Spec me a dehumidifier please?

jpaul said:
where, in house, are you running it then ? I mean I would be opening kitchen window, maybe running ventilator, and keeping door closed whilst cooking, similarly for bathroom showering.

what was the external relative humidity in comparison too, with any door opening is the internal air just being replaced by more humid external air.
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We mainly had it in the hallway.

Yeah we do open windows when cooking and run the extractor hood.

I'm just surprised that during the week of running the unit the absolute humidity barely changed. So given it's using a considerable amount of energy at considerable cost, I have to be asking if it's worth it.

Yesterday it was clear and cold out, so I opened all the windows and flushed through the air in the house all day. The gauge in the living room read 16 degrees at 59% by the time I closed the windows late afternoon. I then heated the house up to 20 quite quick - the RH went UP to 65%. It does not make sense.
 
danlightbulb said:
Yesterday it was clear and cold out, so I opened all the windows and flushed through the air in the house all day. The gauge in the living room read 16 degrees at 59% by the time I closed the windows late afternoon. I then heated the house up to 20 quite quick - the RH went UP to 65%. It does not make sense.
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I agree dehumidifier result / lack of reduction is confusing.

turning heating on and finding rh increases, because warm air holds more water less so ?
 
jpaul said:
I agree dehumidifier result / lack of reduction is confusing.

turning heating on and finding rh increases, because warm air holds more water less so ?
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The warmer it is the more water vapour can exist, so you would expect if the amount of vapour is constant that the RH would decrease as temperature goes up. Assuming your measurement device is correct then there is only one logical conclusion, if your temperature went up and your RH went up further then there is some other factor actively introducing moisture into your system. Which would seem to agree with the initial issue of the RH not decreasing despite water being extracted.
 
Gammawolf said:
The warmer it is the more water vapour can exist, so you would expect if the amount of vapour is constant that the RH would decrease as temperature goes up. Assuming your measurement device is correct then there is only one logical conclusion, if your temperature went up and your RH went up further then there is some other factor actively introducing moisture into your system. Which would seem to agree with the initial issue of the RH not decreasing despite water being extracted.
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Its been a couple of weeks now since I returned the Ebac dehumidifier and not yet got a replacement. But we're not seeing any change in absolute humidity. Today its clear outside and the internal gauge is reading 72% at 16.5 C. That is 10.1 g/m3 absolute, same as what it was pretty much throughout the time I was dehumidifying.

If I was introducing water at the same rate as I was extracting it, then why did this suddenly stop the day I stopped dehumidifying?
 
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Gammawolf said:
if your temperature went up and your RH went up further then there is some other factor actively introducing moisture into your system
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yes, I badly expressed it, but was speculating, if you had condensation on inside colder surfaces, like windows say, from breathe,
and increased temperature, that could evaporate increasing the RH, so it could be counter productive.
(this am with a few windows a jar overnight some condensation on the inside - if I closed window and turned heating on in that room, say)
 
Still not decided what to do, ebac 3850e or try something like a positive input ventilation. But now it's not the time to be pumping cold air into the house.

I feel the majority is purely down to wife and child at home all day, no extractor in kitchen but do always open windows when cooking.
It can only be breath and cooking.

Even the corners of the window frames get condensation on, bay windows.
 
My old house didn't get any condensation at all, and I hardly ever opened the windows in the winter. It was an early 90's build, concrete floor, old double glazing, so not particularly efficient by modern standards. Yet the humidity gauge never went past 50%. Even when I had a shower and opened no windows, I'd get a little condensation then in the upstairs bedroom window but it would vanish quickly. I dried all my washing inside.

The new house gets condensation without doing anything. Its got newer double glazing than my old house, good loft insulation, but single brick walls and wooden suspended floors.

It doesn't really make sense. The old house was more modern of course, but my lifestyle in it was terrible. Now Im doing everything I can to manage the moisture levels but its having no impact.

How can just the difference between concrete floors with cavity wall, and wooden floors with solid wall, make such a significant difference?
 
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Can you guys recommend any good smart humidity monitors? Saves having to turn on the dehumidifier everythime I want to check. I'd like a smart one so that i can automate it to turn on the dehumidifier when the humidity reaches a certain level.
 
