Radiator Size

Mark_96

I have a single pipe steam system. The radiators seem to be randomly sized throughout the house. Several large rooms with small radiators, and small bedrooms with two very large radiators. Should I get them resized, or would thermostatic radiator valves help with the uneven heating situation?

Brad White_9

Start with TRV's

They are a lot less hassle and have uses in several rooms if you eventually re-size a radiator here and there.

Re-sizing can be done but so can digging a tunnel between Great Britain and France.

ALH_4

...or

digging a tunnel under Boston. ;-)

Mike T., Swampeast MO

Room size alone isn't the best way to judge how the rads are sized. Sizing of radiators is based on how much heat the particular room looses. The best way to find out well (or how bad) things are balanced is to conduct a room-by-room heat loss calculation and compare to the installed radiation. In general, the dead men who designed the system at least tried to get decent balance even if they did sometimes use "rules of thumb" that are rather primitive by modern standards.

That said it's quite possible that the rads in some or all of your bedrooms were originally sized under the assumption that at least one window would be at least partly open. The 1918? flu pandemic created a HUGE movement for "fresh air". Also if these bedrooms are on the highest floor and ceiling/attic insulation has been added, they're now relatively oversized to the load...

I suppose it's also possible that some radiators have been changed over the years--not very difficult with one-pipe steam because there's only one connection. If you (or someone) carefully examines the system and essentially performs a reverse engineering you [should] be able to determine if radiator sizes have been significantly changed via examination of the piping.

As Brad mentioned, TRVs have a good chance of helping significantly without getting into the expensive nightmare of re-sizing all of the radiation which could very easily involve changing piping as well...

As long as things are hideously out-of-whack, I'll venture to say that TRVs on the rads in spaces that typically overheat will help.

Don't forget that a FREE heat loss program is available at this site. It comes from a Slant Fin who manufactures both emitters (baseboard) and boilers, and has "extra" functions to help with using their emitters, but they attach no strings and ship free-of-charge to anyone. While not the most comprehensive heat loss program available, it's certainly VERY reasonable and quite easy to use.

Get the heat loss program, spend some time measuring, BUY DAN HOLOHAN'S BOOK "THE LOST ART OF STEAM HEATING", study well and you'll be well on your way to understanding what should (and shouldn't) be done to your system as well as anything you can DIY given your general skills, time and tools.

Mike T., Swampeast MO

Haven't heard much about the "Big Dig" recently. Is it still the same disaster with leaks, failures, graft and hideous cost above the original budget?

Brad White

I was trying not to mention

The Big Dig... call it a form of denial..

The collapsed portions have been re-built and re-opened. Leaks are "managed".

The graft and hideous cost above original budget endures. This is Massachusetts. Put a fence around our government buildings and give everyone inside 15-20.

Mark_96

TVR's

Great info. Thanks. Any suggestions for a good source for TVR's?

Mike T., Swampeast MO

"Managed" leak. Sounds like my South-facing dormer. I've worked on it. Two professional roofers have worked on it under my guidance of "tar is NOT a solution". Nobody seems to understand why it leaks--sometimes--but it still does when the wind is whipping around with heavy rain...

Clean up the slight mess and cover the stains...

I'm almost ready to try tar.

Mike T., Swampeast MO

Danfoss 1-pipe steam TRV bodies with integral vacuum breaker. Cost is a bit more than other TRV bodies made for 1-pipe steam but I've NEVER heard of a problem related to the TRV itself--can't say that for others...