Current Furnace BTU rating method changed from earlier method!!!!!

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On Sat, 29 Jan 2011 12:00:39 -0600, The Daring Dufas

It's better not to go looking for trouble. You start out responsible for the AC, and you don't need responsibilty for the whole house.

Let me see what they say.
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The low monthly rate is 8 dollars plus tax, which is low for some, but I see it as 96 dollars a year every year,and there's a 150 dollar removal charge for cancelling in the first year.
Plus everything I have is old, so I won't even collect much. I want this to save myself the headache of replacing things, plus I like everything I own. It's like they are family.
The electric company one might be better than the Square-Ds (you need two of the cheaper one, one for each leg) or even the Intermatic one for 100 dollars, or not. ;-)

Thank you TDD and Trader and James for all the help.
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Looks like you figured this racket out. You can buy one for $100 to 125 and if you can put in a circuit breaker, you can install it yourself. You can compare the ratings, IF you can even find the ratings for the one the electric company rents to you. My bet is that the Intermatic is as good as, or better than theirs. They all use MOVs and there is no lock on the technology or what it takes to make one.

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I recently replaced my upstairs 2 1/2 ton split ac. It was a bit under a grand for new goodman outside unit and new cased coil. I installed both. I did the 90k gas furnace downstairs with the new, damaged in shipping = dented a little on one corner, fridgedare gas furnace for $400 from a freight liquidator, plus $50 or so for bits and pieces. I've got a couple hundred in a set of guages and a bargain vacuum pump. Those have come in handy like when one of my trane heat pumps at our lake house cracked a small copper line. I soldered a scrap of copper over it with silver solder, vacuumed and recharged. Cost to me $50 in r22. So yes warranty is an issue but I've saved so much that I don't care so much about warranty. Besides they hardly ever break in the warranty period. Trane was 6 years old when it broke.
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On Thu, 27 Jan 2011 05:42:18 -0800 (PST), snipped-for-privacy@optonline.net wrote:

It's either that gas IS different from oil or that some change occurred beween 32** years ago and 27 years ago. Somehow I think you're right, but I don't know why I think that.
** Mine is really closer to 32 now.

Of course since gas furnaces are so much more efficient now, your input BTU requirement would go down, even as your output btu requirement remained the same. If you went from 70 to 95 efficient that's more than 33% more efficient, so you could go down 33% in input. If you had 80 and went to 95, that is an amost 20% increase in efficiency, so I'm not sure it would make up for a 33% decrease in input.

None of the 4 guys who came out here measured the load either. (The first guy never got back to me with a price, afaik?)

I don't think mine ever does that. What is their reason to go so small, to save money on the furnace, or something better, like the reason one shouldn't have too big an AC unit, because it makes one feel clammy?

Good point.

I'm not sure how long mine takes, but it's never seemed like too much. (I tend to leave my coat on when I come in from the cold, even when it's warm inside.)

I don't think I've ever waited more than an hour, probalby not more than 30 minutes, but then again, I have 85,000 BTUS for a 1400 ft2 house (plus basement). I don't know how much they would recommend for me now, but the architect said 85K.

I think you're right.

Well, until your reply, I thought it was too small for me, but maybe it's not. I was mostly dubious about this kind of story. Of course it must happen once in a while, but once one has read it somewhere, he might want to use it whenever he has a clean-looking furnace. Or maybe dirty ones can be cleaned.

This is the first item. And while the ad never quite says he's homeowner, it comes close, yet his ebay id is abcabchomeimprovements. I wonder if he put in the new one and took out the old one, which would be okay, except it wouldn't be possible to talk to the guy who actually knows how old it is. Maybe it was used more than 4 months.

I don't want to take mine out until spring, and I really don't have the space to store a second one at my house until then. I have a storage locker that would hold it, but that doubles the loading and unloading work involved. So in a way I shouldn't even read the auctions before spring, but I want to know what is out there.
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LOL. I had one guy calling me every day to follow up. He was almost 2x higher than the lowest guy. The lowest guy was there to answer any questions, but never followed up beyond that. And then there was the guy recommended by a good friend. A neighbor of his. Took him a week to come buy and look. Then said he'd work up a quote and never heard from him again. I think the best ones were the guys that sat down at my kitchen table and wrote out the quote on the spot. Geez, it aint' rocket science. One would think they could have a binder with pricing info and all just do it on the spot. It's basically just a few line items.

If it's oversized in a major way, I think the issue is it won't have enough run time to even out the heat in the house. It could kick the thermostat off and you'd have wider variation, room to room. Also, possibly notice hot spots when it's running compared to correctly sized one. Still, the furnaces themselves are generally the same efficiency, within the same product line. So, if you have one that is 20% oversized, I don't see any efficiency issues, or increased cost to run it. You get less heat out, it runs longer and winds up burning the same amount of gas. If anything, oversizing might mean it costs less, because you could have less blower run time, assuming the blower sizes are the same.

It depends on how far it's set back. Mine comes up at about 5.25deg an hour when it's in the teens outside.

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On Thu, 27 Jan 2011 09:20:54 -0800 (PST), snipped-for-privacy@optonline.net wrote:

Yeah. They have the same set of numbers to add up for everyone and for most they probably push 2 or 3 oil furnace and 2 or 3 gas furnaces.

