Is a Geothermal Heat Pump Worth It? My Net Zero Home

Heat pumps are the most efficient way to heat and cool a home, but they're not all created equal. Geothermal or ground source heat pumps are more efficient and effective at a wider range of temperatures than air source, but at a cost. It's way more expensive up front, but that should even out over time, at least in theory. Now I'm going to be the Guinea pig for everybody out there because we went with the geothermal system for our new home. So what does the setup look like? What do the costs look like? And in the end, is it going to be worth it? I'm Matt Farrell, welcome to undecided. This video is brought to you by Span, but more on that later. Using heat pump systems almost feels like cheating because of how much energy you get out versus what you put in. They seem to defy physics, but the laws of thermodynamics are still in play. Heat pumps do end up using a little energy transporting heat around. And while heat pumps are hands down the most efficient way to maintain comfortable temperatures within your home, they're not without their disadvantages. Standard air source heat pumps tend to have a slightly higher upfront cost versus the traditional gas and electric HVAC systems that are out there. And in the past, heat pumps have struggled in very cold climates, but that's changing with newer air source technology like variable speed compressors, smart controls, and advanced defrosting. On all those points, I've got videos that go in more in depth if you're interested. But if you want the Bugatti of heat pumps, most people will point you to geothermal, also known as ground source heat pumps. When my wife and I started building our new home with the goal of trying to achieve net zero energy, geothermal was definitely something I was interested in for efficiency alone. But that brings up a very important point that I have to lay out right at the top, and that's goals. I've said this about my experiences with solar panels in my previous home. But if you want to figure out if something is worth it, you have to clearly lay out your own goals. And these are of course personal decisions, so my goals may not align with your goals. But in my case, my wife and I set out to create our forever home. For us, that meant building with components that had a long expected lifespan of the gear and construction methods that we chose, high efficiency for lower energy use and monthly cost of operation. And because we have solar power, this will help achieve net zero energy over the course of the year. And finally, upfront cost that will make sense over the expected lifetime of the product and our time in the house. Now, that last point is tightly linked to the first two and how long we're planning on living here. But before I discuss whether or not the geothermal system helped my wife and I achieved those goals, I want to explain why we sprung for it in the first place. So here's a super quick recap of why geothermal is so efficient. Instead of extracting the heat out of the air around your home, which is obviously affected by temperature fluctuation, the geothermal system exchanges heat from deep underground, where the temperatures don't really change that much at all. And once you get down to about 6 to 10 feet below the surface, the Earth becomes a consistent 50°F or about 10°C. But the actual temperature will vary a bit based on where you live. Either way, no matter what time of year it is, we can always count on having that roughly 50°F to pull heat from in the winter or move heat into during the summer. And the exterior air temperature is less of a concern. Again, I'll refer you back to my previous videos for an in depth primer on how heat pumps work. But by using a compressor, they can boost that heat up or cool the house down as needed. And for my home, that meant drilling a single geothermal well down about 400 feet and feeding a closed loop tube into the well and back up into the house. The process of drilling the well was absolutely fascinating, which I actually covered in a previous video. However, the one thing I didn't get into was the cost. Brace yourself. Drilling our geothermal well cost $18,550 which definitely has some sticker shock to it. Gave me a lot of pause. Before we get too caught up in the cost, know that it's specific to my location and what we had to do here. My house had to go with a vertical well due to the space constraints and the location. But if you have the room you can go with a horizontal loop. That's when they dig down maybe 6 to 10 feet around a large area of your property. Then they loop the line horizontally before filling the earth back into place. It's a cheaper option versus drilling a vertical well, but requires more space. And on that note, there are companies bringing more compact and efficient drilling rigs to the market, which should help drive down the drilling cost. For instance, the US companies, Terra Sonic is doing this with Sonic drilling rig technology. Let me know if you'd be interested in the video going into further detail. But back