Question:

- Hide quoted text — Show quoted text – One thing to keep in mind is that blowing insulation into empty walls creates a significant draft/infiltration barrier in addition to the actual insulation added.  Also, comfort depends a lot on the evenness of the temperature, and both insulation and well-sealed windows help in terms of eliminating cold spots and drafts in the house.  Which one will be most effective depends in large measure on which is worse to begin with.  Also, doing a halfway job on both is probably better that just fixing one or the other, since eliminating drafts from one source doesn’t do much good if the other source is still leaking badly. Dan, How do you provide an effective vapor barrier in old homes that you blow insulation into?  How do you keep moisture from penetrating the walls from the inside, only to condense inside the insulation surrounding your structural lumber?  Ten years from now will you need to open the walls up for rot repair?  How much money will that save? These are all questions you must ask when retrofitting older homes. What seems simple and common-sense sometimes just isn’t.

Many older homes have ten coats of oil paint on the plaster walls, providing a very good vapor barrier.  Also keep in mind that the vapor barrier issue, like most of these issues, depends on where you live and how cold it gets.  (Also on how drafty the house is otherwise, as that affects inside humidity.) You need to take all of these factors into account.

Response:

… Okay.  But my experience is just the opposite.  I think it depends how bad the windows are.  But recognize that walls are the least likely place for insulation value according to the "experts". One thing to keep in mind is that blowing insulation into empty walls creates a significant draft/infiltration barrier in addition to the actual insulation added.  

Not in my experience. Sorry.  Have you ever done this upgrade?  I have — three times in all permutations and combinations. Also, comfort depends a lot on the evenness of the temperature, and both insulation and well-sealed windows help in terms of eliminating cold spots and drafts in the house.  

Windows make far more a difference. Which one will be most effective depends in large measure on which is worse to begin with.  Also, doing a halfway job on both is probably better that just fixing one or the other, since eliminating drafts from one source doesn’t do much good if the other source is still leaking badly.

Poorly installed windows are FAR worse than poorly insulated walls. Tom             Need info on COTTAGES and CABINS?                http://www.cottageliving.com

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How do you provide an effective vapor barrier in old homes that you blow insulation into?  [snip] Dense-pack cellulose forms a very effective air and vapor barrier in walls. — Sam Remove IT to email. Visit  http://sites.netscape.net/pulaski3

So if your walls are constructed, from the inside out, Paint texture sheetrock framing (two by fours) tarpaper fir siding and I want to blow insulation into the cavity, I don’t need to worry about further vapor barriers? ( I am in Central Texas,  we do have humidity and heat deflection is the main concern) Pat

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You can weatherstrip windows. Makes a lot of difference, cheap. Replaceing windows is very expensive. For me, just storm windows cost 3 times as much as the wall insulation. I’m not saying windows replacements won’t help, just that other things are more cost effective. Bob

snip . – Hide quoted text — Show quoted text – Poorly installed windows are FAR worse than poorly insulated walls.

Response:

Thanks everyone for such comprehensive advice and opinions.  I have a follow up question.  Does anyone know of a formula for calculating the amount of BTU’s required to heat a 1800 sq. ft home ion Maryland?

You can make a fairly good estimate by observing your current furnace. If it is 100,000 BTU you can probably figure it’s 50-65K BTU output. Time the percent of time it runs on the coldest night, then take that percent of 50-65K.

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Replace the furnace.  You can plan for a "major expense" instead of an emergency. We had two quotes from several dealers – for 92% efficiency and for 96%. Then figured how long it would be for the cost difference to break even. We opted for 92%.  Include new transition and any duct upgrade. Consider a furnace mounted humidifier and "built-in water heater". We later replaced the windows and upgraded the wall insulation – one side at a time.  (Did all this when we re-sided due to a hailstorm.) Or – You could BUY OUR HOUSE.  We are moving to Lower Florida!  My closet will look bare – with one t-shirt and a pair of shorts. Getting older (and wiser) – but – it beats the alternative!

Response:

Thanks everyone for such comprehensive advice and opinions.  I have a follow up question.  Does anyone know of a formula for calculating the amount of BTU’s required to heat a 1800 sq. ft home ion Maryland?