Okay, good reasons not to get too big.

I've never checked on that. It sounds like a good number to know, so maybe I will.
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I agree 100%
.. if you know the BTU OUTPUT of your current furnace and you know how long the on/off cycles are and how well your home is heated under various conditions, you will get a much more accurate result compared to starting from a scratch estimation based on square footage etc..
Mark
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On Thu, 27 Jan 2011 05:42:18 -0800 (PST), snipped-for-privacy@optonline.net wrote:

What you WANT is a 2 stage furnace. It runs on low most of the time, but if it gets cold enough that the furnace runs more than, IIRC, 20 minutes, it kicks onto high. I just dug out the manual and checked the operation - with single stage thermostat (which is what I have) 1)Thermostat calls for heat 2)Inducer motor starts on high High fire solenoid energizes 3)After 3 seconds of pre-purge the pilot valve opens and the ignitor starts to warm up 4)After the pilot lights, the main burners energize on high and light 5)Timed from the opening of the gas valve,the control will delay the Heat Fan On Delay Time before switching the inducer to low speed, de-energizing the high fire solenoid and the fan switches to low speed. 6) Timed from the initial thermostat call for heat, if the call for heat still exists after the low fire delay time(12 minutes) expires, the inducer switches to high speed, the high fire solenoid energizes, and the fan switches to high heat speed.
My furnace is a NTP6050fb, rated at input of 50,000 and 35,000 btu, and output of 40,000 and 28000 btu. It is the smallest "residential" furnace I could buy here in Ontario and the dealer said it is still oversized for my Aprox 20X30 foot 2 story home with finished basement in central Ontario. Last week when we had -26 degree temperatures the furnace ran about 8 hours a day - so I think I'd believe him that the furnace is oversized. Last year's total gas bill was about $700.
A few times in our recent cold-snap I noticed the inducer fan kicking on to high, which virtually never happens during our "normal" winter weather.
We had 2 windows replaced during that cold snap - so had the furnace shut off for about 4 hours (no use heating the great outdoors) and after turning the furnace back on, we were back up to temperature in well under an hour.
We set back the temperature every night - and it is a very rare occurrence to have the furnace run more than 20 minutes in the morning to bring it back up to temperature.

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On Jan 27, 5:45pm, snipped-for-privacy@snyder.on.ca wrote:

While I think two stage can be an advantage, at least in some applications, I think dumb two stage, which is what you have is, welll, just dumb, at least for most people.
I come home earlier than expected to a house that is now at 60F. Why should I sit around in the cold while the furnace fires at only 70% of capacity for the first 12 mins? Or how about each night when it has to recover from setback? It takes longer to recover each day because it wastes 12 mins at the lower output. Consequently, each day the setback period is longer than it could be.
To do 2 stage right, you need a 2 stage thermostat. The thermostat, which has all the info needed to make the right decision, then chooses whether to fire at 100% or 70%. Consequently, in the above two situations, it fires at 100%. In periods where it's just maintaing temp and it's moderate out, then it fires at 70%.
But even that isn't enough. You have to make sure that the furnace you buy supports a two stage thermostat. Some do not and work as you described. Some allow you to choose how you want it to work, with 2 stage thermostat or 1 stage thermostat using the time delay method. Some let you set the time delay period to like 6mins or 12mins, etc. IMO a lot of these get installed by lazy installers who are too lazy to run an extra thermostat wire and do it right. OF course there are cases where it could be difficult to do that and the timed option might start to make sense.
IMO, two stage is way over sold, based on a lot of myths. On most days, whether it fires at 100% or 70% makes no difference, yet they get sold on claiming that it will save LOTS of money on energy usage. What usage exactly? The furnace is 95% efficient whether it runs at 70% or 100%. At 70% it just uses gas at a lower rate, but runs longer. In the end, it uses virtually the same amount. But it does run the blower longer, using more electric.

So yours is a good example of where two stage makes sense. Yours is an atypical situation. With a small house, even the smallest furnace at 100% would be over sized.

It goes up about 5 to 5.25 deg an hour here at my house. Big difference. See why I wouldn't want a two stage that spends the first 12 mins at 70%?

I set it back from 67 to 60 and It's about an hour and a half here. And keep in mind, my furnace runs probably 50-60% of the time on the coldest days of the typical winter. You can see why I'm not a believer in the common advice that your furnace should run 100% of the time on the coldest days. If I did that, you can imagine the recovery time.
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On Fri, 28 Jan 2011 05:25:36 -0800 (PST), snipped-for-privacy@optonline.net wrote:

For a little over 200 bucks I could add a 2 stage thermostat if I thought the extra cost and complexity would buy me anything important.
I figured it was a waste of money, for me.

Nothing to do with lazy installer - they'd GLADLY charge a few hours extra to pull in the 6 wire cable (which my house already has, by the way - 4 wire for heat/cool is minimum)

This is where you are wrong. Particularly with an 80+ instead of a 95% efficient furnace. If a furnace is "too big" it runs short times, and during the warm-up and cool-down it is NOT as efficient as during steady run. As for running the blower longer, mine runs all the time, for the cost of roughly 1 100 watt bulb.

