Clothes Dryer Heat Exchanger

This is a little project I did to recover somee of the heat that is lost when you use your dryer.It should not be used with a gas dryer because of the carbon monoxide produced. All piping is sloped twords the drum to collect condensation in the drum and all pipe joints on straight runs face upward if possible to prevent dripping of condensate.Tape joints with metal tape.Keep pipe runs as short as possible.

Category:

Howto & Style

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• Dryer
• Clothes
• Heat
• Exchanger
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• Money

[OnTheEdgeInEauClaire]

I used it for a year and it worked good. I didn't want the moisture entering the house but wanted to try and recover some of the heat going outside. If I made a new one I would use 3 inch pipes and more of them going through the drum. I would also route the inlet to the top of the drum and the exit to the bottom of the drum. I did not have any moisture or lint problems. I moved and now use a gas dryer so I do not use it any more because of the possibility of carbon monoxide gas.

[OnTheEdgeInEauClaire]

Thanks. The best part is thinking of an idea and seeing it take shape as you build it. Some work and some don't. You keep the good and scrap the bad. Glad to here your project turned out well.

[OnTheEdgeInEauClaire]

Ran it for a year and looked inside. There was hardly any lint. With the removable cover you could take it apart (although it would be a pain) or you can stick a vacuum cleaner throught the inlet and outlet pipe.

[uncroyabla]

Ah that was going well! Shame video did not include the operation of the dryer and results. Well done though, this is the kind of thing everyone should be aware of! Thanks, Ad

[OnTheEdgeInEauClaire]

Check out the Clothes Dryer Heat Exchanger Temperatures 1 and 2 and Clothes Dryer Heat Exchanger Conclusion videos for the operation of the heat exchanger.

[jcdinform]

This is a Great project, Although make sure you consider the Maximum length of the 4" vent pipe.

As an Appliance tech for over 20 yrs, I use a rule of thumb that no length of dryer venting should be longer then 50 ft, so as to NOT place a load strain on the Dryers Blower/Motor, which in turn, lessons the amount of air flow across the heating elements.

However, I am referring to Air resistance fT, not Linear ft.

Each Elbow is to be considered the same as a 10 ft length of straight pipe.

[OnTheEdgeInEauClaire]

Thanks for the info. I may be over the maximum length if I count the elbows. I may need to do some replumbing.

[Poorgeorge2001]

A few ideas

(1) Warm hot air will rust any untreated metal it comes in contact with. Sand & Paint the drum insides with rustoleum

(2) Each 90 degree turn in the vent pipe increases back pressure & the odds of burning out the element. Check the manual concerning pipe diameter and length of run for dryer venting

(3) Smaller heat exchange pipes coiling inside the drum would be more effective. Copper as it won't rust

(4) Skip the fan. Heat rises naturally and the output at the top will be hotter

[cwillson1965]

@OnTheEdgeInEauClaire

Can barely hear the audio...

[MrTweetyhack]

Can you not take some metal duct and make coil it. Then run the hot air through and the heat will be pulled out leaving the moist air to continue out..

[Muhlineks]

use a cloths line, saves a lot of energy.

[josephdupont]

How about stuffing it with old soda bottles filled with water. I guess run the heat on top and have it exit on the bottom.

[htomerif]

@OnTheEdgeInEauClaire I know its a moot point after so long, but you could buy a CO detector for not that much and use it with a gas drier. Also, feeding the heat exchanger outlet into the air intake of the drier (if possible) would let you increase its efficiency during summer months when you dont want the heat in your house. Good catch though on needing the inlet at the top, heat exchangers work a lot better when the two flows are against eachother instead of in the same direction.

[chrisnotap]

By the way, great project, you are a thinker, keep going, great job!!

[chrisnotap]

I asked myself this question: use dryer heat to heat the room/house or make a better vent door/flap that seals when the dryer is off. I did that and can't believe how warm the room stays now. Check the temp. of the vent pipe when the dryer is not in use. You'll be surprised how cold it gets. A dryer gets used for an hour then not for the other 23 hours of the day. The room can get quite cool/cold from a cold vent pipe especially if you leave the dryer door open. Check it, you'll be surprised.

[chrisnotap]

@OnTheEdgeInEauClaire shouldn't be a problem with a gas dryer. Just be sure all of your joints are sealed

[DCVU2]

Over thought over kill, but smart. Check out the idea behing the rocket stove, and you'll see what I'm talking about. Just make the exhaust pipe super long.