WEBVTT Kind: captions Language: en-US 00:00:00.000 --> 00:00:03.040 Now that we know what heat  pumps are and how they work,   00:00:03.040 --> 00:00:06.093 it’s time to talk a little more about their  future. 00:00:06.093 --> 00:00:07.898 If you’ve not seen the first video, 00:00:07.898 --> 00:00:10.683 well you definitely should fix that before  watching this one 00:00:10.683 --> 00:00:15.229 as there will be a lot of stuff we talk about here that assumes prior knowledge. 00:00:15.229 --> 00:00:16.567 I’ll summon a card. 00:00:16.567 --> 00:00:17.920 Bippity Boppity Card! 00:00:18.480 --> 00:00:19.246 Great! 00:00:19.572 --> 00:00:22.539 A link is below, and probably in a pinned  comment, too. 00:00:22.539 --> 00:00:23.755 You ever heard about those? 00:00:23.755 --> 00:00:24.483 They’re neat. 00:00:25.040 --> 00:00:27.616 I want to start with a clarification of sorts. 00:00:27.616 --> 00:00:30.459 Heat pumps definitely are the future of home heating, 00:00:30.459 --> 00:00:31.766 at least if I can help it, 00:00:31.766 --> 00:00:33.661 but they’re also not new. 00:00:33.661 --> 00:00:36.068 And some people hate them! 00:00:36.367 --> 00:00:38.861 It seems for every person who thinks heat pumps are 00:00:38.861 --> 00:00:42.125 wicked neat-o closest-thing-to-free-energy-out-there devices 00:00:42.125 --> 00:00:43.172 (that’s me) 00:00:43.172 --> 00:00:45.440 there’s another who hates theirs with a passion. 00:00:46.160 --> 00:00:48.877 Allow me to submit that you don’t hate  your heat pump, 00:00:48.877 --> 00:00:50.405 you hate your thermostat. 00:00:50.800 --> 00:00:54.301 See, as we learned, as the outdoor temperature  approaches freezing 00:00:54.301 --> 00:00:57.374 it gets harder for air source heat pumps to work. 00:00:57.374 --> 00:00:59.915 A smaller temperature difference between the source of heat 00:00:59.915 --> 00:01:03.860 and the evaporator absorbing it causes the efficiency of heat pumps to drop 00:01:03.860 --> 00:01:05.578 and eventually their output as well. 00:01:06.160 --> 00:01:11.469 Unfortunately, it is under these precise  conditions that demand for heat goes up. 00:01:11.986 --> 00:01:13.464 It’s kind of a bummer. 00:01:13.464 --> 00:01:17.437 So, most systems with heat pumps have some sort of backup heat source, 00:01:17.437 --> 00:01:18.964 be it electric resistive heat 00:01:18.964 --> 00:01:22.770 (often this is called the heat strips, though I prefer to think of it as a giant hair dryer) 00:01:22.770 --> 00:01:25.769 or a fuel-fired furnace might be utilized. 00:01:25.769 --> 00:01:29.839 The trouble is, until quite recently the  thermostats controlling these systems 00:01:29.839 --> 00:01:35.663 would just run the heat pump as hard it could until the  output wasn’t enough to maintain the set point. 00:01:35.663 --> 00:01:38.510 Only then would they switch to the auxiliary heat. 00:01:38.880 --> 00:01:41.231 That meant that air coming out of your heat vents 00:01:41.231 --> 00:01:44.336 would get milder to the point it was barely heat at all 00:01:44.336 --> 00:01:47.608 before the thermostat gave up and switched  heat sources. 00:01:47.608 --> 00:01:49.563 That is undoubtedly annoying, 00:01:49.563 --> 00:01:52.118 and if you’ve lived with a heating system that behaves  like this 00:01:52.118 --> 00:01:54.253 I can see why you wouldn’t like it. 00:01:54.253 --> 00:01:58.322 But it doesn’t have to be that way, and it’s  not the fault of the heat pump. 00:01:58.322 --> 00:02:02.127 Instead of trying to run the heat pump until it just isn’t  enough anymore, 00:02:02.127 --> 00:02:05.851 a more thoughtful thermostat could handle things more thoughtfully. 00:02:05.851 --> 00:02:09.877 If the heating system can determine its current coefficient of performance, 00:02:09.877 --> 00:02:13.700 it can determine whether it makes  sense to run the heat pump in the first place. 00:02:13.700 --> 00:02:18.184 You could even program at which COP it should switch to auxiliary heat. 00:02:18.184 --> 00:02:22.458 That would allow you to prioritize comfort, energy costs, or emissions. 00:02:22.458 --> 00:02:24.669 Now, if your backup heat is electric, 00:02:24.669 --> 00:02:29.407 any COP greater than 1 will benefit you from a cost and emissions perspective 00:02:29.407 --> 00:02:34.678 and that’s largely why these systems will use the heat pump as long as they possibly can. 00:02:34.678 --> 00:02:36.677 It’s saving you money! You ungr.... 00:02:37.221 --> 00:02:40.395 But you could still use this to force the backup heat on 00:02:40.395 --> 00:02:43.280 before you notice the output falling if that’s what you really wanted. 00:02:43.920 --> 00:02:47.187 If you have natural gas or some other fuel as  your backup heat, 00:02:47.187 --> 00:02:51.684 you could choose to input the COP that is your break-even point on cost. 00:02:51.684 --> 00:02:56.413 Now, here in the Chicago area, we have pretty cheap electricity and pretty cheap gas. 00:02:56.413 --> 00:03:02.282 By my calculations you need a COP of about 4 in order for a heat pump to beat the cost of gas here. 00:03:02.282 --> 00:03:05.109 That’s certainly achievable on many winter days with a heat pump, 00:03:05.109 --> 00:03:07.329 and certainly in the fall and early spring. 