What's your humidity at home?

always_sunny

if you have a hygrometer, what's your usual humidity at home usually?
How do you keep it low? Just dehumidifier?

DRP

1. Open the windows until humidity drops.
2. Ensure you don't have a damp problem.
3. Ensure underfloor space is well ventilated and air bricks are not blocked.
4. Use extractor fan when carrying out moisture-generating activities e.g. cooking, drying washing, showering etc

Before having damp and ventilation problems seen to, our humidity was up to 80%. We did have a dehumidifier that brought it down, but it went straight back up again (within a few hours).

Now it is generally 45-65% (weather dependent).

daveyjp

Currently reading 70% as its throwing it down and has been on and off for almost 24 hours.

When we have an extended dry and warm period it will be around 55%.

Neither concern me, its just a number and I'm not living in the sealed box required to reduce the figure.

DRP

If you have high humidity and other problems - e.g. lots of condensation or mould on furniture or walls, then they can probably be improved by lowering the humidity.

Waldir

DRP wrote: »

Before having damp and ventilation problems seen to, our humidity was up to 80%. We did have a dehumidifier that brought it down, but it went straight back up again (within a few hours).

Now it is generally 45-65% (weather dependent).

Very interesting.
May I ask what the problem/solution was in your particular case?


In my case I do have some temperature&humidity sensors inside and outside the house, with a little computer formula to tell me if the humidity is below or above the "mould-can-develop level" (for the current temperature), and very often the outside humidity is above that level (almost always when the temperature is between 18 and 22... just when you don't want the extra heat from the dehumidifier ), so opening the windows would make things worse.
According to the sensors, as soon as the humidity is bad outside it becomes bad inside (especially when windy! I guess it's a hint that my house has too many holes but it's not easy to figure them out... I'm thinking it comes from the floor )
In that case I was wondering about DRP's advice "Ensure underfloor space is well ventilated"... I was tempted to actually block those air bricks to see if it would stop the humid outside air from entering the house via the flooring. Maybe a smart thing that would only block it when the outside air is too humid?

esuhl

At the moment, I'm not running a dehumidified and the humidity has been at around 60 to 65% for the past few weeks.

Over winter it got as bad as 80 or 85%, which is when I started using a dehumidifier for the winter months. It took being on for several hours a day for three or four days for the humidity to drop below 60%. After that only occasional use of the dehumidifier was required.

I got the humidity down to 45% for a while, which was nice because it made the house feel so much warmer! It stayed low until it rained or humidity built up in the house (from cooking, showering and drying clothes).

DRP

You're never going to maintain your house at below atmospheric humidity. As i see it the idea is to keep air in damp regions moving through and out.

Our issue is that we have damp muddy ground under the floorboards. The small gap between ground and floorboards had been filled with rubble and airbricks blocked at front and back (block paving and crappy conservatory respectively). This caused damp joists and a nasty rotten damp stink in the house. Wooden furniture would grow a green haze over it.

Over the course of a year my wife and I lifted every floorboard and dug the rubble out. I lowered the block paving near the house, and introduced an new air brick under the front doorstep. When we had a rear extension to replace the conservatory, we made extra sure that we over-did the provision of air bricks at the back , too.

It has all made a huge difference, lowering humidity and no smell.

always_sunny

Thank you - it's not so bad then. Usually it's in the low 60/high 50% but it has been really wet lately so keeps around 70%. There's plenty of breeze and air circulating but it is humid outside. The river is also very close so I am not expecting to be 45%...

Waldir

Thanks DRP!

Always_sunny, I found this "calculator" useful: http://www.dpcalc.org/
You can set temperature and %relative humidity, and see the "mold risk" and "days to mold" on the right.

always_sunny

Waldir wrote: »

Thanks DRP!

Always_sunny, I found this "calculator" useful: http://www.dpcalc.org/
You can set temperature and %relative humidity, and see the "mold risk" and "days to mold" on the right.

It's interesting that the mould risk is only after 65% humidity and takes 2 months to form?

DRP - someone suggested PVA to seal the walls, but wouldn't that prevent the air-bricks to let air in?

lstar337

Ours ranges from about 45% - 60%.

It is up at 60% at the moment due to the muggy as hell weather.