1 00:00:00,000 --> 00:00:03,040 Now that we know what heat  pumps are and how they work,   2 00:00:03,040 --> 00:00:06,093 it’s time to talk a little more about their  future. 3 00:00:06,093 --> 00:00:07,898 If you’ve not seen the first video, 4 00:00:07,898 --> 00:00:10,683 well you definitely should fix that before  watching this one 5 00:00:10,683 --> 00:00:15,229 as there will be a lot of stuff we talk about here that assumes prior knowledge. 6 00:00:15,229 --> 00:00:16,567 I’ll summon a card. 7 00:00:16,567 --> 00:00:17,920 Bippity Boppity Card! 8 00:00:18,480 --> 00:00:19,246 Great! 9 00:00:19,572 --> 00:00:22,539 A link is below, and probably in a pinned  comment, too. 10 00:00:22,539 --> 00:00:23,755 You ever heard about those? 11 00:00:23,755 --> 00:00:24,483 They’re neat. 12 00:00:25,040 --> 00:00:27,616 I want to start with a clarification of sorts. 13 00:00:27,616 --> 00:00:30,459 Heat pumps definitely are the future of home heating, 14 00:00:30,459 --> 00:00:31,766 at least if I can help it, 15 00:00:31,766 --> 00:00:33,661 but they’re also not new. 16 00:00:33,661 --> 00:00:36,068 And some people hate them! 17 00:00:36,367 --> 00:00:38,861 It seems for every person who thinks heat pumps are 18 00:00:38,861 --> 00:00:42,125 wicked neat-o closest-thing-to-free-energy-out-there devices 19 00:00:42,125 --> 00:00:43,172 (that’s me) 20 00:00:43,172 --> 00:00:45,440 there’s another who hates theirs with a passion. 21 00:00:46,160 --> 00:00:48,877 Allow me to submit that you don’t hate  your heat pump, 22 00:00:48,877 --> 00:00:50,405 you hate your thermostat. 23 00:00:50,800 --> 00:00:54,301 See, as we learned, as the outdoor temperature  approaches freezing 24 00:00:54,301 --> 00:00:57,374 it gets harder for air source heat pumps to work. 25 00:00:57,374 --> 00:00:59,915 A smaller temperature difference between the source of heat 26 00:00:59,915 --> 00:01:03,860 and the evaporator absorbing it causes the efficiency of heat pumps to drop 27 00:01:03,860 --> 00:01:05,578 and eventually their output as well. 28 00:01:06,160 --> 00:01:11,469 Unfortunately, it is under these precise  conditions that demand for heat goes up. 29 00:01:11,986 --> 00:01:13,464 It’s kind of a bummer. 30 00:01:13,464 --> 00:01:17,437 So, most systems with heat pumps have some sort of backup heat source, 31 00:01:17,437 --> 00:01:18,964 be it electric resistive heat 32 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) 33 00:01:22,770 --> 00:01:25,769 or a fuel-fired furnace might be utilized. 34 00:01:25,769 --> 00:01:29,839 The trouble is, until quite recently the  thermostats controlling these systems 35 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. 36 00:01:35,663 --> 00:01:38,510 Only then would they switch to the auxiliary heat. 37 00:01:38,880 --> 00:01:41,231 That meant that air coming out of your heat vents 38 00:01:41,231 --> 00:01:44,336 would get milder to the point it was barely heat at all 39 00:01:44,336 --> 00:01:47,608 before the thermostat gave up and switched  heat sources. 40 00:01:47,608 --> 00:01:49,563 That is undoubtedly annoying, 41 00:01:49,563 --> 00:01:52,118 and if you’ve lived with a heating system that behaves  like this 42 00:01:52,118 --> 00:01:54,253 I can see why you wouldn’t like it. 43 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. 44 00:01:58,322 --> 00:02:02,127 Instead of trying to run the heat pump until it just isn’t  enough anymore, 45 00:02:02,127 --> 00:02:05,851 a more thoughtful thermostat could handle things more thoughtfully. 46 00:02:05,851 --> 00:02:09,877 If the heating system can determine its current coefficient of performance, 47 00:02:09,877 --> 00:02:13,700 it can determine whether it makes  sense to run the heat pump in the first place. 48 00:02:13,700 --> 00:02:18,184 You could even program at which COP it should switch to auxiliary heat. 49 00:02:18,184 --> 00:02:22,458 That would allow you to prioritize comfort, energy costs, or emissions. 50 00:02:22,458 --> 00:02:24,669 Now, if your backup heat is electric, 51 00:02:24,669 --> 00:02:29,407 any COP greater than 1 will benefit you from a cost and emissions perspective 52 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. 53 00:02:34,678 --> 00:02:36,677 It’s saving you money! You ungr.... 54 00:02:37,221 --> 00:02:40,395 But you could still use this to force the backup heat on 55 00:02:40,395 --> 00:02:43,280 before you notice the output falling if that’s what you really wanted. 