See http://www.hvac-calc.com/ and download the free trial, then consider the $39 one-home version. John

Response:

One thing to keep in mind is that blowing insulation into empty walls creates a significant draft/infiltration barrier in addition to the actual insulation added.  Also, comfort depends a lot on the evenness of the temperature, and both insulation and well-sealed windows help in terms of eliminating cold spots and drafts in the house.  Which one will be most effective depends in large measure on which is worse to begin with.  Also, doing a halfway job on both is probably better that just fixing one or the other, since eliminating drafts from one source doesn’t do much good if the other source is still leaking badly.

Dan, How do you provide an effective vapor barrier in old homes that you blow insulation into?  How do you keep moisture from penetrating the walls from the inside, only to condense inside the insulation surrounding your structural lumber?  Ten years from now will you need to open the walls up for rot repair?  How much money will that save? These are all questions you must ask when retrofitting older homes. What seems simple and common-sense sometimes just isn’t. John

Response:

- Hide quoted text — Show quoted text – … Okay.  But my experience is just the opposite.  I think it depends how bad the windows are.  But recognize that walls are the least likely place for insulation value according to the "experts". One thing to keep in mind is that blowing insulation into empty walls creates a significant draft/infiltration barrier in addition to the actual insulation added. Not in my experience. Sorry.  Have you ever done this upgrade?  I have — three times in all permutations and combinations.

My parents did it in an 80-year-old farmhouse.  Seems to have worked. Also, comfort depends a lot on the evenness of the temperature, and both insulation and well-sealed windows help in terms of eliminating cold spots and drafts in the house. Windows make far more a difference. Which one will be most effective depends in large measure on which is worse to begin with.  Also, doing a halfway job on both is probably better that just fixing one or the other, since eliminating drafts from one source doesn’t do much good if the other source is still leaking badly. Poorly installed windows are FAR worse than poorly insulated walls.

Generally true, but I’ve seen some pretty porous walls as well.  The point is that balance is important.  You can get an amazing amount of draft through the electrical outlets on an outside wall, for instance, probably enough to equal a window in some cases.

Response:

If current windows are in ok shape and you like them well enough I would not recommend replacing them for cost savings unless you live in the very far north.  $400-800 dollars per opening for decent windows (installed)  times how many did you say?  Figure up the total cost, figure 10-15% (max) savings in heating costs, run the numbers and see how long the payback is.  Here, heating cost is $800 per year, 15% savings is $120/year.  Twenty windows at $400 each would run $8000. Payback is 8000 / 120 = 67 years, and that is assuming no cost of money (interest).  Not a good investment. I agree with previous posters that your current furnace efficiency is probably 50% or even less. They don’t last forever(45 years is old) and you probably will need a new one soon.  Replacing the furnace now is a good idea.  Do it in the non-heating season–not on an emergency basis.  I recommend the 80-82% efficient models, not the 90-95% condensing models, again for payback considerations.  The 80’s are simpler, cheaper, fewer parts to break when you need it the most.  Get prices for both, calculate the fuel savings difference between the two, and run the payback numbers yourself (don’t just take the sales person’s figures at face value).  You may be surprised.  Also, if your furnace doesn’t run 24 hours a day on the coldest days it is too big. Consider getting a smaller one and save yourself even more money, in both purchase and operating costs. Personally, I was a little put-off by the previously mentioned DOE web site.  It seems to be run by a bunch of home improvement contractors and appliance retailers.  Lots of flash and no real data. John – Hide quoted text — Show quoted text -My home has a 45 year old 100,000 btu natural gas forced air furnace. The furnace works fine but I’m considering replacing it with a furnace with a 80 or 92% efficiency rating hoping to cut back on my energy cost.  Does any one know what effect if any replacing my furnace will have on my utility bill or are replacement windows a better energy conservation investment?  Any advice would be deeply appreciated.

Response:

… Generally true, but I’ve seen some pretty porous walls as well.

I suspect wall porosity is not what you mean:  try permeability.  And even then, there is very little that gets through plaster, gypsum board or even decent wood.  The point is that balance is important.  You can get an amazing amount of draft through the electrical outlets on an outside wall, for instance, probably enough to equal a window in some cases.

Very true.  Drafts could easily add to a full open window. Those little foam gaskets are a heck of a lot easier to install that either wall insulation or new windows! Tom             Need info on COTTAGES and CABINS?                http://www.cottageliving.com

Response:

I did it and it sure made a difference. You could FEEL the difference. The house really felt warmer and less drafty. And it is a lot cheaper than windows. Okay.  But my experience is just the opposite.  I think it depends how bad the windows are.  But recognize that walls are the least likely place for insulation value according to the "experts".

