Heat pump dryer

[Cybrvanr]

Has any company ever experimented with a heat-pump as a source of heat for a dryer? I guess the complexity would reduce the reliability of the dryer, but I would think that a significant savings in could result if it could be perfected. My thought on one is to have two evaporator coils, one that was exposed to the ambient room temperature, and one that was on the exhaust port of the dryer.

Instead of generating heat, it would absorb heat energy from the ambient room. If one stood in front of the dryer while it was running, they would feel cool air discharging out of it. An internal blower would then blow air across the condenser coil (high side) and blow the air into the drying drum. When the air is exhausted from the drying drum, it would also be cooled, with the refrigerant absorbing it's heat, and further used to dry the clothes.

 

[brisnat81]

From memory

Asko had such a thing 10 years ago, but I havent heard of one recently.

 

[panthera]

AEG and Blomberg make these

Our version of consumer reports, Stiftung Warentest, promptly lowered their already poor opinion of other clothes dryers' efficiency yet again when they came on the market.
I can't find any data on their reliability, note that every 10 years or so they are "newly discovered", cost a fortune and then sort of disappear for a while.
A good idea, but I bet the high purchase price holds them back.
See the link, sorry it's in German - the main idea is, they get an efficiency rating of "A" instead of "C" (very rarely "B") on energy which is otherwise standard here for dryers.

http://www.stiftung-warentest.de/online/haus_garten/meldung/1327506/1327506.html

 

[foraloysius]

Here's a link to the British AEG site.

http://www.aeg-electrolux.co.uk/node146.asp?ProdID=3743

 

[logixx]

Here is the link to the English Blomberg homepage:

http://www.blomberginternational.com/en/
Click on "Free Standing" to see their dryers.

Also check out their TOL dishwasher:
http://www.blomberginternational.com/EN/Products/DishWasher/InformationFile.htm
Alex

 

[hydralique]

Nice idea, but . . .

I'll be Panthera is right, the high price (not to mention complexity) is an issue. You'd also have to have a really, really good and foolproof lint filter, with some sort of pressure sensor to turn the dryer off if it is clogged. This is because an evaporator coil, unlike a gas flame or electric resistance element, has rows of fine fins which transfer the heat from the coils to the air. Any amount of moist lint would coat the fins and dramatically reduce the efficency of the whole system. I'd be willing to bet that there have been issues with the long term performance of these dryers for this reason. For commercial applications, where space isn't such an issue as in homes, and professional maintenance can be assumed, the concept might work better.

 

[logixx]

The Blomberg dryer uses triple-stage filtration: a regular lint filter and two sponge filters.

BTW: these dryers (and probably most other dryers, too) don't use pressure sensors to shut off in case of a restricted air flow. Several thermostats measure the internal temperature - if it gets too hot the machine shuts off.

User's manual:

http://www.blomberginternational.com/NR/rdonlyres/66B3B8BF-44A2-4123-B038-D1852498EA90/0/TKF1350.pdf

 

[foraloysius]

How could I forget that V-Zug has a heatpump dryer too? The design of this one is different, there is a huge box for the heatpump on top of the dryer. Very unlike the AEG/Blomberg model that has a much smaller heatpump that fits in the standard cabinet.

http://www.v-zug.ch/v-zug/internet.nsf/PageID/F19687C7DD31CC08C1256CDA0039E9D1

 

[gansky1]

Way off topic, but do I get this V-Zug dishwasher has a "fondue" program/cycle? If you click on the "?" next to it in the list, a picture of people around a fondue pot comes up!

 

[danemodsandy]

Fondue Party...

A fondue cycle would have to be one helluva cycle, probably running for a week or two, with a whole bottle of detergent. ;-)

I mean, have you ever tried to clean a fondue with scorched cheese in the bottom? MOIDAH, LOL.

 

[foraloysius]

The fondue cycle has an active soak phase.

I scrape my "caquelon" (earthenware fondue pot) with a wooden spoon and the cheesebits come loose. What's not removed disappears in the dishwasher.

 

[toggleswitch]

Low tech version:

Electric dryer, unvented
Dehumidifier in room.

I have actually seen this situation when hard-headed husband refused to open hole in wall for vent.