And in MOST houses, the furnace supplied by the builder is oversized. If it will take a house up from setback to full temperature in 5 minutes it is oversized by a minimum of 30%

what's the big deal?????

You should spend some money on insulation, and mabee seal up the cracks around the windows and doors.

than what you have right now - and with a properly sized 2 stage, likely less than that - because your low would be lower than you have now, and the high the same or slightly higher.
But hey, it's your house, your furnace, and your money - you can do as you please.
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On Jan 28, 3:19pm, snipped-for-privacy@snyder.on.ca wrote:

Around these parts, they don't quote furnace installs by the hour. They quote a price for a given furnace, installed. They might call out including a new thermostat, but none of the 4 quotes I got called out the specific thermostat. So, upon figuring out that they were one wire short of two stage happiness, what do you think they would likely do? Run new wiring, or set up the furnace as yours is, to run at the lower stage everytime first, for a given period? In fact, some 2 stage furnaces are of such stupid design, that they always run 10 mins at the low stage, no matter what the installer does.
As for 4 wires, whoopee de doo. That's the minimum you need for a single stage furnace and AC anyway.

What moron would buy a two stage furnace that is 80% in the first place?

Yes, I agree if a furnace is SIGNIFICANTLY over sized for the house, then it will result in short run times which are not as efficient. You basicly have a two stage furnace that runs almost like a single stage, on the low output because your house is too small for the furnace. But that isn't what we're talking about, now is it? We're talking about a furnace that is correctly sized for the house. I'd love to see all these energy savings due to two stages documented. Most people don't understand the simple fact that if you burn 70% of the gas, you wind up burning longer to get the same heat output and consume almost the same amount of gas. They see, wow 70 vs 100, that's a lot I'm saving....
Here's a research paper where they conclude that even the alleged 3% extra efficiency that the DOE tests attribute to two stage is really due to the fact that the test was not designed with two stages in mind. With the new proposed test procedure to correctly test two stages discussed, the supposed savings vanish.....
http://ees.ead.lbl.gov/bibliography/residential_two_stage_gas
"Overall, the DOE test procedure shows a reduction in the total site energy consumption of about 3% for two-stage compared to single-stage furnaces at the same efficiency level. In contrast, the 2006 ASHRAE test procedure shows almost no difference in the total site energy consumption. The 2006 ASHRAE test procedure appears to provide a better methodology for calculating the energy consumption of two-stage furnaces. The results indicate that, although two-stage technology by itself does not save site energy, the combination of two-stage furnaces with BPM motors provides electricity savings, which are confirmed by field studies."
I'd be happy to see any research that shows two stages are more efficient overall and save any significant amount of money.
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On Fri, 28 Jan 2011 15:19:04 -0800 (PST), snipped-for-privacy@optonline.net wrote:

Exactly what I said - I said 4 is the minimum for heat/cool and mine has 6. Learn to read.

I resent that you self righteous fool - I bought the furnace I bought for good reason.Condensing furnaces are much more trouble prone and have, generally, a significantly shorter life span. Also, with my 80+ % furnace costing $700 a year to heat the house (including hot water - so let's be really pessimistic and say the furnace costs $600 a year,) the difference between 80% and 95% is something like $95 per year savings. The difference at the time mine was installed was about $750.That's an 8 year payback. Assuming there is no problem with the furnace. I know LOTS of high efficiency condensing furnaces that have been replaced in under 10 years due to repeated failures. And the 80+% efficient furnace is supposedly running about 85% as installed - so the savings would likely be less, and the payback longer. Going to a DC blower over the standard AC blower saved me close to 4 times that much since I run the blower on low 24/7/52. I'm very happy with the furnace I bought, for the price.

they are installed in. I'm not talking McMansions here - I'm talking "normal" family sized homes owned by lower middle class to middle class folks to whom the cost of housing and heating is a significant issue, not "morons" as you would call them who think a big fancy house is an "investment".

Hey, I can give you numbers for my house. It ran 4 hours and 12 minutes on Tuesday, and 4 hours both wednesday and Thursday. It was down to -26C Monday night. It's run less than 4 hours today (it got up to -4C this afternoon) So my total heat loss today is approxemately 4X28000 = 112000 BTU, and my total fuel usage today was about 4*32000= 128000 BTU, or 128 cu ft of natural gas. (equivalent to less than a gallon of #2 fuel oil or Kerosene) (or 10 lbs of coal)

for comparing an 80+% to a 95% furnace in my "average" home. Can you show me a better than 8 year payback, and document the probability that the furnace would significantly outlast that payback period, making the purchase of the non-condensing furnace 8 years ago a "moron"'s decision? My furnace is now something like 8 seasons old, and I expect it to last at least another 16 - I don't figure I'll be around when it needs replacement the next time.

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On Jan 28, 10:48pm, snipped-for-privacy@snyder.on.ca wrote:

Supposedly is the key word here. According to whom, exactly is an 80% efficiency furnace suddenly 85% efficient, depending on how it's installed or used? I'd like to see a furnace manufacturer that specs it. I've looked at several different manufacturer's product lines and have seen no such distinctions. Just because some installer told you that and you believe it, doesn't make it true. I showed you a research report that says essentially, according to the DOE test procedures, you get a theoretical 3% advantage with 2 stage but that it's due to the test methodology. With the new proposed test methodology, you get basicly zippo.

