Anyone use a desiccant dehumidifier?

rich68

Hi

I just wondered if anyone has any opinions on desiccant dehumidifiers. I understand the normal refrigerant ones are rated at 30 degrees celsius and do not work well at low temps.

My flat is currently at 10 degrees and 90% relative humidity. I have no condensation problems at all but wonder about the humidity. I should mention that I cannot feel humidity at all, it's only due to having a hygrometer that I know it's high. Opening the windows reduces the humidity somewhat over a couple of hours but then the humidity increases again as soon as the windows are closed.

Would there be any benefit from reducing the humidity or would it just increase costs? I could heat the place more but I have no timer on the heating boiler so if I want heat in the morning it has to be on all night. I can't justify that at the moment as I live alone (it's rented) and it's not that cold yet.

Thanks for any opinions. This isn't something I am thinking about seriously but just wondered what the general views are.

Broadsword

There are dehumidifiers that will work on low temperatures but the "dinky toy" desssicants might work in a wardrobe but do nothing for your problem. The first thing I would do is check your hygrometer. Some are adjustable. 90 is very wet. Outside today, very wet after torrential rain , is in the 80's. Inside I usually manage around 60 (although my hygrometers seem to think 40-60 is normal). If I open a window, it will normally go up not down. So something appears to be wrong. At 90 it should feel very damp. Clothes and bedclothes will often be a good test of dampness (remember camping in a tent?). Are you sure your flat is only 10 centigrade? This should feel pretty cold for normal living (usually 18-20) Humidity will also vary greatly by temperature and warm air can hold more, not less. Suspect the accuracy of the readings, or look for a cause of such dampness. At these levels your tumble drier must be venting inside!

For more information on humidity and calibrating a hygrometer see

http://www.cmhc-schl.gc.ca/en/co/maho/yohoyohe/momo/momo_002.cfm

rich68

Thanks Broadsword, that's really helpful.

I will certainly try to calibrate the hygrometer. I put it in the kitchen tonight and it went up to 100% while I was cooking. There was still no condensation on the window so you may be right about faulty readings.

Yes it is quite cold but just about manageable when I am wrapped up well. As you say, the temperature reading may not be accurate either.

Thanks again

rich68

Although I haven't yet calibrated the hygrometer/thermometer I thought I would bring it to work to see what it reads.

It is currently reading 22 degrees C and 38% relative humidity in the office. So my flat is a lot wetter whether or not the readings are accurate.

Edited to add that the office has no air conditioning.