Dehumidifier

acass106

I got a dehumidifier in 2005 because it was advised to address a damp problem in a cluttered storage room and found my clothes dried quicker there. I've never had condensation issues since. It heats the room as well as drying it. Just look after the plastic tray. I lost a great dehumidifier once because the plastic was brittle and split.

EssexHebridean

Ours will cheerfully increase the temperature in our respectably sized front room by a full degree or more in just a few hours running. It was on for 7 hours in there last night and my tapo plug tells me that equalled 1.22kWh - about 18p on our off-peak rate. 

RainbowsInTheSpray

Would very much like to know other people's opinions and recommendations on this.

Have been thinking about using an electric dehumidifer in my kitchen to address not only condensation issues - kettles boiling, pots steaming, washing up etc. - but also to speed indoor drying of laundry, which I gather these can do. Thoughts on running costs such as the above would also be appreciated.

Qyburn

One thing to be aware of is that a dehumidifier works best if there's no ventilation. You're trying to get the air drier that it would be with through ventilation, so that's a waste if your nicely dried air is vented to the outside world.

Max68

Interesting.  I purchased a De Longhi mobile air con unit many years ago where yopu stuck a flume through the window and emptied the back of the unit when full of water..  Stopped using it as an air con because it was too expensive and even as a fan was more pricey than a general oscillating tower fan but never used it on the dehumidifier setting.  Might be worth a try in the bedroom to try and stop the awful condensation on the double glazing.   Anyone know if you would have to stick the attachable  flume outside the window on dehumidifying mode as it doesn't say in the manual. Apologies if that's a stupid question especially considering the above comment re no ventilation!

jadey2024

I've just started using mine through the night these last 2 nights. I have a dissicant one. I'm in a first floor massionate and have it on landing where all other rooms can be entered from. I leave all the doors ajar, windows shut and find very minimal condensation on windows in the morning. A little is there but on mornings it was not running and with having windows open through night I was getting way more condensation so I'm sold to run it every night through winter now. On med setting. I can't say on running costs for sure as have so much other stuff running through night with 2 storages and 2 panels but I've estimated a kwh or 2 at most. This is 13p a kwh for me during off peak. I run it from 12.30am to 7.30am continuously. The temp in that area before it came on last night (windows were open at that point too and had condensation  which I wiped off) was in the low 13 deg. I was up on and off through night and temp was ranging from 15 deg to 15.4 in kitchen and higher in landing to about 15.8. (No heating in landing/kitchen or bathroom in use) I was going to use a oil filled rad for this area but decided to stick with dehumidifier as these temps are good enough through night. My clothes on horse on landing are a lot dryer by morning too.

acass106

Qyburn said:

One thing to be aware of is that a dehumidifier works best if there's no ventilation. You're trying to get the air drier that it would be with through ventilation, so that's a waste if your nicely dried air is vented to the outside world.

I do indeed shut all the doors and windows but leave trickle vents open and the dehumidifier works great. At night I also throw out glasses of water lying about because the dehumidifier is in the kitchen.

siri_do_one

Max68 said:

Interesting.  I purchased a De Longhi mobile air con unit many years ago where yopu stuck a flume through the window and emptied the back of the unit when full of water..  Stopped using it as an air con because it was too expensive and even as a fan was more pricey than a general oscillating tower fan but never used it on the dehumidifier setting.  Might be worth a try in the bedroom to try and stop the awful condensation on the double glazing.   Anyone know if you would have to stick the attachable  flume outside the window on dehumidifying mode as it doesn't say in the manual. Apologies if that's a stupid question especially considering the above comment re no ventilation!

Possibly not, the quickest way to find out is to try it and see what is coming out of the pipe, if its warm and damp then out the window it goes!

Modern near silent desiccant dehumidifiers only do moisture removal and this requires a far smaller heater element than an a/c unit which also heats.

My daughters dehumidifier operates at about 150w (about 6p/hr these days) which allows her to dry baby cloths indoors without turning the house into a sauna or running the heating on high with windows open. The model she has can extract up to 10 litres a day, but at this time of the year it’s removing more like 2-3 litres per day - that’s still two full kettles boiled dry worth of moisture.

Old Air-con units can be very power hungry (multi Kw), to achieve the set humidity level they create two streams of air at the set temperature with one at near 100% moisture content & the other at near 0%*. Mixing those streams to create the desired humidity level and allowing year round environmental control by simply brute forcing the desired levels, only the most recent computerised units actively monitor the incoming air and adjust the dry/wet ratio on the fly to save energy.

*The external pipe is required to dump all the excess heat generated whilst doing this.

As a simple rule of thumb, whatever energy a device uses to perform it’s job will be converted to heat within the machine and that has to go somewhere.