at my new home, our geothermal runs up into the mechanical room. That's the house is kind of beating heart. You can see the lines coming up into the room over there. And then over here is the water furnace Series 7 geothermal system. And for full transparency, water furnace did partner with me on this build and help supply some of the system. But my opinions are my own and they had no say over anything in the video. They're seeing this for the first time right along with all of you. The specific reason I wanted to go with the series 7 was its variable speed so it can ramp itself up or down to keep the house at a precise temperature. In my previous house we had a high efficiency gas furnace in central air which was two stage, and most systems work that way. A stage operates at a predefined speed and efficiency. For example, one stage maybe 50% capacity and the second stage maybe 100%. That means the system kicks on and off at random intervals to maintain a comfortable temperature. Being variable means it can ramp down to 10% or just up to 40% for whatever it needs. Less kicking on and off. But probably my favorite part of the geothermal setup though, is my D Superheater. And this helps us create a lot of hot water at virtually no cost. So what is a Desuper heater? Well, at a high level, when a geothermal system is running, the compressor is doing all the heavy lifting to get the air to the right temperature, and that operation itself generates excess heat. A desuper heater captures that excess heat and cycles it into a holding tank filled with water for virtually no extra costs. You're getting hot water from heating and cooling the air in your home. And my desuperator tank then feeds into a heat pump water heater that can top up the hot water if it's not hot enough before delivering it to the faucet or the shower. On average, AD Superheater, you can supply roughly half your hot water needs in the house. I'm planning on doing a deeper dive into my hot water setup, the challenge that we had getting it ready, and more. There were lots of challenges, so stay tuned for that one. Meanwhile, still in the mechanical room, you'll see a Renew Air EVL Energy Recovery Ventilator, or erv this is what's supplying our house with fresh air while exhausting the stale indoor air out. An airtight home is great for energy efficiency, but it's also great for controlling how the air comes in and out of the house. The way it works is pretty clever and simpler than you might think. In my house, I have a series of exhaust fence, one in each bathroom, one in our laundry room, and one in the kitchen. The Erv is running 24 hours a day at a very low level and exhausting the stale air out the back of the house. For the first time I ever heard of an erv. My initial thought was, isn't this just injecting all that heated and conditioned air that you just created? Well it turns out not really. Instead the erv passes the stale inside air through tiny vents or channels on the way out. Now parallel to those vents and channels are another set where fresh outside air is passing through as it comes in. Now these areas are separate but in contact with each other and a fair amount of the heat moves from the hotter vents to the cooler vents. This means that in the summer you're pre cooling hot outside air as it comes in, and conversely in the winter you're heating cool outside air as it comes in. It's really cool now, my home system. The fresh incoming air is filtered, then mixed with the recirculated air inside the water furnace system, and finally distributed throughout all the HVAC vents throughout the house. There are other high end erv systems like Zender which have dedicated intake and exhaust lines separate from the HVAC system, but the setup we went with was sufficient for our house and saved us some money. But I'll get to the cost in just a bit. Now, one side benefit to the erv is that I opted for a higher rated MERV filter. And MERV stands for a minimum efficiency reporting values. And it lets you know what sizes are particulates it can filter out. And we've got MERV 13 filters which capture the majority of particulates that are over 1 Micron and about half the ones that are smaller than one Micron. Now I've got pretty bad allergies and August and September are the worst months for me, but I've had no noticeable issues in this house. My wife also commented within the first week of living here that the air is also super fresh all the time. You've got to love in the RV. This piece of gear that you see over here in my mechanical room is a whole home dehumidifier. And because of the air tightness of my house, there will be times of year like the spring and early fall where the water furnace system won't be running enough to really dehumidify the air. I've experienced this in my previous house too. The central air conditioning on the House would hit temperature so fast that the air wouldn't get dehumidified. The problem is as the relative humidity level gets closer to the temperature, like 70% humidity at 70°F gets a bit uncomfortable. This dehumidifier removes