radiator vent location. or should it be in the lower port, and if so why

sz9

is this acceptable location for vent, ?

bburd

If that is a steam system, the vent should be in the lower opening about 1/3 of the way up on the side opposite the steam supply valve.

The radiator sections are connected across both top and bottom. With the vent in the upper location, which is meant to bleed air from hot water systems, steam— which is lighter than air —will rise up the first few sections, flow along the top of the radiator and close the vent long before the rest of the radiator fills with steam. The usual symptom is a cold room.

sz9

thanks for the info, explains the cold room. rad does get warm but never really hot.

Long Beach Ed

"Acceptable?" — It will heat, but not most effectively, quickly or efficiently. Water vapor is lighter than air. The risk of this configuration is that steam entering the radiator will rise to the top nipples, run through the top of each section to the vent, closing the vent and leaving virtually everything below the top nipples blocked by air, and cold.

The cold parts will eventually heat as the steam condenses and condensate falls through the radiator.

A vent closer to bottom of the radiator should coax steam through the lower nipples where its lighter-than-air weight will cause some of it to rise up each column filling the radiator, hopefully before the vent closes and stops it all.

This is further advanced or retarded by the quality and velocity of the steam, size of the vent, and the differential between the iron and ambient temperature. So, in some systems, this venting deficiency might be negligible, in others it will be apparent.