In message , The Natural Philosopher
writes
On 14/06/16 14:21, dennis@home wrote:
On 14/06/2016 13:59, The Natural Philosopher wrote:
On 14/06/16 13:38, dennis@home wrote:
On 14/06/2016 12:05, The Natural Philosopher wrote:
On 14/06/16 11:56, dennis@home wrote:
On 14/06/2016 11:04, Tim Lamb wrote:
Underfloor heating.

Insulation thoughts... the existing ground floor has 25mm Jablite
topped
with 22mm chip. Recommendation is to over fit 25mm of pre-grooved
insulation and a further set of flooring: chip + Vinyl or engineered
hardwood.

Downside is loss of height in doorways.

What is the real energy loss in heating a relatively uninsulated
floor
slab in a roughly square building? For 24 hour occupation, doesn't it
come down to what is lost at the edges?

Nowhere near what is lost through the roof and walls before
insulation.
I would guess at less than 10% before any insulation for a solid
floor.
With 25mm of insulation that will take it down to about 2% another
25mm
will take it down to about 1%. Unless the insulation is really cheap
and
labour free it will never pay for itself.

Confirming once again that Denise cant read a post before replying.

And has no understanding of heat loss in buildings or why its different
with UFH.

You really don't understand physics do you!

I do understand physics

If you put pipes onto and they are at 55C that will only about double
the heat loss through the floor and that loss is only the 1%

No, its noth8ng like as low as that

Of course it is, just read what I said and think about it.


I did, and you are still talking ********.

If the house is even remotely well insulated, the dominant heatloss
will be through the floor.

No if the house is at 20 degrees and its 5C outside, that is 15C
across 'whatever the overall path to the outside is' through the soil.

Take that up to 50C with UFH in the floor itself, and its *45C* across
that path, thereby TREBLING the heat loss.

But then I have designed and lived in a house with UFH, have a degree
in engineering, and have done the calculations for heatloss, and you
are a clueless ****, so its all not surprising.

Come on chaps! Keep it clean...

So the 4" concrete pad in the middle of the cottage is in close contact
with piping at 55C. The pipe temperature will vary due to thermostat
demands but should settle at something above say 10C for the surrounding
ground. Slow thermal response is not a huge concern for 24 hour
occupation.

Within the site, I assume there will be a thermal gradient between the
concrete and the subsoil. Is this likely to cause significant losses
other than near the edges?

New work will probably have 4" of insulation under the screed and pipes.




--
Tim Lamb