that issue and again, so far it's doing a great job. Now about those costs and keep in mind this is relative for where I live and cost of installation and labor and all those kind of things. So you have to take this with a grain of salt based on where you live, but the water furnace system, including the DS superheater and what it took to run venting throughout the house came out to $59,450. The Erv dehumidifier and the associated ductwork came in at $21,000. So for all the tech that we've walked through so far, we have a grand total of $99,000. Yes, you heard me right, almost $100,000. So have your eyes popped out of your head yet? Because I'm still trying to get mine back in. So while you're feeling around for your corneas, let me give you some added context for those figures. And first of all, this was a new house. So the price includes the cost of running all the ductwork and the labor that's involved with that. The vertical geothermal well is a pricier option versus a horizontal loop, so that jacked up the cost too. All in all, the budget you need for updating an existing house would look very different from mine. But that raises the biggest question, was it worth the cost? Before you jump the gun and say no, let's walk through the other options we weighed before going geothermal. We also considered air source ductless mini split heat pumps and a more traditional central air source heat pump system. And just the air to air central heat pump system would have cost around $38,000. But that's not including the hot water, dehumidifier and ERV system, so that doesn't equate to as big of a gap. For more apples to apples comparison, the water furnace system and drilling the well cost $78,000, which means that we spent about $40,000 more than we would have with an air source system. Still a hard pill to swallow there. However, there's a clean energy federal tax credit of 30%, much like with solar that you can claim on your tax return now. That means my wife and I can deduct $23,400 from how much we owe in our taxes this year, and this brings the out of pocket cost of the system down to about $54,600 now. It's still more expensive, but we're now down to about a $16,600 premium for the geothermal system again. Is it worth it? Well, if you're focused on just the upfront costs, the answer looks like no. But this is our forever home and we're looking at things in the long term. Once again, I want to stress the imortance of setting your own goals. And for us, efficiency was high on our list. Now this system is dramatically more efficient than the central air to air system that I've been comparing it to. My geothermal system should cost almost half what the other system would to run each year, and that could be roughly a $1000 savings year to year. This chart wasn't for the water furnace system specifically, but it's still worth looking at because it's comparing the operating cost of another comparable geothermal system that we looked at compared to the air to air system. And looking at 5-10 and even 25 year time spans, you can see how the geothermal system closes the gap easily and ends up coming out way ahead. It might take 14 to 15 years for my specific setup to hit that point of parity and then come out on top. But again, if you're upgrading an existing house and you do a horizontal loop, you could potentially hit that price parity in seven to eight years. Now for my wife and I, the longevity of the system was appealing. The well we drilled shouldn't need any real maintenance in our lifetime. They can last over 50 years easily. And the actual mechanicals inside the house typically last 20 to 25 years, maybe even longer with good maintenance now, where many splits might need to be replaced after 10 to 15 years. Plus, this includes the hot water generated by the system, which might be as little as a couple $100 in electricity each year now. That's about half what it might cost without the de superheater system included. So was it worth it? Well, given my goals, it's ticking all the boxes. But the jury is still out. I'm going to be making update videos over the next six months, one year, two years. I'm going to be documenting all of my experiences with upkeep and costs. So I'm hopeful that this system will come close to the projections. I saw similar things play out with my solar panel system on my old house, so I think this will be the same, but you never know. At the end of the day, I'm a big fan of heat pump, all the things, whether that's air source or ground source. With the latest technologies, it's really hard to go wrong. Do you want geothermal for your home? Jump in the comments and let me know and be sure to check out my follow up podcast is still to be determined. We'll be discussing some of your feedback. Thanks to all my patrons who get ad free versions of every single video. And a big welcome to new suorter LUS members Issa Ahola, Brett Chandler and Roducers Justin and Michelle Nastos oen in Bush of your names. I'm really sorry if I did. Your support really is important to the channel. I'll see you in the next one.