Radiator Type 11, 21, 22

karlitob

Hi all

In general, our house is quite cold. We renovated 10 years or so back - windows, insulation, electrics. I was big on insulation and appropriately sized radiators. We’ve a north east facing kitchen / sitting room. It’s a standard 3 bed semi.

I’ve just learned about type 11, 21, and 22. All our radiators in the whole house are 11. I think our sitting room / kitchen is 8m x 6m x 2.4m. One wall is effectively windows - double glazed. Two type 11 rads were put in. One behind a couch. Both about 1m x 600mm. If I’m correct it’s woefully underpowered.

Ive a flexicom 18sx

Am I correct in presuming that the rads are underpowered for the house in general. Would replacing help.

Thanks for advice and observations

thanks

10-10-20

Hi, if the rads were sized correctly 10 years back, then they aren't technically under-powered now; although when I put those rough details into a radiator sizing tool I get a requirement of 5kW (5068W). Your rads don't seem to match up - 60cm * 100cm in an 11 style of rad is around 1kW, so 2kW for the room in total?

The sizing is based on the setpoint of the boiler and the average room temperature (called delta-T), best check whether the boiler is running at the required temperature for maximum heat output. Most likely yours were sized off a delta-T of 50C.

https://www.bestheating.com/info/understanding-your-heating-output-a-guide-to-delta-t-radiator-specs/

If you're still not able to heat the room, you can move to a more powerful rad, type 22 are the common double ones with interconnected fins. Replacing would help if that's the cause of the heating problem and providing that the 18kW boiler is up to the task.

As far as I can see, a similarly sized type-22 rad to what you have would be spec'd at 1700W, so a good improvement. Perhaps you could go wider though?

karlitob

Thanks. I didn’t put it in but we had a bit of trouble with the plumbers at the time. The downstairs of house has always been a bit cold. Upstairs heated up in 20 minutes - no problem. Downstairs on the other hand. They didn’t put insulation on the pipes under the suspended floor (build caught it for us). And a few other things that all added up.

Thanks for that. Upstairs and downstairs are never on at same time. Neither is the hot water to be fair. So I think - if I’m reading things a correctly - that the boiler is plenty powerful for the ground floor. We’ve turned off the utility radiator by the TRV, have the toilet down to 1, the office down to 2, and have the hall turned off as well so it’s only a radiator in a small sitting room and two in a large kitchen : living room. It shouldn’t be this cold I don’t think.

thanks for the help. And for the link. Much obliged.

10-10-20

Oh and to add... I sized the room with a wall of 40m^2 of double-glazing off what you said - whether that was right or wrong - I don't know, but don't take it as factual until you enter in the parameters yourself. 👍️

https://www.bestheating.ie/btu-calculator

And a rough and ready sizing is to add-up the rads like this:

Sizing:

• 1 kW for small radiators.
• 1.5 kW for an average-sized radiator.
• 2 kW for large radiators.

Then factor in around 3.5kW for the cylinder.

karlitob

One other question, if you wouldn’t mind.

Im changing the size of the rad in the small room. It’s very long and the new wardrobes won’t fit in. Is there a general aesthetic when it comes to rad to window size. The current rad is just about the same width as the window width. Too narrow will look silly. So I presume somewhere in the middle.

10-10-20

It's personal preference really but it should be aligned with the center of the window. Oversized rads is all in at the moment as it allows you to run the system cooler.

karlitob

Good man. Thanks again.

karlitob

I’m planning on replacing the radiator. It’s just too wide to fit the new furniture in. It’s a small room.

I presume a standard radiator from Chadwick’s would be satisfactory.

I have to come in about 300mm (150mm each side). Do you reckon there would be any problems with the pipes. I’m hoping it’ll slide across ok once I knock out a bit from the noggin.

do I need to buy tails etc or will they come with the radiator or perhaps I can reuse those in this. thanks

10-10-20

I'm not sure what I'm seeing there. Isn't that a new 11-type rad piped up off copper tails and new pex run under the floor. I think I see the original copper pipes over to the right side, so the original rad was piped from the side like that. Am I right?

Most rads only come with mounting brackets and not valve kit or tails, at least my Stelrad ones (from Chadwicks) didn't. Copper tails are normally made-up onsite using a pipe bending tool, so in the absence of one of those, you'll have to either use straight copper and elbows or use pex. You can get pex in straight lengths rather than coiled, so it looks better than loopy tails.

Just about that joist - unfortunately it appears that it could be compromised now due to the cuts made into it. What's it sitting on, earth or stone across the full length of the base? You aren't supposed to cut notches like that, drilling is the only really acceptable way, but maybe it was done as the access to run the pipe up the wall was too tight. If it's not fully supported along it's length then I'd probably brace the joist by sistering it with a strong piece of lumber and work out how to get the new pipes through it.

https://www.thermodial.ie/wp-content/uploads/2016/10/Holes-and-Notches-in-Joists-RECI.pdf

Anyway - a bit of chewing-gum for the mind. 😁

karlitob

Sorry. No context. That was the photo from the original renovation.

Here’s the current one.

The IKEA cabinets come out 60mm and cos the room is so small, I need every inch of space. So I have to get a smaller rad so as to squeeze in the units.

This picture shows the 60mm from the wall where the unit stops. I need the pipes to start there so have to have a narrower rad. Hence my question on what the look of the smaller rad under the window.

My main question is whether you reckon I can just move the pipe across - that there’d be no pressure on the elbow or cause a kink. Might be hard to answer that question of course. Really don’t wanna drain the system. Plumbers didn’t put in a drain off.

Joists: point noted, thank you. I presume I can brace it simply.

Thanks for your comments. Much appreciated.

10-10-20

Right, get you now. I was wondering about your choice of flowery curtains alright. 😂

That's a 100cm x 60cm type 11 rad (~980W). I'd go get a 80cm x 60cm type 22 (or "K2" in Stelrad terms) rad (~1,385w), and install it 5 or 10cm off-center of the window somewhat. That should give you clearance on the lock-shield valve. So what if it's not centered, space and effective heating is the priority here, right? Then go on an notch that joist as you need, but I'd probably look at whether you need to fit a sister under the notches (a single continuous piece of wood) depending on the support under the joist. That is going to mean taking up some more floorboards and also cleaning out that sub-floor. There are guides on sistering online but I think it's 1 nail per 3" of dimensional lumber at 16" spacing.

Yes, this DIY project has just grown legs. 😁

karlitob

It’s a total pain. It’s all in the prep!!!!!

One final (ha) question - I think I’ll have to move the pipes 200mm or so in at either side (or as you suggest, one side and off centre). I’m wondering whether that’ll change it to a straight connection rather than it staying curved - if that makes sense

10-10-20

I’m wondering whether that’ll change it to a straight connection rather than it staying curved - if that makes sense

On the RHS, yes, I would not put an elbow there - go straight. Make sure you have replacement inserts for the qualpex though.

https://www.boards.ie/discussion/comment/121715058#Comment_121715058

karlitob

Hi

Progressing slowly.

Draining system tomorrow.

RHS

Gonna connect up lockshield first. Then gonna put in a straight connector.

LHS.

I presume just cut a bit off and connect back into the elbow. Other option is another straight connector and leave the elbow alone but that’s another connection to worry about.

I have inserts bought.

Anything else I’m missing or comments to make. It’s all going ok so far.