Yes, I know how you talk about the miracle energy savings of that ECM blower. Which is why I was surprised that you'd buy an 80% furnace. I didn't know you actually had one.
Lets look at :
A - An 80%, two stage furnace, with ECM blower
B - A 93 or 95% efficiency, two stage furnace, with ECM blower
The cost difference is a few hunderd bucks. The essential difference is the addition of another heat exchanger and a draft inducer. And I don't know what's going on in Canada, but in the USA in many locations, today you can get utility rebates that at least eliminate that differential, if not more. If you bought it here last year, you'd get a 30% federal tax credit on the cost of the 95% furnace, including installation. If you bought the 80%, you'd get zippo.
It's also interesting how you draw lines in the sand about what constitutes acceptable tradeoffs. Apparently you have no problem with the increased cost, potential failure rate, potential increased service costs, for that ECM blower. Yet for some reason, an additional heat exchanger and small draft inducer blower, which can get you 19% more heat out for every dollar you put in, is unacceptable. And that efficiency is documented by the manufacturer. It's right in the data sheet, as opposed to the increase efficiency you "supposedly" get from two stage, which BTW, has it's own increased complexity issues.
Also regarding two stages, I can show you people that say they should NOT be used in large homes, because the blower runs so slow on first stage that it can be incapable of getting air to all parts of the house. So, while it might work great in your small house, it might not work so well in a 3000 sqft two story house. I looked into that a bit and it was interesting. The speeds that those blowers will run at when on first stage varies greatly from one manfacturer to another. With some, you can select it within a couple of choices, some are fixed.
Lets' take a 2000 CFM max air handler. On some furnaces it might run at 1600 for heat full output and 1300 for first stage. Another it could be 1600 for heat full output and 800 for first stage. That lower speed is for guys like you who want to run the blower 24/7 and are impressed with the low energy usage rate they can then quote on the spec sheet. But, if you have a large house, that speed might not get hot air to where it needs to go. And if you buy the wrong furnace, where you can't change it, you're screwed.

Then that is a problem with the furnace selection upon installation. You can just as easily oversize a two stage furnace for a house as you can a singe stage.

Which says nothing about efficiency of a two stage furnace vs a single stage furnace in a typical house, assuming both are correctly sized for the house.

My comments were based on making that decision today, upon which I thought the discussion thread was basicly centered. I don't know about what cost differentials were back then, but I'd suspect that it still would have been better to get a 93 or 95% furnace, instead of an 80% one.
And i base the savings of an 95% furnace to those of an 80% furnace on the figures that are right in the data sheet for the furnace. Put $1 of gas into the 95% furnace and you get 95cents worth of heat out of the furnace. Put $1 of gas in the 80%, and you get 80 cents out.

From everything I've read around here, I doubt you'll get 24 years out of a furnace installed 8 years ago. Haven't you seen people here talking about how all newer furnaces are not lasting as long as older one?Those 24 year numbers were achieved with furnaces from the 70's and 80's. Today, from everything I've seen, 15 years is more typical, even if you have a single stage, 80%. Like so many things, they just are not built to last as long.
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On Sat, 29 Jan 2011 09:01:48 -0800 (PST), snipped-for-privacy@optonline.net wrote:

efficiency furnace, and test documents the dealer had showed it to be approxemately 85% efficient when running in the mode mine is running in (timed low burn) with the specified temp rize across the heat exchanger etc. Since the company that installed it 8? years ago is no longer in business I cannot ask for copies of that documentation. It included all kinds of stack temperature and stack airflow measurements as well as gas-flow measurements.

My furnace HAS the draft inducer, which according to your statement above makes it "not" an 80% furnace - and as I stated, it was sold as an "80+%" furnace . It is identical to the condensing 94% furnace but with the second heat exchanger deleted.

I bought the furnace 8 years ago and got the full rebate available at the time.

As stated before, and above, my furnace DOES have an inducer blower. I chose NOT to have the secondary heat exchanger in my furnace because I have seen too many failures with the condensing heat exchanger and the required drainage systems - and the dealer I bought from agreed that the condensing furnaces at that time did not have as good a record as the non-condensing furnace, all else being the same.
With running the blower on low all the time, his figures showed the furnace I bought had a lower overall operating cost than a condensing furnace with a conventional blower. Their service records showed a very negligible increase in failure rate for the BDC blower over the AC blower, particularly on the smaller furnace(which uses the same electronics as the larger furnace, with a bigger blower motor - Mine is 1/2 HP, the larger units run 1HP on the same controller) The drive electronics are all over-spec for the motor installed and the load it drives.

And my furnace has a choice of 4 speeds for the continous run- from 600-1000cfm@0.10" static, and 8 speeds for heating and cooling ranging from 550 to 1350 cfm at 0.50" static. The speed setting is selected by the installer to obtain the proper heat rize across the heat exchanger at each output setting. In a larger house you would use a 1HP blower, with 1000 to 1750cfm constat at 0.10" static, and 800-2100 cfm at 0.50" static for heating and cooling. A similar spec (but different manufacturer) furnace installed in my daughter's 6 level condo handles the airflow just fine too.

