2021 Webinar Series - 19 The Magic of Heat Recovery and Simultaneous Heating & Cooling

A transition away from fossil fuel heating to heat pumps presents greater opportunity to recover thermal energy with one piece of equipment taking on both the heating & cooling tasks.  This is particularly true when a building (or industrial process) needs both heating and cooling at the same time.  This panel will provide examples where heat pumps bring up system efficiency to levels which you might find hard to believe.  With heat pumps moving into a larger role, we all need to identify and take advantage of these opportunities.


  • Michael Albertson / WaterFurnace International
  • Todd Van Hyfte / ClimateMaster
  • Steve Hamstra / The GreyEdge Group
  • Richard Gerbe / Highmark







      1. How high can the COP's get?
        1. typically a larger tonnage simultaneous system could be as high as 7, energy recovery is about the same
      2. It would be useful if you estimated the reduced grid demand from a geo source versus an air source.   It would be useful to include a cooling tower and boiler (or other ambient water sources too such as a river or lake) in that comparison too.
        1. S. Hamstra  Yes, this is a good thought and it should be part of any feasibility study.  The challenge with air source heat pumps is how we handle the extremely cold conditions in northern parts of the US.  As we saw in Texas last winter, these extreme conditions can also occur when the electrical grid is heavily taxed.  If the air source heat pumps cannot keep up AND if the heating loads must be met with electric resistance heat (COP 1.0) it can cause a series of consequences that may have catastrophic implications.
      3. Which college campus is presented by WaterFurnace?
        1. M. Albertson - University of Miami OH
      4. Can data centers play a role in a community thermal energy system?
        1. S. Hamstra  Yes!  These can be fantastic sources of heat!  They pay all winter long to dump that thermal energy - maybe in some cases they could be compensated for providing that energy to the district/community thermal energy system.  When considering beneficial electrification of HVAC, if you do not have space for a geothermal borefield or thermal storage, the district thermal loop is really the best option.
      5. Would it make sense for a building to sell excess heat to neighboring buildings? Is that done? What would make it reasonable to do this?
        1. S. Hamstra Yes!  This is being widely discussed and I am aware of one district energy system that is considering how best to do this.  The idea is that the system is composed of "consumers" and "prosumers", where the prosumers may be able to "sell" their thermal energy back into the system.  Stay tuned - several folks are working on this, including The GreyEdge Group (https://greyedgegroup.com/index.html#home) with ambient temperature loops!
      6. Manufacturer question... who is making 6 pipe chillers now? Can they fit in older buildings?
        1. S. Hamstra  Waterfurnace, Trane Arctic Chill, Multistack, Aermec and others.  Several offer modular options that can fit through a standard doorway and then assembled to provide 100's of tons of heating and cooling capacity.
      7. Can you explain wet vs. dry chiller?
        1. S. Hamstra  Not sure if this is in regards to actual water-cooled and air-cooled chillers or to Dan’s presentation, but for chillers, the difference is how the heat is ultimately rejected to the atmosphere, either by cooling towers that use water or by running the refrigerant directly through an air coil.  In Dan’s presentation, they are using dry coolers (basically like a car radiator - the heat pump loop fluid passes through a coil and a fan blows outside air over it, cooling the fluid down if the outside air is cooler than the fluid).  This is often referred to as a Hybrid system, but Dan’s group takes this further and runs the dry cooler more often to provide a more balanced thermal load to the borefield.