Under floor heating

[xaero1]

Right people, it's been a while since my last proper rant

Under floor heating.

Which absolute inbecile decided this would be a good thing to put throughout my apartment (which I rent) when it was built? Then, which absolute imbecile decided to put underlay and carpets on top of it?

The result is this. Underlay makes it more difficult for heat to rise upwards and into the room. This means my heating elements need to be at the maximum 30 degrees in order for the room temperature to reach about 20.

This means my apartment is using 35 units of electricity per day. According to Southern Electric an average UK household uses 10. Apparently, it would be 3 times cheaper to heat my bedroom using an oil filled radiator than it would to use under floor heating.

I'll repeat that: 3 times cheaper to use an oil filled radiator

That's crazy, absolutely crazy.

I've been really careful with the heating too. Only certain areas have it turned on and even those are on timers. My hot water tank only heats up at night so I get cheaper rates etc.

Let me give you an idea of the difference in bills with heating turned on and heating turned off:

May - August (off) = £89
November - Feb (on - winter) = £401

Ridiculous.

So this is a lesson to all. Anybody that is doing up their house should avoid under floor heating like the plague. You have been warned.

[Miguel - Newera]

We used to have under-floor heating in our old house in Tokyo. Tried it and loved it... nice & toasty floors But were shocked to see it had cost around 600 quid to heat the house for just one month, so we never used it again for 7 years after that. Just used electric oil filled heaters instead which cost a small fraction in comparison.

In Japan mostly fan assisted parafin heaters are used. They're pretty economical, the only pain is filling them up with Parafin from time to time and having to go to the petrol station / home centre to fill 20 litre containers up every couple of weeks. They work well - where we live now can get pretty cold sometimes in the winter... although probably no colder than most of the UK at the same time of the year.

Funny enough most houses (even new ones) don't have central heating in Japan, only air conditioning (Which is a bit useless in the winter)... If we ever get to build our own home around here - I want to make sure we have proper wood burning stove connected to a boiler to heat water in two circuits. One for use, one for heating. Doubt we'd have under floor heating again though!

[tonigmr2]

That is the way to do it! My parents have underfloor heating which is very toasty (under concrete and tiled floors mind, seems daft to put carpeting on top!!). But they are linked up to a huge wood burning furnace!

[RSVFOUR]

Problem is underfloor heating heats the floor not the room .
Unless you have tiles its near as useless

[Robbie J]

its only worth using if you have that solar or that heat exchanger under the garden....

[craftymonkey]

You might find that it has something to do with sound regulations for the apartments.. the flats could have fail the sound checks then they installed underlay and carpets to get it through regs. The electric heating cost is crazy but my friend has just got a £900 gas bill!!!

[gavman]

Originally Posted by RSVFOUR

Problem is underfloor heating heats the floor not the room .
Unless you have tiles its near as useless

rubbish
you just need the correct underlay

[gavman]

Originally Posted by xaero1

So this is a lesson to all. Anybody that is doing up their house should avoid under floor heating like the plague. You have been warned.

i couldn't disagree more- underfloor heating is the best thing since sliced bread.
however it needs to be combined with a ground source heat pump to be cost effective.
it has cost me just over a grand to heat my house for a year, including hot water, and it's been bare feet and t-shirt right through the winter. there's even an air conditioning unit that takes the heat out of your house in the summer and puts it back in the ground, making your heating run more efficiently

i strongly suspect that your flats have the wrong underlay fitted. any underlay designed to insulate noise will also prevent underfloor heating from working correctly.
also, underfloor heating run from a conventional boiler is very inefficient....

e2a
just checked my leccy bill, £1500 for 18 months including heat and hot water

[Zed Ed]

I've got some electric underfloor heating, under tile, and it works well. On all the time, which I think is cheaper than on/off cycles, where the floor loses retained heat.

No experience of it under carpet though.

[gavman]

mine is under a thick carpet and the proscribed underlay for underfloor heating, and like you say runs 24/7

i have a concrete floor and the combination is still nice and springy/soft to walk on

[gtrsmiles]

Originally Posted by gavman

i couldn't disagree more- underfloor heating is the best thing since sliced bread.
however it needs to be combined with a ground source heat pump to be cost effective.
it has cost me just over a grand to heat my house for a year, including hot water, and it's been bare feet and t-shirt right through the winter. there's even an air conditioning unit that takes the heat out of your house in the summer and puts it back in the ground, making your heating run more efficiently

i strongly suspect that your flats have the wrong underlay fitted. any underlay designed to insulate noise will also prevent underfloor heating from working correctly.
also, underfloor heating run from a conventional boiler is very inefficient....

e2a
just checked my leccy bill, £1500 for 18 months including heat and hot water

Agreed, best way to have under floor heating is with a wet central heating system. Problem with radiators is that they are always next to a wall so a lot of the heat you are paying for is just soaking into the wall, and the rads have to be hot so they are able to emit the heat into the room.

With under floor there’s non of that heat loss, and the water temp can be considerably less and still reach the thermostat temp in the same amount of time as heat is coming from a much larger surface and rising up into the room. Much more cost effective than using conventional radiators. And the posh systems have a digital thermostat timer in each “zone” so you have dining room, lounge, hall and kitchen for example, so you can tune the times and temperatures in the areas on the house to suit your life style (no point heating the kitchen all evening if no one’s going to be in there) making it even more cost effective.

Only thing is its expensive to install so payback period will be very long, but if your having a new central heating system installed its defiantly worth looking into it.

[TAZZMAXX]

I've never like the idea of underfloor heating as I don't like having warm feet. We do have an open fire in our living room so that's where we spend most of our time. My wife shovels coal on like it's a Pacific loco - sod the carbon footprint! My car drops down to 4 mpg when I really nail it so I'm unlikely to worry about burning fossil fuels.

[gtrlux]

Cool thread,

Had been looking in to this things recently as I am planning for my future house.

Basicly the under floor heating is only eco if you use appropriated boilers, pipes and in best case ground heat or solar energy input.

Here in japan where many old houses have only one floor, they put long flat cussions under the floor (wood or tatami), these cussions get filled with a substance that keeps heat better then water. Throught the middle of the cussion flows your avarge central heater hot water.

So if you want to be eco in a sense of optimal energy usage which equals cheaper heating cost for the household, these are the tree points you have to look at:
1) What floor are you using (stone, laminate, wood ex . . .)??? get appropriated materials for floor heating
2) Choose a new boiler and in best case combine it with solar energy or ground earth heat sources.
3) Don`t go for the cheapest piping/cussion systhem for under the floor, as you need something that spreads heat and is easy to heat up. Then the systhem has to be durable and as many cheap installations loose performace over the years.

[Turks]

I have just installed this in my house in the bathroom and kitchen, both of which are tiled on a concrete / screed slab. I have used the electric system as this was much easier to install - a wet system would have meant either breaking out the concrete to lay the pipes and re-pour or raise the floor about 100mm to lay the pipes on top of the existing slabs. I know that there are systems that are thinner but resistance wiring was good enough for what I needed.

I have to say that underfloor heating is fantastic, used in the right way it can be very energy efficient. Heat rises so what better way is there to heat a room than evenly distributed heat over the footprint of the room? Wet systems are the most efficient when combined with the correct boiler and heat exchanger - Solar / GSHP / ASHP.

xaero1, as others have said, your underlay is acting as insulation. The heat from the wires isn't conducting through properly and therefore not radiating throgh your carpet as it should. Lots of air pockets for the heat to get through before it reaches the carpet. So, the problem isn't your UF Heating, it is your floor covering... could change the rant to daft Landlords?


Turks.