Moisture control

Energy efficient construction methods and insulation
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Joeboy
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Moisture control

#1

Post by Joeboy »

Hey Guys,

The temperature dipped here a couple of days ago and we saw some serious condensation on the windows in the morning. Its mostly my fault as I was running a kettle on the woodstove and that contributed massively to the problem :oops:

I've taken my lumps and ran two dehumidifiers for two days so far. In total we have pulled 7 Ltrs of water out of the the air (nasty)!

It led my to wonder what you guys run for moisture control in the house? As we head into Winter there is no doubt that the full home ventilation we normally do via open windows won't be happening. At the same time and as i've sealed the home up there is a greater need for moisture control in Winter. The units we are running are an Ebac2600EX and a Delongi DEM10, very impressed with their work rate.

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They run at 170W (Delongi) to 225W (Ebac), plan is to run the delongi 24/7 on its own at a lowish setting once tanks are not receiving much water. IF i survive SWMBO's wrath. :cry: :roll:
15kW PV SE, VI, HM, EN
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Bugtownboy
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Joined: Tue Jun 01, 2021 12:35 pm

Re: Moisture control

#2

Post by Bugtownboy »

If the house would have lent itself to a whole house MVHR (and we could have afforded it ;) ), I’d definitely have considered one.

We did install a single room MVHR (VentAxia - runs at 2-3W from memory) in the bathroom running continuously, and it certainly ‘feels fresh’ in the house - the unit has a humidistat to go into hyper drive - usually only when we use the bathroom to shower or have a bath.

We do use an externally vented cooker hood to minimise increasing humidity from cooking.

We never fully dry clothes inside the house - tend to wash to the weather forecast And get them on the line early - even in the depths of winter, gets them about 85-90% dry. Don’t use a tumble dryer.
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Stinsy
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Re: Moisture control

#3

Post by Stinsy »

I too face this problem. And from what I've read damp is typical in any property that has had its insulation/air-tightness upgraded. Our bedroom is doubly inflicted because the en-suite is where we shower and the extractor in there is a bit lethargic. I'd be interested in any thoughts on an economical (in purchase price and energy consumption) solution.

We did have a dehumidifier in our bedroom that worked well (in that it filled its drawer with water very quickly, I didn't notice a difference in dampness), but I lent it to someone and it is yet to be returned.

I've read good things about positive pressure ventilation products. Basically this is a fan you place in the attic that forces air into the house and when the air escapes through the cracks it takes moisture with it.
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(Artist formally known as ******, well it should be obvious enough to those for whom such things are important.)
Mr Gus
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Re: Moisture control

#4

Post by Mr Gus »

I've often wondered why kettle atypical plug placements in kitchens don't have a moisture snorkel to the outside, sucking it out before it becomes a problem.

More tech & cappable points within the building, however a change I could get used to easily, if presented the opportunity.

Yup, it sounds daft but...

Upstairs from yesterday we needed to run a dehumidifier for the season.
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Stig
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Re: Moisture control

#5

Post by Stig »

Stinsy wrote: Tue Nov 02, 2021 1:24 pm I've read good things about positive pressure ventilation products. Basically this is a fan you place in the attic that forces air into the house and when the air escapes through the cracks it takes moisture with it.
Is pushing moist air into all the cracks a good thing though? I'd have thought negative pressure (i.e. extractor fan) might be better, I guess it's risky with room-fed combustion appliances though (reversing the flow through the flue :shock: ).

My north-facing downstairs windows (oldish double glazing) were also covered in condensation this morning due to last night's cooking. I don't have an extractor fan in the kitchen (because it's got the room-fed gas heating there), just a DIY MVHR between the bathroom and main bedroom.
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Joeboy
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Re: Moisture control

#6

Post by Joeboy »

Reading the Ebac Web page, they say that it can take a week to two weeks to stabilise the moisture balance at an acceptable level. Humidity in Winter should be 55% to 65%. We are currently at 53% down from 65% 2 days ago.

Historically in rental properties we have seen in one bedroom houses a full three days after decorating for house to be fully dry ( emulsion paint). We are now seeing way less water here at home and I've turned one unit off. I'll run the Delongi unit over Winter in an upstairs room and see if it can pull from the big lounge on the woodstove rising air currents.

I wouldn't mind seeing a link to a drawing Stig if you get a moment?
15kW PV SE, VI, HM, EN
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200ltr HWT.
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Stig
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Re: Moisture control

#7

Post by Stig »

Joeboy wrote: Tue Nov 02, 2021 4:03 pm I wouldn't mind seeing a link to a drawing Stig if you get a moment?
You mean my DIY MVHR? I did a write-up of it (with photos) on the other forum but I'll dig out the photos and see if I can write something again here. Drawings were literally on the back on an envelope at the time!
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Stinsy
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Re: Moisture control

#8

Post by Stinsy »

I've just ordered a dehumidifier from Amazon...

This one seemed to have the best ratio of price/power/economy/reviews:

https://www.amazon.co.uk/dp/B089YK765Z
12x 340W JA Solar panels (4.08kWp)
3x 380W JA Solar panels (1.14kWp)
5x 2.4kWh Pylontech batteries (12kWh)
LuxPower inverter/charger

(Artist formally known as ******, well it should be obvious enough to those for whom such things are important.)
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Joeboy
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Re: Moisture control

#9

Post by Joeboy »

Stig wrote: Tue Nov 02, 2021 5:41 pm
Joeboy wrote: Tue Nov 02, 2021 4:03 pm I wouldn't mind seeing a link to a drawing Stig if you get a moment?
You mean my DIY MVHR? I did a write-up of it (with photos) on the other forum but I'll dig out the photos and see if I can write something again here. Drawings were literally on the back on an envelope at the time!
Please Stig, that would be smashing!
15kW PV SE, VI, HM, EN
42kWh LFPO4 storage
7kW ASHP
200ltr HWT.
73kWh HI5
Deep insulation, air leak ct'd home
WBSx2
Low energy bulbs
Veg patches & fruit trees
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Joeboy
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Location: Inverurie

Re: Moisture control

#10

Post by Joeboy »

Stinsy wrote: Tue Nov 02, 2021 5:46 pm I've just ordered a dehumidifier from Amazon...

This one seemed to have the best ratio of price/power/economy/reviews:

https://www.amazon.co.uk/dp/B089YK765Z
Good for you! I was hesitant to bring this subject up as it's like the darkside of all the good RE work we do. :) I'll plug the Delongi into a meter and update on power used over a few days?
15kW PV SE, VI, HM, EN
42kWh LFPO4 storage
7kW ASHP
200ltr HWT.
73kWh HI5
Deep insulation, air leak ct'd home
WBSx2
Low energy bulbs
Veg patches & fruit trees
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