# Free heat for clothes drying



## shank

I have recently read a couple of articles about feeding your electric clothes dryer with pre heated attic air. Seal all vent and gaps on your dryer, Install a 6 inch intake duct which feeds to your attic. I'm sorry I cannot post links yet. Google them and read. 

1. clothes dryer expel 100-150 cfm from your home, this air is replaced with outside air that needs to be reconditioned by your hvac.
2. Using attic air to feed dryer will decrease attic temps during those hot summer months. ( I live in south Louisiana)
3. Intake air to dryer is preheated requiring less electricity to dry clothes

I am thinking of trying this and installing a small air conditioner filter at the intake to remove any possible dust or insulation from entering dryer. Any thoughts or ill effects of doing this mod. Send me your thoughts


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## shank

http://www.builditsolar.com/Experimental/AtticToDryer/AtticToDryer.htm

http://www.instructables.com/id/Summer-Energy-Savings-by-Modifying-Your-Electric-C/

http://www.johnsavesenergy.com/ClothesDryer.html#.U77EBtEg_IU


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## de-nagorg

I have a thought, interesting concept, but what about the smells that accumulate in the attic. I. E. bathroom smells, cooking smells, musty odors, babies room smells, even the cat litter box.

They all get up there, and then vent out the attic venting.

ED


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## shank

I personally don't have anything that smells in the attic. Bathrooms are vented outside.


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## beenthere

150 CFM won't make a noticeable difference in your attics temp in the summer.


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## shank

Ok, might not cool the attic off. But what about pre-heated air feeding your dryer, and not exhausting your homes conditioned air through the dryer.


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## beenthere

A bit of a wash.

If your basement air is at 70°F and has 70%RH, when its heated to 125°F, its RH is now only 13.1%.

If your attic is at 125°F, and has 30%RH, it will take a lot longer run time to dry the clothing. So you might want to check the RH in your attic before doing this project.


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## shank

Not sure what you mean by RH. My dryer is in the home. Summer time temp in the home is 76. Attic temps run about 125.


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## beenthere

RH=Relative Humidity. Which references how much moisture the air can hold based on its temp.


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## Pat Martin

Such a nice idea, and must say that we need more supporters of eco and sustainable living in every way!

Thanks for the post, it has inspired many of my own ideas!

All the best!


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## High Gear

You may be overthinking this.
My parents used an outside clothesline in the summer and a clothesline in the basement in the winter.


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## jogr

High Gear said:


> You may be overthinking this.
> My parents used an outside clothesline in the summer and a clothesline in the basement in the winter.


 Much greener than running a dryer!


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## jogr

Lill Daddy, Your hot attic air will be at very high humidity in La. It will take a lot longer to dry your clothes. Might actually take more energy than using the electric. Clothes line outside is the way to say energy.


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## ddawg16

A better method would be a heat exchanger. As the hot air goes out, it heats the incoming air.

One of the problems with drawing air from the attic is restriction. The dryer depends on a low restriction input. Any type of tube up to the attic would need to be pretty large to prevent restriction. 

RH is an important factor. As the air temp goes up, the potential RH goes up. Any moisture in the air is more moisture added to the clothes that has to be forced out.

If one really wants to reduce energy usage and be more Eco friendly, the old tried and true method is hard to beat....clothes line. In the winter time, hanging clothes to dry in the house has an added benefit of adding moisture to the air (more RH) and thus raising the 'perceived' temp.

BTW. Electric dryers have to be one of the most enefficient ways to dry clothes. I know some people don't have much of an option (no gas).


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## Oso954

Sealing the dryer box and running hot air to it will raise the operating temp of the motor that spins the drum.

Motors that run hotter tend to fail sooner than motors that run cooler.
How many years of motor life are you willing to sacrifice ?


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## mnp13

> Free heat for clothes drying


The sun. ;-)


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## r0ckstarr

It get's up to about 90 degree's in my garage during the summer time. My washer/dryer are in the corner of the garage. Hanging next to it is a clothes rod from a closet. Above all of that is a ceiling fan. I wash the clothes, then hang them on hangars on the closet rod with the fan on high. They'll all be dry within 20mins.


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## fortunerestore

These are some highly useful tricks! I am sure I’ll be able to practice them to reduce the use of electricity for drying clothes. I really loved the idea of using attic air.


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## PoleCat

Regardless of temperatures feeding your clothes dryer with outside air is a great idea. Like you said the air will come in anyway as the dryer blows it out. Your attic should be well enough vented to count as outside air.


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## gma2rjc

My mom had a couple wooden clothes rack that she hung the washed clothes on and stood it over the heat vents, in the winter.


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## Startingover

I have a wooden rack in the garage and put tops on hangers to air dry. Only use dryer for sheets. I'm home all day, temps have been around 100, 1,430 sf house and my elec bill was $98 which I didn't think was bad for one person with weekend visitor.


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## NickTheGreat

Startingover said:


> I have a wooden rack in the garage and put tops on hangers to air dry. Only use dryer for sheets. I'm home all day, temps have been around 100, 1,430 sf house and my elec bill was $98 which I didn't think was bad for one person with weekend visitor.


If I did that in my area in the the winter my shirts would resemble plywood :laughing:


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## Hick

A follow up question to something beenthere mentioned earlier.

