How do you keep humidity under 70% in the UK?

koalakoala

Turn the heating up?

TELLIT01

We live in a 1930s built house with cavity wall insulation and loft insulation plus double glazing etc.  Even when external humidity is 90%+, the internal doesn't go above 60%.  Lack of ventilation is possibly the cause of excessively high internal humidity.

ProTofik

Status update, spoke to my friends and turns out 2 of them were in exactly the same situation, that is after insulating their house they started suffering from high humidity. Both invested in PIV and both say it did the magic by bringing down humidity from around 70-75% to 50% with no significant hit on house temperature. 

Anyway, I have just ordered PIV unit and it should arrive within the next 2 weeks. I will report back once I have it installed with results... 

twopenny

It's not even cold yet.
I'd have thought between the mild weather and rain it would be best to open the windows and doors unless you are in a very high crime area.
A machine and running costs seems overkill.
3 min shower or extractor fan plus extractor for cooking if you do a lot plus ventilation would work.

BikingBud

ProTofik said:

Status update, spoke to my friends and turns out 2 of them were in exactly the same situation, that is after insulating their house they started suffering from high humidity. Both invested in PIV and both say it did the magic by bringing down humidity from around 70-75% to 50% with no significant hit on house temperature. 

Anyway, I have just ordered PIV unit and it should arrive within the next 2 weeks. I will report back once I have it installed with results... 

Not sure I understand this. Did they have high RH or condensation?

Insulating the home should increase the temp, reduce cold patches and cold bridging and enable the air to carry more H2O, dew point moves up.

If you're wiping windows down every morning then their is a cold surface perhaps the fact that they are not new (7 years old) may be part of your problem. Do you leave them open at all overnight?

ProTofik

twopenny said:

It's not even cold yet.
I'd have thought between the mild weather and rain it would be best to open the windows and doors unless you are in a very high crime area.
A machine and running costs seems overkill.
3 min shower or extractor fan plus extractor for cooking if you do a lot plus ventilation would work.

I do open windows for 5-10 minutes 2-3 times a day whenever weather permits, but when it's raining opening windows just makes humidity inside the house worse. Running cost of PIV is near to nothing, it draws like 15W at full speed and apparently I will rarely need it running at full speed. 

BikingBud said:

Not sure I understand this. Did they have high RH or condensation?

Insulating the home should increase the temp, reduce cold patches and cold bridging and enable the air to carry more H2O, dew point moves up.

If you're wiping windows down every morning then their is a cold surface perhaps the fact that they are not new (7 years old) may be part of your problem. Do you leave them open at all overnight?

Both, RH of about 70% and condensation on windows in the morning. My windows are indeed 7 years old, I can see manufacture date printed inside every single one of them saying 2014. I do not leave windows open overnight, that would be a huge waste of heat. I do not wipe them every single morning either, but I had to do it few times over the past 2-3 weeks as temperature outside gets into single digits and inside at night is 17C or so.

I do open all windows in my house 2-3 times a day for 5-10 minutes at the time to exchange stale air. On a day with good weather, it drops indoor RH down to about 60% or so but it's usually back up to 70% within 2-3 hours. My bedroom with door closed at night gets up to 80% in the morning.

Anyway, my PIV is on its way, I will report back once it is installed.

VT41

ProTofik said:

twopenny said:

It's not even cold yet.
I'd have thought between the mild weather and rain it would be best to open the windows and doors unless you are in a very high crime area.
A machine and running costs seems overkill.
3 min shower or extractor fan plus extractor for cooking if you do a lot plus ventilation would work.

I do open windows for 5-10 minutes 2-3 times a day whenever weather permits, but when it's raining opening windows just makes humidity inside the house worse. Running cost of PIV is near to nothing, it draws like 15W at full speed and apparently I will rarely need it running at full speed. 

BikingBud said:

Not sure I understand this. Did they have high RH or condensation?

Insulating the home should increase the temp, reduce cold patches and cold bridging and enable the air to carry more H2O, dew point moves up.

If you're wiping windows down every morning then their is a cold surface perhaps the fact that they are not new (7 years old) may be part of your problem. Do you leave them open at all overnight?

Both, RH of about 70% and condensation on windows in the morning. My windows are indeed 7 years old, I can see manufacture date printed inside every single one of them saying 2014. I do not leave windows open overnight, that would be a huge waste of heat. I do not wipe them every single morning either, but I had to do it few times over the past 2-3 weeks as temperature outside gets into single digits and inside at night is 17C or so.

I do open all windows in my house 2-3 times a day for 5-10 minutes at the time to exchange stale air. On a day with good weather, it drops indoor RH down to about 60% or so but it's usually back up to 70% within 2-3 hours. My bedroom with door closed at night gets up to 80% in the morning.

Anyway, my PIV is on its way, I will report back once it is installed.

Any recommendations on a PIV? What’s the difference between that and a dehumidifier? 

koalakoala

You need a lot more fresh air in your house than that !

Rosa_Damascena

ProTofik said:

Status update, spoke to my friends and turns out 2 of them were in exactly the same situation, that is after insulating their house they started suffering from high humidity. Both invested in PIV and both say it did the magic by bringing down humidity from around 70-75% to 50% with no significant hit on house temperature. 

Anyway, I have just ordered PIV unit and it should arrive within the next 2 weeks. I will report back once I have it installed with results... 

Please do. I want the low down on this kit.

I have an old fashioned barometer that I kept safe during my recent build and you have reminded me to dig it out and hang it up again! I want to know how humid my home is now.

Just checked - humidity is 69%, its beautifully sunny outside but the barometer predicts storm. It cost £4 from a chazzer, you can't get much better value than that!

twopenny

My bedroom window is open 75pc of the day.
The back door an hour or two.
Moisture content in the air is important to your breathing especially if you have central heating.
Humidity in the house should be up to 60pc.
Are you monitoring the air or the plaster?