maximum heat output per m2 from underfloor heating

[mointainwalker]

@ Tony Agile

When it is a question of gas regs, you have a reputation for " If it's gas call a gas-safe engineer, you must not touch it ! "

You really ought to adopt the same attitude to UFH if you really don't know too much and you keep introducing irrelevancies :

"For most people I would still not advise UFH as the main heat source in the bedroom because most people like it warm when undressing for bed and to cool shortly afterwards when they are in bed. Its not nice for me to have to wake two hours later to adjust the duvet when the room has finally cooled down. "

The OP wasn't talking about bedrooms before you introduced the topic .

Are you next going to talk about heating garden sheds ?

 

[big-all]

come on lads can we have a truce please

the thread is so much more valuable with the well reasoned points bought up
its a real shame you cant just both take a step back and respect each others point off veiw

i think points have been misunderstood on both sides [joys off the internet ]

if you dont both hud yer weeshed you will have this big fat hairy scotsman trying to french kiss you both

 

[mointainwalker]

@big all

You're response is good in some ways, however many would say that the forum is best served by highlighting and elimnating the wrong and irrelevant posts.

 

[Norcon]

I've no vested interest in UFH but do install it from time to time.
Have the bs en 1264 performance tables on my desk in front of me and have been scouring the net for them in order to post them up here but no joy. ( came on them a few days ago when I wasn't looking for them)

It states a whopping 216w per/m output with room temperature @15c for screed/ceramic tiles@ 50c flow temperature@100mm pipe spacings@35c floor surface temperature for peripheral areas.
Deep pile carpet according to the bs ( bull sh*t?) can acheive 106.9wper/m with the same parameters.


Not everyone needs their bedroom heated like a sauna.
For children about 15-17c is fine. And then off once the duvet is pulled.
The master bedroom where the old fogeys are sleeping could have a rad fitted to supplement the ufh.
I would usually recommend a radiator in the most frequented living space with its own zone valve.
Ceramic tiles give a superb performance and coupled with a controller capable of boosting the flow temp on start up the two hour re-heat is history.

 

[caz26]

so are you guys suggesting with ceramic tiles underfloor heating is now a more flexible and responsive, i.e. heats up quickly, so no longer really has to be "left on" ? site visit tomorrow from an installer so will post back. Soory mointainwalker not so easy with cellars, they are stone and combed so can't just insulate below.

 

[caz26]

having had a visit from heating guru he said we are looking at 6kw to heat our kitchen dining area. Floor space isn't sufficient for this to be provided by UFH so that appears that. Which takes me back to my initial thoughts that does this mean it's only useful in a very well insulated modern home?

 

[mointainwalker]

6 kW sounds enormous.

How many m3 do you have and what -if any - existing insulation ?

 

[caz26]

Hi,

It's an old detached house of solid stone outside walls (17m of) single glazed window 2m x 1m and another single glazed glass door 3m x 1m total surface area is approximately 28m2 with ceiling height of 3.1m Stone floor with the cool cellars underneath. So total volume of 84m3
some insluation to ceiling above.

 

[Agile]

Which takes me back to my initial thoughts that does this mean it's only useful in a very well insulated modern home?

Thats what many of us have said in this thread. Not just modern though but well insulated as old properties can be made well insulated too.

Mountainwalker has been somewhat scathing of some of the things I and some others have said. He seems to want to convey his satisfaction with his own system to others even if it would not be suitable for their homes or lifestyle.

The reality is that it may well satisfy him but not others! He has already admitted that he does not notice a few degrees and only has his kitchen at 13°C. That would be far too cold for most of my customers when they microwave their recipe dishes.

Be aware that most British people in France are retired and so around the house much of the time for which the heat up delay or the inefficiency of the cool down with UFH is not a problem. Being older they often dress like my father in thick trousers and pullovers.

The reality of my customers in London is that they work and party at all sorts of irregular times and when at home expect to wear shorts and teeshirts. They dont do real cooking and heat up prepared food. For them UFH is not very suitable and particularly not in the minute flats they occupy.

My lounge and kitchen are both at 22.4° but the humidity is 42% and 54% respectively. Real cooking is done here but then the extract fan is used to maintain the normal conditions.

Tony

 

[caz26]

Tony,
My wife might agree that I dress like your father too but I'd beg to differ. We too like to cook but will be cooking with radiators on walls in this instance.

Was about to close thread but now searching pros and cons of an unvented system so thought I'd be cheeky and ask you before I do close this one.

We've an oldish underpowered combi for this big house of ours. I was advised to go for an unvented (attic converted) system. Sounds good pressure wise, so if so couple of questions,

1) what boiler (are any other than worcester that everyone up here recommends up there with them?)

2) take it we don't need a system boiler for this-is there any benefit of such?

3) is there a real risk of existing pipe work failing with this?

Thanking you,

Caz