This thread has me thinking. If i redirect my air vent from the dryer through my floor to the underside of my home, would that help heat my floors from below?

No basement, just underpinning around my house. Could that help on heating bills by warming my house from below with the excess heat from the dryer. Also could I re-cycle the same air from under my house to power my dryer instead of the attic as mentioned in this thread?


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## beenthere

How cold does it get under your house? The drier will be putting a lot of moisture under the house, so you could get mold.


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## ddawg16

beenthere said:


> How cold does it get under your house? The drier will be putting a lot of moisture under the house, so you could get mold.


That would be my worry as well. There is a tone of moisture that comes out of that dryer vent. You really don't want that under the house.

If you have insulation, it will not do anything for you. 

If you don't have insulation, installing the batts that are covered in plastic will do wonders for making the floor warm.


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## PoleCat

The air coming out of your dryer is near 100% saturation and full of lint. It should never be recirculated into the structure in any fashion. Using a heat exchanger or heat sink to scavenge heat from the exhaust will result in heavy condensation and lint build up in the pipe. Blow that stuff outside as directly as possible.

The source of the intake air will normally come from the immediate area the dryer is sitting in and this is conditioned air. The best economy enhancement will be realized by supplying outside air for the intake to eliminate exhausting your conditioned air. It is a marginal improvement in energy savings so don't stop shopping for that Prius if you have a green agenda to meet.


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## Hick

Well, I already have the prius so no worries there XD

thnx for the speedy answers. It would just be for the winter time. For summer I simply use a close-line & during the winter the wood burning stove is normally for heat.

Just thought I could maybe recirculate the pre-heated air under the flooring but will not be doing that lol.


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## de-nagorg

There used to be a device made for dryers where venting to the outside was impossible. 

It consisted of a bucket about 2 gallon sized, with water in it, the dryer vented into the bucket, the water caught the lint, and the warm moist air was expelled into the room, 

The only drawback was needing to clean it out occasionally, and keeping it filled with clean water. 

I used one a few years ago in one of my temp jobs, babysitting teenaged drug addicts. 

Actually night guard/ resident warden at a re-hab facility.


ED


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## Jump-start

Oso954 said:


> Sealing the dryer box and running hot air to it will raise the operating temp of the motor that spins the drum.
> 
> Motors that run hotter tend to fail sooner than motors that run cooler.
> How many years of motor life are you willing to sacrifice ?


x2 Appliances today are under engineered, so that would be an issue.


Personally, if looking for an efficient dryer go heat pump or condenser dryer.


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## SeniorSitizen

de-nagorg said:


> There used to be a device made for dryers where venting to the outside was impossible.
> 
> It consisted of a bucket about 2 gallon sized, with water in it, the dryer vented into the bucket, the water caught the lint, and the warm moist air was expelled into the room,
> 
> The only drawback was needing to clean it out occasionally, and keeping it filled with clean water.
> 
> I used one a few years ago in one of my temp jobs, babysitting teenaged drug addicts.
> 
> Actually night guard/ resident warden at a re-hab facility.
> 
> 
> ED


Possibly not all that much different than an engine's oil bath air cleaner. On field equipment we cleaned those twice/day.


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## PoleCat

de-nagorg said:


> There used to be a device made for dryers where venting to the outside was impossible.
> 
> It consisted of a bucket about 2 gallon sized, with water in it, the dryer vented into the bucket, the water caught the lint, and the warm moist air was expelled into the room,
> 
> The only drawback was needing to clean it out occasionally, and keeping it filled with clean water.
> 
> I used one a few years ago in one of my temp jobs, babysitting teenaged drug addicts.
> 
> Actually night guard/ resident warden at a re-hab facility.
> 
> 
> ED


Those are not a good thing to use. My parents had one. The hot moist air and lint condensed on every cool surface in the laundry room and as the humidity built to total saturation the drying of the clothes ceased and the dryer could run for hours with still wet clothes in it.


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## NickTheGreat

And wet surfaces combined with lint or dust in the air is NOT a good combo . . .


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## de-nagorg

PoleCat said:


> Those are not a good thing to use. My parents had one. The hot moist air and lint condensed on every cool surface in the laundry room and as the humidity built to total saturation the drying of the clothes ceased and the dryer could run for hours with still wet clothes in it.




If you live in a dry climate they do work, And a key to usability, is to keep them cleaned out, and filled with clean water. 

Would I use one in my home ? NO . 


ED


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## mske390

You could always use something like below in the airstream from attic:

http://www.airfilterusa.com/commercial-industrial/moisture-separators-mist-eliminator


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## Greg.Now

mske390 said:


> You could always use something like below in the airstream from attic:
> 
> http://www.airfilterusa.com/commercial-industrial/moisture-separators-mist-eliminator


I really don't think it's a good idea even if you have good filter etc. Clothes would smell different if not funny.


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## mske390

Just curious if anyone who says that air in the attic is humid has taken a humidity measurement up there? Why do you feel that the air is so humid? Unless you are running a humidifier the air will not see an increase in humidity to what the outside humidity is, it will actually be less humid. When you heat air (which occurs in the attic) you lower the relative humidity. 

If you install this system you are passing hotter air through a metal ducting that is surrounded by cooler air if you do not insulate the ducting more moisture will condense prior to reaching the dryer. 

Dryer's currently use indoor air as the supply, there is humidity in that air.


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