Balance issues in a single-pipe system

SpencerB

Hi,

I moved into a house with a brand new steam boiler 2 years ago and my brother promptly lent me the Lost Art of Steam Heating, which sat on a shelf until recently. In the interim, I'd been told by enough contractors that I should insulate my basement pipes, so I came to this forum and got some excellent advice. The partial insulation I did has made the basement cooler, but high usage and bad distribution are still a problem. So I dusted off the old book and was surprised to see it sending me right back here! Glad there's a close tie between all these smart people.

Anyway, I've done my best to come up to speed, but I am just a dumb homeowner so bear with me. My main complaint is that the 2nd floor rads don't put off enough heat. The thermostat is on the 1st floor, so when it gets to 70, the 2nd floor is only at 63. I'm also getting some noises when the system is running, which we don't really care about, but is probably indicative of an issue. The boiler seems to fire every 20-30 mins or so for about 4.5 mins, but obviously this varies with the outdoor temperature.

It's a single-pipe system and as best I can tell, it's been piped correctly — see pictures. There are two levels to the floor in the basement and the boiler is on the lower part. The lowest part of the main is in the other section, so to get the "A" dimension, I'm measuring from the ceiling. The waterline in the gauge glass is 55" below the ceiling and the lowest main is 13-16" below the ceiling (not sure whether to use the top, center or bottom of the pipe). The mains and risers are 2" pipe; the header is 2.5" and the returns are smaller though I haven't measured.

There are 4 rads on the first floor, 4 on the 2nd and 1 in the attic (currently off because we don't use it). They are tube-style rads with 4 tubes. They're all about 22" high from the floor and most are about 8.75" deep, with the bathroom one being about 5.5". Using some charts, I calc an EDR of about 311.

The vents on the rads are all Gorton Cs, with the exception of two on the 2nd floor that use a heat-timer vari-valve that looks like this (https://www.amazon.com/dp/B009ATMA2I?psc=1&language=en_US). These two are set to be all the way open, though there's really no difference in the heat between any of the rooms on the 2nd floor; they're all cold.

So, is there anything I can do here? What else would help diagnose the issue?

Thanks again as always to this impressive community.

ScottSecor

I'm short on time right now. I'm very simple terms, reduce the size of the vents on the first floor radiators to #5, #4 for room with stat. Use #6 vents for upstairs. Make sure your steam mains are well vented. This would be where I suggest you start.

EBEBRATT-Ed

You want to vent the mains as fast as possible. Then vent the radiation based on how it heats. If you have a large vent in the room with the thermostat that could shut the boiler off before the upper floor are heated.

But the first thing is to start with the main vents. The main vent in your last picture looks like an antique so that may be the place to start. Measure the length of your two mains and get the pipe size for each and someone can help size the main vents.

You have 2 mains so you should have two main vents so you need to find the other one

Long Beach Ed

Before looking at the venting, you must ascertain that the radiators are properly sized to the rooms.

You don't have sufficient heat in the second floor. The heat is turned off in the attic. It's quite plausible that the second floor radiators are sized with the assumption that the third floor is heated. With an unheated attic,the second floor ceilings now face unconditioned space. So your second floor radiators may be grossly undersized (think 30%) for their current use. Try turning the radiator back on in the attic.

A room-by-room heat loss calculation vs. radiation capacity should be done.

Now if those second floor radiators are simply not heating, then the venting recommendations above are certainly a place to begin. In either case, good quality main vents will speed up heat distribution.

ethicalpaul

https://forum.heatinghelp.com/discussion/comment/1838894#Comment_1838894

^^ this is what I would say. Your radiator vents are too big generally. The steam is going to go where it wants to go unless you force it to go where you want it to go via vent sizing.

Additionally, you can forget about all those dimensions you listed. They don't matter at all in a 1-pipe system.

PS: good job sizing your radiation. Just out of sick curiosity, what is the "Sq. Ft. of Steam" number printed on the boiler?

PPS: replace this ancient main vent:

SpencerB

Thanks to all, as always, for the rapid and insightful feedback. I'm away from home for the day, but tonight I'll measure the mains and try to find the second main vent if there is one. I will look into replacing that old main vent and post the sqft of steam number, too. Long Beach Ed - the 2nd floor rads are heating, just not enough. The one in the attic is small, ancient, and isolated to the front of the house, so I'm not sure how much of an impact it has, even when turned on. I'll give it a try though.

Overall, it sounds like my best approach is to start with the main vents, then move onto re-sizing the ones on the rads if needed. Right?

ethicalpaul

Yes. Resizing the ones on the rads is going to be needed IMO. You have a bunch of wide open holes on your radiators, the steam is going where it wants.

