By Mike Berry, engineering intern, Mechanical design & building science lead Apex Technology
Mini-split heat pumps are cool … and hot.
I understand this is coming from an E-Council nerd, but these heat pumps have the potential to gain serious popularity in our market.
When you think of mini-split heat pumps, you probably think of the wall-mounted, rectangular blower similar to the one shown in photo at the far left. If you have spent any time abroad, you likely will have seen these in a European hotel room, a café or a Caribbean home.
These mini-split heat pumps (or ductless heat pumps, or variable refrigerant flow (VRF) HVAC systems, or whatever other confusing name nerds like me come up with) have been prevalent across the world for nearly 30 years and are now gaining ground in the United States residential market.
The most common response I hear about these systems is that they are an eye sore and no homeowner in their right mind would put one in their house. Now, homeowners across the world seem to be totally fine with the aesthetics. But if you are thinking, “Yeah, but this is America, where we love trucks, freedom and clean walls free of ugly things,” then feast your eyes on the smaller photo at left.
That’s right — it’s the typical air handling unit we all know and love, except it has the same VRF technology as those ugly wall things. Now we can keep our precious ceiling registers and still get all the performance benefits of this technology.
These (whatever you want to call them) heat pumps can vary their output all the way down to 15 percent of their capacity. HVAC should be sized for the hottest days of the year, but most of the time (98 percent to be exact) we do not need the full-capacity. Typical HVAC systems have two speeds, 100 percent on and off, which can hinder its ability to reduce humidity and that means many of us feel the need to crank down our thermostats to feel comfortable. Since the VRF systems can vary the cooling delivered, it does an amazing job dehumidifying air, which may even help us turn our thermostat a few degrees and save on utility bills without sacrificing comfort.
The E-Council dedicated two luncheon meetings to ductless heat pumps. I hope you were able to attend, but if not and if you need any further information, send me an e-mail ([email protected]). I’ll tell you everything I know, and that will probably include some good resources.