by High Performance HVAC | Boilers |
Boiler Circulator Pump: The boiler circulator pump induces the flow of hot water through the boiler and the boiler loop. Usually, the boiler circulator pump is controlled by the aquastat. However, there are various levels of control that can be found that control pumps.
One way is by the aquastat as mentioned above. Another way is an end switch in a zone valve. A thermostat in a particular zone will call for heat and the thermostat calls for the zone valve to open.
When the zone valve is fully open, an end switch closes the circuit to energize the circulator pump. Typically, the circuit is a control circuit so when the end switch closes it closes the circuit for a relay to energize the circulator pump (more…)
by High Performance HVAC | Commercial HVAC |
Water Tower Pumps and Controls | Pumping Systems - Water towers maintain a ready limited supply of water for communities in the event the water main goes down. Many towers are used for emergency situations for the fire department to have water for fighting fires and for water fire suppression systems to have a supply of water for the emergency if it should arise. (more…)
by High Performance HVAC | Commercial HVAC |
Day Tank for a Diesel Generator | Critical Facilities - This is a photo of a generator day tank for a diesel generator. The tank has floats inside that keep the fuel level automatically topped off in the tank so when the generator starts there is a fuel supply ready to go. As the generator consumes fuel the pump activates and resupplies the tank to keep the generator fueled and running. (more…)
by High Performance HVAC | Boilers |

Old Bell Gossett Circulator Pump Bearing Assembly - This very old Bell Gossett Circulator pump and bearing assembly was found still functioning even after being flooded out several times in a basement. The pump, probably on its last leg, is at least 20 years old and still functioning.
It is unusual for an electric motor to continue to operate after being subjected to flooding. A circulator pump is comprised of an electric motor and a bearing assembly which holds the impeller. (more…)
by High Performance HVAC | Boilers |

Boiler Piping Plant Renovation - Hot Water Boiler Piping for a commercial boiler application. Boiler project being renovated and getting all new DDC controls for optimum hydronic control and efficiency. Boilers are an excellent way of providing good hot water heating to a large building or community.
In this case, new boilers were installed to replace the old inefficient boilers. The piping was rearranged and a hot water boiler economizer preheater added to make efficiency better. New controls were added for remote monitoring and control and to improve efficiency. Lastly, the entire plant got a makeover to make things more reliable, efficient, and modern. (more…)
by High Performance HVAC | Oil Heat |
Oil Furnace Boiler Pump - A major component of oil furnaces is the oil pump and its job is to pump oil from the oil tank to the oil burner. It is important that the oil system is primed and free of any objects or particles that can plug the system. As well the oil pumping system must have integrity with no holes in the oil pipe where the pump can suck air into the oil line. Any air sucked into the line or a plugged oil line will cause problems with the oil burner that may result in a non-functional burner or a burner that does not produce efficient heat. (more…)
by High Performance HVAC | Technical Reference |
Hydronic Pump Cavitation - Pump cavitation can cause severe problems to a pump if not addressed and corrected. To understand the cause of cavitation you need to understand the pressure-temperature relationship of the liquid in the loop. Whether it is water or water/glycol mix. As the water passes through the pump it changes the pressure from the suction side to the discharge side of the pump.
If the water’s static pressure drops too much vapor is created causing tiny bubbles in the water or fluid in the loop passing through the pump. These bubbles are unstable and collapse causing severe turbulence inside the bearing assembly and can damage the impeller. (more…)
by High Performance HVAC | Air Handlers |
This is a horizontal flow air handler installed in the attic. Notice the drain pan under the air handling unit to catch condensation if the primary pan were to overflow. This is the secondary condensation pan which is installed under the air handler to save a ceiling.
Also slightly visible is a float switch which offers triple protection against flooding in an attic if the primary drain were to plug up. The primary and secondary drains coming from the air handler also drain into condensation pumps. These pumps have floats inside them and a reservoir. (more…)