings delta of $ 215/year against base & $ 51/year against 80% unit - pays back in ~21.5 years assumed premium of 1100$
The 95% efficient unit est @ $ 367/year (savings delta of $ 215/year against base & $ 51/year against 80% unit. It pays back in ~9.8 years assumed premium of $500 - 1100$ less $600 credit)

Of course this simple analysis is predicated upon the assumption that your furnace must be replaced and the minimum efficiency is 80%. Models like this are also very sensitive to changes of assumptions. For instance if the rate we to go up by 10%, the payback shows an almost year improvement. The other things not factored here are rate of inflaction, cost of borrowing, and /or the return on alternative investment. Depending upon what you think about those things, make your choice accordingly.

[paul cottingham]

Here in Minnesota, heat pumps are generally used in conjunction with a natural gas or propane furnace. Below a certain outside temperature the heat pump shuts off and the furnace takes over. I don't know if heat pumps really save any money here in Minnesota, or if HVAC companies simply want to sell them to make more profit.

I have zoning between first and second floors in my house, but the zoning was put in place when the house was built. It could potentially cost a lot of money to zone an existing house depending on how the duct work was run. I have a separate trunk to second floor for the zoning. I don't know if they would have trunked it like that if I didn't have zoning.
I believe Mitsubishi (its called zuba central i believe) makes a heat pump that produces heat all the way down to 30 below. Mine has a built in electric heater that takes over when it is too cold. It is so efficient that I pay very little for heat or cooling.
mind you, I live in a very mild climate.
i still believe they are much cheaper to run regardless of climate.

[David Weaver]

i still believe they are much cheaper to run regardless of climate.

Than Gas? No. As you get closer to zero, the consumption of a heat pump (including the mitsus) approaches the same BTU output that you would get from a coil heater.

Mine (mitsu) goes down to minus 13 degrees before it will shut off and refuse to run. There are rare times here where we will get a temperature like that. The result would be catastrophic.

Anyway, the cost per btu for electricity in a coil heater is a little more than 3 times the cost per btu in gas. It's no big surprise that's the case, the power generating stations create a lot more thermal energy than they can yield in electricity (same with nuclear). You can cheat the system in warm temperatures when a heat pump can make 3-5 times the BTUs of heat vs. old fashioned coil heaters, but the times where the heat pump has to run the most in a very cold area are when it's also running at its least efficient. That's why they're a great idea for places that don't see below freezing too often, but not great for places that commonly see stretches of $0 temperatures overnight.

High efficiency heat pumps are also expensive. I paid a guy to install mine (it's only 15k btu) and it was around $3k. The local certified mitsu installer wanted over $4k - that's about the price it would cost me to get a high efficiency 125k btu furnace installed. They (heat pumps) don't last forever, and the warranty covers parts (not labor). As you go up the scale to larger heat pumps, their seer goes down. I don't know why, but it does.

If gas is not available cheaply to you, then a heat pump is cheaper than things like propane and oil. If you're in a cold place where you're on or near a pipeline, gas is cheaper for heat.

[paul cottingham]

Here where I live, gas pricing is unpredictable, and has been very high at times. I also really like the air conditioning that comes with it.

[Greg Portland]

Sadly its time to replace my 40 yr old gas furnace (and A/C) with something modern. I'm considering the following options which are being quoted by 3 different installers. I don't have all the pricing info yet but the furnace models are 1) Rheem 80% efficient, single stage, and single speed blower; 2) Lennox 80% efficient, two stage with variable speed blower; 3) Lennox 96% efficient, two stage, variable speed blower; also, 4) more info coming on a model from Day and Night and 5) American Standard. Anyway, what I think I have learned is that a two stage furnace is the way to go (basically two power settings so that the high power setting is used only on the coldest days). ALso, a variable speed blower is a good thing to have, especially when including A/C. What I'm really wondering if the extra efficiency of a 95+% unit makes sense as compared to a modern 80% efficiency unit. The 80% units will be less expensive to install since they can use the existing chimney flue whereas the high efficiency units vent thru PVC pipe and a sidewall. I'd appreciate hearing from others who recently when thru this process of replacing a worn out furnace. Thank you

I recently went through this and any recommendation depends on where you live. For example, I calculated the heat load of my home figured out how many days out of the year I would need to use the gas furnace (versus the heat pump). In my location, it turned out that I would VERY rarely use the gas heat so I went with the 80% efficient furnace (some people even skip that and go with electric strip heat). I got the best heat pump I could find + a fully variable fan for maximum power savings. I calculated the cost difference over getting something cheap and I will pay this difference off in 3 years (energy cost savings) assuming electric & gas costs stay the same.

