standalone humidistat for bathroom extractor

[sm_jamieson]

Where can I get a standalone humidistat to control a bathroom extractor fan ? Where could it be mounted, and can the control dial be in the bathroom (regs / wet hands etc) Thanks, Simon.

[Andy Wade]

Most electrical wholesalers will have one, or be able to get you one to order.

Here's one example

just Google for "humidistat".

High up is best, as water vapour rises in air. The manufacturer should provide information on which zones[1] their equipment is suitable for. In the absence of such information it will need to be in zone 3 or beyond if operating at mains voltage, or zone 2 if operating at SELV, with the SELV source in zone 3 or beyond.

[1] If you aren't familiar with the zoning concept, try this:

[meow2222]

however it will cost you money in lost heat, and a dehumidifier works out cheaper in the end.

NT

[John Rumm]

Where could it be mounted, and can the control dial be in the bathroom

In Zone 3 - and yes it has to be in the room in question to make any sense since the dial and the stat are part and parcel of the same unit.

Note the unit linked to above is quite deep if surface mounted. IIRC you can partially flush mount it if required (i.e. in a flush box - but the front still protrudes a little).

I have used one in the past and they work nicely.

[sm_jamieson]

Interesting. Any of you folks installed a dehumidifier instead of bathroom extractor ? I guess you could put it under the bath, drain extracted water automatically down waste pipe ? I never really thought about that before. It is of course a problem with extractor fans - the wasted heat. I wonder how long it will be before heat recovery ventilation is enforced by the building regs. Simon.

[Stuart Noble]

Not exactly practical in most bathrooms

[Dave Liquorice]

fan. Haven't looked at the TLC offering yet, bet it's pig ugly. B-)

I do like that image though nice an clear, do they have one a similar one for wash basins in bathrooms?

[meow2222]

some of us do.

I doubt it would fit under most baths, but perhaps in some cases.

thats doable if in the right location. The condensate is deionised water, so it has its uses.

yes, thats better than a vanilla fan, but will only recover part of the heat, and suffers with the same inadequate control method as a humidistatic fan. A dehumidifier humidistat gives correct control, minimising energy use, whereas for good control a fan needs to measure interior and exterior RH and temp, 4 things, then calculate from those when to run and when not.

A dehumidifier also has a heat recovery effect. Condensing water vapour releases heat, so you get more heat output than its electrical rating. In summer one can lock the window ajar and switch the dh off.

Stuart Noble thought:

I dont see why.

NT

[Stuart Noble]

Because it would presumably be plumbed in, and need to have a power source in the bathroom. A bit of a performance to save bugger all

[<me9]

It's coming in for new builds if my reading is correct. There doesn't seem to be much available yet at a reasonable price. I'm hoping there is before my dehumidifier needs replacement.

[meow2222]

optional

no harder than installing a fan. I wouldnt describe a fanned draught of indoor/outdoor air heat loss as bugger all myself.

NT

[Stuart Noble]

A fan is fixed, a dh is a floor standing portable appliance. Give us an example of where it might be located and how it would be wired up.

I wouldnt describe a fanned draught of