56 00:02:43,920 --> 00:02:47,187 If you have natural gas or some other fuel as  your backup heat, 57 00:02:47,187 --> 00:02:51,684 you could choose to input the COP that is your break-even point on cost. 58 00:02:51,684 --> 00:02:56,413 Now, here in the Chicago area, we have pretty cheap electricity and pretty cheap gas. 59 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. 60 00:03:02,282 --> 00:03:05,109 That’s certainly achievable on many winter days with a heat pump, 61 00:03:05,109 --> 00:03:07,329 and certainly in the fall and early spring. 62 00:03:07,329 --> 00:03:09,414 But many times it isn’t, 63 00:03:09,414 --> 00:03:12,783 and if you had a thermostat which was aware of the current COP 64 00:03:12,783 --> 00:03:15,418 and could switch to auxiliary heat based on it, 65 00:03:15,911 --> 00:03:19,063 well, you’d be able to optimize for heating cost. 66 00:03:19,063 --> 00:03:21,424 Just compare your costs of energy sources, 67 00:03:21,424 --> 00:03:23,982 figure out what the COP break-even point is, 68 00:03:23,982 --> 00:03:25,600 and set your system up accordingly. 69 00:03:26,160 --> 00:03:29,280 This is actually a legitimate use for smart thermostats.   70 00:03:29,280 --> 00:03:32,403 Even if the heating system can’t determine its  own COP 71 00:03:32,403 --> 00:03:34,452 (which many simpler systems can’t), 72 00:03:34,452 --> 00:03:38,480 that can be reasonably predicted based  upon outdoor temperatures and system specs. 73 00:03:39,040 --> 00:03:42,960 A thermostat that can determine outdoor  conditions can use this to its advantage,   74 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.   75 00:03:48,560 --> 00:03:52,320 Of course, this can be done locally  with a temperature and humidity sensor,   76 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,   77 00:03:56,880 --> 00:04:02,000 it could also help reduce emissions by bending the  COP changeover depending on what’s advantageous.   78 00:04:02,560 --> 00:04:05,766 Ideally we’d have some sort of pricing structure 79 00:04:05,766 --> 00:04:09,228 where the cost of each energy source was related to its emissions, 80 00:04:09,228 --> 00:04:11,768 but that’s getting deeper than this video needs to go. 81 00:04:12,160 --> 00:04:14,087 Oh, and speaking of defrosts. 82 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 83 00:04:18,190 --> 00:04:20,800 because the outdoor unit makes a tremendous racket. 84 00:04:21,520 --> 00:04:23,436 If that’s a reason you don’t like heat  pumps, 85 00:04:23,436 --> 00:04:26,979 you should know that this is also not a necessary thing by any means. 86 00:04:26,979 --> 00:04:29,049 A lot of domestic HVAC stuff 87 00:04:29,049 --> 00:04:32,914 is controlled with little to no brains, if you will. 88 00:04:32,914 --> 00:04:37,649 Often the thermostat is literally the only thing in control of the outside unit, 89 00:04:37,649 --> 00:04:42,978 and simpler systems will just slam the reversing valve while the compressor is still running. 90 00:04:42,978 --> 00:04:45,096 And that’s what’s causing that racket. 91 00:04:45,096 --> 00:04:48,130 If instead the compressor were stopped before it reversed, 92 00:04:48,130 --> 00:04:49,872 allowing pressures to equalize, 93 00:04:49,872 --> 00:04:51,973 it would be much less noticeable. 94 00:04:51,973 --> 00:04:54,106 That’s how this mini-split heat pump does it, 95 00:04:54,106 --> 00:04:57,369 and to my mind that’s obviously better. 96 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, 97 00:05:02,257 --> 00:05:06,219 but apparently it’s not so bad because  lots of systems do this very thing. 98 00:05:06,640 --> 00:05:10,000 Anyway, the point here is the  little annoyances you may have   99 00:05:10,000 --> 00:05:15,275 with your heat pump system are probably nothing  to do with it being a heat pump. 100 00:05:15,275 --> 00:05:17,786 Instead it’s simply bad design. 101 00:05:17,786 --> 00:05:20,418 Or a case of misaligned priorities. 102 00:05:20,418 --> 00:05:24,015 In my opinion, air conditioning systems like the one I just installed 103 00:05:24,015 --> 00:05:26,660 that have no reversing capabilities 104 00:05:26,660 --> 00:05:28,512 should not exist. 105 00:05:28,800 --> 00:05:32,787 There is no reason this device cannot provide  low-emissions heating 106 00:05:32,787 --> 00:05:37,266 other than a few components are missing from it which made it slightly cheaper to build. 107 00:05:37,266 --> 00:05:40,179 This is a case of “but sometimes!” thinking 108 00:05:40,179 --> 00:05:44,544 leading to the embrace of less flexible  systems for virtually no reason. 109 00:05:44,544 --> 00:05:45,557 And it’s dumb. 110 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.   