No, on my furnace there are FOUR operational speeds programmed, constant,low fire, high fire, and cooling. As for buying the wrong furnace, you are accusing me of doing just that, when my furnace meets every requirement you say this type of furnace does not. You need to remember what I've learned a LONG time ago. You can NOT buy on price alone. You need to look at features and requirements, and balance them first - THEN look at price. If a (furnace or whatever) has the features required to meet your requirements, buying more features is a waste of money. If it does not have the features required, it is too expensive at any cost. If my heating costs were in the $2000 a year range, paying several hundred dollars more for a condensing furnace, even if it meant a possible reduction in lifespan of 3-5 years might make some sense (it could concievably save $400 a year in gas costs) but with a total gas useage of $700 including DHW, the extra cost vs advantage didn't make a compelling arguement.
Since I had determined years ago that I WOULD run a constant speed fan, the significant power reduction on low speed offered by the brushless DC fan notor made that "feature" a no brainer. No way was I going to install a furnace with a "conventional" blower motor as a replacement for the one I already had. Also,having a pretty good handle on the run-time of my original furnace, I KNEW I did not need a 50kbtu or higher furnace in my house under normal conditions - and the only way to get a roughly 30kbtu furnace was in a 2 stage unit - which had the advantage of also being able to handle the occaisional extreme cold without stress, and bring the house up to temperature quickly when needed.
I have had the furnace now for 8 years,and with the exception of a loose blower wheel on the inducer fan (which I repaired by myself at no cost) that started getting noisy at just over one year, it has been totally trouble free and has met or exceded all my expectations.

Yes you can - and you can be stupid and buy a Farrari to drive 2 blocks to the grocery store too.
We are not talking about being 100% clueless and stupid here. Many more furnaces are oversized in North America than undersized, and a 2 stage furnace of the correct size range gives all the advantages of a "properly sized" furnace with the advantage of an "oversized" furnace when you (need) it.
If you are going to just go and buy the cheapest furnace you csn get your hands on, and install it yourself, without setting it up properly, assuming it will do the job properly, you are a dreamer. And conversely, if you go out and buy the biggest gee-whiz-golly equipped furnace you can buy, assuming it will do the best job for you, you are also a dreamer.

And you tell me where I can buy a 28000 btu (or less) output furnace that is made for residential (not RV or mobile home) use.
Because I choose to insulate and seal a house rather than heat the outside world, I can get away with a much smaller furnace than if I had a drafty old barn of a house. And I don't even need the 3 bedrooms of my modestly sized home, much less a much larger home, what couple with no kids at home needs a 3000 square foot, or larger, home???

On what basis? a 10% improvement in efficiency would save at best $70 a year in operating costs - and if I forgo the brushless DC motor as recommended bu you guys, the operating cost of the 95% furnace would excede the operating cost of the furnace I now have.

My last furnace was still going strong at 30 years.With only a blower fan motor replacement and about 5 or 6 thermocouples.

That remains to be seen. If in 10 years from now it needs to be replaced, we will look at the available technology then and make a new decision. If in 5 or so years there is a great breakthrough in furnace technology that makes a convincing arguement to replace this furnace with something significantly better, at an acceptable price, I'll replace it then.
8 years ago there was no convincing arguement to do any different than what I did - and other than the fact that non-condensing furnaces are now almost non-existant here, and the rebates likely differentiate between the two, I'd quite likely make the same descision today.
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On Jan 31, 1:54pm, snipped-for-privacy@snyder.on.ca wrote:

Since he believes that a two stage furnaces becomes 5% more efficient when running at the lower firing stage, I'd say that he could meet that qualification. Did you read the Berkely study? Can you show me any study, data sheet, etc that says a two stage furnace, produces 5% more heat from the same amount of gas as a single stage? If it is so, why don't the manufacturers put it in the specs of the furnace? Example: Model XGQ090 90,000 BTUS, 95% efficient using first stage, 90% using second stage. Would be a hell of a selling feature, no?
Instead, all you hear are flapping gums that start with "comfort" and more recently end with big energy savings.....

Where's the answer to my question above? Even in your house, where you only spend $600 on heating, with a 95% furnace, you'd save 16% on that bill, or $96 a year. In two or three years, you've recouped the whole cost of the more efficient furnace. Yesh, I know. That extra heat exchanger could fail some day prematurely. But so could the inducer, ECM motor or anything else in a modern furnace. Actually, the heat exchanger in most new furnaces has the longest warranty, like 25 years or lifetime. What's the warranty on the two stage gas valve or ECM blower, drive electronics, etc?

I guess since most of the basements are heated, it's a good idea that they are often finished. Around here, we generally don't heat them unless they are finished. So, what do you think of the idea of running the furnace blower 24/7 for the rest of those houses in CA? Those with the furnace in an unheated basement, garage, or attic?

Which matters not a wit.....

