Which is more efficient?

[AC_Hacker]

Originally Posted by Daox

The problem with the heat recovery is always the lint.

I have some friends from Germany, and they don't care much for the American practice of throwing washed clothes into a clothes-dryer. Their objection is not so much from the standpoint of energy, it is more from the standpoint of reduced garment life. All the lint that Daox has to deal with, is composed of fibers that have been forcefully removed from the garments by the clothes dryer. If you are going to do a cost analysis of various drying schemes, it might be good to do a ball park estimate of the cost of shortened garment life.

And if you dry clothes inside the house in a room like Piwoslaw's setup that he photographed in an earlier post, there is the additional benefit of offsetting the dryness of winter air, in addition to longer garment life.

But there are still other dryer options, popular in other parts of the world... microwave dryers in Japan, and heat pump dryers (AKA: ventless dryers, condensing dryers) from several European manufacturers, as mentioned in the post below, from another site:

Heat Pump Dryers
The Japanese have had microwave clothes dryers for some time. These use microwaves to heat the wet clothes rather than hot air and by doing so they save approximately 35% in energy consumption. They switch to resistive heating for about the last 10% of the cycle to prevent problems with metal objects. For reasons I am not familiar with these are not available in the United States.

Heat pump dryers are now available in the United States, and these save approximately 65% of the energy consumed by an ordinary dryer. Dryers generally represent around 6% of a households energy consumption, and if you have teenage kids even more. In addition to directly consuming 6% of a households energy budget, dryers also contribute to energy required for heating and/or air conditioning because the air they exhaust to the outside hot came from the inside, and that air will be replaced by cold or hot air from the outside requiring additional energy for heating or cooling the house.

Heat pump dryers cost about $300 more than a conventional resistive heating dryer. Over a ten year lifespan, they will save approximately $1000 in electricity costs assuming the average cost of 8¢/KWh and average household laundry. The savings will be even greater where the rates are higher or if your household has a higher than average amount of laundry. This is before you factor in heating and air conditioning savings which are even greater.

A heat pump dryer is also more convenient to install, requiring only a drain like a washer and no external vent. In addition a heat pump dryer requires only a standard 120 volt outlet, not the larger 240 volt 30 or 40 amp circuit of a resistive heating dryer.

Instead of heating air, blowing it over clothes, and then exhausting the hot air outdoors and taking fresh air from indoors, a heat pump dryer heats air, passes it over clothes, dehumidifies the air, and passes it over clothes again and again. No air is exhausted outdoors, and liquid water from the dehumidified air is simply drained. Heat energy is not wasted.

Not including the savings in heating and cooling, if everyone switched to heat pump clothes dryers it would save 445 billion KWh of electricity every year, 35 billion dollars in electricity costs each year nation wide. Because our trade deficit, and economic woes, are in large part the result of the energy we import, this would be a very good thing for our domestic economy. Surplus electricity could be used by electric vehicles, or we could burn less natural gas for power generation and instead liquify it and use it to power our vehicles instead of imported oil.

It would reduce the average load on the power grid by 50 megawatts, about 1/10th the output of a medium sized nuclear reactor, but it would reduce the peak load by more than this because most people don't do clothes at 4AM.

Anything we can do to save energy consumption will allow a larger portion of our energy needs to be satisfied by renewable and environmentally benign sources and less carbon dioxide will be generated as a result.

Don't get me wrong, I actually like warm weather. It's the species dying off, cities underwater, desertification of farmland and forest, things that really bothers me. Unfortunately they seem to be an intrinsic part of global warming. A great deal of global warming would be happening without our contribution. We should not accelerate or intensify it further by altering our atmosphere.

Even better than a dryer when weather permits is a clothes line. 100% renewable (solar) powered, no electricity consumption.

Future Sustainable Living: Heat Pump Dryers

-AC_Hacker

[creeky]

i'm with the Germans. One thing M and I found is that our clothes, esp. shirts and jeans, seemed to last longer using the "drying room". No dehumidifier, just the pellet stove heat. So it was win-win-win for us.

Of course with drying clothes in the summer outside the fresh scent and the softness that the wind imparts to your clothing is unbeatable (sorry, another pun). However we had issues with some fabrics fading or discolouring in the sun.

How wuz I to know that linen changes colour when wet and dried on a line in the sun?

[Geo NR Gee]

Thank you to all that responded! We have three teenagers and we wash 6 loads or more a week. We have over 90' of clothes line outside for the nice days (which are fading quickly) and a portable drying rack inside the spare bedroom with the dehumidifier.

Our electric clothes dryer rarely get used now and the electricity bill has dropped since we started doing this faithfully 4 years ago. Little did we know about the benefit of lint loss or lack of.

[Piwoslaw]

Originally Posted by creeky

In the winter my wife hung laundry in the "pellet stove" room and we experienced no mold or excessive dampness issues. The humidity just made the air coming into the house more comfortable.

Is the pellet stove fed fresh air from outdoors? If not, then it is sucking in air from the room, and most of the moisture from the laundry with, so that's why there is no problem with excess humidity.

Originally Posted by creeky

Of course with drying clothes in the summer outside the fresh scent and the softness that the wind imparts to your clothing is unbeatable (sorry, another pun).

When drying indoors I usually place a fan next to the hanging laundry. It speeds up the drying, so there is no musty smell. Almost as good as the outdoor wind

[GaryGary]

Hi,
I like Randy's approach:
Converting a Clothes Dryer to Use Solar Heated Attic Air For Drying
Hot air for the dryer comes from a very simple attic solar collector.



Gary

[Piwoslaw]

Originally Posted by GaryGary

I like Randy's approach:
Converting a Clothes Dryer to Use Solar Heated Attic Air For Drying
Hot air for the dryer comes from a very simple attic solar collector.

Looks like something for Daox

[GaryGary]

Originally Posted by Piwoslaw

Looks like something for Daox

It does indeed!

Gary

[Ryland]

When I had checked a few months back, ventless cloths dryers were not being sold in the US, at least that I could find, then Yesterday I was picking up my new fridge and I asked the lady if she knew anything about ventless cloths dryers and to my surprise she said that they have sold one a few months back!
The one that they sell here is a Bocsh, I didn't catch the model, but it's ventless and has a water collection pan (and I drain I would assume) and it was a bit pricy, at $1,100 but not that much more then the $800 electric vented version that it shared the same case and basket with.
Above the savings is said to be $1,000 over 10 year life span at $.08 kwh, my electric rate is $.11 kwh so that would be an even greater savings, more then the cost of the dryer and less then 3 years to offset the increased cost, not to mention the reduced cost of heating your house in the winter and cooling it in the summer.

[Daox]

LG also makes I think 2 different ventless models. They are combination washer/dryers.

[AC_Hacker]

Originally Posted by Ryland

...ventless cloths dryers were not being sold in the US...

Try different Search Terms...

• condensing clothes dryer
  
• condensing clothes dryer
  
• heat pump clothes dryer
  
• heat pump clothes dryer
  
• ventless clothes dryer
  
• ventless clothes dryer

-AC_Hacker