Cold Drum in Condensing Dryer
stk
| Posted in Energy Efficiency and Durability on
I just got a Samsung heat pump dryer DV22N6800HW and I am disappointed in its performance. The drum does not seem to get hot at all…is this normal? I know that it drys at a lower temp than a regular dryer, but the clothes are actually cool to the touch even mid-cycle. It appears to be running fine, but the clothes are still not dry after 2 hours. Any insights from others who have a heat pump dryer are appreciated. Thank you. –Sid
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Replies
Sid
A heat pump or condensing dryer will not roast clothing like a conventional dryer. It is not unusual for clothes to feel cool or even slightly damp when the cycle ends. This level of "dry" is better because it means clothing will last longer.
Steve,
I was mostly concerned/curious if the heat pump dryer drum EVER got warm over the drying cycle. That's why I checked the drum mid-cycle, vice end of cycle. My unit appeared to never get noticably warm (let alone hot), so does this mean that the moisture extraction process is mainly via dehumidification, vice heating/cooking the clothes to drive of moisture like in a traditional dryer? I had expected the clothing/air to be warmed, but not cooked.
I "dried" some towels and pillowcases for about a total of 5 hours and they were still damp! If this is the normal performance to be expected, then I will be returning the unit. After being impressed and satisfied with heat pump performance in my Mitsubishi mini-split and Rheem hybrid water heater, this dryer feels like an epic fail. I was really excited to get it and go vent free, so I am doubly disappointed.
I had read spotty reports on the performance of condensing dryers (I see them on Craigslist at fire-sale prices) and that's why I specifically went for a heat pump unit.
My Miele normally leaves the load quite warm, and dries in an hour to an hour and a half. Currently it's broken, and the behavior is more like what you're describing - hours without drying, and a cold load at the end.
When the Miele tech was here, he stuck a temp probe in the machine. It was running around 25C (i.e. only slightly over room temperature). Apparently it's supposed to be running at more like 35C, which would feel pretty warm.
Assuming you've complied with the basics - keep filters clean and use a high spin rate to get the water out of the load - anything that's taking hours to dry is broken. Samsung and LG have terrible service reputations. Whirlpool I think still has the design flaw described by Trevor below. My experience with Miele service is terrible. I think that leaves Bosch as the only widely available choice.
Sid,
Have you checked the water tank to see how much water is being extracted? If the dryer runs for a couple of hours, but the tank is relatively empty, that suggests an operational issue.
Even bulky items shouldn't take 5 hours or longer to dry. You might try Samsung again and ask them to escalate your problem. I would look at (1) a free service call or (2) a replacement unit.
If it runs for that long and the clothes aren't dry, it's not working.
The clothes that come out of my heat pump dryer are bone dry, and very warm. The heat pump dryer reuses the heat, it doesn't operate without any heat.
Most ventless dryers drain directly to the house drain, like a washing machine. While a tank is an option, I suspect that is only used in applications where a household drain is not available, like some remote cottage with just a composting toilet and no septic system.
Steve, I'm glad you mentioned the water tank...it's not collected any water! I may have gotten a defective unit. I've asked to return it, but now I am thinking I should get a redelivery of another unit to see how it really should work? Definitely feeling gun shy now and concerned about reliability/repairability of the Samsung.
Trevor, is your dryer a Samsung? Has it been mechanically reliable for you? Thanks.
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My Miele heat pump dryer also can get the clothes fairly hot. I would agree that it likely won't get as hot as a gas-fired or resistive electric heat unit, but that is a good thing for your clothes' longevity (as @Steve noted)! However, for a more delicate load of clothing, I often turn down the temperature to medium even on this Miele unit and I have noticed the clothes being less "cooked". This is another verification that the drum can get hot.
Trevor, what is the brand you purchased and do you still like the dryer?
I have a Whirlpool Hybridcare, now discontinued. It's ok. It dries well, and it does use less energy than a regular drier, even ignoring the savings of not pulling in unconditioned air from outside, which I think is the biggest contributor.
It's got some well documented design flaws. One is that it doesn't do a very good job of filtering the lint out of the air stream. This results in the coil fins directly behind the filter screen getting clogged up over time, and it also means you get a small amount of lint accumulating on surfaces in the room the dryer is in. The second design flaw stems from the first, in that it's impossible to access the coil to clean it without half disassembling the whole dryer. I've done this once, and it took a couple of hours. Assuming I manage to retain what I learned the first time, I think next time it will be not much more than half an hour. I plan to do this annually. So if you're looking for set and forget, look elsewhere. While this model is discontinued, I suspect their current models probably followed on from the same basic design.
