High Efficiency Furnace

Dunno, but I suspect the highest efficiency models are working with some sort of catalytic proposition. Still, on cars, the catalytic convertor is known to run pretty hot.

I guess I just don't know. Consider this to be a thread bump.

I have one of the high e propane furnaces in our new studio. However, the installation guys spent three months two winters ago trying to get it working right. It kept shutting down froma buildup of steam in the vent pipe. (Its true that you can use a PVC but it has a liner pipe of SS that is about half the run length (in mine the run length is about 20 feet because its a peaked roof on our second floor of the new garage/studio/ wood shop. The builing is 68 by 42 and it has a rise leading to 14 X 36 adjoining garage thqt holds an RV. The entire second floor is open and the gas heater is just blown warm (or hot) air. We kept the studio at 50 degrees in the coldest winter unless we were working an then we cranked it up.
Well, the entire problem was that the intllers had the rong NOZZLE in the burners.
It worked like a dharm since then qnd it doesnt build up any steam (cause its cooled down.
Its what is known as a ombined cycle heater. The after burner recycles the exhaust gases nd theres a bit ofreclim of some more heat as its leaving the room and goes into vent space in the attic above.

We love it because its efficient and is really cheap to run. The entire unit installed ran about 6500$ and it uses less than 500 gal of propane an entire season (late October through mid April) The buried propane tank ran about 500 cause we dint want to :rent" it from the gas company (we shop around for electricity an gas )
Weve shiut it off for the season .Hot water is served up via a Rennai tankless water heater out there(We sometimes shower or bathe out in a teeny bathroom we had built in (You can get crummy woodworking or printing.

I had a new furnace that was efficient and fabulous in my house in northern California. I'll have to see if I still have the receipt, somewhere in this room full of paper. It wasn't propane, and was fairly small; the house was fairly large, and warm, and my gas bills went way down. Too bad I moved. That was ten years ago, but those furnaces or their follow ups may still be on the market.

I guess they originally had it set up for natural gas? I don't necessarily want to use PVC as an exhaust pipe, I was just wondering if the claim made on the website was anywhere near true. If these furnaces are that efficient and they actually work then I think I'll get one. Thanks.

I have no scale of reference to draw a comparison between the Propane furnace and any other heat source.
I was considering a wood furnace to place out in the pasture and send hot water to a radiant system. However three things were against that

The cost was about 3 times as much as was the propane system

The maintenance and "Stoking" required me to go out to the pasture (even in a blizzard) and load the furnace and chwck the ash pit at least once a day.
It wasted pasture space and would require fencing so that livestock wouldnt cause problems just because they get curious .

The High E blower furnace is about as big as an old fashioned radiator .
Its all thermostatically controlled and I get status info via an app on my phone (I can pre set the temp and lave the house after breakfast and hve the studio all warm when I get over there). Its about the same kind of app that the Generac people use for our generator.

We Love it to death. Stuff like this has only been recentky available because of the opening of new bands for telephones and tvs . And of course, everything of a gizmo nature has gotten waay smaller.
When we first moved into this old house, the basebiard heateing system was fed through a furnace the size of a pick-up truck. Now we have one thats no bigger than a Yeti cooler.

I remember the furnace in house as a kid, it was HUGE, and it didn't even have a blower.
The one I'm looking at online now is 33"h x 18"w x 29"d and it doesn't need a whole lot of clearance around it, it can be stuffed in a closet.
I'm amazed that they can produce so much heat (anywhere from 60,000 - 120,000 btu) and be so efficient.
There's a couple of guys around here with the outdoor wood burners. I talked to one of them a while back and he says all he does is cut wood, something like 40 cords a year. (It provides his hot water as well so his fire is burning all year). Sounds like a pain in the butt. My primary source of heat is a woodstove and lately I've been buying wood instead of cutting and splitting myself, but even that is getting to be a pain. I still have to haul and stack it and it makes a huge mess.

all the Amish around us use these wooden furnaces. As you said, its just a means of making life even more about work.

I dont think Id put th heater in closet though. There needs to be a 6" clearance qll round n 3" on the bottom. If you still use th closet ND HVE KIDS ALWAYS DUMPING CLOTHES into the closet without hqnging them up, you could risk fire The firebox on mine is a 36" long tube with severql nozzles along its bottom. The air i drawn through nd heated TWICE and then puhed out through the exhaust (The fire air nd the hot ir are two different sources. The burning air i drawn in from the outside , used in gas combustion, is then reheated by exhaust gqses nd then thqt heqts the air tube (Which is like a honeycomb) and that air blows into the room. The thermostat sits on a mid point in the room and where we determined would be the coldest spot.The thermostat runs the heater and an AC(gas) unit.
Qlso, I cannot emphasize more, we did spend a bit on big time insultion nd air tightness of the building.

Years ago I had a propane furnace that was NOT efficient, I ended up spending so much on propane that I just decided to trash it. Since then I've put in new windows and beefed up the insulation.
I'm older now and busy with half a dozen different things so cutting splitting and stacking wood doesn't seem as attractive anymore.
I'm ready for propane again. Now that the furnaces are better and the price has gone way down.
Those Amish are funny folks. I was talking with one young man who had just bought a house that had belonged to an "English" family. He was ripping out the plumbing and the tub and toilet. I asked him why he took the toilet out. I said "You don't have to have it connected to running water, you can just fill the tank with a bucket that you haul in from your well. This way, in the middle of winter you can go in there."
He knew all about that and explained to me that their rules didn't really have anything to do with modern technology, but were more concerned with how time was spent. Idle hands are the devil's workshop.

It has been awhile since I shopped for a furnace, but if memory serves:

The step from 80% to 90% efficiency is achieved by having a 90% furnace condense all the water vapor in the exhaust, thereby conserving all the heat in the steam. The condensed water will need to be drained somehow. A standard basement sump will do.

The step from 90% to 95% comes from giving the furnace a high and a low setting, the low setting being more efficient. The thermostat will use the low setting any time the cooling job is less demanding.



Southern climates don't have strenuous heating needs, so the money you save from a cheaper furnace offsets the costs of increased fuel usage.



Condensing the steam to conserve heat leads to cooler exhaust. I have a 90% furnace with a plastic exhaust pipe, and it seems to work OK.

BTW, this may be standard now, but make sure that the furnace has an exterior air intake as well as an exhaust. The risks of carbon monoxide may be small if the furnace draws its air from inside the house, but they aren't zero. So many furnaces can be had with an exterior air intake that there is no reason not to get one.

Presumably your furnace will be installed by licensed professionals who will comply with local building codes.

So long as they comply with building codes you should be all right. If you don't want plastic though, ask them ahead of time if they can use something different.

I wouldn't recommend doing it yourself, regardless of quality of website advice.

Thank You.

Thats why I never would conider one of those "ventless" unitw, They hqve neither intakes nor exhausts. Theywill work OK for a really big spce >10000 sq ft.