111 00:05:51,520 --> 00:05:54,964 And that’s a terrifying prospect - I completely get it! 112 00:05:54,964 --> 00:05:59,018 Nearly everyone around me has natural gas or occasionally propane heating 113 00:05:59,018 --> 00:06:02,682 because in the deepest depths of the winter you frankly need it. 114 00:06:02,682 --> 00:06:08,032 But since nearly everyone around me also has central  air conditioning for our sweltering hot summers, 115 00:06:08,480 --> 00:06:11,050 they already have a heat pump, 116 00:06:11,050 --> 00:06:13,137 but it can only go one way because as of now 117 00:06:13,137 --> 00:06:15,898 few people see the point of redundant heating systems 118 00:06:15,898 --> 00:06:18,715 when you have cheap natural gas anyway. 119 00:06:18,715 --> 00:06:22,235 But since whenever the COP of a heat pump exceeds 2.5 120 00:06:22,235 --> 00:06:26,080 we can heat our homes with  less fuel burned and ultimately lower emissions, 121 00:06:26,720 --> 00:06:29,953 why would we not want to make the  air conditioner reversible 122 00:06:29,953 --> 00:06:32,965 for the many days of the year when that’s absolutely possible? 123 00:06:33,520 --> 00:06:36,054 Well, frankly, the biggest barrier right now 124 00:06:36,054 --> 00:06:38,285 is direct cost to the consumer. 125 00:06:38,285 --> 00:06:42,059 As I said, in my area unless you can get to a COP of 4 126 00:06:42,059 --> 00:06:46,945 it’s just not cost effective to run a heat pump over burning natural gas. 127 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, 128 00:06:52,118 --> 00:06:55,024 even if running the heat pump is more climate friendly 129 00:06:55,024 --> 00:06:57,169 it may not be more wallet friendly. 130 00:06:57,169 --> 00:07:01,225 The added cost of a heat pump may never make financial sense in my area, 131 00:07:01,225 --> 00:07:04,150 no matter how small the added cost might be. 132 00:07:04,150 --> 00:07:08,333 At least, so long as externalities remain  free to energy providers. 133 00:07:08,333 --> 00:07:10,301 [various alarm sounds] Ope, too deep alert! 134 00:07:10,480 --> 00:07:13,525 And that is why they’re not standard equipment around here. 135 00:07:14,069 --> 00:07:14,875 Yet. 136 00:07:15,174 --> 00:07:18,492 But it should be noted that the financial practicality of a heat pump 137 00:07:18,492 --> 00:07:21,800 will depend entirely on your cost of heating fuel. 138 00:07:21,800 --> 00:07:23,301 If it’s not natural gas, 139 00:07:23,301 --> 00:07:26,005 or even if it is but it’s more expensive for you, 140 00:07:26,005 --> 00:07:28,382 that math will be different. 141 00:07:28,382 --> 00:07:33,617 Now, if I were king, I’d proclaim that every central air conditioning system sold 142 00:07:33,617 --> 00:07:35,819 must be reversible. 143 00:07:35,819 --> 00:07:38,545 It’s equipment with a 10 to 20 year service life, 144 00:07:38,545 --> 00:07:44,417 and who knows what the availability and cost of heating  fuel will be in 2041? 145 00:07:44,417 --> 00:07:47,346 Plus, we keep making strides in system efficiency 146 00:07:47,346 --> 00:07:51,795 and air-source heat pumps are becoming viable in colder and colder climates. 147 00:07:51,795 --> 00:07:55,392 In fact, I just read a piece on their use in  Alaska! 148 00:07:55,392 --> 00:07:58,252 It can absolutely be done even up there. 149 00:07:58,252 --> 00:08:02,354 But if you really want a heat pump  to work in the coldest of the cold 150 00:08:02,354 --> 00:08:04,127 using the least amount of energy, 151 00:08:04,453 --> 00:08:06,141 you gotta go underground. 152 00:08:06,800 --> 00:08:07,964 Look down. 153 00:08:07,964 --> 00:08:08,892 See that? 154 00:08:08,892 --> 00:08:10,087 It’s the ground! 155 00:08:10,087 --> 00:08:11,248 Turn around. 156 00:08:11,248 --> 00:08:12,335 There’s a human sku - 157 00:08:12,580 --> 00:08:13,080 sorry. 158 00:08:13,520 --> 00:08:14,932 Thinking of something else. 159 00:08:14,932 --> 00:08:18,583 You know how we have water pipes going every which way underground 160 00:08:18,583 --> 00:08:21,369 and even in the dead of winter they don’t freeze 161 00:08:21,369 --> 00:08:22,596 (usually)? 162 00:08:22,949 --> 00:08:25,848 Well, that’s because the Earth is warm. 163 00:08:25,848 --> 00:08:30,365 Dig just a few feet below the surface and you’ll  find the frost line. 164 00:08:30,365 --> 00:08:33,609 Below this imaginary line the ground doesn’t freeze. 165 00:08:33,609 --> 00:08:36,191 Where that line is changes depending on where you are, 166 00:08:36,191 --> 00:08:37,336 but it’s there! 