One thing to keep in mind is that blowing insulation into empty walls creates a significant draft/infiltration barrier in addition to the actual insulation added.  Also, comfort depends a lot on the evenness of the temperature, and both insulation and well-sealed windows help in terms of eliminating cold spots and drafts in the house.  Which one will be most effective depends in large measure on which is worse to begin with.  Also, doing a halfway job on both is probably better that just fixing one or the other, since eliminating drafts from one source doesn’t do much good if the other source is still leaking badly.

Response:

My home has a 45 year old 100,000 btu natural gas forced air furnace. The furnace works fine but I’m considering replacing it with a furnace with a 80 or 92% efficiency rating hoping to cut back on my energy cost.  Does any one know what effect if any replacing my furnace will have on my utility bill or are replacement windows a better energy conservation investment?  Any advice would be deeply appreciated.

There are a number of on-line resources to help make these decisions. See:  Lawrence Berkeley Natl Lab (DOE) http://hes.lbl.gov/  Efficient Windows Collaborative http://www.efficientwindows.org/ Much depends on where you live since windows can save on cooling, but only if you run a/c. Winter temperature also enters the equation. I live in Seattle where yearly average max (summer) is 75F and avg min (winter) is 35F, so we don’t use A/C and it seldom gets terribly cold (just wet). From the second site, I found that I’d save something like $5 or so per window per year to replace my traditional single-pane double hung windows. From an aesthetic point of view, nothing less than a $400 window would do (we are trying to preserve an old Victorian). So for me it was a no brainer to save the money on windows and replace our ancient coal-converted-to-oil furnace. Of course, if I had the money to do both, I would, but then I’d do a lot of things. Eric Salathe Seattle WA

Response:

Thanks everyone for such comprehensive advice and opinions.  I have a follow up question.  Does anyone know of a formula for calculating the amount of BTU’s required to heat a 1800 sq. ft home ion Maryland? – Hide quoted text — Show quoted text – My home has a 45 year old 100,000 btu natural gas forced air furnace. The furnace works fine but I’m considering replacing it with a furnace with a 80 or 92% efficiency rating hoping to cut back on my energy cost.  Does any one know what effect if any replacing my furnace will have on my utility bill or are replacement windows a better energy conservation investment?  Any advice would be deeply appreciated. There are a number of on-line resources to help make these decisions. See:  Lawrence Berkeley Natl Lab (DOE) http://hes.lbl.gov/  Efficient Windows Collaborative http://www.efficientwindows.org/ Much depends on where you live since windows can save on cooling, but only if you run a/c. Winter temperature also enters the equation. I live in Seattle where yearly average max (summer) is 75F and avg min (winter) is 35F, so we don’t use A/C and it seldom gets terribly cold (just wet). From the second site, I found that I’d save something like $5 or so per window per year to replace my traditional single-pane double hung windows. From an aesthetic point of view, nothing less than a $400 window would do (we are trying to preserve an old Victorian). So for me it was a no brainer to save the money on windows and replace our ancient coal-converted-to-oil furnace. Of course, if I had the money to do both, I would, but then I’d do a lot of things. Eric Salathe Seattle WA

Response:

I did it and it sure made a difference. You could FEEL the difference. The house really felt warmer and less drafty. And it is a lot cheaper than windows. Bob

– Hide quoted text — Show quoted text – Before the windows, weatherstripping, attic insulation, and wall insulation are more cost effective improvements, if they are inaduaquate. I’d question the value of wall insulation.  And so does the NRC and DOE. Tom             Need info on COTTAGES and CABINS?                http://www.cottageliving.com

Response:

I did it and it sure made a difference. You could FEEL the difference. The house really felt warmer and less drafty. And it is a lot cheaper than windows.

Okay.  But my experience is just the opposite.  I think it depends how bad the windows are.  But recognize that walls are the least likely place for insulation value according to the "experts". Tom             Need info on COTTAGES and CABINS?                http://www.cottageliving.com

Response:

Before the windows, weatherstripping, attic insulation, and wall insulation are more cost effective improvements, if they are inaduaquate. Bob

– Hide quoted text — Show quoted text – My home has a 45 year old 100,000 btu natural gas forced air furnace. The furnace works fine but I’m considering replacing it with a furnace with a 80 or 92% efficiency rating hoping to cut back on my energy cost.  Does any one know what effect if any replacing my furnace will have on my utility bill or are replacement windows a better energy conservation investment?  Any advice would be deeply appreciated.

