Home>Discussions>INSULATION & HVAC>How do I 'baffle' a steam heat system?
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How do I 'baffle' a steam heat system?

We just bought a house with a steam heat system. The down stairs will be warm, not toasty, but comfortable. The upstairs will be insufferably hot! I mean temps near 90. There is a large valve coming through the floor & a silver 'rocket' shaped valve on the opposite end. How do I adjust one of both of these valves to get the temps in the bedrooms more in line with the down stairs?

Re: How do I 'baffle' a steam heat system?

The "large valve coming thru the floor" is the radiator steam supply valve with a knob shutoff---the shutoff should be either fully open or fully closed.

The "rocket-shaped" valve on the other end of the radiator is the adjustable air vent---if the room is too hot, the air vent should be adjusted to nearly closed, to allow for slower escape of air during the heating cycle, & thus, less heat in the room---some air vents are non-adjustable, in such a case you will have to go to a heating supply house to buy an adjustable one.

If adjusting the air vent down toward zero doesn't cool the room enough, the radiator shutoff valve on the other side can be completely turned off, so no steam can enter the radiator.

Also go to the "heating help" site, click onto "systems", then onto "steam", then onto "problems that plague one-pipe steam systems"---begin reading where it says "this is why manufacturers make adjustable air vents".

On the "illustrated home" site, click onto the "pages" icon to learn more about steam heat, and onto the + icon to enlarge the images; click onto "back" or "close" to back out of images; at page 1 click onto "One Pipe System" and "air vents"; on page 3, click onto "how steam systems work".

How steam radiator vents work ("rocket-shaped"):

When steam enters the radiator during a heating cycle it pushes the air in the rad ahead of it out of the rad & out of the air vent--you can hear the hissing; once the hot steam arrives inside the rad at the air vent, it hits a tiny little metal cannister (float bellows) filled with alcohol that expands when it heats to push a float needle into the air hole where all the air just escaped, thus closing the air vent so the steam will heat the radiator inside, & not escape into the room; when the radiator cools, the bellows cools & the air vent opens again, ready for the next heat cycle.


Re: How do I 'baffle' a steam heat system?

Fantastic. Thanks so much.

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