We've now had our Miele HP dryer for 3 months and it's wonderful! It's so efficient and only runs on 110V off the solar array. No issues for a 2 person household.
We had the same experience for 10 months, then it died. Unfortunately Miele service is not good. Their online booking tool simply doesn't work. After proposing various ways to blame us (too much soap?), they relented and authorized service - but not until I spent a week badgering them to reflect our warranty in the paperwork. The promised parts delivery on 4/25, then 5/4, 5/11, 5/17, and now 5/23 - clearly just moving the goalposts each time the date is missed. The call center refuses to provide a firm date, or to compensate by extending our warranty for the lost time.
Hopefully you'll avoid this misery, because the efficiency benefits are huge and the machines do perform really well when they're working.
I have a 2022 Whirlpool full size dryer heat pump model WHD560CHW, which is the less expensive of the two currently available Whirlpool full size heat pump dryers. The only thing I wish it had that is on the more expensive one is the inside light.
My clothing comes out dry and noticeably warm to the touch, after approx 1 hour 22 minutes on the Eco setting with dryness set at 4 out of 5. I say approx because it always tells me 1:22 is the dry time duration on the above setting at the start of the cycle, but once it gets down to about 15 mins the sensor kicks in and it will fluctuate from 7 min left, to 9 min left to 4 min left and back up to 8 min left and so on until it is satisfied it is sufficiently dry.
So far I'm happy with the dryer performance. The clothes come out noticeably softer than with a standard dryer.
Mine has 2 lint screens. The manual states to clean the interior one after every load, and the one on the bottom front after every 3 or 5th load (can't remember). I've decided to clean them both after every load, because they both get fairly full.
I bought this Whirlpool because
1. I wanted a heat pump dryer, so the options were limited
2. The reviews on LG and Samsung reliability and customer service and wait for parts are terrible; supposedly the wait for Whirlpool parts is not as long
3. The Whirlpool is the only full size heat pump dryer I could find. My household wanted a dryer large enough to dry a king size comforter.
4. The matching washer was a terrific price, and I got the dryer for several $100 below its MSRP
5. I am partial to Whirlpool because they support Habitat for Humanity by donating appliances for every new house Habitat builds in the US.
6. The dryer is built in the US
After I bought the dryer and read the manual, I saw they recommend service every other year to take the thing apart and get the coils cleaned. I was not aware of that when I bought it, and I would not have been as inclined to buy it had I known. I see others on this thread have either had the coils cleaned or done it themselves. The dryer is VERY heavy so moving it to do this myself may be difficult. The dryer only runs 1-3 times/week, so I'm hoping that, combined with the cleaning each lint screen each cycle, may delay the coil cleaning.
I've seen the hardware cloth screen described by another poster. I believe that there needs to be another screen attached in front of that, which is sealed from the coils on the coil side. Whirlpool probably does not want a screen that can't be removed for cleaning. HOWEVER, anything that gets past the first two screens (and each of those is really a double screen, so it's really what gets past 4 screens) is going to get on the coils. I'd MUCH rather have to lay down in front of the washer and vacuum an accessible screen than take the thing apart to clean coils or pay for service to have that done. Any attempt I would make to attach something would never be as good as if Whirlpool engineered another screen into that location and sealed around it.
What I really hope is that by the time I need to get the coils cleaned Whirlpool will have figured out a retrofit solution, but I don't think they are selling enough of these for that to happen. They are however, constantly sold out of these, so maybe there is hope.
The model the OP referenced is the one sold at Costco. Hopefully OP bought the dryer at Costco and can get a replacement. Also, if you work your way up the chain enough, Costco will put pressure on the mfg to give better warranty service, based on my experience with another appliance.
It's been a known problem for years, and they continue to produce new dryer models that carry over the same design flaw. That tells you they either don't see it as a problem, or just don't care.
I suspect most manufacturers would be happy to have a design flaw that yielded service revenue as long as prospective buyers were unaware of it. I avoided the Whirlpool for this very reason. However, I have buyer's remorse. I'd rather move a heavy machine to clean the coils once in a while than have to deal with Miele service again.