00:03:07.329 --> 00:03:09.414 But many times it isn’t, 00:03:09.414 --> 00:03:12.783 and if you had a thermostat which was aware of the current COP 00:03:12.783 --> 00:03:15.418 and could switch to auxiliary heat based on it, 00:03:15.911 --> 00:03:19.063 well, you’d be able to optimize for heating cost. 00:03:19.063 --> 00:03:21.424 Just compare your costs of energy sources, 00:03:21.424 --> 00:03:23.982 figure out what the COP break-even point is, 00:03:23.982 --> 00:03:25.600 and set your system up accordingly. 00:03:26.160 --> 00:03:29.280 This is actually a legitimate use for smart thermostats.   00:03:29.280 --> 00:03:32.403 Even if the heating system can’t determine its  own COP 00:03:32.403 --> 00:03:34.452 (which many simpler systems can’t), 00:03:34.452 --> 00:03:38.480 that can be reasonably predicted based  upon outdoor temperatures and system specs. 00:03:39.040 --> 00:03:42.960 A thermostat that can determine outdoor  conditions can use this to its advantage,   00:03:42.960 --> 00:03:47.790 and knowing the outdoor humidity can even help it  determine how often it needs to defrost the outside unit.   00:03:48.560 --> 00:03:52.320 Of course, this can be done locally  with a temperature and humidity sensor,   00:03:52.320 --> 00:03:56.880 but if your thermostat were aware of the  current energy mix on the grid in your area,   00:03:56.880 --> 00:04:02.000 it could also help reduce emissions by bending the  COP changeover depending on what’s advantageous.   00:04:02.560 --> 00:04:05.766 Ideally we’d have some sort of pricing structure 00:04:05.766 --> 00:04:09.228 where the cost of each energy source was related to its emissions, 00:04:09.228 --> 00:04:11.768 but that’s getting deeper than this video needs to go. 00:04:12.160 --> 00:04:14.087 Oh, and speaking of defrosts. 00:04:14.087 --> 00:04:18.190 If you have a simpler heat pump system, you might be very aware of when that happens 00:04:18.190 --> 00:04:20.800 because the outdoor unit makes a tremendous racket. 00:04:21.520 --> 00:04:23.436 If that’s a reason you don’t like heat  pumps, 00:04:23.436 --> 00:04:26.979 you should know that this is also not a necessary thing by any means. 00:04:26.979 --> 00:04:29.049 A lot of domestic HVAC stuff 00:04:29.049 --> 00:04:32.914 is controlled with little to no brains, if you will. 00:04:32.914 --> 00:04:37.649 Often the thermostat is literally the only thing in control of the outside unit, 00:04:37.649 --> 00:04:42.978 and simpler systems will just slam the reversing valve while the compressor is still running. 00:04:42.978 --> 00:04:45.096 And that’s what’s causing that racket. 00:04:45.096 --> 00:04:48.130 If instead the compressor were stopped before it reversed, 00:04:48.130 --> 00:04:49.872 allowing pressures to equalize, 00:04:49.872 --> 00:04:51.973 it would be much less noticeable. 00:04:51.973 --> 00:04:54.106 That’s how this mini-split heat pump does it, 00:04:54.106 --> 00:04:57.369 and to my mind that’s obviously better. 00:04:57.369 --> 00:05:02.257 I also can’t see how changing the direction while  the compressor runs isn’t somewhat rough on it, 00:05:02.257 --> 00:05:06.219 but apparently it’s not so bad because  lots of systems do this very thing. 00:05:06.640 --> 00:05:10.000 Anyway, the point here is the  little annoyances you may have   00:05:10.000 --> 00:05:15.275 with your heat pump system are probably nothing  to do with it being a heat pump. 00:05:15.275 --> 00:05:17.786 Instead it’s simply bad design. 00:05:17.786 --> 00:05:20.418 Or a case of misaligned priorities. 00:05:20.418 --> 00:05:24.015 In my opinion, air conditioning systems like the one I just installed 00:05:24.015 --> 00:05:26.660 that have no reversing capabilities 00:05:26.660 --> 00:05:28.512 should not exist. 00:05:28.800 --> 00:05:32.787 There is no reason this device cannot provide  low-emissions heating 00:05:32.787 --> 00:05:37.266 other than a few components are missing from it which made it slightly cheaper to build. 00:05:37.266 --> 00:05:40.179 This is a case of “but sometimes!” thinking 00:05:40.179 --> 00:05:44.544 leading to the embrace of less flexible  systems for virtually no reason. 00:05:44.544 --> 00:05:45.557 And it’s dumb. 00:05:46.000 --> 00:05:51.520 Yes, in my climate there are many days where an  air-source heat pump would leave me in the cold.   00:05:51.520 --> 00:05:54.964 And that’s a terrifying prospect - I completely get it! 00:05:54.964 --> 00:05:59.018 Nearly everyone around me has natural gas or occasionally propane heating 00:05:59.018 --> 00:06:02.682 because in the deepest depths of the winter you frankly need it. 00:06:02.682 --> 00:06:08.032 But since nearly everyone around me also has central  air conditioning for our sweltering hot summers, 00:06:08.480 --> 00:06:11.050 they already have a heat pump, 00:06:11.050 --> 00:06:13.137 but it can only go one way because as of now 00:06:13.137 --> 00:06:15.898 few people see the point of redundant heating systems 00:06:15.898 --> 00:06:18.715 when you have cheap natural gas anyway. 00:06:18.715 --> 00:06:22.235 But since whenever the COP of a heat pump exceeds 2.5 00:06:22.235 --> 00:06:26.080 we can heat our homes with  less fuel burned and ultimately lower emissions, 00:06:26.720 --> 00:06:29.953 why would we not want to make the  air conditioner reversible 00:06:29.953 --> 00:06:32.965 for the many days of the year when that’s absolutely possible? 00:06:33.520 --> 00:06:36.054 Well, frankly, the biggest barrier right now 00:06:36.054 --> 00:06:38.285 is direct cost to the consumer. 