Expansion tanks and pressure vessels that absorb the volume change of heated water and protect your hydronic system. AHHAC supplies the Varem (Hurlcon) expansion tank range.
Water expands as it heats. In a sealed hydronic system that expansion has to go somewhere — and that's the job of the expansion vessel (pressure vessel). A correctly-sized vessel absorbs the volume change as the system heats from cold to operating temperature, holding system pressure within the safe band and stopping the relief valve from weeping.
AHHAC supplies the Varem expansion tank range (distributed through Hurlcon) — Italian-made pressure vessels for heating, cooling, potable water and solar applications. We size the vessel to the system's water content and temperature swing, because an undersized vessel causes pressure spikes and relief-valve discharge, while the wrong pre-charge causes premature failure.
Expansion vessel sizing depends on total system water volume, the cold-fill pressure, the maximum operating temperature and the system height. AHHAC calculates the required vessel volume and sets the correct air-side pre-charge pressure at commissioning. For larger systems, multiple vessels or a larger floor-standing unit are specified. We also fit potable-grade vessels (with a butyl bladder) for domestic hot water expansion.
"AHHAC delivered our 22-zone underfloor system on time, on budget and to spec. The crew were tidy, the documentation was thorough, and the commissioning was textbook."
"We've worked with AHHAC for 17 years. They've installed and serviced our hot water plant across three commercial buildings — and they pick up the phone on weekends."
"Three mobs quoted us; AHHAC's design was the only one based on a proper heat-loss calculation. The system runs beautifully — the others would've been oversized and expensive."