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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Plumbing Questions >> LOG BURNER AND UFH? https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1289467930 Message started by scotspark on Nov 11^th, 2010, 9:32am

Title: LOG BURNER AND UFH?
Post by scotspark on Nov 11^th, 2010, 9:32am

I have a mate who is going to build a garage/workshop.

He wants to put in a log burner but was wondering if he can have it running UFH in the workshop.

the principle sounds straight forward but what needs to be considered in doing this?

Cheeers

Scotspark

Title: Re: LOG BURNER AND UFH?
Post by CWatters on Nov 11^th, 2010, 10:43am

The short answer is yes but..

Wood burners are essentially uncontrolled devices (if the water gets too hot the flames can't easily be turned down automatically). This means that the system has to be carefully designed with safety in mind. For example it's normal to have some kind of large "dump rad" somewhere to dissipate any excess heat once the water in the system is at the set temperature or at the max safe temperature (say 90C). Also a Pressure Relief Valve in case the water does boil.

UFH needs lower temperatures than rads so some way of dropping the water temperature from the burner is usually required - usually either a mixer, a thermal store or both.

There are also issues with using pumps (what happens to the water temperature if there is a power cut?). I believe this means the dump rad is usually on a gravity loop meaning it has to be higher than the burner. Best get it designed properly.

If the combined Workshop/garage is over 30 sqm the workshop will require Building Control Approval and they will take an interest in the level of insulation and heating.

Title: Re: LOG BURNER AND UFH?
Post by scotspark on Nov 11^th, 2010, 4:44pm

there is no planning or building control involvement. He spoke to them and they said what he is doing requires no involvement. (we are in scotland so rules might be different).

still at the planning stages but its gonna be a wooden structure on a concrete base.

I know that there has to be some way for the water to flow in the event of pump failure just wasnt sure what.

guess he is gonna have to speak to someone about getting a proper design done.

thanks SS

Title: Re: LOG BURNER AND UFH?
Post by big_all on Nov 11^th, 2010, 4:53pm

a wood burner will easily heat a workshop on its own and iff you want better distribution off heat place a fan up in the eaves where the temperature will be around 5 degrees warmer ;D 8-)

what size is your workshop ?

Title: Re: LOG BURNER AND UFH?
Post by CWatters on Nov 11^th, 2010, 5:11pm

Yes not much point putting UFH in if the stove is in same room.

Seems you may need a Building Warrant if you fit a wood stove...

http://www.pkc.gov.uk/Planning+and+the+environment/Building+Standards/Building+standards+-+building+warrant+applications+and+completion+certificates/Exemptions+-+domestic.htm

Title: Re: LOG BURNER AND UFH?
Post by scotspark on Nov 11^th, 2010, 8:50pm

his thinking was that you dont want the room to warm to work in but if the floor was warm then you are warm.

Title: Re: LOG BURNER AND UFH?
Post by big_all on Nov 11^th, 2010, 10:03pm

the trouble you have is underfloor heating has a very long time lag is very inificiant and wont warm quickly is designed for continuous use in very well insulated buildings with little heat loss