Hybrid FLU-ACE™
High Efficiency Hot Water Without a New Boiler
The Hybrid FLU-ACE recovers waste heat to provide free hot water but also includes a burner to provide additional flow or temperature, with up to 99% efficiency combustion in a single compact system.

Smarter Capacity, Lower Costs
Unlike conventional economisers, the Hybrid FLU-ACE not only reclaims stack heat but also adds new capacity with its integrated burner. This dual capability makes it particularly valuable for plant expansions, facilities operating at their output limits, or sites looking to avoid full boiler replacement.
By drawing first on waste heat and then natural gas (or biogas), this hybrid water heater maximises energy recovery while significantly lowering carbon output and other atmospheric pollutants. Flue gas temperatures exit only a few degrees above the incoming water, ensuring minimal energy loss.
The Hybrid FLU-ACE produces hot water instantly on start-up and delivers rapid return on investment through significant fuel savings as well as lower overall costs compared to installing additional boilers or conventional heaters.
The Hybrid FLU-ACE is an atmospheric vented heater and is not classified as a pressure vessel. It requires no special supervision or statutory inspections. Its stainless-steel construction is highly resistant to corrosion, providing decades of dependable service with minimal maintenance.
Reliable, Efficient Hot Water on Demand

The water absorbs both recovered and burner heat before exiting at temperatures up to 85°C. Flue gases are cooled to within 5°C of the inlet water, maximising heat recovery and achieving condensing efficiencies of up to 99%.
Performance That Lasts
These specifications reflect a mature, field-tested hot-water system engineered for high thermal efficiency, precise temperature control and long-life stainless-steel performance.
Efficiency:
up to 99% fuel-to-water
Hot water output:
Up to 85°C (185°F)
Flue gas outlet:
Within 5°C (10°F) of inlet water
Construction:
All stainless steel (304L/316)
Capacities:
1,000 to 30,000 kW (4–40 MMBtu/hr)
Boiler range:
4 to 18 t/hr (250 HP – 40,000 lb steam/hr)
Lifecycle:
Decades of reliable service; 5-year tower/packing warranty
Applications:
Domestic water heating, hydronic (space) heating, fresh air heating (via glycol loop), boiler make-up water preheating, and process water heating
Hybrid FLU-ACE in Action
Frequently Asked Questions
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It combines waste heat recovery and new capacity for water heating in one unit.
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Hybrid FLU-ACE can complement existing boilers or replace aging equipment. In both cases, this hybrid water heater raises plant efficiency to condensing levels without requiring a full boiler replacement.
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Hospitals, universities, meat processing, textiles, laundries, and concrete plants, and other industrial plants with high hot water or space heating demand.
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Constructed entirely of stainless steel, Hybrid FLU-ACE is built for decades of reliable operation.
Sustainability that pays for itself
Solutions that deliver verified returns from day one.
Speak to our team
If you are exploring how to cut energy use, reduce emissions or assess the viability of steam, heat recovery or hot water solutions for your site, our team can help you understand what is possible.
- Identify where energy is being lost
- Understand the most effective efficiency improvements for your site
- Gain clear guidance on performance expectations and practical implementation