Response:

Before the windows, weatherstripping, attic insulation, and wall insulation are more cost effective improvements, if they are inaduaquate.

I’d question the value of wall insulation.  And so does the NRC and DOE. Tom             Need info on COTTAGES and CABINS?                http://www.cottageliving.com

Response:

New windows are great, but the fact is the pay back on them is typically very long (10 – 30 years on most "study homes").  A 90%+ furnace will have a much greater impact on your energy savings, up to 20% on your heating bill. With regard to your windows … make sure they are well maintained and caulked to seal against air leaks, this will maximize energy savings in this area.  If you have a need for new windows for other reasons, go for it, you will have some small energy savings, but mainly because of the absence of air leaks, which once again can typically be addressed on your current windows. Some key features of a quality, energy efficient gas furnace:    1.  Stainless steel heat exchanger    2.  Lifetime warranty on the heat exchanger    3.  Direct drive variable speed blower    4.  Electronic or hot surface ignition    5.  Sealed combustion    6.  A minimum of 90% AFUE rating — R. Fromm, Customer Service Efficiency Connection / EnergyMatch "Energy Saving Ideas, Contractors who can help" www.energymatch.com

– Hide quoted text — Show quoted text – My home has a 45 year old 100,000 btu natural gas forced air furnace. The furnace works fine but I’m considering replacing it with a furnace with a 80 or 92% efficiency rating hoping to cut back on my energy cost.  Does any one know what effect if any replacing my furnace will have on my utility bill or are replacement windows a better energy conservation investment?  Any advice would be deeply appreciated.

Response:

    Can’t say from here, I don’t know where you live, how old the furnace is (if it is 40 years old it is past due for safety and reliability reasons) or the condition or design of the windows (are they original?) — Dia ’s Muire duit Joe M

Response:

Both would be great, but if you can only affor one, do the windows first, it will save you money 365 days a year. We have a chart at http://www.superior-air.com – Hide quoted text — Show quoted text – My home has a 45 year old 100,000 btu natural gas forced air furnace. The furnace works fine but I’m considering replacing it with a furnace with a 80 or 92% efficiency rating hoping to cut back on my energy cost.  Does any one know what effect if any replacing my furnace will have on my utility bill or are replacement windows a better energy conservation investment?  Any advice would be deeply appreciated.

Response:

My home has a 45 year old 100,000 btu natural gas forced air furnace. The furnace works fine but I’m considering replacing it with a furnace with a 80 or 92% efficiency rating hoping to cut back on my energy cost.  Does any one know what effect if any replacing my furnace will have on my utility bill or are replacement windows a better energy conservation investment?  Any advice would be deeply appreciated.

Probably your current furnace is under 70%.  Let’s say 60.  If you replace it with an 85% unit then you’ll save about 30% on heating costs. How much windows will help depends on where you live and how bad the current ones are.  You first want to do basic weatherstripping and make sure that insulation is adequate.  If those are already covered then consider the windows.

Response:

My home has a 45 year old 100,000 btu natural gas forced air furnace. The furnace works fine but I’m considering replacing it with a furnace with a 80 or 92% efficiency rating hoping to cut back on my energy cost.  Does any one know what effect if any replacing my furnace will have on my utility bill or are replacement windows a better energy conservation investment?  Any advice would be deeply appreciated.

Well, I don’t think there is any question about which one will give you a higher ROE.  A 45 year old furnace is ***OLD***, and guaranteed to be not efficient.  According to consumers reports, it would take on average about 20 years to recoup the investment in new windows.  Now, I guess that their "average" is exactely that…In other words ever curcumstance is different. But, on the otehr hand, Windows don’t just give you better energry efficiency, but the also add a LOT to the look of the house.  I have been changing over the windows in my house over the past 2 years, partly for energy, but more for looks.  I am using all double hung, with square grids and low-e argon. My new windows are so nice to look at, I can look at them all day. If you are looking purely for ROE go for the furnace, specially since(as another person said) it may just quit on you one day, and you will have to panic buy(NOT a good thing)..  But if you want to "see" your investment, go for the windows. Victor

Response:

My home has a 45 year old 100,000 btu natural gas forced air furnace. The furnace works fine but I’m considering replacing it with a furnace with a 80 or 92% efficiency rating hoping to cut back on my energy cost.  Does any one know what effect if any replacing my furnace will have on my utility bill or are replacement windows a better energy conservation investment?  Any advice would be deeply appreciated.