167 00:08:37,635 --> 00:08:40,640 Management was just really bad  about marking it when they built the place. 168 00:08:41,520 --> 00:08:45,921 Since heat pumps are great at extracting and  concentrating heat energy 169 00:08:45,921 --> 00:08:47,918 from relatively cool places, 170 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 171 00:08:52,919 --> 00:08:55,130 no matter how cold it is outside, 172 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, 173 00:09:00,240 --> 00:09:03,319 we could get more than enough heat to warm our homes 174 00:09:03,319 --> 00:09:05,375 no matter what time of year it is. 175 00:09:06,000 --> 00:09:07,407 And wouldn’t ya know it, 176 00:09:07,407 --> 00:09:09,664 this is a thing we know how to do! 177 00:09:10,080 --> 00:09:12,533 Ground-source or geothermal heat pumps 178 00:09:12,533 --> 00:09:15,653 scavenge heat from the ground below the frost line. 179 00:09:15,653 --> 00:09:17,330 There are two main ways to do this, 180 00:09:17,330 --> 00:09:21,650 and both involve using an intermediary fluid to transfer heat energy. 181 00:09:21,650 --> 00:09:25,181 And yes, some newer ideas don’t use an intermediary fluid but 182 00:09:25,181 --> 00:09:27,166 we’re not talking about them today. 183 00:09:27,166 --> 00:09:30,641 Instead of an outside unit like this with a large fan-driven, 184 00:09:30,641 --> 00:09:32,987 refrigerant-to-air heat exchanger, 185 00:09:32,987 --> 00:09:36,962 these systems will have a refrigerant-to-liquid heat exchanger. 186 00:09:36,962 --> 00:09:40,592 There’s no law saying evaporators have to look like this, after all. 187 00:09:40,960 --> 00:09:43,673 Inside your home the equipment doesn’t  look too much different 188 00:09:43,673 --> 00:09:45,811 from a normal furnace or air handler, 189 00:09:45,811 --> 00:09:48,272 but the compressor (and sometimes there’s more than one) 190 00:09:48,272 --> 00:09:51,347 as well as both heat exchangers are all right here. 191 00:09:51,347 --> 00:09:54,690 And to those worried about noise from the compressors, don’t worry - 192 00:09:54,690 --> 00:09:56,584 there’s plenty of sound deadening. 193 00:09:56,584 --> 00:09:58,058 Engineers are smart! 194 00:09:58,640 --> 00:10:02,662 What’s special about these system is where  they're getting their heat from. 195 00:10:02,662 --> 00:10:06,978 A long, closed loop of piping filled with a mixture of water  and antifreeze 196 00:10:06,978 --> 00:10:10,236 is pumped in a circuit out of the home and underground 197 00:10:10,236 --> 00:10:14,320 where the liquid will absorb heat  from the earth before being brought back inside. 198 00:10:14,960 --> 00:10:18,295 This now warmed liquid is fed to the heat  exchanger 199 00:10:18,295 --> 00:10:23,403 which will absorb and concentrate that heat with the help of our friend the refrigeration cycle. 200 00:10:23,403 --> 00:10:28,000 The refrigerant is then squeezed into the condenser and that  heat is released into the air 201 00:10:28,000 --> 00:10:29,792 and ultimately the living space. 202 00:10:30,160 --> 00:10:34,939 The benefit of doing this is that no matter what  the air temperature is outside, 203 00:10:34,939 --> 00:10:37,688 the temperature of the fluid returning from the ground loop 204 00:10:37,688 --> 00:10:42,218 will be a near-constant 50 degrees Fahrenheit or about 10 Celsius. 205 00:10:42,218 --> 00:10:46,327 That temperature allows a heat pump to  run at peak performance and efficiency, 206 00:10:46,327 --> 00:10:52,516 delivering a nearly constant, near-maximum COP at full  output no matter what. 207 00:10:52,516 --> 00:10:56,670 Right now you can expect it to always meet or exceed a COP of 4, 208 00:10:56,670 --> 00:11:00,172 and that will undoubtedly improve as technology advances. 209 00:11:00,172 --> 00:11:02,631 And that’s obviously a huge deal! 210 00:11:02,631 --> 00:11:07,035 A home with a geothermal heat pump needs significantly less energy to heat 211 00:11:07,035 --> 00:11:10,055 than any other heating technology  available today 212 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). 213 00:11:15,600 --> 00:11:19,520 Even with an entirely fossil-fuel  powered electrical infrastructure,   214 00:11:19,520 --> 00:11:23,742 emissions are drastically reduced when using a  ground-source heat pump. 215 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 216 00:11:29,574 --> 00:11:32,025 and sending its energy the zippy-zappy way 217 00:11:32,025 --> 00:11:34,993 than natural gas itself contains. 218 00:11:34,993 --> 00:11:38,141 That’s astonishing and yet completely possible. 