The way that we heat and cool our buildings has been ever changing. Advancements in the technology used has created cleaner and more efficient ways of keeping us comfortable within our homes and businesses. The wide spread adoption of air-to-air heat pumps like the Mitsubishi Mini-Split, has been a recent addition to the array of options available to owners today. Heat pump technology allows for three different types of system arrangements: Heating only, Cooling only, or Heating & Cooling in one.
Even though the heat pump has recently been popularized for space heating and cooling, it is not a new technology. Our kitchen refrigerators and car air conditioners are early examples of heat pumps. These examples only produce cooling with a by product of hot air leaving the equipment. These appliances are known as air-to-air heat pumps because they use the ambient air as the way of carrying heat away from the appliance. Using air as an exchange medium is an inexpensive way of transporting energy, but not a terribly efficient one. Two, more efficient types of heat exchange are water source and geothermal which use either water or the ground as a way of transferring energy and are better at doing so. The cost for providing the water loop or geothermal wells are expensive and often cost prohibitive to a project.
I think we all have memories of arriving at a motel for the evening and seeing large louvered grills under the rooms window with a pool of water creeping across the balcony. When you get inside your room there is a large box with louvers and a control panel protruding into the room. This unit provides heating and cooling for the motel room and are referred to as PTAC units (packaged terminal air conditioner). While these systems are inexpensive, they are often loud and not desirable to look at either inside or outside of the building.
I recently was introduced to a new type of heat pump that has been in Europe for 20 years but is only just getting its roots established here in the United States. Ephoca is an Italian company the produces a low-profile heating/cooling heat pump that has the convince of a PTAC unit, not requiring refrigerant lines being run to an exterior condenser, with the efficiency and quietness of a mini-split system. They are a sleek, well-designed, units that are located on the exterior wall of a building and provides quiet and efficient conditioning of a building’s spaces.
These units lend themselves to an apartment building upgrade where there may be steam, hydronic, or electric baseboard heat at the exterior wall of the building with a through wall air-conditioning sleeve for cooling the space. The Ephoca HPAC2.0 units can often plug directly into the air conditioners outlet and utilize the air-conditioners existing opening for the small intake and exhaust from the rear of the unit. If there is no existing A/C in rooms that would like it, two six-inch cores can be created through the exterior wall with decorative grills installed on the exterior of the building. Once installed, the need for the buildings central heating system could be eliminated. The often drafty air-conditioner sleeve will be sealed reducing air infiltration into the building. And the often noisy air-conditioner is now replaced with a quiet heat pump.
Air sealing of the exterior wall of a building has the highest return on investment when trying to reduce energy costs. Check out this information for the EPA. Infiltration from even a small crack around a door, window, or A/C sleeve will dramatically increase an occupant’s energy cost. Those same openings that let in the outside air also allow sound into the building. Sealing openings to the exterior as well as between interior spaces will increase the sound proofing of a space and lead to an improved quality of life.
Retrofits of existing buildings is a necessity. I order to maintain an affordable housing stock, buildings cannot be torn down and replaced. They need to be adapted to new technology that is energy efficient and capable of working in an increasingly volatile climate. Berkeley, San Francisco, and New York City are the first large cities to ban the use of natural gas in newly constructed buildings. The shift to electrifying our cities and eliminating the use of fossil fuels is underway. Technology such as these new heat-pumps will help bring us toward that future.