Do both!!! The old relic is over double a typical life expectancy. Its annual efficiency is probably barely 50%. If your gas does what ours is supposed to, your bill is going way up. Just going to an 80% model makes a world of difference. The savings between the 80 and the 90 isn’t as dramatic. Since the furnace is well overdue to be booted, I’d start there then work towards tightening up your house. If the furnace faces a major failure, you’ll probably dispose of it anyway, why wait for that to happen, probably in very cold weather where you’ll have to do something in a panic. — HVAC Advice, Pictures, Links… http://www.geocities.com/~johnmills http://www.appelheat.com alt.hvac Charter, FAQ, Links… http://home.att.net/~alt.hvac/

Response:

My home has a 45 year old 100,000 btu natural gas forced air furnace. The furnace works fine but I’m considering replacing it with a furnace with a 80 or 92% efficiency rating hoping to cut back on my energy cost.  Does any one know what effect if any replacing my furnace will have on my utility bill or are replacement windows a better energy conservation investment?  Any advice would be deeply appreciated.

Response:

Question:

The typical 80% furnaces are reportedly noisy. Lennox makes a 78% or something (WhisperHeat, I think) that is supposed to be quiet, but at expense of a bit of efficiency. The Lennox dealer I spoke with also bragged on them for reliability, as it’s an older well-proven design. The typical 90% furnace is fairly quiet, but a complex beast (for instance it has a sump pump). It vents via PVC and emits steam out the side of your house (which bothers some folks). It also needs well filtered air because of fine tubes in the heat exchangers, so consider an electronic air cleaner or at least use pleated media air filters.

Hmm … that doesn’t square at all with the experience we’ve had with a 90%+ Amana in our new house. This furnace is quieter than the old 80%ish Rheem we left in the previous house (could be ductwork, but …), sends smoke up the stack, and requires no electronic air cleaner or pleated-media filters (though we like using 3M’s Filtrete filter because it pulls a lot of gunk out of the airstream) (note: I work for 3M, but not for the home-improvement group). is doing during a ramp, making override a pain. Still, that is a minor complaint; I’d buy Honeywell again.

Agreed. We’ve had Honeywell electronic thermostats in three houses now and have never been disappointed. — "This is only temporary — unless it works!" — Red Green Steve & Joanne Dropkin: change .not to .net in the address!

Response:

If I had it to do over again I would not buy a 90+ unit.  We bought an Intertherm which has been nothing but a headache.  I think the unit was made by Rheem for Intertherm (Nordyne).  Each of the past two years we have had problems [...]

I had a Trane XE-90 gas furnace installed five years ago along with a high efficiency 3-ton air conditioner, and have had no problems at all with either one.  The furnace is quieter than the old one that it replaced, and the Trane units have saved me a lot of money on my utility bills. So, not all high efficiency furnaces are troublesome. But, I had an 80% efficient gas furnace installed in my previous house. It was a small Cape Cod with the original 1949 furnace.  The HVAC guy told me that since it was a small house, my gas bill would not be much cheaper with a 90% furnace compared to an 80%, and it wouldn’t justify the higher cost of the 90% furnace. – Mary Ryan

Response:

