Radiator Cover Help - Need LESS Heat

cnjamros

Hello everyone.

Let me preface this by saying I'm in the final stages of balancing my one-pipe steam system... a process that's gone on since November (yikes!). I have one or two minor hurdles and I am hoping for some advice.

Quick summary... my upstairs rooms still have the original 5-tube radiators... 2 per room. My DOWNSTAIRS was retrofitted at some point to replace all of those radiators with in-cabinet convectors under the windows. These put out much less heat.

The boiler that's installed is sized to use ALL of these radiators/convectors... so when I turned off some rads upstairs to keep the temperature down, I got major hissing from a few of the rest of the radiators.

I've since turned all the rads back on (except for one, temporarily)... and balanced as much as possible via Gill/Pajek chart and a bit of trial and error (FAST 1st floor vents, SLOW 2nd floor vents (#4s).

However, 2 of the upstairs rooms are still 4-8 degrees above the average.

I'd love to find a solution that keeps these room at a normal temperature, without hissing in the other radiators, and without the Vaporstat working like a draft-horse to keep the pressure down below 8oz (that's where the hissing starts).

HERE'S MY QUESTION: I'd love to put an enclosure over a couple/few of the upstairs radiators in order to still allow them to function, but greatly reduce the heat output. I was thinking I'd build enclosures using the worst design possible ("worst" for those who still want heat to come out, that is)... perhaps a box with just a bit of an opening at the back bottom.

What are everyone's thoughts on this idea? It could be the final piece to silent, even heating in my home.

Thanks so much!

Snowmelt

Sounds good just waisting energy, wouldnt you want the upstairs to bleed the air faster.

Mark N

What type of thermostat do you have? If you have a Honeywell try setting it to 2 CPH, see if it helps.

Mark N

As an experiment try throwing a blanket over half the rad all the way to the floor. That should help muzzle the output by stopping the convection.

Fred

Maybe try one of the Danfoss TRV's on one of those radiators and see if it minimizes the hissing at the other rads?. Those TRV's will open when the room is below the set temp and will close the air vent blocking the steam after the room get to the set temp. They may close close enough to the thermostat setting that you won't get the hissing. They are available at supplyhouse.com. If it doesn't work, you will be out a few bucks but that is probably the price of experimenting???

cnjamros

@ Snowmelt... actually, I want the upstairs to bleed as slow as possible so it takes a long time for steam to reach them and they don't get as hot... problem is, I have the slowest possible vent on there now. I agree, a waste of energy... but perhaps minimal... and preferable to hissing radiators in the middle of the night.

@Fred... saw your suggestion on my other post a couple hours ago... am definitely looking in to that... It will definitely be a trial and error, because I'm afraid when they close the pressure will go up to where it was before... but perhaps you're right in that letting that radiator fill until at, say 70 degrees, when the thermostat is heading for 71, may alleviate just enough of the pressure. And the vaporstat can pick up the slack once they close.

@MarkN... I have a Nest thermostat... not ideal for steam, I now know... but I'm using it without the learning features and simply as a programmable, and I have a record of its "on" times on the web site... it's been great for this troubleshooting. The blankets are a great idea... thanks! cheap beta-test.

Mark N

Too bad you don't have a Honeywell. Set a 2 CPH the boiler would run a shorter cycle. The convectors would heat better and the cast iron rads would overheat less.

Paul48

What does metallic paint reduce the output by.....15%?

Mark N

Metallic paint only reduces the radiant heat not the convective.

ChrisJ

What vents are you using downstairs? Can you draw a diagram showing your current venting plan and radiator sizes and pipe lengths?

Chances are the Danfoss TRVs + direct mount operators will be your best solution. I have two grossly oversized radiators in my two larger bedrooms and nothing helped but the TRVs. Even venting slowly didn't work because the colder it got out, the hotter those rooms got due to longer run times.

For example, we were keeping the first floor around 69F at the time and our bedroom was almost 80F when it was in the low teens out. Now, even at 0F it stays 64-66F thanks to slow venting and a TRV.

If you vent too fast with the TRV it won't have time to react and the room will still overheat so don't view it was a fast throttling device, it's not. It will throttle the venting to an extent, but it's slow.


This is a diagram showing my venting. I've been working on it and slowly tweaking things since 2011.

Snowmelt

You want the upstairs to bleed quicker then downstairs. You want the closest one to be shut, and the furthest one to be open .