SpencerB

A quick follow-up as I start to think ahead towards replacing some vents. Does a variable vent like the Hoffman 1A make any sense? Otherwise, are there brands I should favor or avoid? supplyhouse.com seems to have decent prices on a wide selection

ethicalpaul

Yes supplyhouse is good. I don't really care for Hoffman, they are expensive and the adjuster is pretty jank. I like Gorton just fine, but for figuring out your venting, nothing can beat the low cost of Maid O Mist which allow you to swap their sizing orifices without tools so you can get the sizes on the radiators that work for you.

After that, if you hate them for whatever reason you can get the correct size Gortons to replace them.

SpencerB

Ok, so apologies, I didn't check my vents closely enough! Some aren't even Gortons, let alone all Cs. Below is a full chart of what I'm dealing with. A couple other questions and notes:

• I confirmed that the other main has the same type of old vent. I'm happy to replace both, but is it a safe DIY job? I mean I'll be sure to have the system fully off, but I'm a little leery of just wrenching these things in considering the pressure they need to withstand. Also, any recommendations on a model?
• Looking at the chart, it does appear as though someone did try to size this out, just with what they had on hand. Regardless, it does still sound like I want a 4 for the living room and 5s for the other first floor rooms, right?
• The nursery vent being damaged concerns me, but with all these new spare vents, I'm sure I can swap it out with no problem. But could that be part of the reason it's the coldest room?
• To work on the question of whether or not the radiators were sized correctly, I added each room's square footage and its ratio to EDR. Can I draw any meaningful conclusions from that? I'm not very likely to swap out any radiators but maybe a skewed ratio informs a vent adjustment?

Thanks again as always!

Floor	Main	Room	Room sqft	Typical Temp	Note	Vent Type	Radiator Type	EDR	EDR to Sqft ratio
1	Right	Kitchen	90	69.4	Fine	Gorton 6	Tubular - Four Tube	30	0.333
1	Right	DR	162.5	67.3	Fine	Gorton D	Tubular - Four Tube	39	0.240
1	Left	LR	186	69.6	Fine	Gorton 6	Tubular - Four Tube	48	0.258
1	Left	Plant Room	71.5	63.9	Very cold - hollow floor	Maid-o-Mist C	Tubular - Four Tube	42	0.587
2	Left	Bath	70.125	63.5	Cold	Gorton C	Tubular - Four Tube	32	0.456
2	Left	Master BR	196	64.4	Cold	Vari-valve open	Tubular - Four Tube	45	0.230
2	Right	Nursery	90	62.3	Very cold	Gorton C - damaged	Tubular - Four Tube	30	0.333
2	Right	Guest BR	127.5	65.2	Cold	Vari-valve open	Tubular - Four Tube	33	0.259
3	Right	Attic	huge		Who cares	Gorton D	Gurney Columnar 3-column	15
								314

LRCCBJ

Put Gorton 4's on the kitchen, dining room, and living room. See what you get. Post the chart again after install.

And be sure both mains have at least a Gorton 2 main vent.

delcrossv

Agree with @ScottSecor and @ethicalpaul . You really need to reduce your 1st floor venting.

Replacing your main vents is straightforward. Penetraiting oil and a large wrench is indicated.

ethicalpaul

considering the pressure they need to withstand.

You mean 2 psi?

SpencerB

@ethicalpaul All I know is that I don't want any steam blasting out because I'm a dunce. But yeah, penetrating oil and the right wrench. Also, sorry, I wasn't able to find a "sqft of steam" figure on the boiler or its literature.

So I was building my cart and disappointed to see that the Gorton #2s are $150/ea. Look, I know you'll all hate me for being cheap, but $300 is a real outlay here, plus they're sold out. I don't plan to be in this house long enough to see a real ROI. I can see from the 'Balancing Steam Systems' capacity chart that the current Hoffman #16s are woefully undersized, but could I get away with at least one Gorton #1? One main is 11 ft and the other is 31ft.

My plan is to buy four Maid-o-Mist vents (two 4s and two 5s) for the downstairs as advised, then one Gorton #1 for the 11ft main and one B&J Big Mouth for the 31 footer.

Decent plan?

ethicalpaul

I would just try a Gorton #1 in each location. Or Maid O Mist #1 for more savings.

They can vent a lot of air and the benefit from a #2 might be measured in seconds of burn time.

There’s no loss of heat or efficiency. Worst case is Steam might heading to some radiators a little sooner than others.

Vent replacement is the first level of steam home ownership. You got this

SpencerB

Good enough for me! $100 saved. Thanks for the vote of confidence. Forward with wrench in hand!

ethicalpaul

Send us a picture of your boiler rating plate, we should be able to tell how large it is if you're interested.

If you do find that the longer main is filling noticeably slower than the short one, you can always get a #2 when you are able to for it.