219 00:11:38,480 --> 00:11:42,528 Also important is that methane, the main component  of natural gas, 220 00:11:42,528 --> 00:11:44,300 is a potent greenhouse gas, 221 00:11:44,300 --> 00:11:49,280 and the infrastructure we use to transport it to  homes across the country is notoriously leaky. 222 00:11:49,840 --> 00:11:54,352 Not requiring that infrastructure in the first  place provides its own emissions reduction.   223 00:11:54,640 --> 00:11:59,348 What’s more, the much lower energy requirement of homes with geothermal heat pumps 224 00:11:59,348 --> 00:12:01,454 opens up many more opportunities, 225 00:12:01,454 --> 00:12:05,741 particularly when it comes to  renewable and locally-generated sources of power. 226 00:12:06,080 --> 00:12:09,719 Oh, and of course, these systems are entirely reversible. 227 00:12:09,719 --> 00:12:12,443 In the summer months, well below the frost line 228 00:12:12,443 --> 00:12:15,197 the Earth stays colder than the air outside! 229 00:12:15,197 --> 00:12:19,820 So in cooling mode, the system simply puts heat back into the  Earth. 230 00:12:19,820 --> 00:12:22,246 It’s actually almost poetic. 231 00:12:22,246 --> 00:12:27,306 That heat ends up simply being borrowed in the winter monts and returned in the summer. 232 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, 233 00:12:32,135 --> 00:12:34,725 the system will run at peak performance. 234 00:12:34,997 --> 00:12:35,552 Neat. 235 00:12:35,840 --> 00:12:37,650 So what’s the catch? 236 00:12:37,650 --> 00:12:39,082 Eleven words. 237 00:12:39,082 --> 00:12:43,839 The upfront cost and disruptive nature of the ground loop installation. 238 00:12:43,839 --> 00:12:45,341 That second part’s getting better, 239 00:12:45,341 --> 00:12:49,283 but unless you happen to be lucky and have access to some natural body of water 240 00:12:49,283 --> 00:12:52,664 like a pond that’s deep and large enough to use as your heat source 241 00:12:52,664 --> 00:12:55,184 (which is another way to go about it, by the way) 242 00:12:55,184 --> 00:12:58,453 there will have to be a network of piping installed under the ground 243 00:12:58,453 --> 00:13:01,382 to collect and transport its energy. 244 00:13:01,382 --> 00:13:02,741 For a long time, 245 00:13:02,741 --> 00:13:05,820 this meant excavating a large area  around a home 246 00:13:05,820 --> 00:13:09,549 down to several feet (think about a meter-ish) below the frost line. 247 00:13:09,549 --> 00:13:14,033 Then you’d go all loopy with a bunch of piping, and cover it back up. 248 00:13:14,033 --> 00:13:17,338 Hopefully you remembered  to put the ends of that pipe somewhere useful. 249 00:13:17,680 --> 00:13:23,901 But that’s really disruptive and requires a  large area of lawn or similar open space. 250 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. 251 00:13:28,611 --> 00:13:30,144 It’s the perfect time. 252 00:13:30,144 --> 00:13:34,362 Oh, and one interesting idea that’s  taking hold is community ground loops. 253 00:13:34,362 --> 00:13:37,789 A bunch of homes in a new development can be  hooked up to a large, 254 00:13:37,789 --> 00:13:40,716 shared ground loop that’s piped into each home. 255 00:13:40,716 --> 00:13:44,038 They each have their own  heat pumps extracting energy from the fluid, 256 00:13:44,038 --> 00:13:46,137 but the geothermal equipment is shared, 257 00:13:46,137 --> 00:13:49,445 maximizing its potential and lowering the cost-per-user. 258 00:13:49,920 --> 00:13:53,396 But if you want to add a ground loop to  an existing homesite 259 00:13:53,396 --> 00:13:56,578 it kinda sucks and sometimes isn't possible. 260 00:13:56,578 --> 00:13:59,197 However, a more recent and exciting development 261 00:13:59,197 --> 00:14:03,640 is the use of vertical drilling to go deeper rather than broader. 262 00:14:03,640 --> 00:14:07,512 Using equipment similar to that which is used to dig a well for drinking water, 263 00:14:07,512 --> 00:14:11,125 a borehole can be dug hundreds of feet below the soil, 264 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. 265 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. 266 00:14:23,920 --> 00:14:27,440 Dandelion energy is one company  installing such systems.   267 00:14:28,000 --> 00:14:30,267 Now, these aren’t cheap. 268 00:14:30,267 --> 00:14:34,692 Their own website admits that this is gonna cost about as much as a small car, 269 00:14:34,692 --> 00:14:38,800 and depending on how your energy is  priced you may never recoup that investment. 