Underfloor heetings. Wet or electric

[simoncrute]

Hi,
We're having a new conservatory fitted soon. We want underfloor heating, but we're unsure weather to go with wet or electric.
The conserbatory will be about 21m2, the U value of the glass (two walls) is 1.9, and the roof will be 25mm 4 chamber polyguard at around a u value of 1.6
The floors will have 65mm of insulation between the concreet and the screed.

The wet systems will be cheaper to run, and it looks like it's not too much to install if there will only be one circet.
The electric systems I've been looking at see to have a sensor in the screed as well as a room thermostat to control the heat correclty.

None of the wet systems I've looked at do a sensor in the screed.

So, question 1) is it really nessisary to put a sensor in the screed for a wet system, or is that just to govern the temperature that the electric systems might heat the floor to?

Question 2) I'm looking at Penguin europe this for the electric systems, and Centinental here for the wet system. Does anyone have any stories (good or bad) about either company ? (private is fine)

I'll post a summary of any info I get, and I'll report back with what system I went for and what it's like

Thanks
Simon.

 

[oilman]

Wet systems use the water as the sensor, and set the water temperature. The wet ones have lower fuel costs, but the electric ones have lower maintenance costs.

 

[AdamW]

Seeing as you (probably) already have a boiler and wet central heating system, you might as well make the most of it by using a wet system. Electric heating of any sort can turn out to be VERY expensive to run.

 

[oilman]

Expense of electric systems is usually seen as the running cost. The cost of maintenance of wet systems is mostly conveniently forgotten. There are many ways of illustrating any point you want to make, we have an electric Aga, it runs on off peak electricity. We have had it for around 18 years, and apart from guarantee work when the design was new, we have not had it "serviced". Contrast this with an oil fired one which would cost between £50 and £90, twice a year. This is not to say one is better than the other, but running costs are not the only costs of owning a system. (The running costs of either are about the same).

I make a living out of maintaining peoples wet systems. I have an electrician friend who makes his money by doing almost everything except maintenance. Once he has fitted heating, that's more or less it.

Imagine the cost of sorting out a leak under the floor, and something will HAVE to be done. If the electric heating stops, it just stops, you don't HAVE to DO much.

 

[simoncrute]

People have commented on the maintance cost of wet systems.

What maintance is typically required ? I thought that beyond the anual service of the boiler, not much was required.