Freefaller said:
Can you guys recommend any good smart humidity monitors? Saves having to turn on the dehumidifier everythime I want to check. I'd like a smart one so that i can automate it to turn on the dehumidifier when the humidity reaches a certain level.
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Ive seen some reasonable information about the Govee device, search for it on the rainforest.

There are two models, one with a display and one that is just a sensor with no display. From what I can see, both log data and can sync it to an app.
 
danlightbulb said:
My old house didn't get any condensation at all, and I hardly ever opened the windows in the winter.
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houses get very stuffy though ... at xmas notice this staying at folks, they think environment is normal but not if you open windows most days.

robj20 said:
or try something like a positive input ventilation
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are there any affordable portable units - obviously needs venting too ... that will transfer heat from inside air before exhausting it




I'd bought/tested this fixed one - earlier thread
jpaul said:
so - hygrometer accuracy/salt test of the eti hygrometer

showed it under-reading by 5% humidity, should have said 75% but says 70% .
....ok the product spec said it could be out


24467203937_e01d70a620_z_d.jpg
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Got this one a couple of months ago, seems they have taken the specs sheet away, pulls 180w on high speed. Very quiet, two speeds, easy removal of water tank and it got the humidity level down a fair bit in the few hours I have run it. Once it was down into the 50s I started opening the windows more and that seems to have done the trick keeping the level to around 55%. I occassionaly put it on if it starts to rise again, works a treat..
I got it for £92 as there was a discount at the time.
 
I've been waiting for weeks for the MeacoDry Arete® One 20L to come back into stock as it seems to be the dehumidifier in that size with the best reviews. Stores are now quoting a 7 week wait so I need another instead. The electriQ 20 Litre looks comparable. Has anyone had any experience with this unit or can recommend something similar?
 
danlightbulb said:
My old house didn't get any condensation at all, and I hardly ever opened the windows in the winter. It was an early 90's build, concrete floor, old double glazing, so not particularly efficient by modern standards. Yet the humidity gauge never went past 50%. Even when I had a shower and opened no windows, I'd get a little condensation then in the upstairs bedroom window but it would vanish quickly. I dried all my washing inside.

The new house gets condensation without doing anything. Its got newer double glazing than my old house, good loft insulation, but single brick walls and wooden suspended floors.

It doesn't really make sense. The old house was more modern of course, but my lifestyle in it was terrible. Now Im doing everything I can to manage the moisture levels but its having no impact.

How can just the difference between concrete floors with cavity wall, and wooden floors with solid wall, make such a significant difference?
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You get condensation when you have warm damp air meeting cold surfaces. Single brick walls = cold surfaces. If the whole house is warm you don't get the moisture condensing out of the air.

They probably breathe as much moisture into the house as out, I suspect. The efficiency of your bathroom and kitchen extractors will be a big factor too.

On the dehumidifier front, I've an old Whirlpool unit. 370w @ 80%RH, 290W @ 60%RH. 20 litres a day.
 
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Doobedoo said:
3 year warranty for £245.90 here

www.meacodehumidifiers.co.uk

Meaco DD8L Zambezi Desiccant Dehumidifier - FREE 3 Year Warranty - DD8LZAM

Experience the pinnacle of dehumidification with the Zambezi Dehumidifier, designed with meticulous attention to detail and exceptional functionality. Built from customer feedback, this versatile unit is perfect for flats, houses, cellars, garages, boats, caravans, holiday homes, and anywhere...
www.meacodehumidifiers.co.uk www.meacodehumidifiers.co.uk
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Just beware these things pump out a lot of heat

Heatpump inverters work better, they are more energy efficient and produce less heat
 
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Blackvault said:
That gives me a ball park to work with. Time to go shopping for a dehumidifier then.
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Mould will grow at over 60% RH, so keeping under 60% is recommended but everyone is different, I personally find 45% to 50% the most comfortable.

Also there is such a thing as too low, you don't really want to go under 30% as not only does it dry your skin out, but it will damage all wooden furniture and your house and it causes the air to contain more static electricity
 
Raymond Lin said:
Bought a Meaco 12L, quite heavy for its size, I guess it's the compressor.

I like the target humidity setting, laundry setting too (i don't have a tumble dryer). It will be useful this winter.

osvn07A.jpg

(Bought one because upstairs humidity has hit 70% where i keep my guitars...and that is bad for guitars!
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Could be the radiator/heat exchanger that adds weight, that's the case with mine (picture below with the back cover removed)

 
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