Second Floor Much Warmer Than First FLoor.

Rob_40

Single pipe steam system in small two floor 1920s house with attic and basesment. On cold days, second floor can be ten or more degrees warmer than the first floor. Should I vent the second floor radiators more slowly. Seems I cant stop the heat from rising to the second floor. Maybe I can minimize the temperature difference. Vintage Honewell thermostat on the first floor.

Thanks in advance.

Rob Harold

nicholas bonham-carter

That could be the first step. What sort of main vents are on the system?—NBC

EBEBRATT-Ed

Maybe increase the first floor venting

Rob_40

I have Gorton Air Eliminator #1 on the ends of each main pipes.

kenlmad

Slowing the 2nd floor rads' vents may help if you find the first floor rads do not get as hot as fast as the second floor's rads. I assume the lower level rads work fine since you didn't mention any issues.

You may have better results if you locate and seal air leaks. If warm air is rising and escaping on the upper level it likely is being replaced by cold air leaking backfilling the house on the lower level. Such as poor Windows seals, Exterior door seals, leaky thresholds, fireplace dampers not shut, cloths dryer or bathroom vent damper flaps not closing properly due to lint build up.

Perhaps simply try to reduce drafts by keeping the door to the basement shut, close the doors to the upper level rooms and seal/insulate the attic access door/panel.

Cover/Seal any AC units that must remain in walls or windows during the winter.

Using the shrink plastic film kits on leaky windows helps a lot.

Rob_40

It is a drafty house, so that may be a very big reason why the heat is migrating upstairs so quickly.

bburd

Your situation is unfortunately extremely common in multi story homes with single zone heating systems. Especially older, poorly insulated, drafty homes. This is why zoned heating was invented.

As a poster above pointed out, this is largely caused by the stack effect that worsens in cold weather:  cold air enters low in the house, and warm air leaves at the high points.

Your system balance should go back to normal once the extreme cold goes away.

dabrakeman

I would suggest adjustable vents upstairs. Something like a Ventrite #1 that will allow you to throttle them down to almost closed when it is really cold out and open them up a little more in mild weather. This might sound backwards but your cycle times will tend to be longer on the very cold days so more steam will end up in those slower vented radiators upstairs eventually, particularly after the downstairs radiators have filled..

SteamingatMohawk

Survey each radiator vent and post the make and size on HH. If it's variable, post the setting, too.

If you have Heat Timer Varivalves, they cannot be set below a #5 capacity. Lots of comments about this fact in other discussions.

VentRite #1 can go from fully shut off to a #5.

To learn more about vents, go to my favorite HH reference on this subject here:

https://heatinghelp.com/systems-help-center/balancing-steam-systems-using-a-vent-capacity-chart/

The tables tell you a lot.

mattmia2

TRVs on the vents on the second floor is also an option if you can't find a balance that works both in warmer and very cold weather.

Hap_Hazzard

Usually the biggest difference between the first and second floor is doors, and sometimes bigger/picture/bay windows, so focus on those things first. Basically just look for leaks around anything that's unique to the ground floor. Light a stick of incense to see where drafts are coming from.

Once you fix the leaks, you might look at installing ceiling fans to circulate the air. They're nice in the summer too.

ethicalpaul

I'll add that in my house all the first floor rooms suffer from cold intrusion in the basement (cooling the first floor floors) from the rim joist and nearby areas. I'm going to reduce that with 2-part foam this spring.

Rob_40

Radiators

FIRST FLOOR

Living Room main 22"H, 7"W, 42"L, 17 Sections 37.4 sq feet radiation
Gorton No. 6

Living Room small 37"H, 7"W, 17"L, 7 Sections, 28 sq feet radiation
Gorton No. 6

Dinning Room 22"H, 7"W, 37"L, 15 Sections, 33 sq feet radiation
Gorton No. 6

Kitchen 22"H, 7"W, 12"L, 5 Sections, 20 sq feet radiation
Gorton No. 6

SECOND FLOOR

Master Bedroom 26.5H, 7"W, 32"L, 13 Sections, 33.8 sq feet radiation
Varivalve

Front Bedroom 26.5"H, 7"W, 24"L, 10 Sections, 26 sq feet radiation
Maid of Mist "0"

