OT- water heater heat reclaimer

Can a small fan be put into the exhaust on a propane water heater- something like they have available for stovepipes- to pull some of the heat off the pipe and into the basement? I notice the wall where the pipe runs gets noticeably warmer in winter when the heater is running.

I might be way off base, but I think that if you cooled the exhaust gas it might not rise up the stack and would kill the draft. A small exchanger could work but be sure to have a carbon monoxide detector installed.

you could try surrounding the pipe, with proper clearances, and install a "small" circulator fan, with an intake screen in the top of the surround and a discharge screen in the lower portion to pull the heat off the pipe.
Loren, the Acg.

It can work. However you must be VERY careful to not cool the flue gases so much that condensation forms inside the flue. This will cause corrosion (rusting) inside the metal flue duct. Also the cool exhaust gases may not rise up thru the chimney and will instead back up into the living space (think carbon monoxide!)

Don't waste your time & $$. BTDT several years ago. Then made the mistake of allowing a Gas Co. person into my house. He red tagged my furnace & shut off the gas. Reason was as indicated above.

I was thinking cooling the exhaust gasses would be a problem. That wall sure can get warm though.

That is why I sugested a "again small fan" and suround to cool the wall and utilize the heat in the area adjacent to it. You will disperce the radient heat soaking into the wall, and not cool the combustion gases to the point of condensation in the pipe. Key word is small fan, just big enough to move the air around the pipe.

As mentioned, that heat is needed for the gasses to properly vent out of the house. Without the heat, no chimney effect. No chimney effect, no gas flow out of the house. No gas flow out of the house, no wake up after you go to sleep. Get it? While wasteful, its essential to have that heat there.

If you want to save that heat, you can but you have get a power vent. Those are a fan that forces the gas out of the house when the burner runs so the "wasted" heat is not needed. Then, that extra heat can stay in the water heater (or furnace). Power vents also have flappers on them to stop the flow of air after the burner turns off so warm air dont keep going up the stack on its own, even when not needed.

So can you capture and save that heat? Yes. Can you use a fan to do it? Yes but you wont if you are smart and want to continue waking up in the mornings. Is it worth trying to save that heat? Not economically. If you are doing this for economic reasons, there is much lower hanging fruit to get. If you are a Gore-zombie willing to spend more than you will ever save, there in no talking logic or reason to you so I will just say have fun and be safe.

A non-leaking water heater and discarded patio door would make a super cheap batch type water heater and would save more energy that a death trap fan setup ever would. All it takes is a little of your time and some scavenged materials. http://www.builditsolar.com/Projects/WaterHeating/water_heating.htm

I'm thinking this house I live in doesn't have a whole lot of insulation. The walls are only a few inches thick, could be "balloon walls". I just know it cools off in a hurry once the wood furnace goes out.

I'm thinking if I spend the time fiddle-fartin around with that cutting firewood instead I'll be a lot farther ahead. I have been leaving my hot bath/shower water in the tub, figure there's no sense sending ALL that heat directly down the drain. It was just another idea that I wanted to see if I was crazy or not rather than just spend a bunch of cash for nothing.

There's a solar panel on the roof, has a blower that pulls air through the ceiling to warm it, but there is a really big old elm tree in the way for half the day. It really needs to come down but it's over the house, garage, and a power line.

Unless you use a lot of hot water the burner will not run long enough to create a measurable amount of exhaust heat to recapture.
The power to run the fan would probably cost more than the heat being lost. As well as the saftey concerns already listed.
If you have a cool room that your tank is located in, there are lots of plans out there to hook up a small heat exchanger to the tank to shed some heat into the room.

Install instructions for gas equip usually have more pages about venting than anything else (safety, liability, yada yada). Btu's, how many appliances, vent length/type, chimney. There are times when you have to use insulated pipe instead of single wall between equipment and chimney, just to retain heat to aid in draft as other's have said. On a related note CO DETECTORS, as or more important than smoke detectors IMO.