Wet underfloor heating, why not do it this way?

[nel5on]

Firstly I don't know about underfloor heating, and didnt understand why you put rad's under windows, until a heating engineer told me about how it worked, heat hits cold window then "tumbles" into room, creating better movement of heat....? I could understand this now...

For wet underfloor floor heating, why not,
Install wet pipes(screeded over), connect to C/H system via two taps and or maybe a Rad thermostat. All done, control the heat via the flow? Could it ever be this simple.

Also my floor is existing, so was going to "chase" the floor for the pipes, will I "lose" any heat downwards as I cant rip up the floor and insulate? (I know heat rises)

Is Wet better than Electric, as opted for Electric in bathroom, but now working on kitchen, much larger area?

Thanks for any advice
Nel5on

 

[Mrs Spanner]

I lived abroad for a bit where they had this sort of system and personally I really didn't like it - it took absolutely ages to heat up and cool down, so you couldn't adjust room temperatures easily. This was especially true in the 'heating up' period because the floor itself gets toasty quite quickly but it didn't heat the room up at all quickly. Other people may think it's the best thing since sliced bread though, so this is just my opinion..

 

[ChrisR]

Install wet pipes(screeded over), connect to C/H system via two taps

Because the floor then gets to 80 odd degrees and you can't walk on it. Many have tried.
There's not much new in the world - spend half an hour reading the various mfrs websites and you'll have a good idea of the diffrerent systems.

 

[wishiwascorgi]

If you decide to channel out your floor for the pipework you will create work and problems that you don't really need. If you have a solid floor then i would recommend what we use in conservatorys although it is not a cheap option, but is very easy to install.

Visit www.hepworth.com

Or your local plumbing merchant has plenty of brochures

 

[nel5on]

My thoughts are, if I reduce the flow, this will in effect alter the floor temp?
I'm not saying anybodys wrong, just want to understand why this wont work?
Cheers,

 

[billy bob]

You will not alter the floor temperature by simply altering the flow, the water needs to be blended to a maximum of 50 deg C

You would need somthing like this http://jupiter-system.com/Productbrochures/MR2A.pdf

 

[Balenza]

Billybob wrote

You will not alter the floor temperature by simply altering the flow

Actually their are valves available to do this but considering what the Op is proposing I would advise him to avoid UF heating.

 

[Corgigrouch]

Its very important that the floor be insulated...you are heating the room not the ground below it!

The whole aim of underfloor heating is to produce an overall ambiance, not a point heat source. Your floor acts as a huge heat store and takes time to heat up and cool down so the water temperature should be closely controlled an predictive controllers are good.. I still see people turning their UF heating on and off and complaining about slow reaction times

Is it just the British who cannot use a thermostat?

 

[welshbikersdotorg]

If underfloor heating is done properly it is very effective. Infact the Romans knew this 2000 years ago, they heated their homes using underfloor heating and cavity wall heating.

Despite people saying it isn't used because it isn't very good they don't know what they are talking about. Ask someone who knows about Physics and you will get an accurate answer as to if underfloor heating is good or not.

The reason we have the traditional central heating system we have with rads hung on walls and pipes coming down the walls and along skirting is for no other reason than ease of instalation. In the UK most housing is from the coal fire era, hence most homes have a fireplace and chimney. to install a complete underfloor heating system in an existing house would be very expensive to the point of not being viable. A far easier and obviously a lot cheaper option of upgrading from coal fires is to hang something that radiates heat from easily accesible walls (radiators) and simply run pipework along the skirting board. This keeps the install much simpler and obviously the price too.

As for the poster who said it can't be done because you wont be able to walk on the floor, well all i can say is it never ceases to amaze me of the level of education this country is offering people. What he doesn't grasp is basic school boy physics of convection/radiation. So here is a lesson for him, and the others that think it can't be done. As the floor area is a lot larger than a radiator stuck to the wall, the temperature required to heat the room to the desired temp would be a lot less from the large floor than it would be from a small radiator on a wall. The other advantage of underfloor heating is a much more even temperature throughout the room. Where as a radiator doesn't have any where near the capability of distributing heat evenly in a room as the heat source is in a far more concentrated area.

The reluctance to install underfloor heating in new builds is for no other reason than because it isn't the norm. Another improvement on a focussed heat source such as a radiator is heating in the skirting board. The entire skirting board heats up so just like underfloor heating has it's heat source much more widely spaced out thus giving a more evenly heated room over the rad and again because the heat is more widely spaced the actual temperature of the skirting is lower than a rad to keep the room at a set heat level.

The skirting board route may be a better option for you as you don't have to chase out the floors, so it would be much easier to incorporate it into an exisitng home.

 

[welshbikersdotorg]

I still see people turning their UF heating on and off and complaining about slow reaction times

Is it just the British who cannot use a thermostat?

My wife is just like this, she thinks that if she turns the thermostat up the heating works faster. Us Brits really are a dumb nation

 

[Balenza]

welshbikersdotorg wrote

As for the poster who said it can't be done because you wont be able to walk on the floor, well all i can say is it never ceases to amaze me of the level of education this country is offering people.

Well I think it is obvious (mebbe not to you) that the poster was referring to the OP's comments on running the UF system direct from the radiator circuit.

 

[Corgigrouch]

In the Summer I do a fair few heat pump installations in shops and offices, I have noticed that when I ask the customer to turn on the unit, they switch it on and then instantly turn the stat from 30C down to 16C, when I ask them why they did that, the answer is always the say same.. Its so it cools down quicker.. once they start to feel cold, then they turn the stat right up to 30... and so on.They always have an English accent but I suspect that if I was to attend a unit in Wales the answer would be the same... I have no axe to grind as I am a Kraut.

Sometimes I really do feel that a small box of plastic is smarter than most human beings

 

[WDIK]

I still see people turning their UF heating on and off and complaining about slow reaction times

Is it just the British who cannot use a thermostat?

My wife is just like this, she thinks that if she turns the thermostat up the heating works faster. Us Brits really are a dumb nation

i was given this tip by a bms engineer.

"how to keep women happy in the office enviroment, just mount roomstats with no wiring"
and let them play to their hearts content

 

[nel5on]

I have no axe to grind about where ppl come from, I'm a kiwi, and I guess thats why I don't take some things from granted...I have a basic understanding of heat, and also know, that if I reduce the flow to one of my rads I can adjust that rads temp output(rad expelling more heat than is getting due to reduced flow) increase the flow a little and it will get warmer.

So the air around the rad is reducing the temp by dissipating more temp than its getting? Is this a fair statement?

Also in regards to the underfloor heating being better, thats why I like the idea, Rads heat rises and stays at the roof, leaving the floor cool, If the rooms heated by the floor the temp is more even, and better convection is achieved.

 

[WDIK]

Ive never seen it done as a retrofit.
ive been to many faults up and down the country where wet and dry systems were fitted all in the same clients premisses.
the trouble is that they require quiet sophisticated levels of control to be effective, very often this consideration is thrown out the window.
oh and in answer to your point about restricting the flow, you will end up with a hot spot as it enters the circuit and it will go cold as it exits.
underfloor heating too hot will damage the floor. seen it happen.
for it to be efficient you need major insulation below it.
sorry but you not thinking this out clearly.