Air Management in Hydronic Piping Loops

by | Commercial HVAC | 2 comments

Air Management in Hot and Chilled Water Piping Loops
Air Management in Hydronic Piping Loops - This is a secondary chilled water pump in a large pump room designated for pumps and piping in a data center. After a few minor tweaks and corrections, these pumps all operated flawlessly. There were very few issues with the secondary pump start-ups.

Unlike the primary pumps where cavitation was encountered on the primary chilled water pumps and the condenser water pumps for the chiller. The diagnosis for the cavitation of the primary pumps and the condenser water pumps was that the loops were not properly purged. This caused those pumps to cavitate.

The secondary pumps, pictured here, did not have that problem. Kudos to the team that purged the loops on this side of the chilled water system.

That was an initial installation issue. It was also a lesson in priming the system to ensure all the air purged from the loop. After all, cavitation in the pumps can cause damage to the pumps. Even after the initial installation purge, it is important to ensure air does not build up in the water piping loop. To do this we need a few devices to help purge the air before it becomes a problem. This will prevent nuisance problems such as hydronic air block in branch circuits of the loop. It will also prevent any damage that may be caused by pump cavitation as a result of too much air in the system.

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Hot Water Boiler Expansion Tanks – HVAC Hydronics

by | Boilers | 7 comments

Hot Water Boiler Expansion Tanks - There are two types of expansion tanks used on hot water boiler systems. The steel expansion tank and the bladder-type expansion tank. These expansion tanks are used to provide a cushion for the expansion of water when it is heated.

Without this cushion of air, the pressure in the boiler system would exceed the setting on the pressure relief valve. Finally, this will cause the pressure relief valve to open and discharge water to relieve the pressure. (more…)

Boiler Piping Plant Renovation | HVAC Hydronics

by | Boilers | 0 comments

Boiler Piping Plant Renovation
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…)

Hydronic Pump Cavitation | HVAC Water Problems

by | Technical Reference | 0 comments

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…)

HVAC Piping Valves | Heating and Cooling Hydronics

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HVAC Piping Valves | Heating and Cooling Hydronics - Automatic Flow Valve

Automatic Flow Valve

HVAC Piping Valves | Heating and Cooling Hydronics - Triple Duty Valves are three valves in one as the name implies. Triple Duty Valves act as a check valve, balancing valve, and shut-off valve all in one valve.

From the smallest hydronic loops to the largest hydronic loops triple duty valves are very a popular selection for engineers when designing hydronic loops for chilled water and hot water applications. The triple-duty valve consists of a threaded stem attached to a disc. The disc has a spring that will allow the disc to open when the flow is induced throughout the loop. (more…)

Automatic Air Vents | HVAC Hydronics

by | Boilers | 4 comments

Automatic Air Vents
The automatic air vent is found in the piping system of water loops. If air is introduced into the water loop system it eventually finds its way to the automatic air vent where it is vented. The automatic air vents are located throughout the system. Automatic air vents may also be found throughout any hydronic loop system. A hydronic loop is a water loop.

These water loops can be for hot water or chilled water. Any hydronic loop needs an air management system or automatic air bleeder system to keep the air out of the system otherwise, the air will be up in the system and air will block or prevent the flow of water throughout the loop. Water naturally has air in it. Air vents help the water loop by: (more…)

Boiler Water Loops | Hydronic Piping Systems

by | Boilers | 12 comments

hot water boiler piping
Boiler Water Loops - In boiler water loops there are different ways to arrange the piping depending on the budget at installation time and how efficient and balanced you want the hydronic piping system to be when the job is complete. Some piping arrangements require more pipe upon initial installation. However, they are easier to balance and provide even heat throughout all the radiators or baseboards.
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Boiler Supply and Return Piping

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Boiler Supply and Return PipingBoiler Supply and Return Piping - Any heating pipe system will experience a heat loss in the pipe even when the pipe is insulated. The loss is far greater when the pipe is uninsulated. Good boiler piping insulation will reduce the heat loss experienced in the pipe run throughout the loop especially where the pipe runs in unconditioned or unheated spaces where heating is not necessary.

Boiler Supply and Return Piping

Good Supply and Return Insulated Pipe will increase the efficiency of the boiler and reduce overall the heat loss of the entire system as a whole throughout the heating season. Insulate exposed piping wherever you find it and replace old insulation that is falling off. Be careful to identify the correct insulation and never ever disturb asbestos insulation. Asbestos is dangerous especially if you breathe in the particles from it. A professional asbestos remediation company must be hired to remove it safely.

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