This Concrete Slab Heats (and Cools) an Entire Building

[00:00:02]Wait, do you guys hear that?

[00:00:04]If you listen closely, it's completely silent.

[00:00:10]That's because this concrete, you wouldn't expect it to make any noise, right? But this is the heat emitter for this entire building.

[00:00:17]You can do radiant heating systems by making a total concrete slab your heat source.

[00:00:22]You can also do it with cooling, and we're going to talk about all the things that you need to make that happen in this video. Stay tuned.

[00:00:29]>> Come see Eric at Build Show Live. Scan the QR code or click the link in the description for tickets. Use code Eric 26 for 25% off.

[00:00:43]>> All right, so we talked about the floor being the radiator. This is how we do it. We've got a This is called a radiant manifold. Really, it's just a couple pipes with multiple tubing connection ports on it. We can control flow rates through the tubing, that kind of thing. There's some shutoff valves, some gauges that show us gallons per minute running through it.

[00:01:03]And we've got to circulate water through and back to our heat source. That heated water is going to elevate the temperature of the slab, right? It does it very evenly with a very low energy input. This is really the most basic part of the system. We have to install that tubing. It gets installed in serpentine loops. We limit the length of those loops, okay? That half-inch oxygen barrier PEX tubing. We don't want it to run more than about 250 to 300 ft per loop. So one end of the loop and the other connection here might be the corresponding end of that tubing. So we've got five loops in the floor, probably about 250 ft per loop, and you can do the math at 9 in on center or 12 in on center. You could even figure out the square footage of the building just looking at that. So this is the main component. These come in all different configurations, materials, and everything. Over the years, we've seen ones made out of plastic, like an engineered plastic.

[00:02:04]We've seen them made out of stainless steel like this, copper and brass. We've had it all. This is a very basic normal system right here. We're going to circulate glycol through here. That's a form of antifreeze, right? Safe for heating systems like this. It's non-toxic and it's very stable and will last a lot of a long time in a system like this. We've just washed all of that out. In particular in this job, we'll be adding it later. But this is it. We're going to circulate the water through here. Let's look at some of the other components.

[00:02:35]We know about the radiant tubing. We know about the manifold. We know about the glycol. We know that we can circulate either hot or cold water through the system, but we have to have some sort of energy source, some sort of heat source. In this particular building, what we've done is we've removed an electric boiler, an electric resistance boiler. Now, I know a lot of people hearing that are going to going to shriek when they think, "Oh my gosh, you use electric to heat." But in some parts of the country, that's totally normal. Here in Montana, they've got lower electric rates. It makes electric heating systems very attractive for a building like this, very low maintenance and long-lasting. I use a lot of electric boilers in the Midwest in Minnesota, too. We've got incentives from your electric companies to use electric. So, totally normal application, electric boilers actually low-cost and easy to operate and maintain for long, long time. This particular system now, though, eliminated the electric boiler and we installed an air-to-water heat pump. We didn't go gas or it didn't have gas to start with, which is very normal, too, in a hydronic system, but we went to We wanted to stay with the electric side of things. We don't have to add any additional components to the system like venting or gas lines or anything like that. We can stay with electric and go to a heat pump. So, that air source heat pump is going to capture energy in the atmosphere and it's going to transfer it from the air through the refrigeration cycle into the water and that is going to be our heat source. It comes with a couple components that we need to make that happen. We've got the outdoor unit, right? Side discharge air conditioner looking unit that's a heat pump so it's got heating and cooling capacity. We've got piping systems in between like where you I'm holding this 1-in PEX tubing, okay, and some insulation just to give you an idea. You'll see the installation of that as we we're putting it in and this is going to convey the heated or cooled water between the outdoor unit and the indoor unit hanging on the wall.

[00:04:28]Seems like we got a lot of things going on here but we need these individual components to make all of this work because that indoor unit has all of the controls. It tells the outdoor unit what to do, how long to operate, at what temperatures to to operate at. It tells it what water temperature it needs to send to the system and then the indoor unit actually directs the water where it needs to go because that indoor unit can also the system can also provide domestic hot water and it can do two cooling and it can be connected to different devices or emitters like air handler or radiant floor things like that. In order for this to operate smoothly and efficiently overall, the piping in the like the real nuts and bolts of the system, there's a buffer tank. So up on the mezzanine above the bathroom there where we had the radiant tubing, we've got all these components and that is where the buffer tank is sitting. It's a 20-gallon tank and it's got a bunch of piping connections. And what this does is it just adds some volume to the system. We need that extra volume, that liquid volume, to keep that outdoor unit running more smoothly. We don't want it to turn on and off on and off if there's only a small load on the system. We want a larger load in a sense so we can keep it running longer so it stays at its peak efficiency. A couple other components other than valves and things like that, we have to turn the system on and off using a room type control. We've got a sensor on the outside of the building so we can tell the whole system what it's up against, the heat load. We're using that sensor to input information through electrical protocol to the control on the indoor unit. That sensor is going to enable that indoor unit to say, "Hey, it's getting colder. We need warmer water in the system because our heat load is increasing. Or it's actually a lot cooler that or a lot warmer than normal and we could start lowering the temperature of water going into the floor to match the heat load at any given time. Those are the basics and one last component really besides the piping is the pump, right? Or the circulator.

[00:06:28]We need to move this water around and the only way we can do that is with the assistance of a circulator. We're using an ECM circulator or electrically commutated motor or permanent magnet motor that's super low energy usage and it's got some really cool features built into it. circuit board. It's got kind of its own computer. And we can access that and set it up how we want it to optimize the heat delivery to the system. We can do that even with just a our mobile device and an app. It's very cool cool technology that we're dealing with now. Although this is all super modern and relatively new, it's not any different than even systems we were installing 20 or 30 years ago.

[00:07:08]The concepts are the same. We've got the floor in this case or some other type of heating emitter. We're going to circulate warm water. We need to make that water warm and we're going to do it with our heat source. In this case, it's the heat pump or the air to water heat pump system.

[00:07:23]And as a bonus, this system is going to also be operated in cooling mode. So we're going to use this floor as a radiator, but we're going to cool it way down. So when you walk in, it's going to pull the heat off your body. It's going to pull the heat out of the atmosphere.

[00:07:38]It's going to absorb it into that slab and send that heat back through the water to the outside. It's going to be really cool. Well, pun intended and I can't wait for it to get going. So, thanks for watching guys. That is their main components of a hydronic system.

[00:07:54]Each one of them has its own function.

[00:07:56]They're pretty easy to understand when you break them down and you kind of get to see how it all goes together. I appreciate you guys. Have a good one.

[00:08:04]>> [music]