steam rads -steam distribution-- don't understand why and what may be the logical reasons

LS123

Hello,

Majority of the time most my rads get steam distribution well. But today I notice one large rad (lets say RAD A) that would be the last one to get HOT ( I mean burn HOT) got heated faster than the heater across the room ( RAD . RAD B is near Gorton #2 main vent. RAD A was HOT, and RAD B had 1/2 way hot..not completely. Few hours later increased the temp... this time as usual RAD B got hot first as expected. RAD A and B are both fed steam from same pipe (that changes from 2 inch to about an inch. room is probably 40x25 guessing this )

(Q) What would be the reasons that RAD A got hot first this morning?
(only diffidence was that sight glass was about between the red lines but was not at max water capacity in the boiler
** I think this probably happen randomly with smaller rads that I dont pay attention to.. all rads in this note are on first floor. Pipes are in basement, and insulated.

If anyone understand why this might happens with steam rads, please let me know.
Thank you!

LS123

second sentence should be
But today I notice one large rad (lets say RAD A) that would be the last one to get HOT ( I mean burn HOT) got heated faster than the heater across the room RAD B .

Zipper13

For my house, the best I figure when this happens is that this time of year the time between heat cycles is longer so the mains and runouts have more time to cool differentially. So Rad A might need more time for its supply (which might be longer, less insulated, near a drafty basement window, etc) to get back to temp than the other rads. In the peak of winter, they all get to temp at the same time since none of the lines cool down more than teh others between the more frequent cycles; they all stay equally preheated in really cold weather basically, but not so much in mild weather when it might fire every few hours instead of every hour..

ethicalpaul

They are both fed from one pipe? That is not a situation that lends itself to consistency. Depending on what kind of rads and which vent is open or closed at any given time I think you’ll have unpredictable steam fill

LS123

@Zipper13 - I think the RAD b may have got colder than usual... good point and good explanation... now I understand the logic of this mornings rad heating,) its near a basement window, wind was 20+ miles last night I am in the hills of CT... that may explain why RAD A was slow to heat, because somehow it may have got much colder than I would have thought.

@ethicalpaul .. Rad a and rad b are about 5 feet long, may be a little less than a foot wide, may be little less than 2 feet tall. I managed to draw a pic with my none dominant hand (good hand will be out of commission for months due to RC surgery... a layout of the rads and pipes in the pic. It is on the plan to get fine tuned the steam system off heating season. All the main vents (two gorton 2s, and rad vents do work) but most likely replacements would be best for next heating season.

there are also two big (not as big as Rad A, & go to two rooms on the second floor, and one smaller one to bathroom.

Majority of the steam mains are in the basement are 2 inch I think, then reduced to 1 inch to connect to the rads. We definitely think gorton 2 by RAD A probably would help....

Honestly, overall RADS get hot (burning hot) in 30 or 40 mins, I just wanted to know if there were some other reasons why it happened this morning... both you and @Zipper13 clarified it for me....for some reason I always want to understand how steam systems works... and work at best efficiency..

took me a while to type... I need to set up my laptop to speach recognition and type what I say...would be much faster

ethicalpaul

Oh ok they are both supplied from a counter flow main, that’s fine. I was under the impression that a single runout fed both

LS123

Is the definition of counter flow main mean that main steam pipes gets to feed rads at different locations and the steam feeding lines are set in a slope? thank you @ethicalpaul

ethicalpaul

It means the condensate flows back against the flow of steam.

LS123

thank you @ethicalpaul !