270 00:14:39,360 --> 00:14:43,600 But regardless of where you are it  will reduce greenhouse emissions,   271 00:14:43,600 --> 00:14:46,641 and hopefully energy starts getting priced to  reflect that 272 00:14:46,641 --> 00:14:48,938 [alarm sounds return] oh sorry goin’ too deep again… 273 00:14:49,360 --> 00:14:53,012 What Dandelion and companies like it are doing is  really important 274 00:14:53,012 --> 00:14:56,049 for making geothermal heat pumps more approachable. 275 00:14:56,049 --> 00:14:58,855 Simply negating the need to tear up an entire yard 276 00:14:58,855 --> 00:15:02,886 is a huge step in the right direction for getting the reluctant onboard. 277 00:15:03,440 --> 00:15:06,766 But it’s by no means a one-size-fits-all solution. 278 00:15:06,766 --> 00:15:09,445 Unless you have the rights to dig that far down 279 00:15:09,445 --> 00:15:12,027 and there’s nothing below you that could be a  problem 280 00:15:12,027 --> 00:15:15,120 like abandoned mines, subway tunnels, etc… 281 00:15:16,000 --> 00:15:17,465 well you can’t do it. 282 00:15:17,465 --> 00:15:19,688 And what about in like, ya know, 283 00:15:19,688 --> 00:15:20,912 cities? 284 00:15:20,912 --> 00:15:25,002 How’s a large apartment building gonna get all the heat  it needs from a borehole? 285 00:15:25,600 --> 00:15:26,886 Well, it can’t. 286 00:15:27,200 --> 00:15:30,338 District heating, though, may be an indirect  way to provide 287 00:15:30,338 --> 00:15:33,834 geothermally derived heat to large urban spaces. 288 00:15:33,834 --> 00:15:37,628 District heating is unfortunately not that common in the US 289 00:15:37,628 --> 00:15:39,346 which is a giant shame. 290 00:15:39,346 --> 00:15:42,797 Basically it’s a network of underground insulated pipes 291 00:15:42,797 --> 00:15:47,418 bringing really hot water into buildings  that is then fed through radiators to heat them. 292 00:15:47,920 --> 00:15:50,322 One of the more clever ways to heat that  water 293 00:15:50,322 --> 00:15:53,388 is with the waste heat of conventional power stations, 294 00:15:53,388 --> 00:15:56,697 and many countries have been doing this for decades. 295 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, 296 00:16:01,840 --> 00:16:07,365 especially since water-loop systems for heating  buildings are by no means a recent development. 297 00:16:07,760 --> 00:16:10,751 But anyway, that practice can be used to provide  heat 298 00:16:10,751 --> 00:16:14,264 to urban centers without requiring combustion of fuels onsite 299 00:16:14,264 --> 00:16:19,163 or the immense electrical supply which would be needed with resistive heating alone. 300 00:16:19,163 --> 00:16:22,465 What you use to heat the water, then, is  arbitrary. 301 00:16:22,465 --> 00:16:26,472 It could be a large geothermal station running massive heat pumps. 302 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, 303 00:16:31,693 --> 00:16:33,546 if you’re feeling adventurous. 304 00:16:33,546 --> 00:16:36,185 This is all stuff that’s being researched right now, 305 00:16:36,185 --> 00:16:39,188 and as usual there’s pros  and cons to every one of these. 306 00:16:39,188 --> 00:16:40,193 What gives? 307 00:16:40,720 --> 00:16:43,346 Well Ellen, there are no easy answers. 308 00:16:43,346 --> 00:16:45,803 But this video was about heat pumps. 309 00:16:45,803 --> 00:16:49,402 While geothermal heat pumps may not exactly… 310 00:16:49,402 --> 00:16:52,295 work in the concrete jungles of New York City, 311 00:16:52,295 --> 00:16:55,301 air-source heat pumps certainly can. 312 00:16:55,301 --> 00:16:58,633 And maybe they won’t make sense  to use on really cold days, 313 00:16:58,633 --> 00:17:02,802 but really cold days are only some of the days of winter. 314 00:17:02,802 --> 00:17:04,564 We really gotta stop this whole 315 00:17:04,564 --> 00:17:09,508 “Only Solutions Which Cover Every Single Possible Contingency are Feasible” nonsense 316 00:17:09,508 --> 00:17:13,051 and start using what we can when we can. 317 00:17:13,280 --> 00:17:15,059 That’s kind of my whole point with the 318 00:17:15,059 --> 00:17:18,296 “every air conditioner should be reversible” thing. 319 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. 320 00:17:24,240 --> 00:17:28,006 We have the technology, so... so use it when possible! 321 00:17:28,480 --> 00:17:30,735 Oh yeah. Here’s a really dumb thing. 322 00:17:30,735 --> 00:17:34,842 Electric cars, which nearly universally have air conditioning, 323 00:17:34,842 --> 00:17:38,278 are only just now starting to make that reversible. 324 00:17:38,278 --> 00:17:43,328 Cabin heat is by far the largest non-locomotive energy use  in an EV, 325 00:17:43,328 --> 00:17:46,603 and is a large part of why range drops in the winter. 