I have to imagine that you will require heavy use of a gas furnace (versus a heat pump) given your location. Figure out how much gas you'd save (e.g. 15+% of your annual gas bill) by chosing the high efficiency option and see when you'd pay off the difference. Somes states still offer energy discounts so this may factor in more savings for the more expensive unit.

I would only look @ Lennox, Carrier, Trane, or York. The other brands tend to be made by these companies @ a lower standard & rebadged.

Edit: Install is critical. Get an Angie's List membership and find a good contractor to do the install.

[Pat Barry]

I did a quick search and found this about heat pumps vs AC on the Carrier website. "The primary difference between air conditioners and heat pumps is heat pumps can both cool and heat. The trade-off is that the air conditioner is a little more energy efficient at cooling. Generally, a heat pump heats best down to about 40 degrees. Below that outdoor air temperature, you may want a furnace as your primary heating source." Here in MN if we get 40 degrees in the winter we all go out in shorts and try to catch a tan. I don't think this is for me.

[Pat Barry]

OK, I have the quotes from several installers. Equipment quoted included American Standard, Lennox, Gibson, Day and Night, Ameristar, Rheem. Packages included AC unit and ranged from around $2000 for equipment only from Ameristar at 80% efficiency to complete Lennox high efficiency system at $8110. On average, excepting the Ameristar and one other low end unit, the price for high efficiency was $1100 to $1500 more. What I have decided on is an American Standard package with a 97% efficient two-stage variable speed blower furnace and a 14.5 SEER AC unit. A couple realtor friends of mine both felt the high efficiency unit would be a selling point if I were to put my house on the market in a few years. I meet with the installer Monday to go over the details and finalize things. The total cost (as of last night) is $6700 before tax and rebates. I think between the US Govt Tax credit, and the utility rebates I might be able to recover $750 ultimately. So, I think its a good price. I don't want to see any scope creep. Interesting note - one of the installers quoted a new Honeywell digital thermostat to replace the round mercury switch unit we have. He quote $160 for the unit and programming. Home Depot has a better unit on sale for $60. I think I can manage the programming.

[George Bokros]

one of the installers quoted a new Honeywell digital thermostat to replace the round mercury switch unit we have. He quote $160 for the unit and programming. Home Depot has a better unit on sale for $60. I think I can manage the programming.

When I had my new unit installed last November the dealer included the new t-stat in the price ~$6,700 before rebates, gift card, pizza certificate, utility rebate. This was for a Trane 97% efficient furnace and 14 SEER AC unit.

Programming the t-stat is easy peasy.

George

[Michael Schneider]

Pat,

We have an Office in MN that I try to visit in the spring an fall of the year. Snow and bitter cold in the winter, and some mighty big mosquitoes in the hot summer :-) , but a truly beautiful place. It must be nice to have all the lakes around to play in.

I am sure there are some rather unique HVAC requirements for your part of the country.

Take care, and enjoy the weekend,
Michael

[Jim Becker]

The cost difference to go to very high efficiency is not huge, so I'd personally go with the 96% efficient system. The cost to vent is also minimal in all honesty. I have two systems in this home; one is 80% and one is 96%. The only reason for the former is I didn't know better at the time.

What is MOST critical is that the system is sized properly for your home. Too small is an obvious problem, but all too often folks don't pick up on the fact that too large is also not a good thing...more expensive to run and you get uneven heat/cooling because the system is constantly shutting off. The previous owners of this property had a system in the original house footprint that was nearly twice as big as required for the space. It was a monster! And the house never felt "comfortable". What replaced it was sized correctly and the comfort is there.

Don't forget to ascertain if there are any rebates available from your power/gas company, too.

[BOB OLINGER]

Well, this isn't likely applicable to the specific question, but we had 2 furnaces; one was due for replacement and the other likely in 5 or so years. So, we put in a geo-thermal system a couple months ago - replaced both furnaces with one geo-thermal. So far, it's terrific. We'll see what the winter utility bills run.