And what principle of physics or physiology does that rely on? I'm at the same comfort from a furnace that runs the blower for 15 mins an hour or constantly. I don't have hot spots or cold spots. But if I ran the blower 24/7 in winter during periods when the furnace isn't firing, I would suspect I could have more drafts.....

We're not limiting the discussion to your tiny, atypical house, which you said is too small even for the smallest furnace. Anyone familiar with construction in the USA and I suspect CA too, knows that almost all houses have duct work run in exterior walls. How exactly do you insulate those from basement to 2nd floor? Inside the outside wall cavities, when the ducts are put in, there is very little space left for any insulation. Ever hear of water pipes freezing in outside walls? That should tell you how warm it can be inside some of those walls. I have ducts that run 55 feet through the unfinished basement, to the far end of the house, then go from the basement up to the second floor. How much heat do you think gets lost along that route when you're pumping air around constantly as opposed to only running the blower when actually heating? And I say simple logic tells you that you are going to lose heat there. The more you move the air around, the more you lose.

to go back and make the duct work the builder installed perfect? Can they insulate in those now closed walls? Add more ducting to the 2nd floor without tearing the house apart or putting chases in the living rooom, etc? In some cases, things can be done. But it isn't easy or cheap. If it can be done within reason, I'm all for it.
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On Mon, 31 Jan 2011 12:42:05 -0800 (PST), snipped-for-privacy@optonline.net wrote:

He didn't say that, and nor did I. I said it is an 80+ % efficient furnace, which he stated is likely running closer to 85% than 80%
By your own words, it cannot be an 80% efficient furnace because you said one of the differences between an 80% and a 90% or higher furnace is the presence of a draft inducer blower - WHICH THIS FURNACE HAS.

There is a small but measurable difference in OVERALL efficiency with a furnace that runs longer at a time, therefore having fewer purge cycles and fewer warm-up/cool-down cycles than a "larger" furnace.
The rating of the furnace at 80+% means the furnace will excede 80% efficiency in any approved installation. High fire, Low fire, timed, or dual stage thermostat. If it will excede 80% (say for arguement 81%) in a marginal installation, where it is significantly if not grossly oversised and run on high fire only, it should/will excede 83% if properly sized to the house/heat load.(on high fire or low fire). And I don't care what kind of math you use, 83% is closer to 85% than it is to 80%

I do not consider this house to be tiny, and it is far from atypical in a large percentage of the 20-40 year old subdivisions in any of the major cities or towns within a 60 mile radius. It is significantly larger than many in the 30-70 year old developments (early post war).

I am familliar with construction in Canada. Particularly in Ontario. My dad was in the construction business most of his working life, and I worked with him enough to know that was not the business I wanted to be in the rest of my life.
There is NO ductwork in the exterior walls of this house, nor in virtually any others in this neighbourhood/subdivision, nor in the vast majority of homes in this city or province. Putting ductork in the exterior walls is a foolish way of trying to heat a house!!! ALL of the ductwork goes up the center bearing wall of the house to the second floor, where it then runs between the floor joists to where the heat registers are located - so any "lost" heat simply warms the floor above. Any heating contactor who tried to do otherwise, except in very rare conditions, would be laughed off the job site, The cold air returns are also run through the same wall.
Same with running heating ducts in an attic. In houses without forced air heat (hydronic or radiant in-floor, for instance) that want central air conditioning you will occaisionally end up running the AC ducts through the attic - but only as a last resort, because cooling an attic is also a foolhardy endeavour. Running AC ducts up outside walls in these instances is not terribly uncommon, but attic mounted air conditioners or furnaces are EXCEPTIONALLY rare here. And today 2X4 walls are almost unheard of (last 10 years or so virtually all 2X6 or staggered double 2X4)) and sprayed urethane whole house envelope insulation is becoming pretty common. ICF is also gaining a fair momentum in residential construction, and is really taking hold in MURB construction up to about 15 stories.

Water pipes are also virtually NEVER installed in outside walls here, and the whole house is insulated - not the heating ducts - the american practice of wrapping heating ducts is almost unheard of here. Any heat that escapes from the ducts heats the (interior) walls, it does not escape from the "insulated envelope" of the house, so it is not wasted.

My inside walls are on average 2 degrees F warmer than the outside walls today when it is about -5F outside, except for the section of wall where the heat ducts go upstairs - where they are just about 3F degrees warmer than the outside walls of the same room.(measured with infrared thermometer)

