[00:00:03] Speaker A: Hello, and welcome to the Consulting Specifying Engineer Podcast. I'm your host, Amara Roskas, and I've connected with Rob Tanner and John McCrae from Johnson Controls. We're going to be discussing H vac systems, including heat pumps, and touching on the hot topic of decarbonization.
So here's some background. First, about my guests.
Rob Tanner is the Director of Marketing for Applied Equipment at Johnson Controls, located in York, Pennsylvania. Rob has more than 30 years of experience in the sale, application, design, installation, service, and marketing of commercial H VAC products and technologies.
John McCrae is the equipment Area General Manager for Applied Equipment at Johnson Controls.
He's worked at Johnson Controls and sales for nearly 28 years. Thanks for joining me today, Rob and John, how are you doing?
[00:01:01] Speaker B: Great, thank you.
[00:01:03] Speaker C: Fantastic. Thank you, Amara.
[00:01:05] Speaker A: Excellent. Well, this topic and decarbonization, it's not something we talk about a lot, so I'm happy that we're speaking today.
Rob, let me start this with you. What are some of the practical ways consulting engineers can help facility teams achieve their decarbonization goals, either in new buildings or existing buildings?
[00:01:28] Speaker C: Amara, I appreciate you asking that question because we do talk a lot about decarbonization, particularly as it relates to buildings.
And the approaches are different when we look at new and existing buildings. And so as a manufacturer and a supporting resource to the industry, we have solutions and approaches to address both.
John, I'm thinking we start with our discussion on some new buildings and talk about some of the technologies we have there and approaches for consulting engineers and then shift from there into our existing buildings.
[00:02:11] Speaker B: Yeah, yeah, absolutely, Robin. I think we can expand on it, but I think one of the biggest things that you need to recognize as you approach decarbonization is that what we're talking about most of the time in existing or new buildings is eliminating the burning of fossil fuels. Right. So we're looking mainly at heating the building in a way that is all electric.
And when you recognize that and you think about the different ways that you can accomplish that, first off, you can look at electric resistance heat, which has been around forever.
But the problem with that is it's very inefficient.
And heat pump technology is really the key technology that's going to enable us, I believe, to decarbonize both new and existing buildings. So when you think about the coefficient of performance of an electric resistance heater, you're talking about 1.0 cop.
And in the case of a heat pump, you can have a COP of 2, 3, 4, or even up to 6 or 7, depending on the application.
And if you compare that to the COP of a gas boiler, you're talking about, you know, somewhere in the 0.8 to 0.95 range.
So the cops are much, much higher. And that's not automatically translated into operating cost savings. That has to be a separ examination, I guess.
But that's, it's essential that we use heat pumps because the electrical infrastructure we'd have to have for electric resistance heat would be multiple times more and of course the utility bills would be a lot higher. And hardly anybody is willing to accept higher operating costs as they decarbonize, as they invest in decarbonization.
So I would say heat pumps in general.
Today we're going to concentrate mostly on talking about hydronic heat pump systems.
And that's where of course, what we would see in larger buildings, typically we see chilled water and hot water buildings in larger campus buildings, hospitals, commercial buildings, etc.
And we'll get into this. But you can use water to water heat pumps and also air to water heat pumps in both new and existing buildings. And they each have unique challenges.
[00:04:46] Speaker A: Okay, yeah, that's a really good overview. Thank you for that.
And John, to kind of follow up on this, what challenges do consulting engineers commonly encounter when considering heat pumps or throughout this whole process?
[00:05:00] Speaker B: Yeah, absolutely. So the first one has to do with how a heat pump works. And that's a heat pump basically takes a low grade heat source from somewhere and uses the refrigeration cycle and high lift compressors to raise that, that heat to a useful temperature.
And the challenge, number one challenge is what heat source are you going to use for that heat pump? And so you know, you need to look at does your building have simultaneous need for cooling and heating?
If you need chilled water cooling all year long, for example, like in a hospital, you're going to have a heat source there that's a low grade heat source. And a water to water heat pump can use that chilled water load as its heat source and make useful hot water out of that. So that would be one example of a heat source that you could use.
And that's actually where you get the best payback, the most energy savings, lowest operating cost, because you're putting one electrical input into that heat pump and you're getting two beneficial outcomes. You're getting chilled water and you're also getting hot water. So it's a two birds, one stone situation. And that's where you really get the highest cops in the 5, 6 or 7 range. And that's really because you're avoiding a lot of natural gas costs in the building. You're trading that for a little bit more electric cost.
But that's if we want to take one of the big takeaways from this I'd love everyone to have is that, that, that simultaneous heating and cooling is your biggest opportunity for energy savings, for, for energy cost savings.
