Solar Cooling Diagram

Heat pumps for heating and cooling

Most hydronic heating and domestic hot water systems use gas or propane fired boilers to generate heat. Boiler efficiencies in these systems typically vary from 50% to 90% depending on size and load factor. In many cases on these sites, there is a simultaneous requirement for air-conditioning or chilled process water.

"Chromasun recommends that boiler operators consider simple heat pump configurations wherever there is a simultaneous requirement for chilled water and hot water. This approach can double boiler efficiency and halve gas consumption."

Solar-Enhanced Heat Pump Design

Chromasun can design and supply systems that supplement hydronic heating and domestic hot water boilers with far greater system efficiencies than traditional boilers. Heat Pump designs can produce HHW and DHW at 160% efficiency and simultaneously output chilled water at 60% efficiency. The combined system efficiency is 220% which provides excellent fuel efficiency and big savings on natural gas/propane.

Single effect heat pumps are used which can be fired with natural gas/propane and supplemented with solar thermal energy from Chromasun MCT panels for even better performance.


Heat Pumps

Advantages of solar-enhanced heat pumps.

Highest Boiler Efficiency: Solar Enhanced Heat pumps provide hot water and hydronic heating at up to 160% efficiency and can be fired with solar or gas/propane. This efficiency is nearly double the efficiency of traditional boilers and offers boiler operators a tremendous way to reduce natural gas or propane consumption.

Highest rooftop utilisation: More useful energy can be provided to a building using a solar-enhanced heat pump approach than by any competing method. The chart below shows how the supply of both chilled water (CHW) and hot water (DHW) provides more than double the amount of energy from a rooftop than photovoltaic panels can (when used to drive an electric airconditioner) or traditional flat plate collectors can on their own.

Rooftop Efficiency Comparison

Baseload Capability: Heat pumps can be fired with solar or natural gas/propane. The combination of the two energy sources mean that the DHW/HHW/CHW loads can be satisfied with solar during the day and natural gas or propane at other times.

Reliable: Heat pumps have few moving parts and a far longer design life than electrically driven mechanical vapor compressors. Chromasun MCT Panels are also reliable, providing a sustainable onsite energy source that is backed up by natural gas which is not prone to blackout or peak summer demand limitations.


  • Tell me more!

    Chromasun assists mechanical engineers and building designers in engineering for solar. Chromasun also collaborates with Mechanical and General Contractors to source and install complete heat pump systems.

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  • Case Study

  • Solar Thermal Heat Pump/Chiller

  • Chromasun Heat Pump Solutions
  • Helisorber report


  • technology papers

Robur Heat Pumps