03.7 / Work ExampleInnovative Technology

FRESCo is always looking for the next technology that will help save energy, reduce GHGs and be a cost-effective solution that we can offer our clientele. We have been fortuitous to be involved in several pilot initiatives that test out new technology. This has included the FortisBC Condensing Makeup Air Pilot project,  which successfully demonstrated high levels of energy savings. This led to the development of a new rebate program for this technology.

Here are some examples of current/recent projects:

Gas Absorption Heat Pumps (GAHPs)

Absorption is common for large chillers worldwide and emerging for domestic combined heat and DHW. GAHP’s are making their way into new applications in North America. FRESCo is acting as the energy specialist on pilot sites that are testing out  the use of this technology for domestic hot water in multi-family buildings. The technology has the potential to achieve much higher levels of efficiency than are available by conventional high-efficiency gas-fired appliances (e.g. condensing boilers).


Potential Benefits:

  • High efficiency – ~140% average;
  • Reliability – may not require back up heating,
  • Emissions/Combustion safety – GHG decreased by up too half; Climate – use natural refrigerant;
  • Flexibility – demonstrated range is 10 to 140 KBTU/hr, single family to MURB and other applications, process, DHW. Can operate in hybrid with conventional equipment; Hydronic or forced air;
  • Principle of operation: Commonly, electricity is used to power an induction motor that drives the refrigeration compressor. Air-sourced gas-absorption heat pumps use a gas burner to drive the refrigeration cycle. Heat is also added into the system by the gas burner as it heats the refrigerant and absorbent solution in the ‘generator’ – this should ideally be configured to allow condensing of the combustion gases to maximize performance. The output from the heat pump can be used to supply low-temperature hot water for space heating and/or for the production of domestic hot water via an indirect heat exchanger/storage tank heater.
  • The gas-absorption heat pump comprises a sealed thermodynamic circuit, normally containing an ammonia water solution that acts as the working fluid, with ammonia being the refrigerant and water the absorbent. Traditional air-to-water electric heat pumps typically use modern fluorinated refrigerants (such as the HFCs R407C and R410A). Ammonia, a naturally forming chemical, offers no harmful effects to the ozone layer. The ammonia water working fluid has zero ozone depletion potential (ODP) and zero GWP. Low GWP may provide a credit when assessing buildings. (See BREEAM). similarly, the lack of CFC will ensure that the Energy and Atmosphere prerequisite for the LEED (Leadership in Energy & Environmental Design) rating system’s Fundamental Refrigerant Management will be satisfied. Ammonia refrigerant is toxic and flammable. However, the commercially available units are designed for outdoor installation

Gas Absorption Heat Pumps (GAHPs)

Domestic Hot Water Recirculation Control Pilot


FortisBC wanted to evaluate the energy impacts of on-demand recirculation controls and engaged FRESCo to support a pilot project to test Enovative’s technology.

Domestic hot water (“DHW”) recirculation systems in commercial buildings reduce the waiting time that building occupants experience when they make a hot water draw far away from the water heater.  Typically, the recirculation pump operates continuously, pumping water from the water heater through a loop that traverses around the entire building and returns to the water heater. The DHW in the loop is maintained at an elevated temperature, resulting in significant heat loss, whether or not there is demand for DHW.

The purpose of demand controls is to operate the recirculation pump only in response to DHW demand.  This results in lower temperatures in the DHW loops and less pump operation, leading to a potential 5-20% of natural gas and electricity savings.

How could demand control technology deliver energy savings?

  • It reduces water heating gas consumption by eliminating the need to continuously maintain water at high temperatures.
  • It reduces electrical usage for pump operation from running 24 hours per day, seven days per week down to approximately six hours per day, reducing.


What are the potential long-term benefits?

  • Lowers property operating costs and increases property market value.
  • Minimizes pipe occlusion, pinhole leaks and damaging mineral deposits.
  • Extends product life of the entire water heating system.
  • Compatible technology with solar-thermal water heating systems.


Domestic Hot Water Recirculation Control Pilot

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