Exploring a Heat Pump Clothes Dryer | Ask This Old House

Ask This Old House plumbing and HVAC expert Richard Trethewey tests out a new dryer that uses a heat pump to dry the clothes.

Steps:
1. Standard electric dryers use electricity to power an element that heats the dryer to dry the clothes inside. The water, lint, and excess heat is then vented outside.
2. A heat pump dryer, on the other hand, uses refrigerant to catch the hot air from the dryer and that element is then pushed through a compressor to make it even hotter. That new hot air is then pushed back into the dryer and the cycle repeats itself.
3. Heat pump dryers don’t require vents, but they do need to drain. There’s a hose that can be run to a drain or there’s a built-in catch that collects water for up to two cycles before it needs to be dumped.
4. Heat pump dryers need 40-50% less energy than a standard electric dryer, though the operating time required for the heat pump dryer is slightly longer.

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From the makers of This Old House, America’s first and most trusted home improvement show, Ask This Old House answers the steady stream of home improvement questions asked by viewers across the United States. Covering topics from landscaping to electrical to HVAC and plumbing to painting and more. Ask This Old House features the experts from This Old House, including general contractor Tom Silva, plumbing and heating expert Richard Trethewey, landscape contractor Jenn Nawada, master carpenter Norm Abram, and host Kevin O’Connor. Ask This Old House helps you protect and preserve your greatest investment—your home.

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Exploring a Heat Pump Clothes Dryer | Ask This Old House

[emmanotsostrong]

I'm here from the Technology Connections video on heat pumps.

[vrdrew]

I have a Bosch model that is pretty much identical to the unit Richard was demonstrating. I live in the UK (where most people don't have dryers at all) and the only laundry space was a lower-level utility room that would have been difficult, if not impossible, to vent to the outside. I was advised to go for the heat-pump model and I've been very glad I did.

Energy use is noticeably lower than with conventional dryers. There is a tiny bit more maintenance due to the need to empty the condensate tank and clean the heat-exchanger unit. Condensate pretty much every cycle. Heat-exchanger fins every couple months.

It doesn't make clothes as "crispy dry" as most Americans are used to. Even on the "very dry" setting, items like socks, towels, and sweatshirts need to spend some time in the handy "airing cupboards" most UK houses have. On the positive side, its probably not very good for your clothes to expose them to very high heat.

I was concerned about moisture build-up in the utility room. But there has been no problem in the 18 months I've been using it. I generally leave the door ajar, or run the overhead fan (the utility room doubles as a lower-level half bathroom.)

Overall I'm very happy with both the efficiency and operation of my Bosch heat-pump dryer. Especially when I see my neighbours trying to dry towels and bedsheets outside on a rainy, freezing, Sunday afternoon in February.

[fiat.freakx]

I just got a GE Washer/Dryer Combo which is only one unit. Never have to transfer the wash load to a dryer but goes into a drying cycle using a HEAT PUMP. I've had it now for 2 weeks and loving it!!

[pmichelen]

I bought the Miele W1 +T1 washer and dryer in May 2020, expecting the same perfect performance as my Miele dishwasher, but it has been a head banging experience from the start. It’s the dryer. The touch screen stops responding, so I can’t dry the clothes. I’ve had the Miele technician out twice. The first time, the technician said the dryer was fine, even though I told him the fault was intermittent. A week later, the dryer stopped altogether. Because of Covid, there is a 2-week wait for a service call. I dried my clothes on a portable line outside, while my $1, 900 dryer stood inoperable. The 2nd tech replaced the touch pad control panel, and I had a month of trouble free drying. Today the touch screen stopped working again. I had to call Miele 3 times because I was disconnected after being placed on hold for extended periods of time. I asked for a new machine, and was told this was not possible until the 4th tech visit. Again I will be waiting 14 days before the tech can come out for the 3rd call. It has become clear that the only satisfaction I will get from this experience is taking a loss, buying a machine that works, and moving on. This seems to be the new Russian roulette of purchasing appliances, sometimes you win, and sometimes you get a hole in your head. I’m posting this to create a record for future buyers who want to make an informed purchase.

