Electric underfllor heating with humidistat.

[dlt27]

Hi all, thanks in advance for any help.
I have been asked to do some electrical work in a convent and they have been asked if an electric underfloor heating matt could be controlled by a humidistat.
The room is going to be an archive room so needs a dry environment.
I can't see how a hunidistat is going to help as, if stat is satisfied humistat won't work anyway.
I just wondered if anybody else had any experience with this sort of install and if there was another way of keeping the room dry.
The room is only 3m x 2m.
Thanks again.

 

[GBDamo]

Never done anything similar but surely the wrong approach.

Would you not run a dehumidifier off of a humidistat and the heat mat off of a room stat?

Heat will lower the absolute humidity initially but if their is a source of moisture then eventually the air will become saturated again.

Assuming the only source of moisture is from people, i.e.the nuns (stop sniggering at the back) and not damp in the fabric of the building, aim to maintain a constant temperature and then control the humidity.

 

[dlt27]

Thanks. That seems more logical to me.
It is the architect that was asking if I could do it.

 

[Jim_e_Jib]

A dehumidifier set to maintain the correct humidity for whatever they are archiving (paper records?) is definitely the way forward. It's worth investigating the temperature requirements too as it could be that cooling is also required. Consistency is generally as important as absolute values for temp and RH.

 

[davesparks]

I think the best thing woukd be to consult a specialist, as has already been mentioned consistency is important. It is possible that you could end up drying the room out too much and causing damage to the archived materials.

 

[Jim_e_Jib]

The National Archives have some useful information and possibly contacts too

Caring for archives - The National Archives - http://www.nationalarchives.gov.uk/archives-sector/advice-and-guidance/managing-your-collection/caring-for-archives/

 

[davesparks]

A couple if years ago I did some work fitting lights and power into display cabinets at the V&A and the national maritime museum. They are very particular about the environmental conditions inside the display cabinets.

 

[dlt27]

Thanks for all the advice.
I have recommended a humistat controling a dehumidifier and the underfloor heating being controlled by the room stat. So 2 seperate entities. However client is still saying they just want heating matt controlled by humidistat and can't see a problem with it.
Obviously I wouldn't do anything without it being in writing.
I have always installed the matts as a kit before so does anybody know if it could be done?
Am I right in thinking underfloor sensor protects matt from overheating so all that could be done would be to switch supply to underfloor stat via the humidistat.
I just want a bit more of an understanding of why I couldn't do it before going back to client.
Thanks again for any help..

 

[dlt27]

Sorry , one other question when you say a specialist, do you know a company that could advise. I have tried technical division with various matt suppliers and they seem clueless.
Thank you

 

[Jim_e_Jib]

Sorry , one other question when you say a specialist, do you know a company that could advise. I have tried technical division with various matt suppliers and they seem clueless.
Thank you

I don't think an underfloor heating company would be the right people to advise. The National Archives as linked to above might be able to point you in the direction of specialist companies who deal with controlling environmental conditions within archive vaults.

Another option would be to see if your local council has a records archive. They should also be able to advise.

I work in a film archive and for us, the key things are reducing humidity with dehumidifiers and reducing temperature with aircon and keeping the levels consistent.

I don't think heating when the humidity is too high is a good way forward, hopefully your client will listen to you!