So that, that's, that's a part of it. But then what else? If you don't have enough chilled water load, let's say your building has a little bit of simultaneous heating and cooling going on. But where do you get that secondary heat source to heat the rest of the building if you're going to use a heat pump?
So that's, that's a big challenge and there are a lot of different answers to that. One step you can take, which is kind of interesting is you can turn off airside economizer or not design it in the first place. And that seems counterintuitive because we think of that as free, free cooling.
But if you turn off airside economizer and cool with your chilled water coils, you're going to have additional heat source for your water to water heat pump that you can use and keep that heat in the building. So that's one step.
Another you can use is to put cooling coils in the exhaust air ducts.
If you have relatively warm exhaust air that's being thrown out into just the outside.
If you cool that first and extract the heat out of it before it leaves, that's another heat source that you can get.
Another possibility is maybe you're, you're lucky and your building is near a large body of water. It could be by a river or a lake and you could use that as a low grade heat source.
Another possibility, and a lot of universities are looking at this, is you can drill wells into the ground and use a, what's called a geo exchange strategy where you're going to reject heat from chillers into, into the bedrock and then during the winter you're going to be able to extract that as a heat source. It's a pretty big investment, so you have to have the budget for it. But that's another approach. But if all else fails, one of the easiest options is to use the ambient air to, as your secondary heat source.
So unless you're in a super, super cold climate in say maybe Canada, you're, you're, or Alaska or something like that, you should be able to use an air to water heat pump as an additional source of Your heating.
Rob, do you have anything you want to add?
[00:09:06] Speaker C: The one thing I would comment on John, and is and I think this is an important piece of this, all of these challenges really come from this place of we're now thinking about what we do with heating and cooling energy in the building differently than we used to. As you mentioned, we're talking and our focus here is systems that use chilled and hot water.
But traditionally, and this is part of the change and change is hard, we're moving from one appliance, a boiler, a fossil fuel fired boiler, typically providing the heating and a separate component, a chiller providing the cooling. And never the two shall meet.
Right. And it's it. But we're in a. When we're thinking about decarbonization, we've got to think about the flow of energy. We've got to think about we can't just throw heat energy away anymore. We've got to think about how do we repurpose this. Repurpose it. So coming back to your, your conversation of saying let's use the chilled water as a source for heating where we can and the supplemental sources, we're using that heat pump technology to move energy and not so much convert it as we've always done in the past. And I think that's when we start thinking that way that brings the creativity and some new thought processes that we have to think through in terms of how we going to accomplish this and support the heat pump with a system that allows it to do what it does best, which is, you know, give us a high cop as we're, as we're repurposing energy throughout the facility.
[00:10:53] Speaker B: Yeah, absolutely, Rob. Yeah, definitely.
And I, I think of one thing I wanted to make sure we, we mentioned is that when you have an air to water heat pump, there are products on the market today and we, we make one of them that also acts as a water to water heat pump. So when the opportunity is there to extract heat from the chilled water loop and move it to the hot water loop, some air source heat pump products on the market are able to do that. Take full advantage of all the simultaneous heating and cooling that's there, but then also supplement that with the same, same equipment extracting heat from the air as well to provide the hot water.
And there's, there's a second challenge I wanted to bring up and that has to do with the water temperatures that are available.
And so if you think about existing buildings, for example, what would you say Rob, what, what is, what's the most common Design temperature for heating systems that we, we see for existing.
[00:12:03] Speaker C: If we look at buildings, you know, even 20 years old and older for sure most of those buildings commercially were designed to use water temperatures.
A supply water temperature of about 180 degrees Fahrenheit with a return temperature of 160 Fahrenheit. So somewhere in that, in that range, what we would refer to as a, at least in the commercial heating business has a high water temperature.
[00:12:33] Speaker B: Yeah.
[00:12:34] Speaker C: And that, and that high water temperature creates some opportunities for can a heat pump do that? Right. If I really want to decarbonize, I want to replace a boiler.
Can I get to those temperatures with water heating? And I think John, as you could describe those are, those products are available.
[00:12:57] Speaker B: Yeah, they, they, they definitely are in the water to water heat pump arena.
And, and that's recently changed. The hotter temperatures are now available at much smaller sizes. But yeah, our compound centrifugal water to water heat pump. And then there are multiple high lift screw chillers heat pump chillers on the market that can achieve hot water temperatures in the 17175 ish range while at the same time making 41, 42, 43, 44 degree chilled water.
So those water to water heat pumps could achieve it.
