Proper terminology. Furnaces heat air. Boilers heat water. If
everyone uses the proper terms, especially on a home repair group, it
There are some specialized units that use hot water to heat the air,
thus they are a hot water furnace, but the end product is heated air.
Water is just the heat source.
micky wrote: "How does he do that? "
I do not know. All I saw was the sticker on the side
of my boiler with fields "Checked by"' "Date", and
"Efficiency", filled in by different technicians over
Usually a probe in the stack with a meter. I've seen it done but have
not done it myself. They can also read what gasses are in there since
on industrial boilers you usually have to keep the EPA happy.
Okay. I guess they measure unburned hydrocarbons. Now that I think
about it, isn't that what they measure when the put a probe in the car's
tailpipe? Something they don't do if your car is new enough, of if
you are old enough and don't drive more than so much, or if you live
where air polution is not so big a problem.
On Tuesday, January 27, 2015 at 11:43:24 PM UTC-5, micky wrote:
People didn't believe you because you were wrong. I replaced my nat gas
furnace back in 2010 with a 93%. There were other units available that were
even slightly higher. All of that was available from all the typical
furnace manufacturers. 90%+ furnaces have been available for at least
a decade, probably a lot longer. The essential big change was when they
went to *condensing* direct vent ones. There was a lot of energy in that
steam that went up the chimney.
On Friday, January 30, 2015 at 5:53:07 AM UTC-5, micky wrote:
No, I was just thinking in the context of this current thread,
which started with a question about the efficiency of gas furnaces.
I missed the segue into oil furnaces. But even so, there are
condensing oil furnaces that are as high as 95%, Adams Manufacturing
has one for example, though they may not be mainstream or practical.
IDK what they cost.
On Fri, 30 Jan 2015 06:43:33 -0800 (PST), trader_4
I mentioned those but "condensing" is the word I couldnt' think of. I
suggested Retroactive, incandescent, and self-descending, (At least I
got the c and sometimes the n,)
I r ead that they are expensive and not often sold, I don't know how
expensive, but no one who came out to sell me a furnace even mentioned
On Friday, January 30, 2015 at 9:27:03 PM UTC-5, micky wrote:
I guess a good question is why? The essence of it should be
a larger, better heat exchanger to extract more of the heat. I
wonder if something bad happens with an oil burner when you cool the
gasses that much, like some nasty gook forms, that you don't get with
nat gas? But on the other hand, at least some companies are building
them, up to 99%, so IDK....
If your fuel bill is $1000/yr, an 80% efficient furnace would use $800 to heat your house and $200 would go out the exhaust.
If you bought a 98% efficient furnace, your fuel bill for the house would drop to $816, $800 to heat your house and $16 up the chimney.
FWIW, don't count on saving any money over the life of the furnace though. High-efficiency furnaces break down a lot as they age.
Any fuel savings you accrue today will be eaten up with expensive repairs after the furnace is 10 years old or so.
A co-worker paid $260 to have a safety switch replaced on her high efficiency furnace last season. This year was another $610 for a draft inducer.
In my opinion, high efficiency furnaces are poorly engineered junk.
My first power vent natural gas furnace was purchased from Sears in 1982. It was made by Heil-Quaker in Tennessee, if I recall correctly.
It used double wall steel vent pipe, vented horizontally thru basement wall and was supposedly around 90% efficient.
In the 10 years I owned that furnace, every moving part on it was replaced at least once.
My second power vent furnace was a Thermo Pride that vented thru PVC. It lasted around 18 years and required lots of repairs in the last six years of its life as well.
I currently have a Goodman. It's been trouble-free so far but I expect the yearly break-downs to start soon.
Originally I had planned on getting the furnace replaced last summer and
when I asked for advice here, Goodman was the most recommended. One of
the reasons was that a "do-it-yourselfer" such as me would be able to
repair it. I inspected the unit and doubt if anything should present a
problem. The parts are guaranteed for ten years and since I'd replace
them myself don't think it's going to cost me a fortune to maintain.
In the 35 years I've been in my house I've done 100% of the appliance
repairs myself. Compared to the industrial equipment I worked on for my
job, home appliances are not a big deal.
As to the old "they don't make them like they used to" adage.
Yep, my old oil-burning furnace definitely had better sheet metal than
the one I just had put in. OTOH: If that oil burned could go six weeks
without breaking down or needing some type of maintenance, I was lucky.
BTW: I will get a fairly decent rebate from "Focus on Energy"
It looks like anyone who gets a high-efficiency furnace qualifies for a
$150 rebate, but since I'm retired my income will qualify me for a
higher rebate. Will have to submit the paperwork to know the
amount...but it's up to $850
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