Porter Hall
One Pipe Steam Radiator

Porter Hall is heated with a one-pipe steam system. Steam from the Central heating Plant is piped into the building where it is controlled by automatic valves located in the mechanical spaces of the basement.
Sensors located throughout the building monitor the room temperatures and report that information to an Energy Management Computer System also located in the basement. This information is transmitted to a Master Computer System in the Central Heating Plant where it is checked against a heating program dedicated to the Porter environment. The automatic valves respond to this program to maintain the spaces at Setpoint ( the equivalent of a Thermostat setting).
The Engineer operating the Heating Plant when necessary can override this program.
Steam radiators are located in every room and have some control associated with them. They are convection dependent devices and require adequate airflow to work properly. A covered or blocked radiator will not function efficiently.
Each radiator has a two valves connected to it. An Air Valve that vents the radiator, and a Steam Valve that permits steam to enter the radiator and condensate to exit. Condensate is the result when the steam has surrendered its thermal energy to the cast iron radiator sections. This process condenses the steam and now in liquid form it uses gravity to follow the pipes back to the basement and eventually to the Central Heating Plant where it is recycled to become steam yet again. When the valve is turned counter-clockwise all the way to it’s stop, the valve is ON and the radiator will HEAT when the steam is available. When the valve is turned clockwise all the way to it’s stop, the valve is OFF and NO HEAT will result when the building’s automatic valve cycles to heat the rest of the building. If you leave your steam
valve off and leave your room, your room will not get the heat needed to maintain your room at a comfortable temperature. When you turn the valve on, there is no guarantee that steam will be available at that time. Thus no guarantee that your room will begin to receive heat, and in fact it may be several degrees cooler than any rooms that had their valves open during the same time period. This valve should always be either all the way ON or all the way OFF. Any other setting can trap water in the radiator and contribute to banging pipes. Banging, known as Water Hammer, occurs when Steam collides with condensate.
The silver device on the opposite end of the radiator is called an Air Valve and controls the rate that the radiator can heat.. It allows the steam to displace the cool air in an empty radiator by venting that air. When the hot steam reaches it’s temperature sensitive element it closes, thereby trapping the hot steam in the radiator where is must surrender it’s Btu’s to the surrounding cast iron. The hot cast iron warms the nearby room air and convection moves the warm air around the room to heat the space. The setting on this valve controls the rate at which this venting process occurs, thereby the rate at which the radiator heats and is set relevant to the rest of the radiators in the building.
Never, Remove The Air Valve or Turn it Upside Down! This can allow raw steam to escape from the system and enter the room.

Data provided by MHC Facilities Management Department