Gotanewlife, you want a non-HR far running constantly? Isn't this a rather reckless throwing away of heat, after all we read on these pages about the importance of airtightness?
You say your wood is cheap but that's not really the point is it? It's still carbon, regardless of the price.
If there really are issues with the effectiveness of the heat recovery fans then i can see that the money seems like a waste but I find the idea of using more energy (albeit not much) to pump out heat rather difficult to accept.

Ali.G - nice try (and I am very grateful!) but I want the automatic humidity control (they say it is possible but they don't seem to sell the part), and I don't like the sound of the "one shot" overload protection, 40 deg is a real possibility here. Most worryingly though, they sell the HR25H at a much higher price than others, the manual boost switch is double what it should be and so it could be one of those 'if it seems to good to be true.....' situations. And a core drill is soooo much fun!

Arthur - last I looked burning wood from renewable sources was carbon neutral; no, what IS "reckless" is opening all my windows everyday when the external humidity is less than 60% or putting the dehumidifers on if not, which is what I am and what I have to do at the moment. With 300m2 or so (once upstairs becomes liveable), solutions need to be cost effective. Of course I could have saved so much money by not installing a wood burner and TS in the first place? I am happy with my choices, solar panels, PV making about as much as I use pa, wood for heat: I guess you will accept that.

Sorry Sam - I am in danger of hijacking your thread here.

Gnl, whether or not wood is really carbon neutral (lets not get in to those endless debates here) my point is that burning more than necessary just because it's cheap is still wrong.. Someone else could be burning it more usefully, or the wood could be staying unburnt (and be a carbon sink rather than carbon neutral). Americans could say their petrol is cheap so why not waste it (as they do).

I don't understand the argument about 300m2.

I still can't accept that it's worth spending all that money on solar pv etc and then using a fan to blow heat out of the building. Everything we read on here seems to suggest that airtightness is far more cost-effective and energy-saving-effective measures but, if you have tackled airtightness that seems to me undermined by ventilating in this way.

I don't mean this to seem like a personal attack, I'm just intersted in understanding this issue

My problem with these devices, apart from cost, is that they are mostly designed to operate continuously and therefore do not have a shutter. So if you switch it off, because too noisy at night, there will be a draught coming in.

This one has a shutter:

Silavent Energex Heat Recovery Fan

http://www.silavent.co.uk/products/heat_recovery/energex-features.asp


In Dan’s comparison it is more powerful, therefore more effective? But noisier?

Has anyone any experience of using the Silavex?

Peter