Objectives

• After studying this unit, you should be able to
• describe a basic hydronic heating system.
• describe reasons why it is desirable for a hydronic system to have more than one zone.
• list four heat sources commonly used in hydronic heating systems.
• explain the difference between a wet-base and a dry-base boiler.
• state the reason a boiler is constructed in sections or tubes.
• discuss the reasons why air should be eliminated from hydronic heating systems.
• explain the effects air has on a cast-iron or steel boiler.
• describe the function of the air cushion or expansion tank.
• explain the operation of circulator pumps as they apply to hydronic heating systems.
• describe the importance of the “point of no pressure change.”
• describe the purpose of limit controls and low-water cutoff devices.
• state the purpose of a pressure relief valve.
• state the purpose of a zone valve.
• list the various types of zone valves that are available.
• explain how “outdoor reset” can be used to increase system efficiency.
• sketch a series-loop hydronic heating system.
• sketch a one-pipe hydronic heating system.
• explain the function of the diverter tee.
• explain the differences between a two-pipe, direct-return hydronic heating system and a two-pipe, reverse-return hydronic heating system.
• explain the application that requires the use of a balancing valve.
• list the benefits of primary–secondary pumping.
• describe the operation and function of mixing valves.
• describe the differences between radiant and conventional hydronic heating systems.
• list three common types of radiant heating system installations.
• describe a tankless domestic hot water heater used with a hydronic space-heating system.
• list preventive maintenance procedures for hydronic heating systems.
• describe the differences between passive and active solar systems.
• describe the declination angle and the effect it has on the sun’s radiation during winter and summer.
• list the typical components in a liquid-based solar system and describe the function of each.
• describe the operation of a solar domestic hot water system.
• describe a swimming pool solar-heating system.

Next: Advance to the Learning Center Dashboard and complete the lessons.