Absolutely none in my house, and most others around here, because the basement is MOST often heated. Land and construction costs (not to mention heating) are high enough that only the rich, generally, build all their living space above ground and relegate the basement to "cellar" status. And most of them would rather have a nice heated games room, gym, or media room in the basement than leave it go to waste. (particularly in a bungalow)
Kinda stupid to have the furnace at the far end of the house too, isn't it?? And the chimney pouring all that heat out the outside wall. OK, the furnace is on the end wall of my house too, but I don't have 55 feet of ductwork running across the length of the house either**. ANd high efficiency furnaces don't pump much heat up the chimney - but with high efficiency furnaces you do not need a chiney at all, so there is no reason not to have the furnace centrally located so you "loose" less heat, and have a much easier job balancing air flows/heat output. (particularly if you are not planning to "finish", heat, and use the basement)
**Would be very difficult (to have 55 feet of heating duct running accross the basement) on the (large side of )average 60 foot urban/suburban lot. Vast majority of urban/suburban lots TODAY are 45 feet wide, with a minimum 3 or 4 foot side yard setback requirement. Add to that the REQUIREMENT that there be at least one legal sised parking space behind the building line, which means at leat 10 feet is used up by driveway, carport, or garage, and a 55 foot WIDE house is pretty rare, and 55 feet DEEP is not common either. There are a few subdivisions with 1/2 acre lots but fewer and fewer as the developable land is quickly being built up, and infilling is the only way to free up more lots. The few large lots available run $450,000 and up for a bare lot here in Kitchener-Waterloo,(saw a couple advertized for $650,000 plus) and well over double that in Toronto. You cannot build a new home (or anything else) in the greenbelt area, and the "right to farm" has limitted the urban sprawl here in Waterloo Region.(where my "not atypical" 2 story house with attached garage is worth something just under $300,000 on a 55X115 foot corner lot)(which is pretty well the average selling price of resale housing in the area)

Your logic is faulty.

Often the main "trunk" duct in the basement and the connection to the furnace (plenum) is what needs the most attention - and the addition af a few "ballance" flaps, and proper adjustment of them, makes a HUGE difference

What do you think people do who retrofit houses built 30-40 years ago with electric baseboard heat????? It is done a LOT up here. You open one side of the (internal) living room (or kitchen) wall, tear up a bit of flooring, and install the ducting the way it should be done. "You either go big, or go home". Is it cheap? no. but it is cheaper than continuing to heat with electric baseboard heat with todays electricity costs. Occaisionaly you cut corners and run the duct up a "chase" as you call it, in a corner of a room. But if you do it that way, you just reduced the resale value of the house by as much as it costs to do it right, generallly speeking. (unless you get an uneducated buyer with "limited" funds who does not get a home inspection, and is generally satisfied just being able to say he owns the roof over his head)

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On Jan 31, 5:46pm, snipped-for-privacy@snyder.on.ca wrote:

Let me refresh your memory. Here's exactly what you said:
" And the 80+% efficient furnace is supposedly running about 85% as installed -"
And you said the dealer said this:
" It is an 80+% efficiency furnace, and test documents the dealer had showed it to be approxemately 85% efficient when running in the mode mine is running in (timed low burn) with the specified temp rize across the heat exchanger etc."
So forgive those of us who are totally confused at this point. Is that furnace that the manufacurer spec'd at 80% really running at:
A - around 85%
B- closer to 85% than 80%, ie at least 82.6%
C - closer to 80%, which is what the Berkley study I cited shows?

I made the mistake of assuming that 80% furnaces don't have a draft inducer. I'm wrong on that point. I just looked at one online and it has one too. But that detail is a distraction, because it only makes your apparent advocacy of an 80% two stage furnace more difficult to defend. The only difference left between that furnace and a 93% or 95% furnace today is the latter has an additional heat exchanger and costs about $250 more. The cost differential easily recovered by the 16% reduction in fuel costs. Even if your fuel bill is only $500 a year, you'd recover it in 3 years and then be ahead. And that is without rebates from govt, utilities, etc. For many people, that makes the 95% furnace less expensive from day one. You can't get a rebate that I know of from anyone for an 80% furnace.
Yeah, I know, that extra heat exchanger could fail, but since they are covered under long warranties, like 25 years, seems like a reasonable risk to me. You have yet to answer that simple question, which goes to the core of the issue:
Say we have a guy with a 2,000 sqft home, living in say Ohio. Would you say he should buy an 80% furnace today, or a 95% furnace?

I believe the EPA test methodology includes that. And oddly, the Berkely study came to the conclusion that two stage furnaces actually benefit from the current test methods, which they said do not accurately reflect actual two stage operation. The new proposed test method, which Berkley believes more accurately represents two stage operation shows no efficiency advantage to two stage. None...

Lets' assume the above is true, and the two stage furnace is 83% efficient in some installations, Then using the same exact arguments, the 95% furnace has a slightly higher potential output too. So what? 83% is still a long way from say 97% and the latter will save about 16% on fuel
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On Tue, 1 Feb 2011 08:09:15 -0800 (PST), snipped-for-privacy@optonline.net wrote:

You REALLY CAN"T READ, can you??? It is an 80+% efficient furnace as advertized by the manufacturer. That means it is somewhere between, say, 80.5% and 100% efficient.

Gee, you were wrong?? What a revelation!!!