The challenge becomes when you don't have enough chilled water load as your heat source, you'd have to add to that through the methods that I mentioned.
You could also put some two pipe air source heat pumps in place to essentially false load the chilled water loop and allow heat pumps to load up and be able to provide all the heating for the building. So that's one strategy that you can use if you want to use an air source heat pump. By itself though the maximum temperature that's typically seen is about 140.
We can do 130 at 0 degrees ambient. That's another point of reference. And then if you get really cold, the coldest they can operate, ours will operate down to -13. Others are very similar and we can produce 122 degree water at that ambient temp. So as it gets colder and the lift is higher, the water temperature that you can make keeps going down.
So if you can design your building new for 130 degrees and your outdoor design winter ambient temp is 0 degrees or higher, then you're good to go using air source heat pumps exclusively.
Another approach is you could add air source heat pumps that can give you 130140 degree water and that might cover you for the majority of the year.
It might Cover most of your heating, but you'd have to turn your boiler on for part of the year. Right. So that's still beneficial and that might, may be a good.
[00:15:19] Speaker C: And John, when we think about, we talked about the higher temperature needed for, you know, older buildings and even some buildings that have some special heating purposes or I think about some of the manufacturing facilities where higher temperature water is always needed. But there's been a lot of, there's a lot of buildings in the last 20 years that are designed to use lower water temperature.
And so yes, when we talk about a new building, we can start with any design water temperature we want and optimize it for a low temperature to be able to use a heat pump solution like an air to water.
But what we, what we can also do is in an existing system, right, that's designed to use a lower water temperature, we can replace boilers that were maybe low water temperature boilers already condensing gas fired boilers that are pretty commonly used and the most efficient fossil fuel appliances for that can actually be used to replace those boilers. And we can actually do a direct air to water for, for a boiler replacement where that, where that situation exists in existing buildings. And there are those opportunities out there as well.
[00:16:42] Speaker A: Okay, well, Rob, you kind of talked around this topic, so I want to focus a little bit more on money.
What heat pump solutions would you recommend for projects with conservative budgets?
[00:16:55] Speaker C: You know, I like the term conservative budgets because I, you know, rarely do we get to run into anybody that doesn't have that conservative budget. And I think the, and John had mentioned this earlier, this idea of being able to achieve not just a decarbonization strategy, but one that delivers cost savings, particularly in the area of operating costs.
[00:17:21] Speaker B: Right.
[00:17:22] Speaker C: What we refer to as opex, right. So for a facility team that's responsible for those, and most of them are right, even if they're purchasing those utilities from another source.
The attractiveness of being able to have a system that can offset operating costs to the point where it can actually return a reasonable return on investment.
And when I say reasonable, I'm talking even in the category of three to five years and that those are very achievable. Now all of a sudden that idea of, hey, I'm going to put a product into thinking about existing building first, a product in that's going to decarbonize my existing system.
I've got another driver to do that and very few people are at least at this point. There might be some more panic as we get closer to some of these net zero deadlines for buildings. But right now, there aren't many customers who are very interested in just spending money and spending more operating costs money to decarbonize a lot.
[00:18:41] Speaker B: Right.
[00:18:42] Speaker C: Some of that is part of strategies and has to be balanced in because we've got.
We've got things coming, like carbon credits that are going to penalize building owners that aren't decarbonizing their systems or that don't meet these requirements. But what's real, and I think what's exciting about this opportunity is it's not just the sustainability factor, which is in and of itself is a great thing and we want to be a part of it.
It's giving the opportunity to be able to say, I can replace existing equipment with a heat pump, and there's a. There's a reduction in my operating cost that'll pay for it. And I also get to check a decarbonization box. And so when I think about conservative budgets, this idea of being able to. To have a payback there and then couple that with opportunities for financing, because there's always the capex, right, the capital expenditure, to say, well, I still have to, I still have to buy these things and I still have to pay for the installation.
There are a number of manufacturers, including John's Controls, that offer financing options to help speed that process along and maybe advance ahead of budgetary approvals for, for opex, just to normally, you know, through the, through the process of budget approvals that occur for facility owners to be able to say, okay, the only collateral we need is the equipment, and we can pretty quickly get that going for you. So you can start taking advantage of those and get that implemented as soon as possible. Take advantage of that reduction in energy consumption that comes with the application of this. And I know that was specific to, you know, the retrofit or the what do I do in an existing building. But that strategy holds true as we look at a new building.
[00:20:51] Speaker B: Right.