00:06:38.285 --> 00:06:42.059 As I said, in my area unless you can get to a COP of 4 00:06:42.059 --> 00:06:46.945 it’s just not cost effective to run a heat pump over burning natural gas. 00:06:46.945 --> 00:06:52.118 And since there are many, many days  in the winter where that COP is a lofty goal, 00:06:52.118 --> 00:06:55.024 even if running the heat pump is more climate friendly 00:06:55.024 --> 00:06:57.169 it may not be more wallet friendly. 00:06:57.169 --> 00:07:01.225 The added cost of a heat pump may never make financial sense in my area, 00:07:01.225 --> 00:07:04.150 no matter how small the added cost might be. 00:07:04.150 --> 00:07:08.333 At least, so long as externalities remain  free to energy providers. 00:07:08.333 --> 00:07:10.301 [various alarm sounds] Ope, too deep alert! 00:07:10.480 --> 00:07:13.525 And that is why they’re not standard equipment around here. 00:07:14.069 --> 00:07:14.875 Yet. 00:07:15.174 --> 00:07:18.492 But it should be noted that the financial practicality of a heat pump 00:07:18.492 --> 00:07:21.800 will depend entirely on your cost of heating fuel. 00:07:21.800 --> 00:07:23.301 If it’s not natural gas, 00:07:23.301 --> 00:07:26.005 or even if it is but it’s more expensive for you, 00:07:26.005 --> 00:07:28.382 that math will be different. 00:07:28.382 --> 00:07:33.617 Now, if I were king, I’d proclaim that every central air conditioning system sold 00:07:33.617 --> 00:07:35.819 must be reversible. 00:07:35.819 --> 00:07:38.545 It’s equipment with a 10 to 20 year service life, 00:07:38.545 --> 00:07:44.417 and who knows what the availability and cost of heating  fuel will be in 2041? 00:07:44.417 --> 00:07:47.346 Plus, we keep making strides in system efficiency 00:07:47.346 --> 00:07:51.795 and air-source heat pumps are becoming viable in colder and colder climates. 00:07:51.795 --> 00:07:55.392 In fact, I just read a piece on their use in  Alaska! 00:07:55.392 --> 00:07:58.252 It can absolutely be done even up there. 00:07:58.252 --> 00:08:02.354 But if you really want a heat pump  to work in the coldest of the cold 00:08:02.354 --> 00:08:04.127 using the least amount of energy, 00:08:04.453 --> 00:08:06.141 you gotta go underground. 00:08:06.800 --> 00:08:07.964 Look down. 00:08:07.964 --> 00:08:08.892 See that? 00:08:08.892 --> 00:08:10.087 It’s the ground! 00:08:10.087 --> 00:08:11.248 Turn around. 00:08:11.248 --> 00:08:12.335 There’s a human sku - 00:08:12.580 --> 00:08:13.080 sorry. 00:08:13.520 --> 00:08:14.932 Thinking of something else. 00:08:14.932 --> 00:08:18.583 You know how we have water pipes going every which way underground 00:08:18.583 --> 00:08:21.369 and even in the dead of winter they don’t freeze 00:08:21.369 --> 00:08:22.596 (usually)? 00:08:22.949 --> 00:08:25.848 Well, that’s because the Earth is warm. 00:08:25.848 --> 00:08:30.365 Dig just a few feet below the surface and you’ll  find the frost line. 00:08:30.365 --> 00:08:33.609 Below this imaginary line the ground doesn’t freeze. 00:08:33.609 --> 00:08:36.191 Where that line is changes depending on where you are, 00:08:36.191 --> 00:08:37.336 but it’s there! 00:08:37.635 --> 00:08:40.640 Management was just really bad  about marking it when they built the place. 00:08:41.520 --> 00:08:45.921 Since heat pumps are great at extracting and  concentrating heat energy 00:08:45.921 --> 00:08:47.918 from relatively cool places, 00:08:47.918 --> 00:08:52.919 and since there’s a place right below  our feet that doesn’t get cold enough to freeze water 00:08:52.919 --> 00:08:55.130 no matter how cold it is outside, 00:08:55.130 --> 00:09:00.240 if we could just get the heat energy from that place to the evaporator of a heat pump, 00:09:00.240 --> 00:09:03.319 we could get more than enough heat to warm our homes 00:09:03.319 --> 00:09:05.375 no matter what time of year it is. 00:09:06.000 --> 00:09:07.407 And wouldn’t ya know it, 00:09:07.407 --> 00:09:09.664 this is a thing we know how to do! 00:09:10.080 --> 00:09:12.533 Ground-source or geothermal heat pumps 00:09:12.533 --> 00:09:15.653 scavenge heat from the ground below the frost line. 00:09:15.653 --> 00:09:17.330 There are two main ways to do this, 00:09:17.330 --> 00:09:21.650 and both involve using an intermediary fluid to transfer heat energy. 00:09:21.650 --> 00:09:25.181 And yes, some newer ideas don’t use an intermediary fluid but 00:09:25.181 --> 00:09:27.166 we’re not talking about them today. 00:09:27.166 --> 00:09:30.641 Instead of an outside unit like this with a large fan-driven, 00:09:30.641 --> 00:09:32.987 refrigerant-to-air heat exchanger, 00:09:32.987 --> 00:09:36.962 these systems will have a refrigerant-to-liquid heat exchanger. 00:09:36.962 --> 00:09:40.592 There’s no law saying evaporators have to look like this, after all. 00:09:40.960 --> 00:09:43.673 Inside your home the equipment doesn’t  look too much different 00:09:43.673 --> 00:09:45.811 from a normal furnace or air handler, 00:09:45.811 --> 00:09:48.272 but the compressor (and sometimes there’s more than one) 00:09:48.272 --> 00:09:51.347 as well as both heat exchangers are all right here. 00:09:51.347 --> 00:09:54.690 And to those worried about noise from the compressors, don’t worry - 00:09:54.690 --> 00:09:56.584 there’s plenty of sound deadening. 00:09:56.584 --> 00:09:58.058 Engineers are smart! 