Understanding Ductless Technology (Podcast)

1 month ago

In this podcast, Jared Grier from Cape Cod Heat Pumps, explains heat pump technology. He outlines how their inverters make them efficient. Then, he talks about zone controls and other advantages of heat pumps.

Cape Cod Heat Pumps · Understanding Ductless Technology

John Maher: Hi, I am John Maher, and I’m here today with Jared Grier, owner of Cape Cod Heat Pumps and HVAC contractor in Marstons Mills, Massachusetts on Cape Cod. Specializing in ductless heating and cooling technology and focused on detail, quality, and professionalism.

Today, our topic is understanding ductless technology. Welcome, Jared.

Jared Grier: Thank you for having me, John.

What Is a Ductless Heat Pump?

John: Sure. Yeah, so Jared, what are ductless heat pumps? And really, they go by several names. They’re heat pumps. We call them air source heat pumps. There’s ductless, mini-splits, people sometimes say, or ductless mini splits. Are those all the same thing, and what are they?

Jared: Yeah, ductless heat pumps nowadays are actually a really broad term, compared to what it used to be 10, 15 years ago. Ten to 15 years ago, this equipment was mostly used in sunrooms, bonus rooms, restaurants, places of that nature. But it’s really developed to a point where we can do a whole home with this equipment, and it comes in all shapes and sizes, capacities, and types. So quite more versatile than they used to be.

They are anything from your standard wall unit, which most people are familiar with. We have floor-mounted units that look like little radiators. We have slim-ducted units, which are mini-ducted units. We have full static-ducted units that can take the place of existing furnaces. So again, that ductless is actually quite deceitful, or I shouldn’t say deceitful, but …

John: It’s kind of a misnomer now.

Heat Pumps Can Connect to Ductwork

Jared: Exactly, exactly. Yeah, again, because it used to just be wall units, but really, what I say is that a lot of the manufacturers for this equipment are overseas, and so they’ve really what I call Americanized their equipment. They’ve made it to fit how we heat and cool our homes here in America.

John: And like you said, yeah, you have these air handlers that can go in the basement or an attic or something like that and either have ducts going to multiple rooms or have a situation where you’re actually utilizing the existing ductwork in a house.

Jared: Yeah, we actually do that quite a bit. We’ll have people that have oil furnaces that are 20, 25 years old and really inefficient. People want to get rid of oil out of their home, maybe save some money on their heating, get some cooling. So to be able to use the existing infrastructure is quite a big savings to that customer. And then when you take the rebates into place, it makes it very affordable as well.

How Do Ductless Heat Pumps Work?

John: So talk a little bit about the technology itself and how ductless heat pumps work.

Jared: Yeah, so as you referred to before, these are what are called and considered air source heat pumps. In all reality, a heat pump is just an air conditioner in reverse, so I try to explain what air conditioning is first because most people can kind of wrap their head around that.

So when we think about it, when we’re cooling a home, what we’re actually doing is we’re absorbing the heat from that home, and we’re moving that heat outside and rejecting it to the outside air. A heat pump system just does that in reverse, so we’re actually going to take heat from outside and bring it inside.

This new equipment has what we also refer to as inverter compressors. What’s the beauty of the inverter compressor? Instead of being all-on, all-off, like we are more used to with our existing heating systems, these systems will actually vary their capacity to meet the needs of the home. So what this actually means is instead of turning on and off and giving you a blast of warm air or cool air, we’re going to run at a much more tempered level so that we’re just constantly giving you enough heat to keep the house either warm or cool.

Now, what’s also beautiful about these inverter units is we can run to very, very low temperatures. We can actually run them up to about 150 hertz, so we’re actually moving that compressor really quickly, and that’s what allows us to extract the heat out of temperatures when it’s very cold outside. And I get the question all the time: “Well, it’s cold outside; how is it going to heat the home?” Well, to you and me, which we’re trying to keep a 98-degree core temperature, yeah, it’s going to feel cold outside when it’s 30 or below.

But to a heat pump, there’s still plenty of heat available. We’re not at zero Kelvin. There’s still heat content in the air, and these units, again, with that inverter compressor, are able to extract that heat and move it into the home in a very efficient manner at very low temperatures.

Benefits of Ductless Heat Pumps

John: Okay, so what are some of the benefits of installing a ductless heat pump in a home?

Jared: Well, as we already touched on, oftentimes we can use the existing infrastructure if we’re going to replace a furnace with an air handler or maybe even replace just a cooling-only system and make it a heating and cooling system now. So that’s really nice.

With the old way, we would retrofit heating or cooling into a house. Oftentimes, we were putting a system in the attic. Obviously, the second floor would be easy to get ducts to, but the first floor would be a challenge. We’d have to run ducts through closets, which is really invasive to the home. So now, with the ductless option, we can still do a ducted setup on the second floor but put a couple wall units on the first floor and again, not have to eat up closet space or be really invasive to that person’s home.

