Sanity Check Radiator Resizing

djd

Ok, about ready to finally fix this problem but wanted to double check I'm not going to create some new issue in the process.

My house:
* 1930's era, newer boiler, single pipe steam
* Tiny 8x8x8' bedroom on 2nd floor
* 3rd floor finished attic ~21x14x6' avg

For unexplained historical reasons the TINY room has a massive EDR 35 radiator while the 3rd floor's is ~24 EDR.

The TINY room has always overheated, unsurprisingly. Even with a thermostatic vent the residual heat in that thing would continue overheating the room even after the vent closed down. Typically we just shut it off completely.

Meanwhile the 3rd floor would be very cold in winter and require supplemental heat with an electric heater. We have just done an insulation and air sealing project as plan to convert this to a year round bedroom. The insulation work will certainly help, but per some calculators online it could probably do with a larger EDR 35 radiator.

Soooo I'm thinking about a switch:
* TINY room gets a new right sized radiator (EDR 8)
* 3rd floor get's TINY's old EDR 35 radiator
* The old 3rd floor radiator goes to the recycling center

Possible unintended consequences:
* I'd be reducing my total home EDR from ~330 -> ~310. Doesn't seem like too much but *shrug*.
* Possibly some rebalancing although both of these radiators are at the end of their runs so I assume minimal impact.
* Other things I haven't thought of... please chime in!

Steamhead

Don't take the old 3rd floor rad to a recycling center. Someone can probably use it.

What size is the steam pipe going up to the 3rd floor?

djd

Steamhead said:

Don't take the old 3rd floor rad to a recycling center. Someone can probably use it.

What size is the steam pipe going up to the 3rd floor?

Pretty sure it's 1.25" and fair enough re recycling. I occasionally see them being swapped on our local Facebook group so can check there.

Steamhead

That should be big enough.

djd

Steamhead said:

That should be big enough.

Otherwise though seems like a sensible plan?

Steamhead

I think so. Let us know how you make out.

ethicalpaul

> I'd be reducing my total home EDR from ~330 -> ~310. Doesn't seem like too much but *shrug*.

You are already reduced because you shut off the too large radiator in the tiny room, don't sweat it

gerry gill

Sounds like you have a good handle on the situation.

djd

Thanks all. Appreciate the sanity check.

djd

Ok so nothings ever straightforward apparently.

Got the new much smaller rad but struggling to get it aligned with the supply valve (pic).
I have tried coercing the supply line up a nudge but no luck.
Doesn’t appear to be an extension coupling that short.
I’m left thinking to drill out the floor slightly at the radiator feet although that feels a bit hacky.

Any other insights appreciated.

jesmed1

djd said:

Ok so nothings ever straightforward apparently.

I’m left thinking to drill out the floor slightly at the radiator feet although that feels a bit hacky.

Any other insights appreciated.

Angle grinder with metal cutoff wheel(s).
Cut off the bottom 1/2" (?) of the radiator legs.
Round over the sharp edges.

EBEBRATT-Ed

Buy an extension coupling the same size as the radiator valve inlet. It comes with 1 male thread and 1 female thread. Install it under the radiator valve.

The coupling will probably make the valve too high, but then you just shim the radiator up with wood spacers you can cut to fit. See below.


https://d3501hjdis3g5w.cloudfront.net/images/products/medium/bmep0114-3.jpg

gerry gill

If you’ve got play in the pipe lift it up or cut the legs with a bandsaw.

Steamhead

Can you get to the pipe below the floor?

djd

Steamhead said:

Can you get to the pipe below the floor?

gerry gill said:

If you’ve got play in the pipe lift it up or cut the legs with a bandsaw.

Yes I can see the full pipe as it runs through a coat closet below. Some lateral movement but nothing up and down. 

djd

EBEBRATT-Ed said:

Buy an extension coupling the same size as the radiator valve inlet.

Looked at that but I’d go from 1/4” too low to prob 1”+ too high.

Probably will start with cutting the feet idea. Hadn’t considered that one.

thanks all

ethicalpaul

Yes I can see the full pipe as it runs through a coat closet below. Some lateral movement but nothing up and down.

If you have good access there you can remove (or have removed) the vertical pipe and replace it with a slightly longer one but otherwise I like @EBEBRATT-Ed 's solution the best. Some little wooden shoes under the radiator feet will be easy.

djd

Job done. No kill like overkill. 

Thanks all.

ethicalpaul

Not bad-- I've seen worse!

djd

And now for the empirical evidence. This room (Guest Room) previously would heat to >90F. Seems to be dialed in now!

In hindsight I should have just replaced the rad to begin with. I spent as much on a thermostatic vent at first, but by the time it shut off, the latent heat in the rad would continue overheating the room.

Anyway, progress!

ethicalpaul

I spent as much on a thermostatic vent at first, but by the time it shut off, the latent heat in the rad would continue overheating the room.

I know this is in the past now, but it's not just the latent heat. If the vent allows steam to fill (any part of) the radiator at any point in the heating cycle, it can't stop new steam from coming in. What happens is the steam that is in there condenses, causing a low pressure zone that pulls more steam in...the vent can't do anything about it.

the only thing the thermostatic vent can do is be closed at the start of the next heating cycle, then no steam will get in and the room won't be heated as much on that cycle

PS: nice data gathering...what product is that?

djd

ethicalpaul said:

PS: nice data gathering...what product is that?

Thanks Paul. Happy to keep learning as I go here.

The data is from Ecobee sensors and recorded by Flair smart vents (https://flair.co/). These control the other half of my balance issues (cooling) by opening/closing register vents based on where the need is (occupancy & temperature). They are a little pricy and the app is a little clunky but they made a big difference during summer keeping the AC pretty consistent in our top 2 floors.