Plumbed or electic heater in sun-room?

Herzlos

I'm looking to get a sun-room build later in the year, about 3x3m, on the North facing side of the house in Central Scotland (so it won't see that much sun).

I figure it's going to need a heater at least over the 8 months of winter, but I'm not sure whether it makes sense to get a water radiator plumbed into the central heating (which means presumably lifting some floors in the house, and plumbing work), or if it can get away with a small electic heater that can be fitted at the same time as the electrical sockets.

Presumably, the plumbed radiator would be the best option, cost much more to install but be cheaper in the long run, and the electic one would be cheap to install but expensive to run. I've no idea how to determine which is the most MSE. Does anyone have any advice?

jblessing

Not sure what the difference between a sun-room and a conservatory, but I do know that for a conservatory, building regs do not allow you to connect directly to the house central heating system, there must be a separate pump and thermostat.

Herzlos

Sun rooms have a tiled roof, and in this case it'll need a firewall, so 1 side will be brick, 1 will be the house, and the other 2 will be brick/glass.

I'll check with the architect about building regs, that may take the decision out of my hands anyway, thanks

Wookey

Assuming you have 3 external walls with this build including largish windows you would be most likely looking at two rads, i would tie it into the house central heating on the basis that if it's cold enough that you have to heat it the house central heating is most likely to be on anyways, the extra water being heated will not be that much. Having the heating on and then running electric heaters is a far larger running cost.

One thing though that should be looked at is whether the boiler output is high enough to cope with the extra space/demand and if the pipe sizing is adequate, two smaller low level rads below windows would be the best option but this is something you need to check with your plumber thoroughly before deciding on.

Herzlos

Thanks, good points. The boiler was slightly over specc'd when I got it fitted so I'm assuming it'll be up to the extra room, but I don't know about the pipework and will need to get plumber to confirm the specs.

Wookey

If the nearest central heating pipes are 3/4" (22mm) then there should be no problem running a couple of smaller rads, if they are 1/2" (15mm) then they will most likely need to travel back until they can connect onto 3/4", one other option depending on if the boiler is outside or in a close by garage would be to take two pipes from it over into the sunroom, this depends on proximity and ease as opposed to possibly ripping up a lot of floors inside the house.

Your plumber should measure up the sunroom including insulation/outside walls cavity thickness, how many walls face north etc to determine the size of radiator(s) needed and the extra output the boiler needs to produce, this is likely to be 5000 btu (1.5kw) upwards.

Alex1983

If you go down the plumbed route and you can get the pipework back towards the boiler I would consider making a separate zone. That way you will be able to have your heating on in your sun room without having to have the whole house heated.