Damp? humidity?

[Tommy91]

I’ve recently moved into a 1940s bungalow and there’s a damp issue in most rooms. As it’s recently became colder over the last month, the damp has increased significantly. 

I’ve been looking at MHVRs as I think one of the main issues I have in the property is that the ventilation in the property isn’t great. 

Does an MHVR system generally reduce dampness / humidity?

[Redbeard]

Tell us about the current heating system, temperatures maintained and relative humidity. What does your ventilation 'system' currently consist of?

[Coanda]

Lots of people here with a lot more experience than me will be along shortly, in the meantime I'll give you my recent experience.

My bungalow was built around 1935 they tell me. I moved in about 5 yrs ago to draughty sash windows leaky wooden floors over a crawl space and virtually no insulation. It was cold but dry.

 

So in goes double glazing, floors sealed up and lots of insulation.

 

Next comes high RF which first showed up as black mould in the bathroom.

I installed better extraction, wiped down the shower after every use and bought a dehumidifier. 

This brought the humidity to bearable levels.

 

I heard about mvhr and did some investigation, turns out Co2 levels are a cause for concern in our modern tight homes.

 

I bought Co2 and RF meters and was astounded by the high levels.

 

I did a DIY installation of mvhr and in one week the change is noticeable.

 

While I was figuring out and installing the system I left the dehumidifier and fans off two weeks.

 

Co2 in the living room and bedrooms with two occupants was well over 2000, I think maybe 2400.

The RF was regularly over 70% sometimes over 80% and one morning 94%

 

After one week of running my system, which is btw underpowered, but better fans are coming, Co2 is down to 1084 this morning and RH was 67. 

A considerable improvement which I think will improve more as the house dries out.

 

 

[JohnMo]

The colder you keep the property the worse the issue. Just put a Shelly H&T (humidity and temperature sensor) in our garden room. Interesting image from today.

 

First is temperature the second is humidity levels. As I heat the building the humidity drops, and as it cools it's starting to increase. Today has been pretty stable outside at zero degs, no wind. So it's not an outside influences.