Undfer floor heating in conservatory revisted

[ChrisJ]

Thanks to all those who replied to my last post back in February.

We used a ramp made from scaffold as the back door is at the bottom of the steps so we couldn't pile rubble there. The ramp has been great. Got lots of other garden jobs done at the same time! The wheel barrow worked a treat even without a huge run up.

As the garden itself is pretty flat due to having been terraced when built the precautions from The Natural Philosopher were great but not required.

The conservatory is on the north face of the house. The east wall of the conservatory is all block, the north and west faces all glass. We have gone for suspended timber floor. The joists are 12"x1" at 12" centres and are at the same height as the current floor so teh damp proof runs through. We've got the water laid on from the new bolier to just inside the house where the door to the conservatory will be ready to run the pipes to.

Quotes for electric and wet kits are about the same at around £400 for

4mx3.5m incl thermostats etc. So I've learned that Electric is easier to install but more expensive to run. Wet is cheaper to run but more expensive to install.

My new question is will electric UFH warm up the room quicker and if so by how much? Will it halve the warm up time or will the fact that the heat loss will be so great counteract this?

Its probably going to be used at the weekends in the spring/ autumn/ winter for the kids to play in and in the evenings in the "summer". If we want to spend a whole summer evening down there and it gets chilly at

9pm we don't want to have to wait until 11pm for the room to get warm. Equally we don't want to have to turn the heating on at 7pm in order to be warm at 9.

Also is it a big job to run the wet UFH at different times to the rest of the house central heating? Our room is in the loft so warms up when the house heating comes on. We don't want to be baked out of bed by the whole system coming on when we only need to take the chill off the conservatory. It normally comes on at around 6am. Obviously electric UFH has its own completely independant timer.

Any comments?

ChrisJ

[Guy King]

The message from ChrisJ contains these words:

Depends on which system you've opted for. If it's part of the main radiator circuit, then it's not really possible unless you're going to run round turning off all the valves. If it's got its own pump or is plumbed back to the CH/HW valve then it's trivial.

[Christian McArdle]

It will start quicker, but the effect won't be huge. All underfloor heating takes time to warm up. However, the electric will cost 3 or 4 times as much to run and will release twice as much CO2.

What you need to do is subzone your heating system. When I moved in, my house was plumbed in as all one zone. However, with the addition of several zone valves, I now have completely independent timing control of 4 zones, which are the loft, upstairs, downstairs and kitchen. The conservatory will be a new zone again.

The ease of subzoning depends entirely on your current pipework layout.

The building regulations do not require separate timing control for a conservatory, although in my opinion they should. They do, however, require separate temperature control for sleeping, living and conservatory areas. This means that a system that overheated parts of the house because another part needed heat would not comply with building regulations. You may need to install TRVs.

Christian.

[David Hansen]

On Wed, 10 May 2006 21:29:50 +0100 someone who may be ChrisJ wrote this:-

Underfloor heating is not something that does rapid changes of conditions. However, with a suitable control system it will cope with changes in temperature easily. The ideal control system has optimum start and stop, using internal and external temperature sensors. You tell it when the room will be occupied and it will turn the heating on and off as it thinks fit in order to have the right conditions when the room is occupied. It will also have weather compensation built in to cope with autumn/winter/spring conditions.

If you want a system to rapidly warm up the conservatory, as and when required, then install power radiators. These still need to be on a separate zone. Control can then be simplified to a time clock, though you might operate them manually most of the time.

The conservatory should be on a separate zone, with separate controls. Then the house and conservatory will operate separately, though the boiler is common.

Separate channel on your existing programmer, if you have a spare one. Alternatively a separate controller. This will control valve(s) or pump(s) and boiler as necessary. The pipework needs to run from a suitable place, which depends on your pipe layout, to the conservatory.

[Christian McArdle]

Separate timing control is normally achieved using a programmable thermostat in each zone, with the main controller either absent to set to 24h.

Christian.

[David Hansen]

On Fri, 12 May 2006 09:25:22 +0100 someone who may be "Christian McArdle" wrote this:-

Works of the devil:-) Instead of having everything in a boy's toys area one has to walk to an individual toy:-) The sooner such things are banned the better:-)

More seriously, controls are best grouped together. This is especially important as they become ever more complicated and it is important to see what is going on.

[Christian McArdle]

I tend to prefer the override controls etc. to be near to the point of use. Why would I want to go down two flights of stairs and faff about in the understairs cupboard because I wanted a 2 hour boost in the bedroom?

Christian.

[Doctor Drivel]

"ChrisJ" wrote in message news:44624cc5$0$5927$ [e-mail]...

A neighbour just had a new conservatory and had electric UFH heating installed. It is so expensive to run they just do not use it. Conservatories are best heated by Myson convector heaters run off the CH hot water system. These can be at high level. You switch on a few minutes before you enter and they heat up fast. Switch off when you leave.

Go to fan convectors:

[Doctor Drivel]

In a commercial setup I would agree. Don't give the office workers control of the temperature as thermostat wars break out. The fat people always want it cool and turn the heat down - I find far people very self centred people thinking only of themselves. Then the normal people get pissed off when the place is too cold. In one office I replaced all stats with tamperproof stats.

In a domestic house centralising the controls with remote sensors as the CM67 can have, serves no purpose. Some like to have a basic cheap timer controlling all the heating, so when they go out, one controller will switch off.

[ChrisJ]

Thanks again to everyone for the feedback. I've had a pair of pipes run to the conservatory from a T at the bolier meaning its not part of the CH for the rest of the house. Currently it has a couple of valves inline so that the rest of the UFH can be plumbed in without having to drain the whole system. The UFH has its own pump and thermostat, not sure about a timer. At weekends the CH boiler is on from 6am to 9pm with the rads all having thermostatic valves (except the one in the loft bathroom for some reason, do you need to have a radiator without a thermostatic valve? Our old bolier had the hall radiator (near the thermostat) permanently on (tap removed). The new boiler is a combi with a wireless thermostat.))

As such the controls in the conservatory should enable us to control the heating in that room without going to the boiler.

ChrisJ