Just wondering: Has anyone ran an external insulated duct type of pipe/hose from the furnace exhaust to their holding tanks to keep them from freezing?This past weekend we fired up our furnace for the first time on the TC and I noticed how hot the exhaust was. Our TC has exposed holding tanks and their associated plumbing, so I was thinking about using some sort of insulated ducting to attach to the exhaust port and run it along the outside of the TC to the back tank area. I would also insulate that tank area and enclose it. The duct would not be mounted permanently, only on when needed. I am thinking that attaching the duct to a piece of pipe with many holes in it running along the bottom of the tanks would disperse the heat down there more evenly.Bad idea or what?Thanks,Del

I'd be afraid of carbon monoxide poisoning.

While I bet a heat exchanger or something could be made,I would think the flame might have to much co in the firebox to burn right as designed.In a lot of industrial stuff the waste heat would be used, but it is designed to work.Might raise the firebox heat too.Had a old trailer and had to be modified to work as the exhaust was to short and it would be sucked into the burner air and slowly smother the flame. Easy fix just extended the exhaust a couple of inches.

Since it is a direct vent I would be afraid of placing any restriction on the vent. It sounds good in theory but IMO not a good idea. Aside from what someone else mentioned regarding carbon monoxide I think it would also potentially shut down or severely overheat the furnace. You could capture the heat that rises about 6-12 inches above the vent and place your insulated duct there. You could also install a small 12 volt fan inside the duct to push the heat through. Trying to push the heat through duct work connected directly to the vent would put a big strain on the system and could cause a potentially dangerous outcome.

You don't want to do this. The condensation in the flue gas is acidic. It will wreak havoc on anything not resistant to acidic water.

Whew, I am glad I asked the question. Looks like a bad idea, so thanks for the warnings and I will put this idea to sleep.Thanks,Del

Using Furnace Exhaust to Heat Tanks | Good Sam Community

11 Replies

time2roll
Nomad
Oct 28, 2015
Are you plugged in?

www.ultraheat.com
FreebirdFlies
Explorer
Oct 28, 2015
On the surface it does sound like a great idea.....
Just so many complicating serious factors that all add up to no-go.

If you keep batting around ideas, you'll eventually get on base. Maybe even a home run!
trail-explorer
Explorer
Oct 28, 2015
Yep, bad bad bad idea.

Doing that has the same effect as piping the truck exhaust in to the cab while driving.
CptnBG
Explorer
Oct 27, 2015
delosholly wrote:
Whew, I am glad I asked the question. Looks like a bad idea, so thanks for the warnings and I will put this idea to sleep.

Thanks,
Del

Glad you rethought it, red flags went up with me just reading the title....
GordonThree
Explorer
Oct 27, 2015
Is it possible for you to tee into the ductwork for your heater, and run an outlet into the underbelly?
Bedlam
Moderator
Oct 27, 2015
It reminds me of my old VW Beetle. I either had heat and CO or cold and fresh air.

Modifying any exhaust will change flow characteristics and possibly the air/fuel mixture as result. I would also be wary of where you are directing the fumes. When we were in a wind storm in MT, the wind was pushing hot water heater fumes into the TC due its strength and direction. I could not position the truck to avoid this so ran my generator and electric water heater instead since the exhaust was located elsewhere.
delosholly
Explorer
Oct 27, 2015
Whew, I am glad I asked the question. Looks like a bad idea, so thanks for the warnings and I will put this idea to sleep.

Thanks,
Del
Mike008
Explorer
Oct 27, 2015
You don't want to do this. The condensation in the flue gas is acidic. It will wreak havoc on anything not resistant to acidic water.
DavidP
Explorer
Oct 27, 2015
Since it is a direct vent I would be afraid of placing any restriction on the vent. It sounds good in theory but IMO not a good idea. Aside from what someone else mentioned regarding carbon monoxide I think it would also potentially shut down or severely overheat the furnace. You could capture the heat that rises about 6-12 inches above the vent and place your insulated duct there. You could also install a small 12 volt fan inside the duct to push the heat through. Trying to push the heat through duct work connected directly to the vent would put a big strain on the system and could cause a potentially dangerous outcome.
kayco53
Explorer
Oct 27, 2015
While I bet a heat exchanger or something could be made,I would think the flame might have to much co in the firebox to burn right as designed.In a lot of industrial stuff the waste heat would be used, but it is designed to work.Might raise the firebox heat too.Had a old trailer and had to be modified to work as the exhaust was to short and it would be sucked into the burner air and slowly smother the flame. Easy fix just extended the exhaust a couple of inches.