Written By: John Jeppesen
The short answer is A lot. Mini Split, also called Ductless HVAC systems have been around since the ’80s but have not been popular until the last five years. At Performance Point, we have discovered several reasons for the increased use.
We talked to Rob Howard, a Charlotte, N.C. Sales Manager at Yandle-Witherspoon Supply, and a Mitsubishi Mini Split dealer. He compared them to conventional central HVAC systems. “It does a good job of keeping a portion of your house comfortable, usually close to the return and where the thermostat is located but the extremities are not as comfortable as you want them to be. It’s not uncommon to see those areas drift three to five degrees off what the thermostat is set to.” He called that “custom comfort.”
Second, he says Mini Splits improve indoor air quality: “Everywhere you have an air handler or a Mini Split you have filtration in that zone because it has a filter built into it.” Central systems have just one filtration point for the whole house.
Then there’s increased efficiency. Most central heat pumps have a mid-range 14 SEER (Seasonal Energy Efficiency Ratio). Higher efficiency systems can push to 17-20. Mini-Splits can have a 20-30 rating. Contractors and developers use this as a key selling point.
Some builders and developers say Mini Splits are too expensive. Not so says Howard: “While the equipment may be more expensive, it (Mini Split) requires little or no ductwork to install. The labor and materials for installation should be significantly less.”
Justin Fulford, Fulford Heating and Cooling in N.C. has installed Mini Split systems all over the world. He too has noticed a significant uptick in Mini Split systems and agrees with Rob Howard. He also notes that these systems are significantly more expensive in a total retrofit or remodeling. That said, Mini Split systems can provide air conditioning to older homes with hot water or boiler heating systems. In those situations, they are the most cost-effective, inobtrusive solution to adding air conditioning compared to window units. They make a lot of sense in an addition or bonus room. Fulford cited his own home: “I put four of them in my house and increased the square footage by 1200 square feet. By increasing footage, putting high-efficiency systems, my power bill went from $270 down to $120. I went from a small house to a big house and saw a huge drop in my power bill.”
Both Howard and Fulford say their customers are amazed at how quiet Mini Split systems are.” The biggest thing I like to talk about is how quiet they are,” says Fulford. “The indoor unit and the outdoor unit are practically silent. You don’t hear moving parts or compressors. That’s a really good feature for people that have a patio or go outside and they’re tired to hearing a loud unit rattling away.”
It has been noted that some architects and interior designers don’t like the aesthetics of a unit hanging on a wall. Fulford says this about that: “I have several architects that are promoting it (Mini Splits) because there are ways to be creative to hide the indoor units and have a lot of indoor options. They need to find a way to hide the equipment. We’ve got several building high-end beach houses and that’s all they want to put in.”
Commercial buildings are yet another application of this technology. “When you get to the commercial level, they don’t call them Mini Splits, the call them VRF (Variable Refrigerant Flow),” says Howard. “You’ve got two levels, VRF heat pumps and true VRF which offers simultaneous heating and cooling. That’s where you get into your highest cost and highest efficiency. This technology takes heat from one part of the building and moves it to another. Maybe you’re in a commercial space where you want cooling in the offices but they want heating in another part of the building. Rather than making the heat, you’re just moving it from one space to another. You’re paying for the cooling and getting the heat for free or vice versa.” Howard shared a Mitsubishi case study on this topic. https://www.youtube.com/watch?v=IeEDFVmvtsk
There are a lot of design considerations with ducted and ductless Mini Split systems, especially in low-load new homes or renovations requiring Manual LLH. Even conventional equipment can benefit tremendously from professional design expertise. In future articles, we will talk about some of these design considerations! This is where Performance Point can help. We are fully up to speed on this technology and can consult with your team if you’re considering a Mini Split system or having trouble squeezing conventional ducts into your house plan.
Visit our website www.theperformancepoint.com or call 704.563.1030 to get started.