326 00:17:46,603 --> 00:17:51,354 It has always been the case that a  heat pump would help a lot with that, 327 00:17:51,354 --> 00:17:53,063 at least on milder days, 328 00:17:53,063 --> 00:17:57,929 and yet even some brand new EV models  on sale do not offer them. 329 00:17:57,929 --> 00:18:00,476 Instead, resistive heat is your only option. 330 00:18:01,237 --> 00:18:04,978 I don’t know if there’s some trick  to ruggedizing reversing valves for road use, 331 00:18:04,978 --> 00:18:09,205 or maybe there’s something else that makes it harder  for cars, but c’mon! 332 00:18:09,205 --> 00:18:11,748 Heat pumps need to be standard in EVs. 333 00:18:11,748 --> 00:18:12,960 Figure it out! 334 00:18:12,960 --> 00:18:17,338 And if you can get a  COP of 2 when it’s zero degrees out, fantastic. 335 00:18:17,920 --> 00:18:19,496 But ya know what’s real neat? 336 00:18:19,496 --> 00:18:22,819 We’re beginning to put heat pumps in more places to do more things 337 00:18:22,819 --> 00:18:25,667 besides just heat and cool our living  spaces! 338 00:18:25,667 --> 00:18:30,703 Fundamentally, heat pumps are just heat energy relocators and concentrators. 339 00:18:30,703 --> 00:18:32,860 If there’s a place where we need a lot of heat, 340 00:18:32,860 --> 00:18:37,070 we can sometimes take it from another  and often with side-benefits as well. 341 00:18:37,680 --> 00:18:42,240 One real-world application of heat pumps  not-for-heating is the hybrid water heater. 342 00:18:42,880 --> 00:18:45,719 OK, well I suppose that is still heating… 343 00:18:45,719 --> 00:18:50,011 but consider a typical North American water heater with a 50 gallon tank. 344 00:18:50,011 --> 00:18:52,499 Until recently, you had two choices: 345 00:18:52,499 --> 00:18:54,210 electric or gas. 346 00:18:54,210 --> 00:18:56,969 Gas is cheaper to operate, but requires venting 347 00:18:56,969 --> 00:18:58,668 and also gas. 348 00:18:58,668 --> 00:19:00,937 Electric is more expensive to operate, 349 00:19:00,937 --> 00:19:04,735 but the device itself is little more than an oversized  kettle. 350 00:19:04,735 --> 00:19:08,739 Now, the benefit of storing hot water in an insulated tank like this 351 00:19:08,739 --> 00:19:11,560 is that you’ve created a thermal battery. 352 00:19:11,560 --> 00:19:16,049 Hybrid water heaters use a heat pump to maintain the water temperature in the tank, 353 00:19:16,049 --> 00:19:19,272 or you could say… to keep the battery charged, 354 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. 355 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, 356 00:19:28,990 --> 00:19:33,713 but provides the additional benefit of  free air conditioning and dehumidification 357 00:19:33,713 --> 00:19:36,344 in the area around the water heater! 358 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, 359 00:19:41,229 --> 00:19:43,703 and it gets cold and wet. 360 00:19:43,703 --> 00:19:48,045 This means hybrid water heaters need a drain line to deal with that condensate, 361 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. 362 00:19:54,128 --> 00:19:56,886 It’s heating my water, and more cheaply than before! 363 00:19:57,200 --> 00:20:00,078 Of course, in the winter this is perhaps a bummer, 364 00:20:00,078 --> 00:20:02,848 but if you have gas heat like I do, 365 00:20:02,848 --> 00:20:05,463 well now your water heater runs on gas! 366 00:20:05,463 --> 00:20:07,239 Just, indirectly. 367 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 368 00:20:11,877 --> 00:20:14,737 after your main heat pump first brought it to your home for you. 369 00:20:14,737 --> 00:20:19,000 Anyway, it’s a hybrid water heater because  these also have traditional heating elements 370 00:20:19,000 --> 00:20:21,231 to deal with periods of high demand. 371 00:20:21,231 --> 00:20:24,836 The heat pump is slower than good ‘ol fashioned hot sticks. 372 00:20:24,836 --> 00:20:28,412 But, assuming you don’t have a showerthon going  on in your house, 373 00:20:28,412 --> 00:20:31,755 it can take its time reheating the water in the tank between uses 374 00:20:31,755 --> 00:20:36,015 using as little as a quarter the energy of an ordinary electric heater. 375 00:20:36,015 --> 00:20:39,581 The potential for heat pumps to be used in water heaters, by the way, 376 00:20:39,581 --> 00:20:43,397 has made me fairly anti-tankless water heater. 377 00:20:43,397 --> 00:20:48,501 It’s a myth that tankless water heaters provide you with “instant hot water” - 378 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 379 00:20:54,960 --> 00:20:57,369 and your plumbing to be completely redone, 380 00:20:57,369 --> 00:21:01,074 or maybe you can get away with point-of-use  booster heaters. 