Back Bedroom 26.5"H, 7"W, 19"L, 8 Sections, 20.8 sq feet radiation
Dole 1933 Super Adjustable

Bathroom 26"H, 7"W, 14"L, 6 Sections, 12 sq feet radiation
Maid of Mist "6"

211 total sq ft of radiation X 240 BTU per hour = 50,640 BTU per hour
Boiler steam capacity: 65,000 BTU per hour

Gorton Air Eliminator No.1 vent on end of each main pipe.

(Sorry to repost, but I tried the edit feature and I couldnt get the edited version to post.)

SteamingatMohawk

What are the settings on the variable vents?

A Heat Timer passes between 0.2, 0.766, and 1.13 CFM at minimum, 50% and maximum settings at 3oz pressure. That's a pretty large range in capacity.

A Gorton #6 can pass 0.3CFM at the same pressure.

Look again at the MoM "0", I am not familiar with that size and it's not in the vent capacity table I referenced above.

Hap_Hazzard

It's probably a C.

Rob_40

I appreciate everyone's interest in this thread. Varivalve is set at about a third away from closed. Meaning the little nub that moves in the slot from closed to open is about a third of the length of the slot from closed to open. (Did I make that more confusing?). The Dole Super 1938 was set all the way open. Seem there are only five positions that are very faded. My past technique in adjusting it was to blow into it and rotate the adjuster until I could blow air through it, which was at the largest setting, somewhere past "D". I have now set it a "4". The Maid of Mist orifice has a stamp, and it may indeed by "C".

SteamingatMohawk

For the Varivalve, estimating the flow at the 1/3 open position, I get around 0.5CFM give or take a bit. That’s 0.5/0.3 = 1.67 times the flow for the Varivalve compared to your Gorton #6s. Your setting might be a bit high. If you want to tweak it, put a skinny mark on the body of the Varivalve before you change the setting, so you can go back to the same setting later. Then try something like ¼ of the way from the minimum setting.

You could make a SWAG as to how much you could reduce the Dole as well.

It’s anybody’s guess how much difference it would make. Recognize, the weather could affect the results as you make adjustments.

Good luck and let us know if you do make adjustments.

ethicalpaul

I think basically all your vents are too big which makes balancing extremely difficult. In order to have balance there must be pressure constraints.

if it were me, I’d buy a new vent for each radiator. 1/2 maid o mist #4 and 1/2 #5.

put #4 on the downstairs ones and #5 on upstairs ones.

then run the system for a few days and see how the rooms FEEL. Do not look at how hot or full the radiators get, that will just distract and mislead you. All that matters is how you feel.

find your coldest room/area and bump up the orifice size on that radiator. Then run it for a day to see. Changing any vent size will affect other rooms. Then repeat this process.

the reason for MoM is because you can swap just the orifice on the top. You have some existing orifices you can use, but I’d stay away from the C, that’s too big.

buy them at supplyhouse.com, so inexpensive 

SteamingatMohawk

@ethicalpaul Good plan. My system is 134,000BTU, so not knowing how smaller systems work compared to mine, I thought reducing the adjustable vents in the hotter rooms would improve the cooler ones and not cost any $$.

@Rob_40 If you have enough vent bodies and want a selection of orifices, call MoM. I did a year or so ago and was sent two sets for free. Apparently, they are not available on the open market as a set, unless someone on HH knows where to get them.

At the top of this page are email addresses and a phone number.

http://www.maidomistheating.com/jacobus.html

Rob_40

Ordered the Maid O Mists from Supply House. Sooooooo, the more I pay attention, the more I notice.
I have never heard the vents on the main pipes make any noise. And working in the basement noticed the boiler would cycle on and off too quickly for any thermostat upstairs to notice an increase in temperature.
I turned up the thermostat, and ran downstairs to put little bits of tissue paper on the Gorton No 1s to see if any air was escaping. Tissue paper were completly still. Pressure went up to 4 PSI. Wondering if my main vents are working, which of course would screw up everything else.

ethicalpaul

There are always new things to notice, good job! But the timing could have been better because you could have put a couple MoM #1 vents in your cart which are way cheaper but functionally equivalent to Gorton #1 to test your main venting.

