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Community and Q&A

What is the best option for dryers?

user-1124821 | Posted in Mechanicals on

In a passive or near passive house (ACH < 1), what is the best option for a clothes dryer that is easily available in the U.S., if used only infrequently (2-4 times per month), with the normal approach being hang drying: a) regular dryer with outside vent (hole in the wall and heat loss) b) regular dryer vented in house through water (humidification issues) c) condensing dryer (more issues mechanically and longer dry times -> more electricity use)?

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  1. user-1109130 | | #1

    Option A only makes sense if your laundry room is outside of the airtight envelope. I'm not familiar with Option B - sounds problematic. We installed an Asko condensing dryer in our recently completed passivhaus and it's been surprisingly good. Yes, the drying time is longer than US brands but that is the case with most European appliances. Our old Bosch vented dryer had long dry times. I don't know that longer drying times necessarily equate to greater energy consumption. The biggest bonus for a heating climate is that the condensing dryer generates a fair amount of heat in the envelope.

  2. GBA Editor
    Martin Holladay | | #2

    According to Natural Resources Canada, "condensing dryers take considerably longer to dry than vented dryers, consume more energy and may result in more wear on the clothes as a result."

    For more information on clothes drying options, see Alternatives to Clothes Dryers.

  3. user-1109130 | | #3

    Thanks for the link Martin. While you have quoted the summary sentence, the body isn't quite so clear on the extent in regards to stand alone air-cooled models.

    "The energy consumption of condensing dryers has not been established because there is no standard test method. However, since vented dryers remove moisture more efficiently than condensing dryers, we expect condensing dryers to be somewhat less efficient than vented dryers, as far as the drying of clothes is concerned. However, condensing dryers that are part of a combination washer-dryers is likely much less efficient than vented dryers for a different reason described below."

    "Stand alone air-cooled condensing dryers are the only dryers that safely recover the energy used for drying clothes and release the heat (but not the moisture from the clothes) indoors." Good for a heating dominated climate (but bad for a cooling dominated climate).

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