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While the majority of HVAC systems in Asia and Europe are already ductless, ductless mini split heat pumps are less popular in the U.S.
But that's changing. Mini-split systems projected to enjoy an annual growth rate of 14% each year through 2020, according to a study conducted by clean technology market consulting firm Navigant Research.
Many people might be surprised to learn mini-split systems are a smart home improvement investment that is both energy-efficient and eco-friendly.
To learn more about ductless mini splits, ProudGreenHome.com talked with Tom Carney, director of sales for Fujitsu and a 30-year HVAC industry veteran.
PGH: What's happening in the HVAC marketplace relative to the growth of ductless heat pumps (DHP)?
TC: We call it the ductless revolution. It used to be that mini spits were thought of for a garage or a sunroom, for spot cooling with a wall-hung indoor head. That's totally been flipped around.
The reason for that is the efficiency of DHP. We have single-zone units that are up to 33 SEER. Compare that to the fact that 72 percent of the traditional unitary HVAC systems sold were 13 SEER. The efficiency level for DHPs is off the charts.
PGH: How does a DHP system compare to other options?
TC: The thing is, when measuring efficiency the Department of Energy SEER ratings do not take into account the loss of air through the ducts. That's what you lose when you're delivering conditioned air through ductwork that might be going through unconditioned space such as a basement or an attic, which is common in the Northeast, the largest DHP market in the country. Ducts running through an uninsulated attic lose a lot of energy from the conditioned air. The DOE has found that ducts lose 20 percent to 40 percent of the effectiveness of the conditioned air through leaks and thermal loss.
PGH: Why are DHPs gaining ground in the industry?
TC: One of the big drivers is flexibility. In the past, units wouldn't operate below 14 degrees F, then it dropped to 5 degrees and then zero degrees. Now we have units that operate down to minus 15 degrees. That allows DHPs to be a sole source of heat, and that opens up the new construction market.
In Maine for example, half of our units are going into new construction applications. For high temperature locations, the DHP performs better than a typical unitary system because there's no duct loss.
PGH: What is keeping DHPs from wider adoption?
TC: The biggest factor has been aesthetics because of the indoor wall-hung units. But manufacturers have developed other options. We have console units that are floor mounted, recessed ceiling cassette units, and slim ducted systems that be can be recessed either vertically or horizontally. The versatility of the indoor heads that manufacturers of DHPs provide now has overcome a lot the aesthetic objections that might have been there in the past.
PGH: How do DHPs work with home automation and control systems?
TC: They have the ability of zoning with the indoor heads and inverter technology to give control via WiFi connected smart devices. A user can control multiple indoor heads off single smart phone.
Over 90 percent of the unitary system are not zoned so if you are able to remotely control that kind of system, you're doing it for the entire structure, not a room or section of the home.
With a DHP you can control the HVAC for say 20 percent of the structure or 40 percent, up to 100 percent. There's a lot more flexibility via remote controls.
PGH: What role can DHPs play in a high performance home?
TC: If you're looking at a zero net energy home, the DHP is perfect for those applications. The geothermal industry is working with government agencies to be considered a renewable energy source because those systems exchange energy with the earth.
We think DHPs should also be considered renewable because they exchange heat with the air. It's one of the best ways to reduce a home's carbon footprint.
Read more about energy efficient home heating and cooling.
Companies: Fujitsu General America