[Stephen Pereira]

I just replaced my 80% gas furnace with a 95% furnace made by York. The difference in price was about $400.00. I installed it myself..it wasn't very difficult. Venting with PVC is fairly easy..read the instructions that come with the manual and ask lots of questions fro the furnace tech dept if you don't understand anything. I chose the least complicated furnace I could find..easier to repair if need be. The replacement parts on some of these new furnaces is out of sight. Most new furnaces come with a 10 yr parts replacement guarantee and a lifetime warranty on the heat exchanger. A combustion motor on a new furnace can easily cost you 1/2 price of a new furnace..these are list prices.

[Brian Elfert]

Where did you find a place to buy your own furnace? Wholesale suppliers usually only sell to those in the trade. There are some websites that specialize in selling to the DIY folks, but they usually sell lesser brands like Goodman.

Is the warranty still valid if you installed it yourself?

[Stephen Pereira]

I bought my furnace from Dey Distributing. I work for a propane company and bought the furnace through them..however. I think that Dey will sell a furnace to anyone who can fork over the cash. If you live in a rural area call your energy co op..tell them you will install your own furnace and want a good deal..maybe 10 to 15% over cost. If they won't go for that tell them to go pound sand and you'll find someone who will..its not that hard ..money talks.Warranty..all you have to do is register online..nothing to it.

[Kev Williams]

There are some websites that specialize in selling to the DIY folks, but they usually sell lesser brands like Goodman. I had an 80% Goodman furnace installed about 4 years ago. The 'estimator' calculated I only needed a 110k BTU furnace. I was replacing a 140k 80% Airtemp, and I kinda disputed his figures at first, but he assured me he I'd be happy with a 110k...

The Goodman is only 2/3 the size of the old Airtemp. I was intrigued by the heat exchanger design, looked like a bunch of twisty pipes. It has spark ignition, a flue blower and a 2-stage burner, all new to me. The only time the 2nd stage runs (has ever run that I know of) is when it first fires. First time it kicked on I noticed the blower came on about 10 seconds after the burner fired. The air coming from the vents was lukewarm at best. I thought "well, I guess I can have them come in a put in a bigger unit"... But was I pleasantly surprised!

In going thru my gas bills 3 years prior the average was just about $85 a month on equal pay. Since the Goodman was installed my average bill has been less than $60 a month.

I've come to the conclusion that the estimator was dead on, and the Goodman is doing something right! Lukewarm air or not, the house is always comfortable, and the money I'm saving has almost paid for the thing. I'd recommend one to anybody...

[Stephen Pereira]

Goodman had a bad reputation for cracking heat exchangers...at least with the HVAC contractors in my local area. I couldn't say if the reputation is deserved but I will say that Goodman has warranted every cracked heat exchanger..no matter the age of the furnace and who installed it. I just called up the Goodman dealer..tell them the heat exchanger is cracked and they send a new one out..no questions.

[ken masoumi]

I have always had good luck with Keeprite furnaces ,last year we had the latest model installed and in the peak of Canadian winter we never paid more than $90 per month, it's 97% AFUE and has a stainless steel heat exchanger,very quiet I highly recommend it.
The KeepRite® VC 97 Variable-Speed Modulating Gas Furnace featuring the Observer™
http://www.keeprite.com/products/vc97.html

[Jim Becker]

A correctly sized unit with multi-stage, variable fan speed and a continuous air flow will keep a home very comfortable. You don't need "hot" air coming out of the vents to replace a lot of cold air that creeps in between furnace cycles because you have a more consistent temperature throughout the home and you use less fuel. With the fan always running, even at low speeds, you also get better filtration of the air. (the same holds true in the summer when AC is online)

[Pat Barry]

A correctly sized unit with multi-stage, variable fan speed and a continuous air flow will keep a home very comfortable. You don't need "hot" air coming out of the vents to replace a lot of cold air that creeps in between furnace cycles because you have a more consistent temperature throughout the home and you use less fuel. With the fan always running, even at low speeds, you also get better filtration of the air. (the same holds true in the summer when AC is online)
I am already finding that having the fan run continuously is probably the way to go. On our old furnace the fan noise was so loud we didn't like to have it running. The new fan, with variable speed, runs very quiet.

[Tom Giacomo]

I purchased a Rheem 94 percent, two speed over the internet. Many mfgs will not sell to DIY.