But this is a great discovery...every 1-pipe system will work way better with operational main venting. As you said, it's the foundation of good balancing.

Rob_40

Ha! I was $27 shy of free shipping minimum on the radiator vents. If I ordered the main vents with the radiator vents, I could have saved about $12. Why are the Gorton's so much more expensive?

ethicalpaul

They perform well and they make just about the only really large capacity main vent (their #2) so I think a lot of people just automatically go to them.

Interestingly, I believe they copied their vent designs and numbering conventions from Jacobus.

You might try taking off those Gortons, slapping them around a little, maybe boiling them in some vinegar to see if they open up. You should be able to blow through them in the upright position to test them for open and they should close when upside-down.

SteamingatMohawk

I assume these vents are back near the boiler on two different returns that connect below the water line. Can you post a pic showing how they run?

Rob_40

Vents are at the end of the two mains that join below, but join above the water line.

ethicalpaul

Yeah that was probably below the water line a hundred years ago when boilers were taller. That horizontal should be lowered. 

The faster main’s steam can close its vent, then go down, cross over and go up and prematurely close the other main’s vent too.

if the mains are the same size and similar length it might work fine though (if your vents didn’t seem to be failed closed.

Especially since each main probably continues quite a ways beyond the last radiator runout.

once your vents are working or replaced you can see if both mains are getting steam to their last radiator before both vents close

Fizz

Assume you have mercury thermostat; what temp is it set at? Does it overshoot?

SteamingatMohawk

@Rob_40 Take a look at "Over Venting" from December 2018 to see more about what I did.

Rob_40

With so many variables in a steam system, I will first install the new vents that should arrive today and wait for a cold day to see how the system behaves. I took off the main vents and soaked them in CLR. I could see a little rust on the bimetal loop. Some grit came out in the wash. They passed the blow test before and after the soaking. But after installing them and raising the thermostat, I saw the vents blow off the tissue sitting on top. So that's some improvement I guess. I will research a bit about the old Honeywell mercury switch thermostat. Seems there is an "anticipator" that can be adjusted that affects the cycling.

dabrakeman

You sure the vents were not still closed by steam on your first tissue test (i.e. if the system had just shut down, vents were still hot and then you raised the thermostat to kick the boiler back on)?

Anyway you should be able to stand there by the mains on a cycle and witness at what time steam comes to each just by feeling the pipes. When steam arrives they get very hot real fast. You can track the progress of steam in both mains and see if it is crossing over from one main to the other well before one of the main extensions has filled. If so then you may want to lower that crossover connection in the summer.

SteamingatMohawk

if you like tools, like most of us, get an infrared thermometer at a big box store. It's great for tracking temperatures without paying the cost of a camera.

And you can use it for checking your griddle temperature when you make pancakes, plus lots of other uses.

SteamingatMohawk

You have two photos of two pipes with two vents. My posts are about the ones closest to the boiler being connected before the combined return gets to the water line ( your picture showing the connection near the chimney.)

Where are the vents shown in the previous photo (insulation around the piping) located? I was mistaken when I first though they were the same vents from two different angles.

Rob_40

Yes, Dabrakeman, the main vents were quite warm when first tested them, so they could have been closed before I raised the thermostat.

StreamingatMohawk: The vents in the closeup on insulated pipes are the same vents on the bare pipes. (I recycled an old photo I took of the boiler before I covered the pipes.)

Yesterday I installed new Maid O Mist vents, #4s on first floor and #5s on the second floor. Called heat and the main vents blew and closed after about 20 minutes. The upstairs radiator all got warm at a little after 20 minutes from startup. First floor eventually warmed up at about 40 minutes from startup and upstairs heat quite strong. Upstairs about 8 degrees warmer than downstairs.

