Under floor heating system problem

[SimonH2]

If you were to plot how the temperature of the floor varied over time as heat was turned on, and then off, you'd get this sort of shape:

Read that again, and look at the chart you've drawn.

According to the people who sold the product to the OP, the resolution of the carpet issue is to have more powerful UFH

So ? And do you believe the physics of that ? BTW - the physics is different between electric and wet systems in case you had missed that detail.
According to the people who sell radiators, the resolution of the "need for smaller radiators problem" is to run the system at a higher temperature. Isn't that just a case of "properly designing" the system - or do you think that "not properly designing a system" is justification for stating that the technology involved is rubbish and con only ever be rubbish ?

Not interested - if a thermometer does not say that the air in the room is at 20° then it is not at 20°, no matter how toasty your toes are.

Then there is no point discussing the issue with you. What you seem unable (or just unwilling ?) to consider is that the actual temperature of the room isn't that important. This isn't some laboratory experiment, it's comfort heating - ie the heating provided to make the occupants of the room comfortable. The better it makes people comfortable with the temperature, then the better the heating system - for that is the primary (and really, only) function of a comfort heating system.
A secondary measure of heating system "quality" is how well it does it for how much energy is put in. If, by making feet comfortable, the room temperature can be dropped by several degrees, then thermal losses from the property will almost certainly be lower - and so the energy used will be less, and the heating bills lower.

 

[North]

Can we focus in my problem?

 

[EFLImpudence]

What do you want to know?

You have all the instructions but you don't seem to understand anything.

I know it's been the weekend but what has happened to your fitters?

 

[North]

My last question is how do i check for resistance? I have a good tester, what do i need to look for.
My fitters I do not trust them too much so i want to double check
Thanks

 

[EFLImpudence]

There is normally a form to complete with UFH to record details of the system.

You will need a low ohm-meter.

Before joining the mats-
One probe on one end of the element and one probe on the other end.
The mats should all be the same resistance.
Then when they are joined, do the same again.
The resistance should be the single mat value divided by the number of mats.

 

[North]

That is exactly what i was looking for . Many thanks!

 

[Taylortwocities]

Also check the resistance of the probe before during and after installation. Should be about 10-15kΩ at room temperature.

 

[North]

By the prob you mean the circuit made by the three mats once their wires have been spliced and joined?

 

[SimonH2]

The mats should all be the same resistance.

Not necessarily. They may be different sizes, and so different power ratings.

By the prob you mean the circuit made by the three mats once their wires have been spliced and joined?

No, he means the temperature sensor that goes in the pocket that should be set into the substrate.
Note that the sensor really should be a in pocket and not just buried in the tile cement (or whatever). That way, if (when ?) it fails, or you fit a different thermostat and it needs a different sensor, it can be pulled out and a new one slid in without having to hack the floor up. They should come with a brass pocket and some flexible conduit so you can bury the brass pocket and bring the flexible conduit up to where it's accessible.

Having now had a look at the supplier's site - I see they don't provide this pocket and conduit.

 

[North]

Yes that is correct i have three mats, one big and two small (half size of the big one).
And yes there is no conduit so once the sensor is gone i guess it is bye bye. But perhaps it should be installed near the wall so if it breaks i only need to remove a few boards...

 

[ban-all-sheds]

Read that again, and look at the chart you've drawn.

I have, and there is nothing wrong with it. I do accept though that not everybody can understand how the X axis works.

So ?

So maybe lagging ones heat radiators is not the smartest idea.

And do you believe the physics of that ? BTW

Yes.

the physics is different between electric and wet systems in case you had missed that detail.

I think you will find that a given material will conduct heat according to its k-value, not according to the type of heat source.

According to the people who sell radiators, the resolution of the "need for smaller radiators problem" is to run the system at a higher temperature. Isn't that just a case of "properly designing" the system - or do you think that "not properly designing a system" is justification for stating that the technology involved is rubbish and con only ever be rubbish ?

The question is can a particular technology ever be used to create a proper design?

Then there is no point discussing the issue with you.

Goodbye.

 

[EFLImpudence]

The mats should all be the same resistance.

Not necessarily. They may be different sizes, and so different power ratings.

Fair enough.

In that case to find the value when all the mats are joined, use the calculator at the bottom of the page here:
http://www.sengpielaudio.com/calculator-paralresist.htm

 

[Taylortwocities]

perhaps it should be installed near the wall so if it breaks i only need to remove a few boards...

It needs to be installed between the wires in the mat.

Do you mean boards? Isnt the floor to be tiled?

 

[North]

Hi it is going to be under laminate wooden floor. I have been told to put the sensor under the underfloor foam mat where the underfloor heating mats rest

 

[ban-all-sheds]

My fitters I do not trust them too much

Hmmm.

You know what the best solution is to all the problems arising from that....