Does anyone have experience of reducing the levels of radon in period houses?
Our house is 200+ years old (Grade II Listed), on the outskirts of Bath, with cellar space under the whole house (the cellar has a number of rooms, and roughly 100 sql metres).
Its fairly dry, and only a little musty - so we wanted to see if we could use as a basement, but reading these forums prompted me to look at both humidity and the level of radon (which is high in the area). (Using Airthings)
It was OK in the summer months (when we started measuring - between 100 and 200Bq/m3), so I added a Tornado ST100 DMEV to help circulation in the room I spent most time, and a DH1200 to help reduce the humidity in a room where we store things (with an exhaust of the humid are through an old coal chute).
As we shifted into autumn, the levels have shot up - getting to well over 1000Bq/m3.
The normal approach to Radon seems to be to dig a sump and use a fan to extract out at roof level - not easy with a listed building, but of course our cellar floor is both large, and essentially limestone flagstone on earth - so I;m assuming a sump is likely to be viable,
Taking a different approach, I read that drawing more air into the cellar (PIV) would help - so I added a large fan, drawing in around 900 m3/h of air from our other coal chute, running during daylight hours (to avoid drawing in colder air during the night). (so theoretically maybe turning over the air 3x an hour - although the internal walls of the cellar and the generally "leaky" nature of the house would impact airflow).
Currently, levels are still averaging 500Bq/m3 - and worse, additional Airthing suggesting that in one of the living rooms above the cellar being too high.
At least humidity isn't too bad - averaging 70ish% (not too different from the rest of the house)
Advice/ideas welcome !
Our house is 200+ years old (Grade II Listed), on the outskirts of Bath, with cellar space under the whole house (the cellar has a number of rooms, and roughly 100 sql metres).
Its fairly dry, and only a little musty - so we wanted to see if we could use as a basement, but reading these forums prompted me to look at both humidity and the level of radon (which is high in the area). (Using Airthings)
It was OK in the summer months (when we started measuring - between 100 and 200Bq/m3), so I added a Tornado ST100 DMEV to help circulation in the room I spent most time, and a DH1200 to help reduce the humidity in a room where we store things (with an exhaust of the humid are through an old coal chute).
As we shifted into autumn, the levels have shot up - getting to well over 1000Bq/m3.
The normal approach to Radon seems to be to dig a sump and use a fan to extract out at roof level - not easy with a listed building, but of course our cellar floor is both large, and essentially limestone flagstone on earth - so I;m assuming a sump is likely to be viable,
Taking a different approach, I read that drawing more air into the cellar (PIV) would help - so I added a large fan, drawing in around 900 m3/h of air from our other coal chute, running during daylight hours (to avoid drawing in colder air during the night). (so theoretically maybe turning over the air 3x an hour - although the internal walls of the cellar and the generally "leaky" nature of the house would impact airflow).
Currently, levels are still averaging 500Bq/m3 - and worse, additional Airthing suggesting that in one of the living rooms above the cellar being too high.
At least humidity isn't too bad - averaging 70ish% (not too different from the rest of the house)
Advice/ideas welcome !
