Are dehumidifiers a false economy in the long run?

shiphen

Hi

I need some expert opinion. We are trying to work out the cheapest way to keep a large house dry. The house is old and is too large to heat throughout the winter and it has some patches that are prone to dampness.

The argument is that although dehumidifiers work well in the short run that in the long run they do damage.

BACKGROUND
I am in charge of a large house in Scotland near the sea (note the possibility of salt spray from storms...) We are having a debate about what is the cheapest way to keep the place dry in the long run. We have fixed the obvious leaks – e.g. in the roof and windows etc – and in most of the house there is no obvious rising damp.

The question is for local damp spots should we use de-humifiers or electrical heaters? Technically dehumifiers will of course throw off more heat per unit of electrical power used than will an electrical heater (due to phase change energy of water). HOWEVER there are concerns that in the long run, dehumidifiers will suck water through plaster and walls (etc) and somehow create dampness in a way that traditional heating does not.

And that using a dehumidifier – although good for recovering from one-off leaks and floods etc – is extremely bad for a building if used over a long period of time. The assumption is that it is something to do with hygroscopic affects of a humidity gradient rather than a thermal gradient.

Is there any scientific truth in this?

J