00:09:58.640 --> 00:10:02.662 What’s special about these system is where  they're getting their heat from. 00:10:02.662 --> 00:10:06.978 A long, closed loop of piping filled with a mixture of water  and antifreeze 00:10:06.978 --> 00:10:10.236 is pumped in a circuit out of the home and underground 00:10:10.236 --> 00:10:14.320 where the liquid will absorb heat  from the earth before being brought back inside. 00:10:14.960 --> 00:10:18.295 This now warmed liquid is fed to the heat  exchanger 00:10:18.295 --> 00:10:23.403 which will absorb and concentrate that heat with the help of our friend the refrigeration cycle. 00:10:23.403 --> 00:10:28.000 The refrigerant is then squeezed into the condenser and that  heat is released into the air 00:10:28.000 --> 00:10:29.792 and ultimately the living space. 00:10:30.160 --> 00:10:34.939 The benefit of doing this is that no matter what  the air temperature is outside, 00:10:34.939 --> 00:10:37.688 the temperature of the fluid returning from the ground loop 00:10:37.688 --> 00:10:42.218 will be a near-constant 50 degrees Fahrenheit or about 10 Celsius. 00:10:42.218 --> 00:10:46.327 That temperature allows a heat pump to  run at peak performance and efficiency, 00:10:46.327 --> 00:10:52.516 delivering a nearly constant, near-maximum COP at full  output no matter what. 00:10:52.516 --> 00:10:56.670 Right now you can expect it to always meet or exceed a COP of 4, 00:10:56.670 --> 00:11:00.172 and that will undoubtedly improve as technology advances. 00:11:00.172 --> 00:11:02.631 And that’s obviously a huge deal! 00:11:02.631 --> 00:11:07.035 A home with a geothermal heat pump needs significantly less energy to heat 00:11:07.035 --> 00:11:10.055 than any other heating technology  available today 00:11:10.055 --> 00:11:15.128 (unless you count home design itself and want to bring up the passive house but that’s a topic for another time). 00:11:15.600 --> 00:11:19.520 Even with an entirely fossil-fuel  powered electrical infrastructure,   00:11:19.520 --> 00:11:23.742 emissions are drastically reduced when using a  ground-source heat pump. 00:11:23.742 --> 00:11:29.574 Remember, exceed 2.5 and you’re getting more energy out of burning natural gas in a power plant 00:11:29.574 --> 00:11:32.025 and sending its energy the zippy-zappy way 00:11:32.025 --> 00:11:34.993 than natural gas itself contains. 00:11:34.993 --> 00:11:38.141 That’s astonishing and yet completely possible. 00:11:38.480 --> 00:11:42.528 Also important is that methane, the main component  of natural gas, 00:11:42.528 --> 00:11:44.300 is a potent greenhouse gas, 00:11:44.300 --> 00:11:49.280 and the infrastructure we use to transport it to  homes across the country is notoriously leaky. 00:11:49.840 --> 00:11:54.352 Not requiring that infrastructure in the first  place provides its own emissions reduction.   00:11:54.640 --> 00:11:59.348 What’s more, the much lower energy requirement of homes with geothermal heat pumps 00:11:59.348 --> 00:12:01.454 opens up many more opportunities, 00:12:01.454 --> 00:12:05.741 particularly when it comes to  renewable and locally-generated sources of power. 00:12:06.080 --> 00:12:09.719 Oh, and of course, these systems are entirely reversible. 00:12:09.719 --> 00:12:12.443 In the summer months, well below the frost line 00:12:12.443 --> 00:12:15.197 the Earth stays colder than the air outside! 00:12:15.197 --> 00:12:19.820 So in cooling mode, the system simply puts heat back into the  Earth. 00:12:19.820 --> 00:12:22.246 It’s actually almost poetic. 00:12:22.246 --> 00:12:27.306 That heat ends up simply being borrowed in the winter monts and returned in the summer. 00:12:27.306 --> 00:12:32.135 And being able to transfer it into a cool liquid means no matter how hot it is outside, 00:12:32.135 --> 00:12:34.725 the system will run at peak performance. 00:12:34.997 --> 00:12:35.552 Neat. 00:12:35.840 --> 00:12:37.650 So what’s the catch? 00:12:37.650 --> 00:12:39.082 Eleven words. 00:12:39.082 --> 00:12:43.839 The upfront cost and disruptive nature of the ground loop installation. 00:12:43.839 --> 00:12:45.341 That second part’s getting better, 00:12:45.341 --> 00:12:49.283 but unless you happen to be lucky and have access to some natural body of water 00:12:49.283 --> 00:12:52.664 like a pond that’s deep and large enough to use as your heat source 00:12:52.664 --> 00:12:55.184 (which is another way to go about it, by the way) 00:12:55.184 --> 00:12:58.453 there will have to be a network of piping installed under the ground 00:12:58.453 --> 00:13:01.382 to collect and transport its energy. 00:13:01.382 --> 00:13:02.741 For a long time, 00:13:02.741 --> 00:13:05.820 this meant excavating a large area  around a home 00:13:05.820 --> 00:13:09.549 down to several feet (think about a meter-ish) below the frost line. 00:13:09.549 --> 00:13:14.033 Then you’d go all loopy with a bunch of piping, and cover it back up. 00:13:14.033 --> 00:13:17.338 Hopefully you remembered  to put the ends of that pipe somewhere useful. 00:13:17.680 --> 00:13:23.901 But that’s really disruptive and requires a  large area of lawn or similar open space. 00:13:23.901 --> 00:13:28.611 I mean, if you’re building a new house somewhere and have  room please just do it. 00:13:28.611 --> 00:13:30.144 It’s the perfect time. 00:13:30.144 --> 00:13:34.362 Oh, and one interesting idea that’s  taking hold is community ground loops. 