Here Are the Types of Expansion Tanks Used in HVAC Systems

HVAC Condenser FansThere are many system components required for the optimal performance of your HVAC. Some of them are not visible from plain sight but still very essential. One of these crucial HVAC components is an expansion tank.

This tank is a pressure vessel that controls or sets your HVAC’s operating range. It also provides a cushion that accommodates the expansion of hot water. Without this cushion, pressures in your HVAC’s boiler will exceed the pressure valve setting and cause costly accidents.

Here are the types of HVAC expansion tanks.

Bladder or Diaphragm Tanks

These tanks include a diaphragm, which separates hot air and water. The extra pressure produced by heating water in your system’s hydronic loop is then absorbed. Since the air and water separate and the tank only holds the expanded water, a bladder tank is usually smaller compared with other tanks.

Plain Steel Tanks

These are the conventional expansion tanks used for HVAC systems. In a plain steel tank, air and water mix. The air found in the steel tank acts as a spring, which absorbs all the extra pressure produced when heating water.

Though the initial costs of a plain steel expansion tank are low, their long-term maintenance costs are higher than bladder tanks.

Open Expansion Tank

Plain steel and diaphragm tanks are both closed tanks. In open expansion tanks, the pressure in hot water is released into the atmosphere. Though cheap, open expansion tanks are uncommon nowadays due to the high risk of corrosion and their inability to control water pressure efficiently.

Knowledge of the expansion tank types is crucial for property owners. It can help troubleshoot any issues with the HVAC’s expansion tank. Any repairs and maintenance work on the tank should, however, only be handled by a trained HVAC technician to avoid burns and other accidents.