DeLonghi dehumidifier DEM10 working well or not?

[YorkshireMidge]

Have had one of these small dehumidifiers for some years and it was last used around three years back to dry out re-plastered rooms and it seemed to be working fine at that point. It has been languishing in the garage since - and I have just stripped it down and cleaned the filter and the evaporator and condenser matrix as they were full of crud.

Running it up (in the warm house, not the garage!) with the case off, all looks and sounds well. Fan runs, compressor runs, evaporator is cool/damp to touch, condenser is warm, good airflow in/out - but it doesn't seem to draw out as much moisture as I was expecting. We don't have any damp problems in our house but I would still have expected more than I got - which was so little, the drip tray was just a bit damp.

The drip tray on these machines has a lip around the drain hole into the water tank, so it needs to fill the drip tray deeper than you might expect before you actually see water coming through into the tank, and I'm used to this delay when the machine hasn't been used for a while and the tray has completely dried out.

So to try and do a more meaningful test, when I got a shower this morning, I filled the drip tray up to the point water started to come through into the tank, and left the machine running and the shower extractor off to increase the humidity. I was seeing a drop of water into the tank every five seconds after this. So I'm thinking it's OK'ish but have nothing to compare it to.

Checking the evaporator matrix temp, it's 8.5 degrees C where the thermistor is clipped on, with a room temp of 22 degrees C so I just wondered if anyone can confirm whether that is normal? These machines probably aren't worth re-gassing if that is what it needs.

Thanks.

 

[Burnerman]

Unfortunately, many domestic dehumidifiers don't work well at this time of the year - when you would think you'd best need it - but haul water out big time during the summer.
An example.....I have one running in a 'dead air' area of the house - there is no evidence of damp anywhere. In the winter it only extracts around 5 litres per week, but in mid summer it can be 5 litres per day (almost!)
If you can see ice forming on the condenser core I think all is well.
John

 

[YorkshireMidge]

Thanks for your reply John. You said condenser core and I assume you mean evaporator? I find that confusing too - as the you'd have thought the core on which the water condenses would be the condenser, but it's actually referring to what is going on with the refrigerant.

Let's just call it the cold matrix to avoid confusion and it's at 8.5 degrees C so I don't see any frosting - and the only time I did was when I ran it up in the colder garage after cleaning out the crud which is to be expected as the refrigerant dehumidifiers aren't designed to run in colder environments anyway. I've established that the cold matrix shouldn't be freezing in a dehumidifier, but I haven't established whether 8.5 degrees is cold enough/normal. My thinking was the interior of a fridge is about 4 degrees so 8.5 for the dehumidifier didn't seem wrong.

I do take your point though that it might just be I'm not getting the humidity high enough at this time of year to test it properly. I might shove it in the airing cupboard with some damp clothes in there and see what it does!

Cheers.

 

[Burnerman]

For sure, I don’t know what happened there.....the evaporator is the cold side and the condenser the hot - sorry!
On my own dehumidifier the evaporator gets coated with ice, the compressor stops and the ice defrosts into the tank. Sorry, I haven’t taken any temperature measurements though.
One test - the property was at approx 8 degrees for 7 days, and extracted only 3 litres of water. Not much!
John