00:13:34.362 --> 00:13:37.789 A bunch of homes in a new development can be  hooked up to a large, 00:13:37.789 --> 00:13:40.716 shared ground loop that’s piped into each home. 00:13:40.716 --> 00:13:44.038 They each have their own  heat pumps extracting energy from the fluid, 00:13:44.038 --> 00:13:46.137 but the geothermal equipment is shared, 00:13:46.137 --> 00:13:49.445 maximizing its potential and lowering the cost-per-user. 00:13:49.920 --> 00:13:53.396 But if you want to add a ground loop to  an existing homesite 00:13:53.396 --> 00:13:56.578 it kinda sucks and sometimes isn't possible. 00:13:56.578 --> 00:13:59.197 However, a more recent and exciting development 00:13:59.197 --> 00:14:03.640 is the use of vertical drilling to go deeper rather than broader. 00:14:03.640 --> 00:14:07.512 Using equipment similar to that which is used to dig a well for drinking water, 00:14:07.512 --> 00:14:11.125 a borehole can be dug hundreds of feet below the soil, 00:14:11.125 --> 00:14:17.422 and a rather simple bit of piping down and then back up can  be run to extract that earthy warmth. 00:14:17.422 --> 00:14:23.200 This is much less disruptive and easier to accomplish in  areas with denser housing and little greenspace. 00:14:23.920 --> 00:14:27.440 Dandelion energy is one company  installing such systems.   00:14:28.000 --> 00:14:30.267 Now, these aren’t cheap. 00:14:30.267 --> 00:14:34.692 Their own website admits that this is gonna cost about as much as a small car, 00:14:34.692 --> 00:14:38.800 and depending on how your energy is  priced you may never recoup that investment. 00:14:39.360 --> 00:14:43.600 But regardless of where you are it  will reduce greenhouse emissions,   00:14:43.600 --> 00:14:46.641 and hopefully energy starts getting priced to  reflect that 00:14:46.641 --> 00:14:48.938 [alarm sounds return] oh sorry goin’ too deep again… 00:14:49.360 --> 00:14:53.012 What Dandelion and companies like it are doing is  really important 00:14:53.012 --> 00:14:56.049 for making geothermal heat pumps more approachable. 00:14:56.049 --> 00:14:58.855 Simply negating the need to tear up an entire yard 00:14:58.855 --> 00:15:02.886 is a huge step in the right direction for getting the reluctant onboard. 00:15:03.440 --> 00:15:06.766 But it’s by no means a one-size-fits-all solution. 00:15:06.766 --> 00:15:09.445 Unless you have the rights to dig that far down 00:15:09.445 --> 00:15:12.027 and there’s nothing below you that could be a  problem 00:15:12.027 --> 00:15:15.120 like abandoned mines, subway tunnels, etc… 00:15:16.000 --> 00:15:17.465 well you can’t do it. 00:15:17.465 --> 00:15:19.688 And what about in like, ya know, 00:15:19.688 --> 00:15:20.912 cities? 00:15:20.912 --> 00:15:25.002 How’s a large apartment building gonna get all the heat  it needs from a borehole? 00:15:25.600 --> 00:15:26.886 Well, it can’t. 00:15:27.200 --> 00:15:30.338 District heating, though, may be an indirect  way to provide 00:15:30.338 --> 00:15:33.834 geothermally derived heat to large urban spaces. 00:15:33.834 --> 00:15:37.628 District heating is unfortunately not that common in the US 00:15:37.628 --> 00:15:39.346 which is a giant shame. 00:15:39.346 --> 00:15:42.797 Basically it’s a network of underground insulated pipes 00:15:42.797 --> 00:15:47.418 bringing really hot water into buildings  that is then fed through radiators to heat them. 00:15:47.920 --> 00:15:50.322 One of the more clever ways to heat that  water 00:15:50.322 --> 00:15:53.388 is with the waste heat of conventional power stations, 00:15:53.388 --> 00:15:56.697 and many countries have been doing this for decades. 00:15:56.697 --> 00:16:01.579 It annoys me greatly that this hasn’t been normal practice  everywhere since power plants have been a thing, 00:16:01.840 --> 00:16:07.365 especially since water-loop systems for heating  buildings are by no means a recent development. 00:16:07.760 --> 00:16:10.751 But anyway, that practice can be used to provide  heat 00:16:10.751 --> 00:16:14.264 to urban centers without requiring combustion of fuels onsite 00:16:14.264 --> 00:16:19.163 or the immense electrical supply which would be needed with resistive heating alone. 00:16:19.163 --> 00:16:22.465 What you use to heat the water, then, is  arbitrary. 00:16:22.465 --> 00:16:26.472 It could be a large geothermal station running massive heat pumps. 00:16:26.472 --> 00:16:31.693 Or you could even drill deep enough to get heat directly from the magma kilometers below us, 00:16:31.693 --> 00:16:33.546 if you’re feeling adventurous. 00:16:33.546 --> 00:16:36.185 This is all stuff that’s being researched right now, 00:16:36.185 --> 00:16:39.188 and as usual there’s pros  and cons to every one of these. 00:16:39.188 --> 00:16:40.193 What gives? 00:16:40.720 --> 00:16:43.346 Well Ellen, there are no easy answers. 00:16:43.346 --> 00:16:45.803 But this video was about heat pumps. 00:16:45.803 --> 00:16:49.402 While geothermal heat pumps may not exactly… 00:16:49.402 --> 00:16:52.295 work in the concrete jungles of New York City, 00:16:52.295 --> 00:16:55.301 air-source heat pumps certainly can. 00:16:55.301 --> 00:16:58.633 And maybe they won’t make sense  to use on really cold days, 00:16:58.633 --> 00:17:02.802 but really cold days are only some of the days of winter. 