Garage Conversion - Big Heating Error

[morningbell]

Hi All,

We've almost finished a garage conversion, just the last snagging items to go.

Unfortunately, we've ended up in a situation where the plumbed in radiator is massively underpowered to heat the room. Clearly either we should have realised, or our builders should have advised that 1 radiator of 6200 BTU and a towel rail of 1000 BTU in the bathroom would not heat the space properly, but now we're in a situation where we have an almost finished garage, with walls plastered and painted, and flooring laid, where we need an additional heating source. I've seen a BTU calculator late in the day which suggests 11-12000 BTU would be needed to heat the room based on the layout.

I attach a floor plan, and 2 images (sorry for the mess!) of the garage. The intended use is as a multi purpose room, and also to use as an extra bedroom. It is around 25m squared with 6m square of glazing (skylight, patio doors, 2 windows).

I'm looking for some advice as to what might be the best course of action to take. We have 3 double plug sockets (marked by the "X" on my basic floor plan) in the room, which could take an electric radiator, or, would you advise the upheaval of plumbing another radiator in? I don't necessarily mind the upheaval of plumbing another in (the boiler could take it), but i'm at a bit of a loss as to know what to do.

Any pointers or advice greatly appreciated!

Make sure you're looking at the BTU output on the best heating calculator that's based on the right T number. Do you need T50 or T60 for your boiler?

If you do need an extra radiator you could put another vertical one here maybe, coming off the bathroom pipework?

Have you tried it? Is it cold? Might just be fine??

What's the capacity of the boiler? Might be your boiler is too small to cope with the extra distance? We had to replace a 28 with a 34 for this reason.

Slightly different idea. Could you add in a heat pump air conditioning unit? That could give you 3kw of heat for 1kw cost of electric and could cool the space in summer when needed dehumidify etc

@SueGeneris - Yes the radiator is getting very hot, and system has been balanced.

@Indecisivelurcher - It's based on T50. Unfortunately that wall would be a no go as we'll be attaching a wall bed there (to maximise room space)

@Kshhuxnxk - The boiler is big enough to cope with the setup as is- although i'd need to check it could deal with another one if added.

@walksen - interesting suggestion, have you got any suggestions for a suitable one to use?

Have you looked at the different output between a white rad and a grey one? When we were choosing rads (10 years ago, admittedly), there was a big difference between the same model of rad in white vs anthracite. That could be an easy fix?

You'll have to ask your builders for some advice on where one could go then I think @morningbell! Try not to worry, I'm sure it'll get resolved.

@ReviewingTheSituation - Yes i noticed white rads seem to output a bit more generally, although the modern looking ones (the ones we like from an aesthetic perspective) tend to output slightly less.

From an aesthetic perspective the ideal would probably be another vertical anthracite radiator on opposite wall near patio, but that may be the most difficult solution to achieve! So i think we'll have to think practically to get the extra output.

@Indecisivelurcher - Yes it will get sorted one way or another i'm sure, there's always something that crops up in a project like this!

Something like this maybe.

I am getting close to 6900 BTu's with the room calculations you have provided. When the rad is not giving out enough heat, it could be that you need a baffle piece inserted on the first section part to push the heat up the vertical rad. This could be your issue really as you mentioned it was 6200 BTu for this rad and then the towel rad separately.

Put an addition rad back to back with the towel rail.
Change the other rad for a larger one with a better BTU output. (Easy pipe mod)
Maximise system efficiency by lagging exposed pipes under floor spaces and outside rooms to reduce heat losses. Add foil as you suggested.
Balance the CH system to ensure the rads in the system evenly warm and distribute heat throughout the house. (See video link)

www.google.com/search?q=balancing+central+heating+system&oq=balancing+centeal.hwatimg.system&aqs=chrome.1.69i57j0i22i30l2j0i22i30i395l3j0i390i395l3.14057j1j7&client=ms-android-samsung-ss&sourceid=chrome-mobile&ie=UTF-8#

Great idea to put another one back to back with the towel rail as this will reduce the plumbing massively.

@saleorbouy, @BigotSpigot - You don't foresee any issues with a radiator in that position not heating the room efficiently (given it's position in the corridor, rather than main portion of room?).

Perhaps that allied with a bigger radiator in the existing position might be the best bang for buck option?

interested in solution (but don't have any wisdom to add)

Wood burner?

You could put the vertical one you have now back to back with the towel rail (and make a different plan for the bed - didn't read that before) and then buy a matching, perhaps horizontal but bigger in the original position to go further along that wall. Again, not much plumbing change and you would definitely be warm enough.

It's a tricky space to heat and underfloor would have been better (but more expensive). At least spacing the radiators would heat more of the space more evenly.

I wouldn't see the position of the rad in the corridor as an issue as you could get a good size horizontal double convection rad there and it will bang out the heat into the room. It would only be a couple of holes through a stud wall and a couple of T joints to modify the pipe work. You could tuck the pipes nicely up close to the rad as they run along the corridor wall so they're not unsightly.
Rads were traditionally placed under windows to make effect of the cold air circulation currents. With modern draft free glazing and insulation this has negligible effect now.

Have a look at infrared heaters rather than mess with your plumbing.
I put an infrared heater mirror into a new downstairs cloakroom, rather than dig the floor up for a radiator squeezed in.
It heats the space really well, and economical to run.
www.herschel-infrared.co.uk/

Just buy an electric eco radiator and put it against the long wall, or wherever you need it. Can be hung or on feet. Just needs a normal socket. You can programme it with your phone. Costs about £200-300?

I'd add another column radiator to the wall to the left of the patio doors. So diagonal to your existing one.

All of your heat is coming from one tall radiator in a far corner at the moment. It won't radiate out to fill the whole space.

It's good that you've picked the issue up now whilst hopefully your plumber is still on the job.

@Aphrodite31 - I'd definitely consider an electric radiator. Any idea how much they cost to run compared to plumbed in? The only downside is i have a smart heating system with smart TRV's on most radiators so that would end up having to be controlled separately, but it's a minor inconvenience.

@PoshWatchShitShoes - That would be my preference for a radiator location from the perspective of saving all available space in the main room. But probably would be the most upheaval to get one plumbed in there.