Hydronic fan coil units for fast heating and chilled-water cooling — wall, bulkhead, cassette and concealed ducted models. AHHAC supplies the MAXA Grimper, HCN, HCNP, HCNA and VE fan coil ranges.
A hydronic fan coil unit is an emitter with a quiet fan that blows room air across a water-filled coil, heating it from a heat pump or boiler in winter and cooling and dehumidifying it with 8–14 °C chilled water in summer. It is the fastest-responding hydronic emitter and the one that makes whole-home hydronic cooling practical. AHHAC supplies and installs MAXA Grimper, HCN, HCNP, HCNA and VE fan coil units in wall, bulkhead, cassette and ducted formats.
Reviewed by the AHHAC Technical Team — licensed plumbers & hydronic engineers, NSW Lic 262528C.How we write & review
Fan coils are the workhorse emitter for hydronic cooling and fast-response heating. A fan blows room air across a finned hydronic coil — warming it from the boiler/heat pump in winter, or cooling and dehumidifying it from chilled water in summer. Where underfloor is silent and slow, fan coils are fast and powerful, making them ideal for cooling-led climates and rooms that need quick warm-up.
AHHAC supplies the full MAXA hydronic fan coil range: the Grimper Anviro series, the HCN / HCNP / HCNA cassette and bulkhead units, the VE residential and inverter range (VMI, VMF, OMP, OMI / VII, VIF, OIP, OII), and concealed hydronic wall units. Each pairs with the MAXA Airmust and CRA thermostat range for precise control.
Wall-mounted (high or low) — the simplest retrofit, like a split-system head but hydronic. Bulkhead / under-ceiling (HCNA) — concealed above a doorway or in a service zone. Ducted cassette (HCN, HCNP) — fully concealed in the ceiling with grille outlets, the premium invisible option. Concealed floor units — for under-window placement. AHHAC sizes each unit to the room's heating and cooling load and specifies the matching MAXA thermostat.
A fan coil that heats well can still be a poor cooling unit, and in Sydney and Brisbane it is usually the cooling load that sets the size. West-facing glass, top-floor rooms under a hot roof and open-plan living all gain far more heat in summer than they lose in winter, so we size each hydronic fan coil unit to whichever load is larger, which in a humid climate is usually cooling.
Format follows the room. A wall unit is the quickest retrofit; a bulkhead unit hides above a doorway or robe; a ducted cassette disappears into the ceiling but needs an access panel for filter cleaning and service. We plan that access before the plasterer arrives, not after.
Fan coils also work well alongside slower emitters. A common layout is underfloor heating in the living areas with fan coils upstairs for cooling and quick warm-up in bedrooms. Each unit runs from its own MAXA wall thermostat, and filters should be cleaned regularly during heavy cooling use.
For the bigger picture, see how hydronic cooling systems work, why hydronic cooling in Sydney relies on dew-point control, and our plain-English hydronic cooling guide.
Written from on-site experience by the AHHAC Technical Team.
AHHAC's in-house design and service team — licensed plumbers and hydronic engineers (Lic 262528C) who have designed and installed 2,400+ hydronic heating, cooling and hot water systems across Australia since 1998.
We only specify equipment after a heat-loss and system-compatibility check, then supply, install and commission it with our own licensed plumbers to AS/NZS 3500 (plumbing) and AS/NZS 5601 (gas), register the manufacturer warranty and service it for the life of the system.
"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."