[00:20:51] Speaker C: Where we get to design it the way we want. Because now I can even design, as John indicated, lower water temperatures, get even higher efficiencies out of the heat pump, and now create a scenario where compared to a traditional system, that operating savings helps pay for maybe any additional components that might be necessary to implement a heat pump system versus something we're really familiar with, which is separating a chiller from a boiler in that, in that scenario.
[00:21:28] Speaker A: Okay, so, Rob, then how do engineers calculate roi? Like, how long does it take? What should they tell their client? What should they tell the building owner to expect?
[00:21:40] Speaker C: And this is I think this is where the consultant provides, that provides a key service because we can look at it from a facility standpoint and say, great, that sounds. I love the idea as a facility manager, I love the idea that you've got something that could reduce operating costs in existing building or as I'm planning for new buildings, can give me an opportunity to lower operating costs from what I may be used to or what we might normally plan based on traditional H vac systems.
The consulting engineer's role in being able to help analyze that is critical. And of course, in order to do that, that consulting engineer will need data, if we've got an existing building historical data of how we operate. John has mentioned a number of times the greatest operating cost savings, the most efficient heat pump operation comes from when we can use the chilled water as our low temp source to provide heat. So that area where we have simultaneous heating and cooling, knowing those base loads for cooling, so you can look at your wintertime operation when you're going to need most of your heat, and saying what's my base cooling load in this facility?
Understanding that helps the consulting engineer in. Right. Sizing the heat pump solution so that we're operating that piece of equipment as efficiently as we possibly can.
The other piece that the consulting engineer will, will look at is an analysis of, you know, what products are available out there and do I need a higher temperature solution based on this existing building? Can we, if we're in a new building scenario, can we look at a low water temperature? If I'm in something that's existing, but maybe we've designed it in the last 20 years and it already has sort of a medium water temperature, what solution is there? And, and the consulting engineer's role is to bring that solution forward to say, what's the right fit? And is it a water to water heat pump, Is it an air to water heat pump? Is it some combination of the two of those?
And are we able to achieve some savings even outside of the operating cost from an energy standpoint and be able to reduce how much cooling tower water that we might use to be able to reject heat? That now we've said, hey, we're going to repurpose it and reuse it for something else because we have that load and we need it and we're not going to fire boilers to do that, we're going to use energy we're extracting from the cooling and put it back into another part of the building or another part of the process.
And so the consulting engineer is critical is a critical part of that. And partnering with, as they typically do already partnering with manufacturers that offer these solutions, they can work together to come to a facility owner, a building owner, and be able to make the right recommendation and analyze what makes sense, even try a few different things on to say what happens when and really guide that decision into something very accurately predictable and very sensible.
[00:25:17] Speaker A: So Rob, it sounds like you're really passionate about this, so let me ask you a question.
[00:25:22] Speaker C: Very passionate.
[00:25:23] Speaker A: Yeah, kind of a fun question for you. What are you doing to decarbonize your own home? I mean, how are you bringing this back to your own home and community?
[00:25:34] Speaker C: Well, you can, as you can imagine, Amara, I've been in this industry essentially my entire working career.
And so from the very beginning, and my wife would be the first one to testify to this, H Vac systems that we have in our homes are always in some state of experimentation and let's try this or try that as it relates to decarbonization. And I really felt this way. I can't talk about our customers decarbonizing their buildings and not do something to decarbonize my own domain, my own home domain.
And so over the last couple of years I've made some moves toward the use of heat pump technologies to electrify and move away from. At one time everything I had was heated by propane and so a fossil fuel. And I've slowly moved, been moving off of that and, and then even for places where I want to continue to use the propane because I it just can't quite take away that gas fireplace or a couple of appliances where that it's just nice to have a fossil fuel firing, even a stove or for cooking is looking at the most efficient appliances that I can. So today as an example, my water heating in my home is done with propane and I just have, I have the most efficient appliance I can buy, right. I'm getting 96% of what I'm paying for versus the 80 some percent of efficient appliance that it replaced. So I'm consciously thinking about these types of things and, and the experimentation part is really, you know, swap out these components and, and then how do I control it, right. What am I doing from a standpoint of control and even monitoring? I've got sensors all over the place where I'm looking at temperatures and measuring consumption of, of, of energy.
Maybe a little over the top. Right. But I'm in this industry, I want to understand it, but I want to do my part in, in an area that I have direct control over to be able to, you know, decarbonize and create a more sustainable environment in my own home.
[00:28:13] Speaker A: All right. Well, that was Rob Tanner and John McCrae from Johnson Controls talking about several H Vac and energy efficiency topics. For more information on H Vac systems, including heat pumps, decarbonization and similar topics, visit Consulting specifying
[email protected]. thanks for joining us today, and goodbye.
