Heating techs talk about rads all day: column rads, tube rads, wall rads, rads that are cold, gurgling or spitting. On steam, each rad's size in square feet of EDR feeds into boiler sizing, and one-pipe rads need a pitch back toward the supply valve. Heavy cast iron rads hold heat long after the burner stops, which is why cast iron systems feel so even.
Rad in the front bedroom is pitched the wrong way, it's holding water and banging, shim the far end up a half inch.
Also heard as
- radiator
Related terms
EDR
Equivalent direct radiation: the square-foot rating of heating radiators, used to size steam boilers.
Bleed
To let trapped air out of a hot water radiator, baseboard or high point by opening its small vent until water appears.
Spitting
Describes a steam radiator vent that throws out water and steam instead of just air.
Main vent
A large-capacity air vent at the end of a steam main that lets air out fast so steam can fill the main.