Myths About Heat Pumps: Get the Truth

John: Okay, what are some of the most common myths about heat pumps that you hear all the time from customers?

Jared: A big one is they don’t work. They don’t work when it gets cold outside, and if that were the case, I wouldn’t have a business whose primary job is to install this equipment for people.

So they absolutely do work in the cold temperatures. We do lose efficiency, and we’re always clear with our customers about that, that the colder it gets, the less efficient they’re going to be. But you also got to look at it as a seasonal cost. Here on Cape, our average heating day outside temperature is 40 degrees or warmer, so we’re not often at those really cold temperatures, where we’re running really inefficiently, or running inefficiently, I should say.

But more, we’re usually running in those more mild temperatures, where we’re actually very efficient and have really high COPs (that’s Coefficient Of Performance.) And they can be over four, which now we’re competing with geothermal systems, so that’s definitely one myth, that they just don’t work.

Another myth is that they can be very expensive. Oftentimes, these actually can be very equivalent to replacing a furnace in your home. And take the rebates with the Mass Save Program into place, and we can actually oftentimes be less expensive than if we were just to replace it with conventional type of equipment.

So those, I would say, would be the biggest misnomers about this equipment and misunderstandings and myths.

Heat Pump Efficiency at Low Temperatures

John: Okay, at what temperature do you start to lose a little bit of that efficiency? How cold does it have to be?

Jared: Well, all this equipment is rated, and there are rating tables, which if a customer is savvy enough to ask the question, we can provide them. Below 30 degrees, we start to lose that efficiency, but the systems we put in for customers where this is going to be their primary source of heat is the LG RED systems. The LG RED systems have full capacity at five degrees and will actually continue to operate down to -13 degrees outside.

That said, five degrees, yes, there’s not a lot of heat in the air. The house is losing more heat to the outside, so we need to work a little bit harder, and that’s where we start to see the efficiencies in that real cold weather. But we will continue to operate. We will continue to be able to keep you warm.

John: And like you pointed out, the average temperature on Cape being 40 degrees or something like that, you’re really rarely getting down to that five-degrees-and-below temperatures. And the fact that, yeah, if your system has to ramp up a little bit, work a little extra hard on those few hours or few days when it gets that cold, then that’s fine. The rest of the time, it’s running really efficiently.

Jared: Yeah, last year, since 2023, we had a stint over one weekend where we got into the negatives, about -10 degrees outside. We actually had zero calls from any of our customers that operated and heated with heat pumps. So again, they will continue to work; they do have to work harder.

But even that weekend, it was just the weekend, and it was mostly just cool at night. During the day, it did get back up into the teens. So even if we do experience those really cold temperatures, it’s generally for a very brief moment of time, and by the time the sun comes out, we’re already warming up.

The Advantages of Zone Heating and Cooling

John: Talk a little bit about zoning your home for heating and cooling by using heat pumps and what that means in terms of comfort for the average person in a home.

Jared: Yeah, glad you asked that. So a traditional heating system with ductwork or cooling system with ductwork, if we want to do a different zone, we have to run a whole new trunk and add a bunch of controls and dampers to allow the person to operate that portion of the home separately. What’s really nice about the mini-split technology is each individual indoor piece of equipment is its own zone, so we often zone with equipment, versus putting different duct systems in a house with dampers and thermostats.

So each indoor unit, if you have eight rooms in your home and you have eight units, one in each of those rooms, you now have eight zones in that house, so you can really individualize comfort. So if you have somebody that likes a little cooler when they sleep, somebody that likes a little warmer when they sleep, and they’re in different bedrooms, they have the ability to moderate the temperature in the space they’re going to be staying in.

John: Yeah, and then when you have something like an air handler that’s using the ductwork in your home, that would just be one zone. So say you had the second floor of a house and an air handler in the attic, and then that was running ducts into ceiling grates in each one of say, three bedrooms on a second floor or something like that, that would just end up being one zone.

But like you said, you could still have that shut off during the day and be warming or cooling the downstairs. And then when you’re going to bed, then you turn that system on, up or down, depending on what season it is, right?

Jared: Yeah, we can’t really use conventional zoning systems with mini-split systems or ductless systems. It mostly has to do with how all the equipment communicates. So the indoor units communicating with the thermostat, the thermostats communicating with the indoor unit, which is also communicating with the outdoor unit. And unfortunately, we can’t put in damper systems because it would interrupt how those systems communicate and operate.

So oftentimes, yes, we’re zoning with individual pieces of equipment, versus zone dampers and ducts. Now, that said, it doesn’t mean that we can’t do multiple pieces of equipment for one floor with its own zones or its own duct work to be able to give you that more individualized comfort. That’s what you’re looking for.