I am considering buying an electric clothes dryer for my home (which is all-electric).   I could go with a conventional vented dryer, or a ventless condensing dryer.   I am inclined toward the ventless dryer because it will keep the heat in the house (beneficial through most of the year in central Illinois); I can also place it near my heat pump water heater.   But there may be other factors to consider, and I also have no experience with a ventless clothes dryer.   Any thoughts or advice?  Thanks, Scott

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One wonders whether the chlorine in the detergent and the fabric softener might not combine with the hydrogen in the wash water to create a modest but nevertheless undesirable presence of Hydrochloric acid in your indoor air.  

Hello Scott!


The electric ventless dryer will, indeed, keep the heat in the house, but it will also keep the moisture from the wet clothing, bedding, etc, in the house.  You may be setting yourself up for a future mold problem, depending on your local climate, general leakiness of your house, etc.   Additionally, unless you use a clothes line in the cooling months, your AC system will have to compensate for both heat and excess humidity. 


In a perfect world, your dryer will have an outside air supply that opens when the dryer is turned on, thus making your "gazoutas" equal to your "gazintas."   If you can make that happen, you will achieve perfect balance, and inner harmony. ;-)  Good luck!

I have the Bosch Axxis condensing dryer in my home.  I live in central coast of California.  Our main driver for going with a ventless condensing dryer was because we wanted to keep the house airtight as much as possible -- we have a passive house and our final blower door test came in a 0.59 ACH.  The dryer is located in the middle of the house in the same mechanical closet that houses HRV and the washer.  We probably used the dryer less than dozen times in the past year.  Most of the time we hang the laundry inside the house on folding racks.  Because the relative humidity inside the house tends to be low (right now RH is 25~30% with the room temperature at 72-75F)  drying the laundry inside the house helps bring up the humidity a bit.  When I have used the dyer I found it to work well and it takes much longer than vented gas dryer.  Also clothes never gets super crisp dry state that a gas dryer produces, but this is OK because if you take it out and hang things clothes immediately after the end of cycle it minimize wrinkles.  If you already have a heat pump water heater then placing the condensing dryer next to it makes sense.


     I would be using the dryer only for sheets and towels.   Does the condensing dryer work well on these items? 

Yes, the condensing dryer works well for sheets and towels IF you don't mind waiting.  It takes A LOT longer than gas dryer and the capacity is smaller.  

I just looked at the installation instruction for my dryer and it requires 208~240 V receptacle on a 30 A minimum individual branch circuit.  Also, the condensing hose needs to be connected to a drain.

I imagine to maximize the intended benefit of condensing dryer heating the air near the heat pump it may require matching the timing of usage of the two appliances.  For example, turning on the dryer when someone is taking a bath or having a long shower so that warm air is available for the heat pump when it needs to raise the water temperature in the tank.

Given that the condensing dryer needs to run much longer than vented dryers I wonder if the energy saving on heat pump water heater from using the hot air from the dryer will be equal or greater to the extra electricity needed to run the dyer longer?

I also  appreciate the report.  I've wondered for sometime how they might work on bigger loads.  When my wife and I have used them while travelling... it has always been for small loads while visiting friends or relatives overseas.  Not the heaver loads of towels.   

One daughter that lived in Germany - while attending school, said her complaint was some students refused to dump the water catch tray... and she'd get tired of stuff not drying as fast because of it; the moldy smells as a result.  or getting wet feet when the tray had overflowed on the previous user...  not the fault of the dryer of course.   She said she just started to dump all the trays when she went down to the laundry room..  Some Americans... just can't adjust.

You didn't mention where the dryer is located... if it is in the garage or an area that doesn't need to be heated. Provide a make up air line to that room... seal it off and add barometric damper to let air in as needed.

If its in the heated portion of the house... you could raise it off the floor onto a box frame, add the make up air into the box and use an automated damper to only open up when the dryer is running.


Last thought,  bringing in cold + dry air during the winter time....should actually speed up the drying time in the winter, for a standard electric dryer.   

Condensing dryers that I have seen tend to have smaller volumes - and can require the users to run multiple dryer loads if there is a lot of laundry.    We've used them when in Europe (Germany) - you must remember to empty the water tray after every use... otherwise the efficiency can drop and/or you can get some mold growing in the water tray...


The dryer would be in the basement, and I would only be using if for sheets and towels, which don't hang-dry very well (too stiff according to my wife).

It sounds like it would be mostly seasonal use...  sheets and towels outside during the summer time on a clothes line.... in that case a controlled damper opening up only when dryer runs might not be unreasonable.  But if you do it... insulate incoming fresh air to keep it from taking on heat until it gets down by the dryer...  include a backdraft damper to keep air from trying to get out... 

The RH of the winter time air is likely to be down in the tweens... which means -- you could nearly dry the clothes just with air and tumble dry.... I suppose a home version of freeze drying  :-)


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