Maybe switch the #4s with the #5s vent orfices?

ethicalpaul

Try that. Take your hottest upstairs room and your coldest downstairs room and swap the orifices.

but honestly with what you are describing, something is wrong. There’s no way steam should get upstairs to a #5 vent 20 minutes before it gets downstairs to a #4 vent

also it should never take 20 minutes for steam to get to the main vent unless all pipes are room temp or something. 

Please time it like this:

- run boiler until main vent sees steam.
- shut down and wait 5 minutes
- run boiler and start timer
- stand at main vent until it sees steam
- stop timer

it should be like 2 minutes. If it isn’t, the steam is going upstairs or out the chimney or somewhere!

But with #5 on your upstairs rads the main vent should take almost all the flow until it closes

neilc

it's that high "wet" return at the boiler,
the 2 dry returns drop only half way to the floor, and one side main loop is closing off both vents, before the other main is vented

SteamingatMohawk

If there is a significant difference in the length of the two mains (including the return back to its main vent), it is entirely possible the shorter main/return is venting through both main vents, lie @neilc states.

The solution is to separate the two returns and have both connect below the water line to the pipe section going back to the boiler. See the sketch below.

SteamingatMohawk

like @neilc states, not lie @neilc states.

Rob_40

I measured the length of the mains from where they split apart. One loop is 26' 2" from begining to vent, the other is 31' 2". The short loop main vent closes first. There is another 7' 6" of pipe between the two vents traveling along the returns. So I doubt the steam in the short loop would beat the steam in the long loop to the the long loop vent.

But I am not taking into account that the return pipes are narrower, and that would speed up the steam from the short loop moving through the returns.

On the other hand, the short loop feeds two first floor radiators and a second floor radiator, The long loop feeds three second floor radiators and two first floor radiators. Maybe the long loop has more steam diverted to the five radiator feeds as the steam makes its way to the main vent. So that may slow the steam reaching the long loop vent. But I think I need to try to do a more careful test of the system.

I am getting consistent heat out of two previously unreliable upstairs radiators after changing out the vents. I believe the second floor is even more warmer than the first floor.

ethicalpaul

But I am not taking into account that the return pipes are narrower, and that would speed up the steam from the short loop moving through the returns.

I wouldn't count on this making any difference. Neither air nor steam significantly flows in any main section (or "return" as it might be called) that occurs after the main vent. It just sits there.

So yeah put the #4s on any still hot upstairs room. Then if that fails you can even turn one or two upside down to prevent any steam from getting up there. Maybe your situation is such that you just don't need much radiation upstairs. I have an upstairs bedroom that I use for storage and I have turned the vent upside down (so that it doesn't vent) and it's really hardly colder than other areas.

But doing so will effectively oversize your boiler somewhat, which may or may not affect your system.

Less drastically, you can cover part or all of various upstairs radiators with a folded blanket..this effectively makes the radiator smaller.

SteamingatMohawk

The steam has a more places to go in the long loop, so even though there is 7' 6" between the vents (if I understand your description properly), my guess remains the same and my suggestion shown in the posted marked up photo to connect below the water line stands.

dabrakeman

Yes the crossover should be below the water line but I also think with two ~30ft mains you are still generally under vented on the mains with just a Gorton #1 on each. I have 2 Gorton #2's on my 30ft main. Then if your second floor is still too warm minimize the venting up there. The 6's you had originally were way to big and so probably are the 5's. Go with the Gorton 4's upstairs and maybe put the 6's on downstairs or even the C in your coldest room. If I had equal venting upstairs in my house as I have downstairs my upstairs would be 5 degrees warmer. Maybe just the way the old house lets heat rise on up through but also may be because my upstairs rads are pretty centrally located above the boiler. Anyway I like my bedrooms cool so even the Hoffman 1a's set on 1 (which is roughly equivalent to the MoM#4) was too much venting so I just took the caps off and made my own device to close more of the vent hole. Now on a typical cycle I get just a couple tubes with steam except on my 30 minute morning recovery cycles I get about 33%-50% fill. Perfect for me. You could probably come up with some ideas to reduce the orifice size even on a MoM#4.