Two Speed Switch for Fan.

[goggs]

Hi guys, I've made up a sort of experimental air con system to transfer heat from the log burner in the living room where it cooks, to two bedrooms via 6 inch Wicks expandable ally tubing. Now the fan is a Screwfix Manrose inline flow fan in the Ducting line I've fitted in loft.
The fan is two speed and I wired live to slow speed terminal in fan via a switch.
Question is, how can I operate the high speed without using a separate switch.
And yes it does heat the other rooms without using Radiators.
Thanks,
Goggs. [/b]

 

[bernardgreen]

You might have created a dangerous situation.

Sucking air out of the room will reduce the efficiency of the chimney to remove the fumes from the log burner. Toxic fumes may be drawn out of the fire and into the house.

 

[goggs]

Err, the multi fuel stove is enclosed by a door. The living room gets hot and the warm air is sucked out of a vent in ceiling and blown into the rooms. No fumes are evident.
This is a sort of simplified system that is fitted in United States/Canada and modern houses in this country via a heat source in loft. They say it does away with radiators in an Air Con way of heating. £'s to run they say but I'm sceptical.
Another variation is to box in the flue pipe, add an inlet and outlet and blow outlet air to rooms. Efficiency improved.
Add a water coil to flue pipe and box in yet again. Inlet and outlet to indirect tank. Efficiency yet improved.
We could go on.
Goggs.

 

[riveralt]

Stoves stipulate that the efficiency of the boiler will be compromised if the set up is as you have stated. The ducting should return to the 'boiler room'.
http://www.stovesonline.co.uk/stove-heat-distribution.html

Regarding your fan - you don't what model it is or its size - there are manrose variable speed fan controls but they are model/size limited.

 

[JohnW2]

Err, the multi fuel stove is enclosed by a door. The living room gets hot and the warm air is sucked out of a vent in ceiling and blown into the rooms. No fumes are evident.

Even though it has a door, unless it's 'room sealed' (which I doubt), it must be drawing air from the room through some ventilation opening in order to burn the fuel. If that is the case then, as Bernard said, a sufficiently powerful fan could (via that ventilation opening), if thereis not sufficent external ventilation, draw into the room fumes which are meant to be going up the chimney. It's good to hear that 'no fumes are evident' but, of course, many of the most dangerous components (like carbon monoxide) are not 'evident' until they show themselves by harming or killing someone.

I think that's why your approach is questionable. For it to be safe, one has to ensure that there is sufficient 'external ventilation' such that when the fan sucks air out of the room, it is replaced by (presumably cold) air from outside the house, not by what was meant to be going up the chimney.

Kind Regards, John