00:17:02.802 --> 00:17:04.564 We really gotta stop this whole 00:17:04.564 --> 00:17:09.508 “Only Solutions Which Cover Every Single Possible Contingency are Feasible” nonsense 00:17:09.508 --> 00:17:13.051 and start using what we can when we can. 00:17:13.280 --> 00:17:15.059 That’s kind of my whole point with the 00:17:15.059 --> 00:17:18.296 “every air conditioner should be reversible” thing. 00:17:18.296 --> 00:17:23.790 It’s unreasonable to me to limit their potential  just because some days heat pumps can’t work. 00:17:24.240 --> 00:17:28.006 We have the technology, so... so use it when possible! 00:17:28.480 --> 00:17:30.735 Oh yeah. Here’s a really dumb thing. 00:17:30.735 --> 00:17:34.842 Electric cars, which nearly universally have air conditioning, 00:17:34.842 --> 00:17:38.278 are only just now starting to make that reversible. 00:17:38.278 --> 00:17:43.328 Cabin heat is by far the largest non-locomotive energy use  in an EV, 00:17:43.328 --> 00:17:46.603 and is a large part of why range drops in the winter. 00:17:46.603 --> 00:17:51.354 It has always been the case that a  heat pump would help a lot with that, 00:17:51.354 --> 00:17:53.063 at least on milder days, 00:17:53.063 --> 00:17:57.929 and yet even some brand new EV models  on sale do not offer them. 00:17:57.929 --> 00:18:00.476 Instead, resistive heat is your only option. 00:18:01.237 --> 00:18:04.978 I don’t know if there’s some trick  to ruggedizing reversing valves for road use, 00:18:04.978 --> 00:18:09.205 or maybe there’s something else that makes it harder  for cars, but c’mon! 00:18:09.205 --> 00:18:11.748 Heat pumps need to be standard in EVs. 00:18:11.748 --> 00:18:12.960 Figure it out! 00:18:12.960 --> 00:18:17.338 And if you can get a  COP of 2 when it’s zero degrees out, fantastic. 00:18:17.920 --> 00:18:19.496 But ya know what’s real neat? 00:18:19.496 --> 00:18:22.819 We’re beginning to put heat pumps in more places to do more things 00:18:22.819 --> 00:18:25.667 besides just heat and cool our living  spaces! 00:18:25.667 --> 00:18:30.703 Fundamentally, heat pumps are just heat energy relocators and concentrators. 00:18:30.703 --> 00:18:32.860 If there’s a place where we need a lot of heat, 00:18:32.860 --> 00:18:37.070 we can sometimes take it from another  and often with side-benefits as well. 00:18:37.680 --> 00:18:42.240 One real-world application of heat pumps  not-for-heating is the hybrid water heater. 00:18:42.880 --> 00:18:45.719 OK, well I suppose that is still heating… 00:18:45.719 --> 00:18:50.011 but consider a typical North American water heater with a 50 gallon tank. 00:18:50.011 --> 00:18:52.499 Until recently, you had two choices: 00:18:52.499 --> 00:18:54.210 electric or gas. 00:18:54.210 --> 00:18:56.969 Gas is cheaper to operate, but requires venting 00:18:56.969 --> 00:18:58.668 and also gas. 00:18:58.668 --> 00:19:00.937 Electric is more expensive to operate, 00:19:00.937 --> 00:19:04.735 but the device itself is little more than an oversized  kettle. 00:19:04.735 --> 00:19:08.739 Now, the benefit of storing hot water in an insulated tank like this 00:19:08.739 --> 00:19:11.560 is that you’ve created a thermal battery. 00:19:11.560 --> 00:19:16.049 Hybrid water heaters use a heat pump to maintain the water temperature in the tank, 00:19:16.049 --> 00:19:19.272 or you could say… to keep the battery charged, 00:19:19.272 --> 00:19:23.819 and it’s ultimately getting that energy from the air of the room it’s sitting in. 00:19:23.819 --> 00:19:28.990 This not only uses a fraction of the energy that  heating the water with electric heating elements does, 00:19:28.990 --> 00:19:33.713 but provides the additional benefit of  free air conditioning and dehumidification 00:19:33.713 --> 00:19:36.344 in the area around the water heater! 00:19:36.344 --> 00:19:41.229 To collect the energy it moves into the water it has an evaporator just like any air conditioner, 00:19:41.229 --> 00:19:43.703 and it gets cold and wet. 00:19:43.703 --> 00:19:48.045 This means hybrid water heaters need a drain line to deal with that condensate, 00:19:48.045 --> 00:19:54.128 but I’d sure like a dehumidifier in my basement that effectively costs less than nothing to run. 00:19:54.128 --> 00:19:56.886 It’s heating my water, and more cheaply than before! 00:19:57.200 --> 00:20:00.078 Of course, in the winter this is perhaps a bummer, 00:20:00.078 --> 00:20:02.848 but if you have gas heat like I do, 00:20:02.848 --> 00:20:05.463 well now your water heater runs on gas! 00:20:05.463 --> 00:20:07.239 Just, indirectly. 00:20:07.239 --> 00:20:11.877 And if you had a geothermal heat pump, well it would get its heat from the ground 00:20:11.877 --> 00:20:14.737 after your main heat pump first brought it to your home for you. 00:20:14.737 --> 00:20:19.000 Anyway, it’s a hybrid water heater because  these also have traditional heating elements 00:20:19.000 --> 00:20:21.231 to deal with periods of high demand. 00:20:21.231 --> 00:20:24.836 The heat pump is slower than good ‘ol fashioned hot sticks. 00:20:24.836 --> 00:20:28.412 But, assuming you don’t have a showerthon going  on in your house, 00:20:28.412 --> 00:20:31.755 it can take its time reheating the water in the tank between uses 00:20:31.755 --> 00:20:36.015 using as little as a quarter the energy of an ordinary electric heater. 00:20:36.015 --> 00:20:39.581 The potential for heat pumps to be used in water heaters, by the way, 00:20:39.581 --> 00:20:43.397 has made me fairly anti-tankless water heater. 