Underfloor heating in conservatory

[nos]

Hi All,

I've just moved into a new house and I'm currently looking at the many projects which will keep me busy for the next 12-18 months. The first question I have (there will be others ) is regarding underfloor heating in the conservatory. Currently the floor is tiled and I wonder if I can use the existing tiles as a base for underfloor heating and then place the new tiles on top. Would this work? Would there be any downside to this type of installation?

This leads on to my next question... what type of underfloor heating system would be best for this kind of installation, electric or water? If either system is suitable, does anyone know the difference in running costs?

One last question, there is currently a radiator in the conservatory, would this still be needed if underfloor heating was installed?

Thanks.
nos

 

[mac391]

Laying underfloor heating then tiling on top of existing ceramic tiles fine so long as you prep the floor correctly with primer (neat neoprene). I don't know about water systems but most sites/sellers will give an estimated cost to run electric heating.

You should use insulation such as marmox to keep running costs down and increase warm up time. Most cable systems for under tiles are 3mm and come on a matt (easy to install) or as a single coil (not easy to install)

Electric heating systems come in differnt watts for each room and are specific for a conservatory so you should be able to take the rad out.

 

[Richard C]

To remain a “conservatory” & not subject to Building Regulations, the heating system must be capable of isolation from the main property heating system & be independently controlled; no idea if your existing radiator install meets or ever met that requirement but it’s not difficult to achieve. You must also have an external door, meeting current insulation standards between the main property & the con’s or it becomes an extension which must meet current Building Regulations; realistically, you have no chance.

That out of the way; given the above, adding a wet u/floor system to your existing property heating system may be problematic so electric is probably the easiest & least disruptive way to go. Marmox under the element as advised or a high % of the heat will be going into the base & will seriously affect warm up time & runnign costs. Allow 200 watts/sqm (with no rad) to make sure it will cope but a con’s is not much more heat efficient than a greenhouse. Don't believe the website blurb, be warned that given the dramatic heat loss of a cons, it will not be cheap to run in the winter months if that's what you plan.

 

[nos]

Thanks for the replies. You've confirmed my initial thoughts. I'll look into using marmox as that makes sense.

We do plan on using the conservatory during the winter a few times a week as a second TV room, it won't be all day everyday, but a few times a week. I'll be interested to see what the running costs will be.

Do you recommend a particular make of system to use or are they all virtually the same (price wise/running costs etc)?

Cheers

 

[big-all]

heat loss in conservatories can be horrendous
underfloor heating is designed to run continuoisly and give low background heat

i would suggest you do your heat loss calculations as i think you will find underfloor heating is likly to only supply 25 to 50% off the heat required on a cold winters day

 

[IJWS15]

When we put our conservatory up my estimate of heat loss with a 15 degree difference was around 5kw.

We don't really use it in winter - the odd days we do we run around 6kw of electric heaters.

 

[Richard C]

We don't really use it in winter - the odd days we do we run around 6kw of electric heaters.

We don't use ours from around November through April either. We have 4.5kw running under 22sqm with decent floor insulation, K glass Argon glazing units, cavity insulated dwarf wall & a 40mm poly roof & although the system will cope down to around 5 degrees but much lower & it struggles, is running at full tilt & costs a bloody fortune. If you want to use it in winter, my advice would be to have a proper garden room but they cost just as much as an extension.

 

[JBenway]

Electric underfloor heating can be considerably cheap to run, but you have to worry about the insulation in the conservatory. I would recommend installing an electric UFH mat with adequate Marmox insulation. You can then place new tiles on top of this without dramatically increasing the height of your floor. I guess you could gain a little more insight here: http://bit.ly/cL413T

 

[Richard C]

As I’ve already said; good Floor insulation & the use of Marmox mats under the element will only reduce heat loss through the floor & improve warm up time by reflecting most of the heat energy up through the tiles. It will do absolutely nothing to prevent the massive heat loss even an above average conservatory construction will suffer through the UPVC roof & all that glass; conservatories by their very nature are only marginally more heat efficient than your average greenhouse!

This thread is also 7 weeks old!

 

[randyandy]

Hi,

We have started to insulate traditional polycarbonate roofs & plasterboard & skim under the existing glazing bars.
Keeps the look of a conservatory roof from the outside with a traditional ceiling on the inside.
Warm in the winter & cooler in the summer.