[ek]

Rich should make a segment dedicated to the different heat pumps for home usage:

1- Space conditioning
2- Heating water
3- Drying clothes

These together with an induction stove and a convection oven are the key to 100% home electrification.

[mmaxx]

The untold story here is that a regular dryer that exhausts outside also has to bring the exact amount of outside air in. If it is 100deg out then that air is brought into the house, your AC then cools that hot air only to have the dryer heat it up again! Likewise if its cold out then you are bringing that amount of cold air in only to wast heated air to the outside.

[mrgylex]

I have 2 of these Heat Pump Samsung dryers (since I have an oversized Samsung Washing machine) and I this machine!!!! Dries very quickly, Super efficient, no humid hot air, just a bunch of water is pushed out, and it's very quiet. More companies should be making these!

[Upstatecashew]

You know your getting old when a tumble dryer excites you

[westaylor]

Live in the USA and have had a Bosch “ventless” dryer for the past 3 years. We love it. Just need to clean the condensation coils every few weeks, the heat temp is lower and power consumption has gone down. This also eliminates the issue of fires as found in traditional vented dryers. We will never go back to a vented dryer.

[joshdw]

For anyone interested in getting one, I'd like to note that A+++ vs A++ vs A+ makes a huge difference, not only in terms of power usage but also time per cycle. An A+++ heat pump dryer can take approximately 3 hours for a cycle to finish. The higher the efficiency, the longer it takes to run a cycle. Keep that in mind, as I spent ages looking for an A+++ enery rating dryer only to realise the cycle was 160 minutes.

[brassinpocket]

I have a new Meile t1 dryer and I like it. If You are used to a huge gas dryer with clothes from a family of like five you’re not going to like it. These are smaller dryers and you have to get used to it they do work a little differently you cannot do huge loads but eventually you get to learn what cycles/ options work best. Remember these are meant to fit where your dishwasher goes. Rich people have them in their yachts. These are excellent solutions if you’re a renter and there is not proper electric for a traditional dryer hook up and nowhere to vent it! 110% better than going to the laundry mat. Also keep in mind this is the way of the future machines will work this way so get used to it there efficient and safe! I would say the load size is no more than what you would consider a medium load in a full-size washer

[mencken]

We got a Blomberg ventless, and it’s great. We got it as a stackable pair with the Blomberg 1600 rpm spin washer. This washer gets a lot more water out of the clothes than a normal washer due to the high speed spin. The dryer coils are protected by a second filter, which the dryer depicted in the video lacked. The water collected by the dryer goes out a hose into the same drain as the washer. We like this laundry pair very much.

[JamesDonatelli]

Better description than other heat pump drier videos. Nice explanation and graphics. Amazing that it is more energy efficient, just takes longer to dry.

[BB-mqnn]

I have this exact model. The thing is crazy efficient. Like half a kWh per drying cycle. I run about 2 loads a week for myself (it's a smaller than normal sized unit) and running this thing with my 14 cents per kWh electricity it's less than $15 for the whole year of clothes drying.

[NeilMagill]

Excellent video, I have a Bosch Heat Pump dryer (which is excellent). This video explains the process much better than the literature that came with the dryer!

[jimmyrippy]

I bought a Whirlpool model very similar to this one. $138 during Fred's going out of business sale! It takes it's sweet time drying, but it's very energy efficient. I've had it for about 3 months, and I'm happy with it.

[aztex]

These have been standard in Norway for a decade now😁 and mine looks almost like this pne shown. Its a great dryer!

[VentureStJohn]

One of the better videos on how condensing washers work
Thank you

[tz]

Just got an LG heat pump and it's incredible. We're using less than half the energy we did before - and we aren't pushing conditioned air out of our house!

[AuthenTech]

This video is SO GOOD!! (Side note, I think a downside of this "keeping the hot air locked inside", struggles to 100% dry the clothes.. always a tad of moisture that can't be squeezed out... doesn't leave the clothes hot and toasty and dry like a normal dryer.)