00:20:43.397 --> 00:20:48.501 It’s a myth that tankless water heaters provide you with “instant hot water” - 00:20:48.501 --> 00:20:54.960 it still has to get through your pipes, and if you want instant hot water what you really need is a hot water recirculation  system 00:20:54.960 --> 00:20:57.369 and your plumbing to be completely redone, 00:20:57.369 --> 00:21:01.074 or maybe you can get away with point-of-use  booster heaters. 00:21:01.074 --> 00:21:04.794 But anyway, now that I know that heat pump water heaters are a thing 00:21:04.794 --> 00:21:07.583 I have no desire to go tankless. 00:21:07.583 --> 00:21:09.341 Save that energy, baby! 00:21:09.840 --> 00:21:13.009 Another really neat development, and perhaps even more so 00:21:13.009 --> 00:21:15.297 is the heat pump clothes dryer. 00:21:15.297 --> 00:21:18.359 Tumble dryers are a sort of guilty pleasure to me. 00:21:18.359 --> 00:21:20.690 Oh sure, they save tons of time and space 00:21:20.690 --> 00:21:24.878 but they also use a lot of energy and are typically vented outside, 00:21:24.878 --> 00:21:27.969 which not only means there needs to be a  vent in the first place 00:21:27.969 --> 00:21:31.640 but also creates significant negative pressure when they run. 00:21:31.640 --> 00:21:33.960 But what do dryers really do? 00:21:33.960 --> 00:21:36.922 Well, they basically just tumble clothes around  a drum 00:21:36.922 --> 00:21:40.734 with hot air blowing through it which makes the clothes dry faster. 00:21:40.734 --> 00:21:43.680 Making the  air hot is the energy intensive part, 00:21:44.197 --> 00:21:45.138 buuuuuut… 00:21:45.280 --> 00:21:46.261 That’s right. 00:21:46.261 --> 00:21:47.328 Heat pump it! 00:21:47.328 --> 00:21:50.216 Heat pump clothes dryers are frankly amazing 00:21:50.216 --> 00:21:53.509 because it’s about the perfect application for the technology. 00:21:53.509 --> 00:21:57.501 You just need to get the inside of the dryer hotter than the outside. 00:21:57.501 --> 00:22:01.713 Yeah, you could do that with heater coils or even with a lil’ gas furnace, 00:22:01.713 --> 00:22:07.875 but there’s plenty of energy from the room  it’s sitting in for a heat pump to take and concentrate. 00:22:07.875 --> 00:22:11.914 And none of it gets lost - it just gets concentrated inside. 00:22:11.914 --> 00:22:16.154 Best of all, you can then exhaust the hot, damp air that exits  the drum 00:22:16.154 --> 00:22:21.065 over the cold evaporator and not only re-collect that energy to be pumped back in 00:22:21.065 --> 00:22:24.084 but also the moisture from the clothes. 00:22:24.084 --> 00:22:27.828 You end up with a clothes dryer that needs  much less energy to run, 00:22:27.828 --> 00:22:29.352 doesn’t need venting, 00:22:29.352 --> 00:22:31.502 and can be placed anywhere. 00:22:31.502 --> 00:22:35.600 Some of them can even be plugged into a standard 120V electrical outlet! 00:22:36.400 --> 00:22:39.964 Heat pump clothes dryers are slower than  traditional vented solutions, 00:22:39.964 --> 00:22:44.092 but they offer great flexibility and a much lower energy cost. 00:22:44.092 --> 00:22:45.918 Even if you have a gas dryer, 00:22:45.918 --> 00:22:50.061 eliminating the need for a vent will lower your heating and cooling demand when it runs 00:22:50.061 --> 00:22:55.205 thanks to there no longer being a machine blowing the air you paid to heat or cool outside. 00:22:55.205 --> 00:22:57.739 It’s really kind of a no-brainer to me. 00:22:58.080 --> 00:23:00.623 Using a heat pump not only makes it cheaper to run 00:23:00.623 --> 00:23:02.912 but solves real problems. 00:23:02.912 --> 00:23:05.449 That is, if you’re willing to have your laundry take longer, 00:23:05.449 --> 00:23:08.112 which I recognize is not feasible for everyone. 00:23:08.480 --> 00:23:12.580 Now, there is one real downside to the  proliferation of heat pumps. 00:23:12.580 --> 00:23:14.874 To make them, we need refrigerants. 00:23:14.874 --> 00:23:19.182 And refrigerants have created a Whack-A-Mole of engineering challenges. 00:23:19.182 --> 00:23:21.775 When we first ventured down the path of refrigeration, 00:23:21.775 --> 00:23:25.348 we were using gaseous ammonia as a refrigerant. 00:23:25.348 --> 00:23:27.635 It was actually a fantastic refrigerant, 00:23:27.635 --> 00:23:32.289 but it was very toxic and leaks were very dangerous to human life. 00:23:32.289 --> 00:23:37.079 That was the problem that Thomas Midgely Junior solved with the creation of Freon. 00:23:37.079 --> 00:23:40.852 Freon was the first non-toxic non-flammable refrigerant, 00:23:40.852 --> 00:23:42.888 and we were thrilled to have it! 00:23:43.200 --> 00:23:46.959 Of course, decades later we realized the ozone  layer was disappearing 00:23:46.959 --> 00:23:50.496 and we figured out that CFCs like Freon were the culprit. 00:23:50.496 --> 00:23:55.191 So, replacement refrigerants were developed like our friend R-134a. 00:23:55.191 --> 00:23:58.134 These HFCs don’t harm the ozone layer, 00:23:58.134 --> 00:24:02.093 but they are ridiculously potent greenhouse gases. 00:24:02.093 --> 00:24:07.217 This here is over 1,400 times better at  trapping heat in the atmosphere 00:24:07.217 --> 00:24:09.182 than carbon dioxide. 00:24:09.400 --> 00:24:10.090 Great! 00:24:10.400 --> 00:24:14.155 Even though in an ideal world it will never leave  the refrigerant loop, 00:24:14.155 --> 00:24:17.283 eventually refrigeration systems develop leaks. 