Heat Pump Dryers - Poor Longterm Reliability?

[dishman]

I was researching heat pump dryers.

The obvious issue is the saving/vs outlay argument and the fact they seem to take longer to dry clothes.

But a secondary issue has caught my attention.

They seem to operate on a similar principal to a condenser dryer, except that unlike a condenser, as much of the latent heat is extracted from the condensed water.

I assume that much like a condenser there is some sort of heat exchanger that performs this function.

However, unlike a condenser, on which the heat exchanger has to be removed and cleaned, it seems that on a heat pump model, the heat exchanger is non-removable and therefore not easily serviceable.

surely this will lead to long term degradation in performance unless a total strip down is performed.

I found a video online of someone trying to clean an in-situ heat exchanger for a heat pump dryer. It looks just as clogged as a condenser one gets, but as it was non-removable an absolute pain to clean.

So, in summary, these heat-pump machines seem to be pretty over engineered, more to go wrong, a pain to service and expensive.

 

[gasbanni]

Regarding dryers a big problem is the lint from clothes, irrespective of whether it's a condenser type or vented. Unless the customer cleans the lint out it will exacerbate the problem. Oddly enough the vented dryers have lint building up much worse than the condenser versions.

It took me a while to work out why.

I personally believe that clothes dryers should be serviced every year just like a gas fire.

 

[dishman]

I certainly agree with you on that....

This applies to the way modern vented dryers are designed.

I have a 30 year old hoover dryer - still going strong. It's filter and vent is directly out the back of the drum. There is no lint build up anywhere other than the simple filter on the back and this can be cleaned in seconds.The venting is direct.

The modern vented ones funnel the air through filters down the front of the door, which are hard to fully clean and then through an inaccessible chamber under the dryer and out the back.

I assume that this is to delay how quickly warm air is evacuated, coupled with the extra insulation on modern machines, I think this is how they have slightly improved the efficiency of the vented type over the years.

But, as you say, the more complicated extraction route causes a lot of hidden build-up

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However, the extra issue with the heat pump type is that is is much hard to clean a sealed in heat exchanger. This will get more easily clogged over time, reducing efficiency than a large vented airway. I do not see how that can be good for the dryer in the medium to long term especially when you consider the removable heat exchanger on a condenser is often blocked with lint after a month or so. so I wonder how much that would affect performance over time.

 

[RichardMNZ]

Cutting back on fabric softener helps them to last longer. Some have self-cleaning condensers where the water from the container is flushed through. Too much softener can leave a greasy sticky buildup inside the machine.