Just FYI about Clothes Dryers.

arcandspark · September 2006

If your Clothes Dryer, electric or gas unit is located inside your home, it is wasting energy. The bad thing is there is not much you can do about it yet, there are some appliance manufactures that are working to fix this problem. The clothes dryer creates a negitive pressure inside your home, that is it takes the air conditioned air during the summer time from in the inside your home and pulls it into the blower intake of the dryer, heats it up to dry the clothes, then blows it outside of the home. During the winter it takes the air that you have paid to have warmed up and does the same thing, blows it outside. At a flow rate on average of around 200 cubic feet per minute, it would be no different than opening a window, putting a fan in the window, and blowing outside air into the house. If the blower is pulling air from inside the house and blowing it outside, this air must be replaced some how. Well yes, its replace by the air from outside of the house. It comes in from window and door leaks, from the attic it is pulled inside the house from the ceiling vents in the bathrooms from ceiling lights and wall outlets, and the vent unit above the stove. Even thought they have flap doors inside them, they leak badly. So anytime you run the clothes dryer, it is costing you energy twice. The energy to use the dryer unit itself, and the energy used to cool or heat the air inside your house. Some manufacture are designing appliances that pull the air from outside through a secondary supply vent and then after using it blow it back outside, which does not waste energy. But because there has not been much complaining from the American public there are only a couple appliance manufactures that are currently looking into doing this. It is acommon design on forgein appliance manufactures like those from Europe and Japan. If you locate your dryer in your garage and have a vent on the garage door to allow fresh air in, than you are not wasting energy twice, or if you dryer is located outside of the living space of your home. Just a little information to make you think. David R. (arcandspark)

niel · September 2006

Re: Just FYI about Clothes Dryers.

you are quite right about it drawing air in and if you are running a gas furnace or hot water tank it will pull co(carbon monoxide) back into the house if all are running at the same time. i had used one of those little devices inside on my electric dryer to keep the heat it produced inside, but it placed too much humidity into the house along with the heated air. though electric dryers i feel are safer and could allow heat recovery better, it is more costly than the gas units to run. a clothes line works better because it only allows so much humidity to enter the air at any 1 time, which is a plus in the dry air of winter. too much humidity can damage things and create molds and mildew.
my other half wants to do too many clothes at one time and wants it yesterday so a clothes line here is a waste of time unless i hear about it. when my last dryer broke down for its last time, i didn't get another for a long time as i wanted to dry things in the air. she won out because she nagged and failed to try to do it so that it could be spread out over days instead of all at once so there were wet clothes lying around for a day or 2 just to pressure me. women don't like to sacrifice and are willing to sacrifice you in order to do less or to do things their way when it comes right down to it. that's when i heard make your own dinners even though that's the only thing she was making for me. i made my breakfasts and lunches with an occassional dinner too so telling to make dinner i really didn't care about. i think i've said enough, but you get the point that some conservation methods just aren't going to happen with most people.

halfcrazy · September 2006

Re: Just FYI about Clothes Dryers.

wouldnt it be feasible if the drier manufacturers made a cold air intake then we could take outside air maybe a vent like they use on the on demand heaters 1 pipe in another? I have no drier i am lucky to have a conservative wife she got a drying rack and a close line on the porch and is happy as a clam even with the 2 of us and 2 kids we try to do a load a day

Brock · September 2006

Re: Just FYI about Clothes Dryers.

When we first built we had issues with our pool heater back drafting when ever the dryer was running. After I put in an air to air exchanger that all stopped. It is basically an open 6" duct so if the house get negative pressure more air will leak in though that duct and luckily it runs though the heat exchanger.

I also have since added a duck with dual inline furnace filters that leads to the main house intake furnace fan. As long as I turn the house fan on it works out quite well, unless we have to dry more then 2 loads in a row. It raises the house humidity about 10% but quickly drops back off in about an hour.

I initially had it just running through the filters and dumping in the living space in the basement but it got noticeably humid, like 80+%, and often would condense on the windows.

There are also some washer/dryers I believe Matt has one from LG that has no outside vent and just takes longer to dry, and does it with about 1/2 the power of a regular unit. Of course in summer or anytime you need cooling this would still be a lot of extra heat added to the home.

In summer I just vent the dryer outside.

System2 · September 2006

Re: Just FYI about Clothes Dryers.

yeah i have ventless one. i was thinking how i read (couple yrs ago) new tight energy efficient houses actually have a small air intake somewhere in the house , it would make sense to locate a dryer in the same rm if possible.

System2 · December 2006

Re: Just FYI about Clothes Dryers.

i weathered stripped my laundry door and put the reflective faom insulation sheets on the walls and just run another dryer vent to the outside and just ended it behind the dryer so it pulls in the outside air and the insulation keeps the cold or hot air in the laundry room while the dryer is off
i think the dryer works better than it did before as i think the heat from the outlet pipe preheats the air coming in as they run with the intake pipe on top of the output pipe

arcandspark · December 2006

Re: Just FYI about Clothes Dryers.

Not a bad idea. The first thing I would try to do is figure a way to reuse the wasted heat from the exiting air duct. Preheating the intake air would be about the only thing that would work, and its free heat (already used) what is going to be wasted anyway. I just cant figure out why the manufactures have not installed a duct system in the units that would do this very same thing??????? Arcandspark

Brock · December 2006

Re: Just FYI about Clothes Dryers.

When I was looking in to the HRV units I came across a duct within a duct. Sort of like a chimney stack with a 4 inch center pipe and a larger 6 inch pipe around that. I was told it was used for newer gas fireplace units that suck fresh air in around the smaller exhaust tube in the center. The thing that concerned me about that was condensation in the exhaust tube since it would be cooling quite a bit, manageable, but you would have to stay on top of it.

mike95490 · December 2006

Re: Just FYI about Clothes Dryers.

On another solar / PV list somewhere, someone menioned they ran a duct from the hot attic, to serve as intake air for the clothers dryer, and in summer weather, it hardly ran the heater - worked fine with the superheated attic air.

BB. · December 2006

Re: Just FYI about Clothes Dryers.

Like the idea of a duct to the attic... My attic used to be quite warm. Now, with my solar panels on the south facing roof it is pretty cool--especially in the winter when I use my drier.

Also with heat exchangers on driers, as they cool the warm moist air, they may condense the water and attract dust--lowering efficiency and possibly causing blockages as well as rusting/holes (if made from steel) and recirculating combustion gas (if natural gas fired).

-Bill

Just FYI about Clothes Dryers.

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