For homes already running a geothermal heat pump for heating, the same loop can pre-heat your domestic hot water — adding negligible running cost.
Geothermal hot water makes most sense as a tag-on to an existing geothermal heating system. The ground loop and heat pump are already there — adding domestic hot water is a small incremental capital cost for excellent ongoing efficiency.
Standalone geothermal hot water (without heating) is rarely cost-effective — air-source heat pump or solar thermal will give better return.
Almost always as an add-on to an existing geothermal heating system. The ground loop and heat pump are already there — adding domestic hot water is a small incremental capital cost for excellent ongoing efficiency. Standalone geothermal hot water (without heating) is rarely cost-effective.
COP of 4.5–5.5 — the highest of any hot water source. Stable ground temperatures (14–18°C year-round at depth) mean efficiency stays consistent across seasons, unlike air-source which drops in winter cold.
50+ years for the buried pipework. The heat pump itself has a 15–25 year design life. Most cost is in the loop install — once it's in, it's there for the lifetime of the building.
"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."