The type of furnace you want will depend on your climate.  If you live in Minnesota, a high-efficiency unit might be worthwhile, but if you live in a milder climate, the higher up-front and maintenance costs are not likely to be off-set by lower utility bills.  About 8 years ago, I bought a 78% Lennox WhisperHeat furnace which has given no trouble at all.  It is a fairly simple furnace, with a spark igniter and flue damper, but no pumps or other doo-dads.  If you want to use your furnace fan for air conditioning, you will want a dual speed blower, which may be standard on the Lennox WhisperHeat.  A higher blower speed in the summer helps lift cool air to the upper floors of the house, while a lower winter speed is quieter and adequate to circulate warm air.  The blower speed changes automatically when the furnace switches from heating to cooling mode. – Hide quoted text — Show quoted text – The typical 80% furnaces are reportedly noisy. Lennox makes a 78% or something (WhisperHeat, I think) that is supposed to be quiet, but at expense of a bit of efficiency. The Lennox dealer I spoke with also bragged on them for reliability, as it’s an older well-proven design. The typical 90% furnace is fairly quiet, but a complex beast (for instance it has a sump pump). It vents via PVC and emits steam out the side of your house (which bothers some folks). It also needs well filtered air because of fine tubes in the heat exchangers, so consider an electronic air cleaner or at least use pleated media air filters. I’ve heard quite mixed reports on variable output (including from knowledgeable salespeople). They run more often and blow cooler air. On the down side, they blow air around and make noise more often, and the cooler air may not be to everybody’s taste. On the up side the temperature should allegedly be a bit more constant, especially in a house with poorly designed ducting or drafts, because the air is mixed better. Variable output furnaces are, of course, more expensive to repair. I have heard very mixed reviews of Lennox, but perhaps some of the negative comments are based on their pulse furnaces. Carrier, Trane and Bryant all have had good recommendations posted here. We have a Bryant; it’s only a few months old, no problem so far. One friend has a Lennox and likes it but it had some problems in the first year. Make sure you get a good electronic thermostat to go with your furnace. We like our Honeywell because it holds a very steady temperature and has a fairly reasonable interface. However, it has a rather poorly implemented feature (that fortunately can be disabled): to prevent overshoot when switching from a cooler period to a warmer one it ramps up over an hour or so. The ramp time varies and we sometimes find ourselves too warm too early in the morning. Also, its display doesn’t properly show you what it is doing during a ramp, making override a pain. Still, that is a minor complaint; I’d buy Honeywell again. — Rusell Shortly I will have to decide on a gas furnace.  I will be most likely getting an AC system as well (later on). The options I see are: regular 80% furnace (recommended by some solid HVAC people; the kless electronics it has the longer it will last) regular 90% furnace – recommended by sales people for thgouse with not very hight budgets dual speed 90% furnace – recommended by sales people for thouse who have the buck and want the best. I wouldn’t mind spending a bit more if it gives me something (dual 90%) but I get the point of the old good HVAC contractors as well. Does anyone know how much you get and how much you lose by going with the more expensive models?

Before you buy.

Response:

The typical 80% furnaces are reportedly noisy. Lennox makes a 78% or something (WhisperHeat, I think) that is supposed to be quiet, but at expense of a bit of efficiency. The Lennox dealer I spoke with also bragged on them for reliability, as it’s an older well-proven design. The typical 90% furnace is fairly quiet, but a complex beast (for instance it has a sump pump). It vents via PVC and emits steam out the side of your house (which bothers some folks). It also needs well filtered air because of fine tubes in the heat exchangers, so consider an electronic air cleaner or at least use pleated media air filters. I’ve heard quite mixed reports on variable output (including from knowledgeable salespeople). They run more often and blow cooler air. On the down side, they blow air around and make noise more often, and the cooler air may not be to everybody’s taste. On the up side the temperature should allegedly be a bit more constant, especially in a house with poorly designed ducting or drafts, because the air is mixed better. Variable output furnaces are, of course, more expensive to repair. I have heard very mixed reviews of Lennox, but perhaps some of the negative comments are based on their pulse furnaces. Carrier, Trane and Bryant all have had good recommendations posted here. We have a Bryant; it’s only a few months old, no problem so far. One friend has a Lennox and likes it but it had some problems in the first year. Make sure you get a good electronic thermostat to go with your furnace. We like our Honeywell because it holds a very steady temperature and has a fairly reasonable interface. However, it has a rather poorly implemented feature (that fortunately can be disabled): to prevent overshoot when switching from a cooler period to a warmer one it ramps up over an hour or so. The ramp time varies and we sometimes find ourselves too warm too early in the morning. Also, its display doesn’t properly show you what it is doing during a ramp, making override a pain. Still, that is a minor complaint; I’d buy Honeywell again. — Rusell – Hide quoted text — Show quoted text – Shortly I will have to decide on a gas furnace.  I will be most likely getting an AC system as well (later on). The options I see are: regular 80% furnace (recommended by some solid HVAC people; the kless electronics it has the longer it will last) regular 90% furnace – recommended by sales people for thgouse with not very hight budgets dual speed 90% furnace – recommended by sales people for thouse who have the buck and want the best. I wouldn’t mind spending a bit more if it gives me something (dual 90%) but I get the point of the old good HVAC contractors as well. Does anyone know how much you get and how much you lose by going with the more expensive models?