00:24:17.283 --> 00:24:22.281 If you ever bought one of these to recharge your A/C, that’s why. 00:24:22.281 --> 00:24:26.263 So these HFCs are being phased out for newer refrigerants like 00:24:26.263 --> 00:24:29.930 2,3,3,3-Tetrafluoropropene 00:24:29.930 --> 00:24:34.093 also known as R-1234yf. 00:24:34.093 --> 00:24:38.190 This refrigerant has a global warming potential of less  than 1, 00:24:38.190 --> 00:24:40.782 so as far as we can tell it’s harmless. 00:24:41.040 --> 00:24:44.168 Currently, these new refrigerants are rather  expensive. 00:24:44.168 --> 00:24:45.840 And the reason is patently obvious. 00:24:46.400 --> 00:24:47.534 It’s patents. 00:24:47.534 --> 00:24:50.446 These next-gen refrigerants are protected by patents 00:24:50.446 --> 00:24:55.201 and their owners are absodidily OK with exploiting that and hard. 00:24:55.201 --> 00:24:57.363 Now, that was once the case for this fella. 00:24:57.363 --> 00:25:02.705 But those patents have expired and that’s why Walmart  can sell it in these cans for less than $5. 00:25:02.880 --> 00:25:05.101 In some states, anyway. 00:25:05.101 --> 00:25:07.864 Perhaps my most radical thought I’ll put forth here 00:25:07.864 --> 00:25:09.867 is that patents on things like, 00:25:09.867 --> 00:25:10.615 oh I don’t know, 00:25:10.615 --> 00:25:14.783 climate-friendly refrigerants that we really need to make a lot more of and fast 00:25:14.783 --> 00:25:16.768 should be invalidated. 00:25:16.768 --> 00:25:19.874 Maybe we ought to consider some classes of things unpatentable 00:25:19.874 --> 00:25:22.878 and instead encourage their development through some sort of prize system 00:25:22.878 --> 00:25:25.505 or just develop them publicly from the start 00:25:25.505 --> 00:25:27.802 I don’t know just spitballin’ here. 00:25:27.802 --> 00:25:33.568 I just think it’s not great that R-1234yf costs 10 times as much as the chemical it’s replacing 00:25:33.568 --> 00:25:34.995 because we need that! 00:25:35.440 --> 00:25:37.517 Then again, there is another option. 00:25:37.762 --> 00:25:41.827 Carbon dioxide can actually be used as a refrigerant, 00:25:41.827 --> 00:25:45.493 although when you do that it prefers you call it  R-744. 00:25:45.955 --> 00:25:47.011 It’s more polite. 00:25:47.718 --> 00:25:48.779 Now if you’re wondering, 00:25:49.280 --> 00:25:52.768 “Well if that’s possible why haven’t we just  been doing that from the start?” 00:25:53.230 --> 00:25:54.000 I’ll tell ya! 00:25:54.469 --> 00:25:58.521 The working pressures you need to make carbon dioxide a refrigerant are... 00:25:58.521 --> 00:25:59.869 quite high. 00:25:59.869 --> 00:26:02.958 Think 1,000+ PSI. 00:26:02.958 --> 00:26:07.808 That means the refrigeration equipment needs to be much more robust in order to handle it, 00:26:07.808 --> 00:26:09.040 making it more expensive. 00:26:09.680 --> 00:26:12.359 More traditional synthetic refrigerants... 00:26:13.338 --> 00:26:15.450 that sounds wrong but, yes 00:26:15.450 --> 00:26:21.639 don’t need such high pressures and so refrigeration systems using them are just easier to build. 00:26:21.639 --> 00:26:23.832 So right now it’s pick your poison. 00:26:23.832 --> 00:26:26.040 Cheap system, expensive gas… 00:26:26.040 --> 00:26:28.640 or cheap gas but expensive system. 00:26:29.200 --> 00:26:32.720 But anyway, we’ve talked about all  I wanted to talk about heat pumps.   00:26:32.720 --> 00:26:34.416 For now, anyway. 00:26:34.416 --> 00:26:38.277 I fully expect them to find their way into more and more places, 00:26:38.277 --> 00:26:42.133 and I’m sure we’ll address many of their flaws  as time goes on. 00:26:42.133 --> 00:26:47.757 And if we can make an air-source heat pump operate with a COP of 4 in arctic temps, 00:26:47.757 --> 00:26:50.489 well golly gee that’d just be neat-o! 00:26:50.800 --> 00:26:52.139 I hope we can do it. 00:26:52.139 --> 00:26:54.774 But one thing is for sure about the future. 00:26:55.100 --> 00:26:57.537 I’m pumped for it. 00:26:58.407 --> 00:27:01.069 ♫ geothermally smooth jazz ♫ 00:27:01.939 --> 00:27:02.492 I wanna - 00:27:02.492 --> 00:27:05.550 [incessant coughing] 00:27:05.550 --> 00:27:09.623 And if you had a thermostat which was aware  of its current ... bleugh. 00:27:10.575 --> 00:27:13.260 Hoo hoo hoo hoo I skipped a word! 00:27:13.260 --> 00:27:15.600 What was that in the script? 00:27:15.600 --> 00:27:17.830 Aware of the current COP… 00:27:17.830 --> 00:27:20.665 yeah that was just an error and I f.. I s.. I.. I made it! 00:27:20.665 --> 00:27:23.949 Turn around. There’s a human sk .. sorry. 00:27:23.949 --> 00:27:25.975 [evil laughter] 00:27:25.975 --> 00:27:29.920 Even with an entirely fossil-fuel  powered electrical infrastru… 00:27:31.200 --> 00:27:34.054 that’s a lot of big words in this one. 00:27:34.462 --> 00:27:39.820 Now the benefits of storing hot water in an insulated tank like this  is that… the benefit! 00:27:39.820 --> 00:27:40.759 Aehehehe! 00:27:40.759 --> 00:27:44.061 A bore hole can be dug hundreds of  feet below the soil, 00:27:44.061 --> 00:27:45.877 and rather than 00:27:45.877 --> 00:27:46.416 [rude raspberry] 00:27:49.189 --> 00:27:51.476 So, are we pumped? 00:27:51.476 --> 00:27:54.000 Are we pumping up the jam? 00:27:54.000 --> 00:27:58.154 You know, somebody probably has that job at the Smuckers factory. 00:27:58.154 --> 00:28:00.916 And then when the jars get put on pallets? 00:28:00.916 --> 00:28:03.509 Those folks always end with jam-packed days.