You ever try to get one replaced under warrantee??????? I know quite a few people who just gave up and paid to replace the furnace. My brother was lucky enough the dealer who sold him the first one (5 years earlier) was pissed off enough about the failure rate and the warrantee hassles he just gave him a new furnace from a different manufacturer at cost

IF he can buy the right sized 95% or better efficient furnace from a reputable manufacturer and he gets a good rebate from the government for putting it in, he should definitely put it in. But I'd STILL reccommend the DC fan and dual stage, because that is what we started talking about in the first place. The whole 80% or 85% efficiency was just "noise" which YOU latched onto.
I said I recommended the 2 stage burner, then said what I had and what my experience was, and why I bought what I bought.
YOU said the 2 stage was not a good idea. YOU said the DC fan was not a good idea, and then you said the 80% was not a good idea.
Well hear's a news flash for you. I totally dissagree on your first 2 points. On the third, it's almost a moot point now in many areas anyway, because anything less than about 93% does not qualify for the grants any more. The new condensing heat exchangers are hopefully better than the old ones, so I'd say go for it - BUT - NO WAY would I install a condensing high efficiency furnace with a conventional AC blower motor, and not very likely in that instance anything other than a 2 stage furnace (because he doesn't need a 75000BTU furnace - and if he does he should be investing in new windows, insulation, and other weather-sealing of his chicken-coop.)

IF the manufacturer is being truthfull in his specifications,( which may be stretching credulity in the US today,) the 95% efficient furnace is 95% efficient - on a good day when all the stars align just right, and the 80+% efficient furnace is something marginally better than 80% efficient under the same circumstances. Nothing says the 95% furnace could ever excede 95%, or they would call it a 95+%, or a 97% efficient furnace, while the manufacturer of the 80+% furnace is saying it is a MINIMUM of 80% efficient - which means it could be any amount better than that. I'll believe about 83%. Which is still "closer to 85% than 80%" no matter how you do your math.
So ENOUGH.
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On Feb 1, 1:17pm, snipped-for-privacy@snyder.on.ca wrote:

Of course I can read. You're the one that's having difficulty here as evidenced by your inability to remember what you posted two posts back. You claimed that your 80% furnacewas running at 85%, then you backtracked and claimed that it's just running at 80%+

See, here's the difference. When I'm wrong on a factual point, I'll admit it and correct it. And as I pointed out, that factual point does nothing to support your argument. With both a new 80% and a 95% furnace having a draft inducer, the only major remaining difference is the 95% has the second heat exchanger and costs a couple hundred dollars more.

You ever try to get that ECM motor replaced under warranty? Or the controller electronics? Or the draft inducer? Or any other part of a modern furnace? The warranties on the above are a lot less than the lifetime warranty you can get on heat exchangers from most manufacturers.

We latched on to it because you took great offense at me suggesting that someone who buys a two stage furnace that is 80% efficent is a moron. And I stand buy that for just about all people buying a furnace today that live in climates that are cold enough to use heating a significant portion of the time, ie heating bills of $500+ a year.
As for "if he can buy the right sized 95% furnace from a reputable manufacturer, what's up with that? They are available from every reputable manufacturer in sizes to fit most homes. Yes, you can find the pathological exception, but is that what matters? I bet I can find a furnace with the same output that you have, but 95% efficient instead of 80%.

Now again, it's you who is confused. I never said 2 stage was not a good idea. I did say that it's not going to give you a 5% gain in efficiency and make an 80% furnace into an 85% furnace. That statement is supported by the DOE testing that shows at best a 3% gain. And the Berkley study that shows a gain of zero.
I also didn't say the ECM blower was not a good idea. I said it's not the panacea that some make it out to be. I provided a study in another thread that showed that how much energy you save depends on a number of factors. Those include HOW it's used and what the existing duct work is like. If you choose to leave the blower running 24/7 and you have good duct work, you save the most. If you have typical duct work, and don't run it 24/7 you still save, but only 20% or so on electric. If you have poor duct work, you save little or possibly increase your electric usage. I would take ALL that into account before choosing what kind of blower to buy, instead of just blindly buying into the great wonders of ECM.

Even without the incentives, it quickly pays for itself. As I keep pointing out, the cost difference between an 80% two stage, ECM furnace and an identical one that is 95% is a couple hundred bucks. If you spend $1000 a year on heating costs, you've recovered that increased upfront cost in less than 2 years. What else has such a fast payback?

Geez, finally....

If he needs less than 75000, there are furnaces rated at less, whether single stage or two stage.

Again, what you believe to somehow be unique about 80% furnaces just isn't so. I can show you spec sheets on 80% furnaces that just state that they are 80% efficient per DOE tests, not marginally better. And I can show you product lines for furnaces labeled as the manufacturer's 90% product line that have efficiencies of 92, 93%. And I have yet to see one where the manufacturer spec'd ANY difference in efficiency whether it's firing at full output or only the lower second stage. Not saying there isn't some small difference, only that in the grand scheme of things, it's neglible and pales in comparison to the documented efficiency increase you get in going from an 80% furnace to 93 or 95%.

Which of course is still a long way from 93% or 95%.
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On Wed, 2 Feb 2011 08:21:47 -0800 (PST), snipped-for-privacy@optonline.net wrote:

I NEVER said I had an 80% efficient furnace. YOU say I have an 80% efficient furnace.
The furnace is an 80+% efficient furnace (which for all you know could be a 98% efficient furnace if I had not specified it is non-condensing.)
So you cannot read, or you cannot comprehend what you are reading, or both.
You also apparrently do not know what you are talking about, as evidenced by your statement that the difference between an 80% and a 90% efficient furnace included the presence vs absence of a draft inducer motor.
Go crawl under your rock (or bridge) and bother someone else.

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