Print

[RSI]

I have been thinking about putting together a kit for clothes dryers. The problem is that to order the small size heat exchangers it costs 3-4 times as much for one as it does per unit if I order larger quantities.
If anyone here is interested in doing it let me know and if we can get enough people together for a batch it would be a lot cheaper for everyone.
I have not decided exactly what size heat exchanger would be best but I am thinking around 6x6" or 8x8" should be sufficient.

I know it works with 180 degree water but not sure how good it will for people that run at the lower temperatures. (ie: 140 degrees)
I have had one setup for a couple years but I just used a single row 12x12 heat exchanger with 1/2" pex feeding it. Using the custom size heat exchanger should work out a lot better because dryers suck air in and I don't think it is going through the entire 12x12 area and the extra thickness of the 3 row coil should heat the air a lot better.

Also, I used a second dryer instead of putting it on the main dryer. Mostly for safety since I didn't want to interfere with the heater on the dryer. Also, this allows to dry two loads of laundry if you get behind.  The dryer I put it on I removed the heat source.
You could probably use your main dryer but it would be up to you to make sure it is safe. (I would highly recommend removing the kit and going over the dryer to make sure it is ok after switching it back for the summer if you do this)
I used to have an indoor wood furnace so there was a spot about the right size for the second dryer where it had been.

It looks like heat exchangers would be around $100 each if we can get to the price break quantity. If we can get more together it would drop it more. Also, if doing it the way I will be recommending, you will need a pump also. I can supply that or you could get it on your own. Other parts would probably depend on the specific dryer but a universal kit may be possible.

If there is interest, I would like to see some pictures of the bottom inside and back of different dryers that you have so we could get the best size heat exchanger. If it could be mounted inside it would be a much cleaner looking install.

[Bull]

Would a heater core from an old car work? About the right size and cheep from a auto salvage yard
 

[oldchenowth]

I could easily be talked into joining the HX core group.  I am on electric everything and it's killing me.  I do not have a dryer to start as of yet, but garage sale season is starting and there is always CL. Lost power for 19 hours yesterday for no reason, really want to stick it to the electric company. I'M IN!

[Ridgekid]

RSI- You come up with some great ideas! If this was 10 years ago when we had three kids living here I would of been in!

Since it's just the wife and I, our electric use has significantly reduced    In fact during discussion of adding the DHW HTX, she could not see adding $800 (Parts and Labor) to something we have on a timer. (Only on 10 hours a day-Morning and evening). Little does she know, If I can find a kit before next winter, to install it myself, I will!

[RSI]

Would a heater core from an old car work? About the right size and cheep from a auto salvage yard
 

They might possibly work but I am not sure I would trust a used one.  Also, not sure if they are thick enough to put out enough BTUs. Probably the only option would be to use radiator hose on most of them.

[RSI]

I could easily be talked into joining the HX core group.  I am on electric everything and it's killing me.  I do not have a dryer to start as of yet, but garage sale season is starting and there is always CL. Lost power for 19 hours yesterday for no reason, really want to stick it to the electric company. I'M IN!

If you watch craigslist, a free one usually turns up. I think I got tired of waiting and paid $50 for the one I used.
I have a Whirlpool (some Kenmores are the same) and it was pretty easy to do. I took the back panel off and mounted the heat exchanger there.
Other brands may be easier or harder. If you can get a gas version it will not require much anything for rewiring but the electric version has a better duct in the back for connecting to. (I ended up using the tube out of an electric on a gas model)

One very important thing is to have good drum seals. Since the dryer pulls air in, if the seals are bad it won't heat up. My first attempt didn't work at all for this reason.

[RSI]

RSI- You come up with some great ideas! If this was 10 years ago when we had three kids living here I would of been in!

Since it's just the wife and I, our electric use has significantly reduced    In fact during discussion of adding the DHW HTX, she could not see adding $800 (Parts and Labor) to something we have on a timer. (Only on 10 hours a day-Morning and evening). Little does she know, If I can find a kit before next winter, to install it myself, I will!

$800 to heat your domestic hot water?
Do you have a tankless water heater?

[Ridgekid]

Yep, thats what the dealer wanted. $400 for parts, $400 for labor. Our HWH is a 50 gallon electric model. AO Smith.

Here's a pic of it: http://outdoorwoodfurnaceinfo.com/forum/index.php?action=media;sa=media;in=35;preview

[dirtryder]

RSI- You come up with some great ideas! If this was 10 years ago when we had three kids living here I would of been in!

Since it's just the wife and I, our electric use has significantly reduced    In fact during discussion of adding the DHW HTX, she could not see adding $800 (Parts and Labor) to something we have on a timer. (Only on 10 hours a day-Morning and evening). Little does she know, If I can find a kit before next winter, to install it myself, I will!

That price is insane......if you have just a "basic" knowledge of plumbing, you can easily install a plate exhanger in your water line "after" your water tank. In 6/09 I paid $169 for a 20 plate (for my polebarn radiant floor heat) couple fittings and done.

BTW, I think the heater core idea is a "winner"

[oldchenowth]

Any of you guys got a source in general for good quality plate exchangers for DHW and this dryer experiment?  I really want to stick it the power company more so than the propane guy.  19 hours without power this weekend, the gennie does everything but bake water and dry the clothes. Hence, I am on the hunt to cure these problems  forthwith.

[RSI]

I just came up with an idea that might make a dryer kit more universal.
What do you think of putting everything in a box and just running a hose into the dryer? It could be mounted a few feet away. There might be a little temperature drop doing it this way but might be ok. Then a 12x12 heat exchanger would work ok.
This way might even be able to use the main dryer and just wire in a switch to disable the heater.

If anyone wants to try it, I will put one together for the price of the parts. Send me a PM if interested.

[Ridgekid]

RSI- Ever think about using a heater core for a car? They are only about $25.

[RSI]

They were mentioned in earlier replies.
Do you have any idea what model car would have a good one? Most of the pictures of them I can find online are constructed like car radiators which I don't like. (end tanks with pipe soldered in, probably with lead or the whole thing is aluminum)

[Ridgekid]

Here's the one I saw that reminded me of your project: (maybe not what your looking for?)

http://www.summitracing.com/parts/PLI-398247/

They have plenty to choose from: (maybe one of these will work?)

http://www.summitracing.com/search/Part-Type/Heater-Cores/?keyword=Heater+core&kr=Heater+core

[RSI]

It looks like all of them are made the same way.
This is why I don't like the looks of them. How It's Made - Car Radiators