Heating Technology in Cannabis Cultivation: An Interview with Jamie Tuinstra of Modine Manufacturing

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Jamie Tuinstra, product manufacturer at Modine Manufacturing, sits down with Cannabis Science and Technology in an informative interview where he discusses how heat exchanger technology can help support energy efficiency, the equipment his company featured at the Cannabis Science Conference Fall 2023, and challenges heaters need to overcome with cannabis cultivation.


Too busy to watch the video? Read through the full conversation below:

Can you explain how using secondary heat exchanger technology and a robust tubular primary heat exchanger design helps with energy efficiency?

Jamie Tuinstra: A standard efficient unit, when we talk about efficiency and we're talking about 80% or a little bit higher, uses a single primary heat exchanger. And what that does is the heat blows through that heat exchanger and a fan goes across it and it pulls that heat out through that primary heat exchanger. So you're pulling the heat out of the metal, into the space. But as time has evolved and as efficiencies become more and more important, technologies move to combining a secondary heat exchanger. So instead of one, now you have two. And the idea is that your heat runs through the primary heat exchanger and then it actually will run through the secondary heat exchanger. And what we're doing is extracting the maximum amount of heat that we can out of those heat exchangers. So all that fuel that's burned, you want to pull as much heat out as you can to put it in the space. Because if you don't, you're basically just taking that heat and throwing it right out the stack and out the building. So having a secondary heat exchanger just optimizes pulling that heat out into the space. So whatever they're burning, the dollars they’re spending on that fuel, they're getting the most in that space versus moving it out of the space. That's really where that comes from and that's why you'd want to have a primary and a secondary heat exchanger in these systems.

What are some unique challenges that your heater overcomes that are specific to cannabis growing?

Jamie Tuinstra: In the cannabis world, or in any really growing world, plants have a requirement for temperatures to grow the best that they can. So it all depends on the stages of these plants, but unit heaters can maintain a constant temperature in these spaces, which is really reliable. Number one, you can put a heater in one building and say that building is growing cannabis and they need it to be a certain temperature. You can have that unit do that. And in another room, maybe it's a different plant they're doing or a different strand of cannabis that they're doing that needs to be a different temperature. These units, once they're set, they will maintain that temperature in that space. That helps with the space. The other thing would be, these plants are sensitive to humidity levels, issues like mold and mildew. So running these heaters can help balance that. Just keeping the heat at a constant temperature will help balance that out. These units also have a blower motor on the back of them, whether it's a propeller fan or whether it's just a blower style motor. And what that does is they can actually have these units run the fans consistently all the time and it'll actually help with air circulation in that space. So you're not having dead spots in the grower’s building, just like a home furnace. You could turn your fan to the on position and it actually helps keep the temperatures more even in the space so these heaters can do that as well. You can have localized heat. We talked about that a little bit, which I think is good for growers, depending on their setups. Some of them have very, very large growers and they have a wide open space and you can have multiple unit heaters in there to heat this space, or maybe they want to segment it off based on what they're growing. So having them in specific areas really helps. I would think lastly, especially in a growing operation, when you look at the overall footprint of the greenhouse, how they make their money is the growing space. So keeping the growing space available, meaning the floor level and maximizing that, that's key for these growers. So these units are designed to be hung above the growing areas, not taking up any floor space or any headroom. Certainly you could have these lower and you can do things like that. But in a growing application, they want to maximize their growing space. So these are tucked out of the way; they're going to be hung up typically near the roof. So you have all sorts of room underneath it, headroom. Basically they're tucked out of the way for these growers. So those are some of the things I think that are really critical for the growers as far as maintaining temperatures, footprints of the units, how they operate, and where they can be placed.

Can the heaters be used for a variety of growing methods?

Jamie Tuinstra: There's a number of ways that, depending on what they're growing, they have what they call “bench growing” where we've actually had our heaters underneath a bench and blowing heat to warm the tables up. So we we've seen that, we've seen all sorts of vertical growth. These are very, very flexible. So what I would say is wherever there is a need, it probably really doesn't matter what they're growing or how they're growing, if they need heated air, our units are going to be able to provide that. They're very flexible as far as where you put them, surprisingly enough. In in a greenhouse market, it's probably the more harsh environments to have equipment in, you can understand what the humidity levels and so forth. We’ve in the greenhouse market for decades and our products are really driven around that. So very flexible, so whatever growing they plan on doing, I'm sure our units are going to work just great for them.

Do you encounter any issues with varying regulations throughout the US?

Jamie Tuinstra: Yeah, currently we don't. Now when you when you look at the cannabis market, there certainly are a lot of regulations on growing and selling and so forth, but for our equipment to go into their space, it's no different than our equipment going into a pole barn or in a manufacturing building. What we're providing these growers with is a source of heat to keep their buildings warm through the winter months. Now, that doesn't mean that there isn't any out there that we don't know about. So it's always critical for these growers and their contractors that are putting in that they check with all local codes and all local ordinances to make sure they're following the proper laws in those spaces, but to our knowledge right now there, there's nothing that says they couldn't put these heaters in these spaces. They're fully certified for greenhouse markets and that's really where we focus on – making sure our product is safe and reliable and meets all those codes to be placed in these facilities. Our products is, but again they would just make sure that they check with the local codes.

What other new innovations are you bringing to the cannabis industry?

Jamie Tuinstra: There's two and the biggest one we touched on in the beginning is the high efficiency unit heater. So for decades, the unit heater market and the unit heater product has always been a mid-efficient product and when I say that, I alluded that to a little bit earlier, is about 80% efficient. So when you when you talk about that the simplest terms is: 80% of the heat is going into the space and 20% is going out of the building. So every time you're heating that and the money you spend, you're losing about 20% of your value going out the stack. So as technology has evolved and as we've gone into these higher efficient units and using these secondary heat exchangers, now you can get north of 97% efficient, so only 3% is going out. That can vary depending on the product, but these units have gotten so much more advanced over the years. So, putting that in perspective for the cannabis growers, the technology to have a high efficiency unit in their growing facility is essential for them to save more money. So you can imagine 20%, you're talking one unit heater. If you're wasting 20% fuel going out to stack, now you're only wasting 6%, 3% going out. And now you start to multiply these units. So say they have 20 units in a growing space, some of them have hundreds in there. Fuel bills for the grower could be their number one expense. So lowering that fuel cost for these for these growers puts more money back in their pocket, more money in their business, so that's probably the biggest thing for the growers right now is putting in high efficiency units in their growing facilities so that they can start to recover some of those fuel costs. So that's the big one. The second one I would say is become more popular as time has moved on, is a building management system. Let’s say you have multiple unit heaters, or say you have one, but they have a computer system that centrally monitors all these homes, all these houses, all their operations, what the temperature is. We actually have a communication system that's already from our factory in there that they can tie into their computer system to tie these all one to one location. So somebody can go in and they can set the temperatures and building 1, or maybe they want to have the fan on in building 2. So it's a centralized system for them to utilize to make their products and their homes more efficient. It's not used widely right now in the greenhouse world. You will see it, but it is something that's kind of unique. So it's out there and it will help for those with bigger operations. Some smaller homes will have them, but bigger ones certainly do. So that's really the two big ones that we have today.