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: The typical 80% furnaces are reportedly noisy. Lennox makes a 78% or : something (WhisperHeat, I think) that is supposed to be quiet, but at : expense of a bit of efficiency. The Lennox dealer I spoke with also : bragged on them for reliability, as it’s an older well-proven design. This is soooo bullshit. We have had MORE trouble with our Lennox in the past 5 years than with the previous furnaces in FORTY years. HELL will freeze over before I *EVER* buy another Lennox HEATING product. : The typical 90% furnace is fairly quiet, but a complex beast (for instance : it has a sump pump). It vents via PVC and emits steam out the side of your : house (which bothers some folks). It also needs well filtered air because : of fine tubes in the heat exchangers, so consider an electronic air : cleaner or at least use pleated media air filters. : I’ve heard quite mixed reports on variable output (including from : knowledgeable salespeople). They run more often and blow cooler air. On : the down side, they blow air around and make noise more often, and the : cooler air may not be to everybody’s taste. On the up side the temperature : should allegedly be a bit more constant, especially in a house with poorly : designed ducting or drafts, because the air is mixed better. Variable : output furnaces are, of course, more expensive to repair. : I have heard very mixed reviews of Lennox, but perhaps some of the : negative comments are based on their pulse furnaces. Carrier, Trane and : Bryant all have had good recommendations posted here. We have a Bryant; : it’s only a few months old, no problem so far. One friend has a Lennox and : likes it but it had some problems in the first year. : Make sure you get a good electronic thermostat to go with your furnace. We : like our Honeywell because it holds a very steady temperature and has a : fairly reasonable interface. However, it has a rather poorly implemented : feature (that fortunately can be disabled): to prevent overshoot when : switching from a cooler period to a warmer one it ramps up over an hour or : so. The ramp time varies and we sometimes find ourselves too warm too : early in the morning. Also, its display doesn’t properly show you what it : is doing during a ramp, making override a pain. Still, that is a minor : complaint; I’d buy Honeywell again. Honeywell is one of the better brands. Hunter sucks the big wet one. : — Rusell

: Shortly I will have to decide on a gas furnace.  I will be most likely : getting an AC system as well (later on). : : The options I see are: : : regular 80% furnace (recommended by some solid HVAC people; the kless : electronics it has the longer it will last) : regular 90% furnace – recommended by sales people for thgouse with not very : hight budgets : dual speed 90% furnace – recommended by sales people for thouse who have the : buck and want the best. : : I wouldn’t mind spending a bit more if it gives me something (dual 90%) but : I get the point of the old good HVAC contractors as well. : : Does anyone know how much you get and how much you lose by going with the : more expensive models? —

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If I had it to do over again I would not buy a 90+ unit.  We bought an Intertherm which has been nothing but a headache.  I think the unit was made by Rheem for Intertherm (Nordyne).  Each of the past two years we have had problems with the inducer fan which takes the moist air from the furnace and sends it outside the house.  Condensation in vacuum lines attached to the fan were causing it to shut off last year even causing a scary back fire one time.  This year the fan is shot, it is leaking all over the side of the furnace and the bearing is going, I have to hit it to get it to start.  We have been trying for four weeks to get service on a part supposedly covered under warrenty but nobody wants to deal with it! We are on our third contractor trying to get this part which is an external bolt on unit that without which the unit does not operate….. So take it from somebody that spent six grand and counting on a heater that does not work, keep it simple and go for a popular brand so you have lots of choices for service.  Even when covered under  a warranty, you still pay labor and just wait to see how much a warrenty repair ends up costing you assuming you are more fortunate than me and can even find someone to do the service.  The money saved on energy bills will not make up for the lousy service available out there.

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Shortly I will have to decide on a gas furnace.  I will be most likely getting an AC system as well (later on). The options I see are: regular 80% furnace (recommended by some solid HVAC people; the kless electronics it has the longer it will last) regular 90% furnace – recommended by sales people for thgouse with not very hight budgets dual speed 90% furnace – recommended by sales people for thouse who have the buck and want the best. I wouldn’t mind spending a bit more if it gives me something (dual 90%) but I get the point of the old good HVAC contractors as well. Does anyone know how much you get and how much you lose by going with the more expensive models? Thanks. Ian

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I came across the following news story: NOW PAINT CAN HEAT UP YOUR HOME A paint that turns electricity into heat at half the cost of traditional radiators has been developed in France. The paint was developed by Giles Thuney and J_C Sinigaglia in Marsellie. "With a car battery connected, it take 2 minutes to heat to 20