ChrisJ

Snowmelt said:

You want the upstairs to bleed quicker then downstairs. You want the closest one to be shut, and the furthest one to be open .

This will cause his upstairs to overheat more, no?

Fred

Snowmelt said:

You want the upstairs to bleed quicker then downstairs. You want the closest one to be shut, and the furthest one to be open .

I think he wants the upstairs to vent as slowly as possible, shy of shutting the valve off. That's where the TRV works nicely. It allows the vent to be open when the ambient temp in the room calls for heat but does shut it down when he reaches temp setting. My thought was, with a TRV and a very slow vent, he could probably get close enough towards the end of a heating cycle that he wouldn't build enough pressure to cause his other rads vents to hiss.

Paul48

Does anyone find it strange that his vents are hissing at 8 ozs?

ChrisJ

Paul48 said:

Does anyone find it strange that his vents are hissing at 8 ozs?

Nope,
Mine start annoying me at around 4 ounces which is why I don't allow the system to ever go above it.

Fred

Paul48 said:

Does anyone find it strange that his vents are hissing at 8 ozs?

Mine hiss (it is actually sucking air and I suspect some of his noise is also suction) only when it is extremely cold outside (0 or below or a wind chill below 0) and the boiler has run an extended period of time and creates just enough vacuum at the end of a heating cycle to pull some of the radiator vents open but not enough pressure to pull the main vents open. I use Hoffman vents with the floats in them. I don' know if the same condition would exsist if I used vents with bi-metal closures like the Gortons.

ChrisJ

Fred said:

Paul48 said:

Does anyone find it strange that his vents are hissing at 8 ozs?

Mine hiss (it is actually sucking air and I suspect some of his noise is also suction) only when it is extremely cold outside (0 or below or a wind chill below 0) and the boiler has run an extended period of time and creates just enough vacuum at the end of a heating cycle to pull some of the radiator vents open but not enough pressure to pull the main vents open. I use Hoffman vents with the floats in them. I don' know if the same condition would exsist if I used vents with bi-metal closures like the Gortons.

It does, but not as extreme.
I had times my Hoffman 1As were screaming from vacuum.

The Gortons hold some, but not near as much.

jch1

Generally speaking, how long do your systems stay on when it is a very cold day and you're trying to increase the temp. by 2-3 degrees? 30 minutes to an hour? Longer?

I'm just trying to gauge what kind of run times are appropriate.

Fred

On a 0 degree day, my boiler will run about 30 minutes per hour. On a day when the wind chills are -20 degrees, it runs about 40 to 45 minutes per hour. On a normal 25+ degree day, about 15 minutes per hour.

ChrisJ

@cnjamros ,
These are the parts you need to make the TRVs for single pipe steam. Don't forget to order a quality straight 1/8" vent to go with it. For your situation I'd say something slow like a straight Gorton #4.

http://www.supplyhouse.com/Danfoss-013G0140-Thermostatic-Rad-Valve-w-Vac-Breaker-1-Pipe-Steam-5551000-p

http://www.supplyhouse.com/Danfoss-013G8250-Direct-Mount-Operator-5558000-p

cnjamros

Great info, everyone.

@ChrisJ... that's great! that's exactly what I ordered. Hope to install tomorrow or Thursday.

As to the hissing/sucking sound, I suspect it's because at some point these convectors were installed to replace the radiators, reducing the load, but the replacement boiler wasn't downsized appropriately... Add to that that I'm also trying to choke the output to prevent overheating and there you go. It seems I now have it under control by setting Vaporstat at 6oz, with a 4oz differential.

Also, 4 of the Gorton #2 vents I installed are situated directly above the drop header, which I'm reading now can prevent them from reopening in a timely fashion. I've bought some hardware to relocate those so they can cool a bit faster and hopefully relieve the radiators of some of their vacuum.

Step by step. Getting close now!

cnjamros

So, I've moved all the main vents so they're away from the header, and actually near a small window... double bonus.

And I put Vent Rite #1s on the problem radiator in the master bath, as well as the larger rad in the bedroom that hisses occasionally. I sat with them for a heating cycle and adjusted just below where they started to make noise.

My system seems to run at about 2.4 oz for most of its cycle. When it starts to go above that, the noisy radiators start and it continues to rise well past 8oz, or until the VaporStat shuts it down. So, I adjusted my Stat for 3oz with a 2oz differential.

With those changes, I'm now finally running a nice, quiet system with even heating in all my rooms. Finally. What a thrill!

Thanks again for all the assistance.
C.