Dryer Efficiency

[jebatty]

Something I've never seen before. On a recent trip to Prague I stayed in an apartment that had a clothes dryer with an integral heat exchanger condenser to both strip the moisture out of the hot exhaust air and warm the incoming air. Water collected from the condenser was deposited in a small container tub that needed to be emptied periodically.

Two big pluses: energy recovery efficiency and keeping condensation out of the vent stack. And I suppose the water could be used too.

 

[Highbeam]

Just plumbing our conventional dryers with outside air would go a long ways!

 

[begreen]

Heat pump and condensing dryers are ductless. These are available in the US too. They are pricey but electrical savings can be 25% according to some reviews. Most are compact, 24" models, but there are some larger units too.
http://www.homedepot.com/p/LG-Elect...ic-Ventless-Dryer-in-White-DLEC855W/202336986
http://www.whirlpool.com/-[WED99HEDW]-1022543/WED99HEDW/

Inglenook topic Jim, but I would like to hear more about your Prague trip if you have the time.

 

[maple1]

That home depot dryer link talks about washing dishes in the description.

A clothes dryer that can also wash dishes - way cool!

 

[begreen]

 

[jebatty]

Heat pump and condensing dryers are ductless.

This dryer also has a duct.

Inglenook topic Jim, but I would like to hear more about your Prague trip if you have the time.

Still traveling but will start a discussion as soon as I catch up on stuff.

 

[Lake Girl]

They have all-in-ones available Washer/Dryer/Steamer $2700 Cdn.
(broken link removed)

Dryer times are longer than a conventional dryer ... up to twice as long.

 

[jebatty]

... and it's a stand-alone dryer. Brand is Below.

 

[jebatty]

Error - brand is Beko.

 

[blades]

Makes sense in an apartment or condo type environment- typically very difficult to get short runs to vent outside. Condensation in vent piping is a real issue in these types of constructions as well being able to clean piping of lint build up over time. Housing is a whole different world outside of the states.

 

[maple1]

I think it makes sense wherever you are. Our washer & dryer are 20 years old - pretty interesting seeing tech evolve, I'll be checking these out whenever ours gets to being replaced.

 

[jebatty]

Another interesting thing is that the dryer's condensation unit also is an additional dust and lint trap. Needs frequent cleaning, easy to do.

 

[semipro]

We've been using one of the ductless condensing dryers, a Bosch Axxis unit I picked up used for $100.
Its shares basement space with our heat pump water heater which creates somewhat of a mutualistic relationship between the two -- the dryer takes in ambient air, heats it, and exhausts it to the room. The HPWH likes the warmer air and exhausts dry cool air which the dryer likes.
More here: http://ecorenovator.org/forum/conservation/4310-experience-condensing-clothes-dryer.html

Condensation from the dryer goes to our septic and condensation from the heat pump along with waste water from the reverse osmosis water treatment system goes to a small in-ground pond outside. The flow is enough to keep it topped off.

 

[iamlucky13]

They have all-in-ones available Washer/Dryer/Steamer $2700 Cdn.

Dryer times are longer than a conventional dryer ... up to twice as long.

The all-in-ones I've used when visiting the UK were universally terrible. 4 hours to run a cycle, after which your clothes come out in a random state somewhere between still almost dripping wet (but hot enough to literally cause a burn) to crispy dry with a slight charred odor. None of my clothes fit afterwards. They'd all be shrunk to a degree I didn't even realize was possible.

The experience makes me extremely reluctant to ever try a condensing drier again, all-in-one or otherwise.

A ducted heat pump drier I would consider, as well as the sort described in Prague.

 

[jebatty]

Basements like ours would be an ideal location or source of intake air for a condensing dryer. The basement is always cool and for many months of year could use additional dry heat. Using the cool air for intake to the condensing unit and the warm exhaust air stripped of moisture for heat to the basement would be perfect. But would not want to inject humid air into the basement.

 

[jebatty]

I did a quick search "dryer condenser" and numerous hits. Here's an aftermarket product:

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I would like to see a test showing the humidity of the before and after output air. The condenser in the Beko dryer was far more technical.

 

[jebatty]

I'm thinking in my case with dryer on the ground floor and using a metal exhaust vent pipe down into the cool basement to help expel heat and allow condensation in the pipe with the condenser box at basement floor level could work quite well. Condensation in the pipe would drip into the box. Worth a try, very inexpensive.

 

[semipro]

I would like to see a test showing the humidity of the before and after output air.

I'm highly skeptical that this add-on device does little more that remove (some) lint from the exhaust. Warm air passing over cool water seems just as likely to pick up moisture as it passes over the water bath. I'd bet that the water level doesn't rise during operation providing proof that the unit is not a "condenser".

 

[Circus]

There use to be commercial tubs that would spin 3 or 4 times faster than modern washing machines. After a minute the clothing came out almost dry, cutting drying time 75%. Maybe we're looking at the wrong appliance.

 

[begreen]

Front loading washers have a high speed spin cycle that extracts a lot of the water. This allows us to run the dryer on low temp and still get the clothes dry in short order.

 

[jebatty]

Wiki has an article on condensing dryers and heat pump dryers. What I might try will use cool basement air to condense the water rather than recycling the dryer exhaust air through a condenser. This won't save dryer energy but will eliminate the exhaust vent, and it will put needed heat into the basement which will save energy. Right now the exhaust vent runs up into the attic and then to an outside wall, about 16'.

https://en.m.wikipedia.org/wiki/Clothes_dryer

 

[georgepds]

So.. noting this is a wood heat forum.. I'll admit I never had a dryer. It's dry by the stove during winter , and out on the line during summer. ( I do have a washer, I'm not a complete wingnut)

I do have a relative humidity meter in the stove room, and it's reallllly dry (~20%) in the dead of winter

 

[georgepds]

The idea that your dryer needs a heat exchange condenser, reinforces my general opinion that material things just require more material things.. It's not that I'm a simplification nut.. but really.. where does it stop?

The exception, as to material things, seems to be a wood stove.. simple iron box with a pipe leading to the outside. Yes, it requires wood, but that's pretty much it

 

[begreen]

According to engineers here it also requires a catalyst, a cat bypass, a thermostat and some secret sauce.

 

[Lake Girl]

So.. noting this is a wood heat forum.. I'll admit I never had a dryer. It's dry by the stove during winter , and out on the line during summer. ( I do have a washer, I'm not a complete wingnut)

I do have a relative humidity meter in the stove room, and it's reallllly dry (~20%) in the dead of winter

While a good concept (drying clothes by the stove in the winter), you obviously don't have a big family. Try that with a few kids ... minimum a load a day when the kids were little.

What would make sense to me would be the ability to utilize some of the heat from the pellet stove for pre-heating hot water. I know there is a cross link for the Harmans but we don't see any of the models available in Europe that are also water heating units. Yes, there are larger boiler units available but none seem to be in the mid-range size or have the ability to do some of each (air and water)