Condensation

[Harry Bloomfield]

I don't know if anyone else experienced it, but yesterday our house suffered from a huge amount of condensation. The north facing double glazed windows were running even the uPVC frames and the wood frames were covered and the walls and ceiling in our en-suite was dripping even though the extractor was on and the window open.,

No such problems here, despite lots of mist over recent days and 100% RH outdoors.

I've never seen it anywhere near this bad before. Humidity was about 75% upstairs and 65% downstairs. We have reduced our heating and closed off unused rooms. Today the humidity and temperatures are the same but everywhere is bone dry.

I am avoiding use of CH, setting it to 16C round the clock, trying to make do as much as possible with a radiant gas fire in the living room. Even then, the CH very rarely fires. The only condensation I have seen, has been on the outside of the DG windows.

I have a total ban on drying any washing inside the main house, it's only permitted in the utility, on lines with a fan + compressor dehumidifier running. I also have a ban on boiling food in pans with no lids and make good use of an extract hood over the hob.

 

[Wayners]

Run a dehumidifier is the answer.
Just no other way to control the humidity in modern warm homes.
6 hours is about £1 a day

 

[jeds]

No such problems here, despite lots of mist over recent days and 100% RH outdoors.



I am avoiding use of CH, setting it to 16C round the clock, trying to make do as much as possible with a radiant gas fire in the living room. Even then, the CH very rarely fires. The only condensation I have seen, has been on the outside of the DG windows.

I have a total ban on drying any washing inside the main house, it's only permitted in the utility, on lines with a fan + compressor dehumidifier running. I also have a ban on boiling food in pans with no lids and make good use of an extract hood over the hob.

Got a lot of bans going on there Harry. Have you considered an instruction manual.

 

[Harry Bloomfield]

Run a dehumidifier is the answer.
Just no other way to control the humidity in modern warm homes.

That should not be necessary. I would look for other reasons first.

6 hours is about £1 a day

A 100watt dehumidifier, even running flat out continuously, is only 3.3p per hour - 33p per Kwh. Most will not need to run continuously.

 

[Wayners]

I was looking at a 280w machine from screwfix.
6 hours is about right but some days will be less.

 

[Harry Bloomfield]

I was looking at a 280w machine from screwfix.

OK - 280w call it 333w, 1/3 Kw. Therefore 3 hours flat out use, for the 33p per Kwh, or less than 66p for the 6 hours..

 

[Wayners]

OK - 280w call it 333w, 1/3 Kw. Therefore 3 hours flat out use, for the 33p per Kwh, or less than 66p for the 6 hours..

I used online calculator.
I see these problems of condensation all the time in houses including my own.
Although our bathroom is in centre of the house with no window and it's fine. Guess the walls and ceiling is warm so don't get much condensation and any evaporates rapidly.
The velux widows and patio window are running in water in the morning though.
I've seen a few homes with (edit... dehumidifier) and they do really work well and considering getting one myself

 

[Harry Bloomfield]

The velux widows and patio window are running in water in the morning though.
I've seen a few homes with humidifier and they do really work well and considering getting one myself

I guess you meant a dehumidifier, but yes they can be really effective, though an expensive fix if they need to run a lot of the time - better to fix the cause of the condensation or excess moisture.

As already said, I do have one, but it is only used for the one purpose - that of drying washing, which it does very well indeed and quite cheaply, but in an enclosed space, my utility room. An enclosed space, because it would be silly to attempt to suck the moisture out of a large space, especially if it were open to the outside. Hang the washing up to dry without the dehumidifier running and a fan - then the washing takes days to dry, and promotes mould on the utility room walls.

 

[jeds]

Dehumidifiers are useful for removing excessive moisture for specific reasons, but if you need to constantly run a dehumidifier to keep your house RH at a normal level, there is something wrong. My house is well insulated, heating has been on over the last 5 or 6 days, at various times, RH for the last 4 days is max; 53 min; 36. You'd call it a modern construction, with good quality dg windows and doors. I have a humidity extractor in the bathroom, a timed extractor in the cloak and a hob extractor in the kitchen which we do use. Trickle vents are open more or less permanently and the bedroom window is cracked every night.

 

[Harry Bloomfield]

RH for the last 4 days is max; 53 min; 36.

Those numbers are exceptionally low, so I would question their accuracy. 40 to 60% RH is considered the normal and ideal. Below 40% can cause your skin to dry out and crack.

I log/graph both internal and external RH and minimising CH use at the moment, so as you would expect, the RH value has gone up a bit. Air temperature is relevant to RH, warmer air can store more moisture content. It has been steady at 60%, except when I take a bath/shower, or cook.

 

[pcaouolte]

I log/graph both internal and external RH ...

I do the same and I'm showing indoor RH between 52% and 57% at the moment (the variation is due to measuring in different rooms). I have never logged RH below 46% anywhere inside the house.

 

[jeds]

Sorry, that was my bad. The min was 46%.

 

[Harry Bloomfield]

Sorry, that was my bad. The min was 46%.

Quite similar to my usual figures then.

 

[jeds]

I use Govee H5075 hygrometers. Quite cheap and simple but effective. I've got a dozen or so that I use for surveys. They are usually quite accurate but I do calibrate or check them against a Protimeter Psyclone.