381 00:21:01,074 --> 00:21:04,794 But anyway, now that I know that heat pump water heaters are a thing 382 00:21:04,794 --> 00:21:07,583 I have no desire to go tankless. 383 00:21:07,583 --> 00:21:09,341 Save that energy, baby! 384 00:21:09,840 --> 00:21:13,009 Another really neat development, and perhaps even more so 385 00:21:13,009 --> 00:21:15,297 is the heat pump clothes dryer. 386 00:21:15,297 --> 00:21:18,359 Tumble dryers are a sort of guilty pleasure to me. 387 00:21:18,359 --> 00:21:20,690 Oh sure, they save tons of time and space 388 00:21:20,690 --> 00:21:24,878 but they also use a lot of energy and are typically vented outside, 389 00:21:24,878 --> 00:21:27,969 which not only means there needs to be a  vent in the first place 390 00:21:27,969 --> 00:21:31,640 but also creates significant negative pressure when they run. 391 00:21:31,640 --> 00:21:33,960 But what do dryers really do? 392 00:21:33,960 --> 00:21:36,922 Well, they basically just tumble clothes around  a drum 393 00:21:36,922 --> 00:21:40,734 with hot air blowing through it which makes the clothes dry faster. 394 00:21:40,734 --> 00:21:43,680 Making the  air hot is the energy intensive part, 395 00:21:44,197 --> 00:21:45,138 buuuuuut… 396 00:21:45,280 --> 00:21:46,261 That’s right. 397 00:21:46,261 --> 00:21:47,328 Heat pump it! 398 00:21:47,328 --> 00:21:50,216 Heat pump clothes dryers are frankly amazing 399 00:21:50,216 --> 00:21:53,509 because it’s about the perfect application for the technology. 400 00:21:53,509 --> 00:21:57,501 You just need to get the inside of the dryer hotter than the outside. 401 00:21:57,501 --> 00:22:01,713 Yeah, you could do that with heater coils or even with a lil’ gas furnace, 402 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. 403 00:22:07,875 --> 00:22:11,914 And none of it gets lost - it just gets concentrated inside. 404 00:22:11,914 --> 00:22:16,154 Best of all, you can then exhaust the hot, damp air that exits  the drum 405 00:22:16,154 --> 00:22:21,065 over the cold evaporator and not only re-collect that energy to be pumped back in 406 00:22:21,065 --> 00:22:24,084 but also the moisture from the clothes. 407 00:22:24,084 --> 00:22:27,828 You end up with a clothes dryer that needs  much less energy to run, 408 00:22:27,828 --> 00:22:29,352 doesn’t need venting, 409 00:22:29,352 --> 00:22:31,502 and can be placed anywhere. 410 00:22:31,502 --> 00:22:35,600 Some of them can even be plugged into a standard 120V electrical outlet! 411 00:22:36,400 --> 00:22:39,964 Heat pump clothes dryers are slower than  traditional vented solutions, 412 00:22:39,964 --> 00:22:44,092 but they offer great flexibility and a much lower energy cost. 413 00:22:44,092 --> 00:22:45,918 Even if you have a gas dryer, 414 00:22:45,918 --> 00:22:50,061 eliminating the need for a vent will lower your heating and cooling demand when it runs 415 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. 416 00:22:55,205 --> 00:22:57,739 It’s really kind of a no-brainer to me. 417 00:22:58,080 --> 00:23:00,623 Using a heat pump not only makes it cheaper to run 418 00:23:00,623 --> 00:23:02,912 but solves real problems. 419 00:23:02,912 --> 00:23:05,449 That is, if you’re willing to have your laundry take longer, 420 00:23:05,449 --> 00:23:08,112 which I recognize is not feasible for everyone. 421 00:23:08,480 --> 00:23:12,580 Now, there is one real downside to the  proliferation of heat pumps. 422 00:23:12,580 --> 00:23:14,874 To make them, we need refrigerants. 423 00:23:14,874 --> 00:23:19,182 And refrigerants have created a Whack-A-Mole of engineering challenges. 424 00:23:19,182 --> 00:23:21,775 When we first ventured down the path of refrigeration, 425 00:23:21,775 --> 00:23:25,348 we were using gaseous ammonia as a refrigerant. 426 00:23:25,348 --> 00:23:27,635 It was actually a fantastic refrigerant, 427 00:23:27,635 --> 00:23:32,289 but it was very toxic and leaks were very dangerous to human life. 428 00:23:32,289 --> 00:23:37,079 That was the problem that Thomas Midgely Junior solved with the creation of Freon. 429 00:23:37,079 --> 00:23:40,852 Freon was the first non-toxic non-flammable refrigerant, 430 00:23:40,852 --> 00:23:42,888 and we were thrilled to have it! 431 00:23:43,200 --> 00:23:46,959 Of course, decades later we realized the ozone  layer was disappearing 432 00:23:46,959 --> 00:23:50,496 and we figured out that CFCs like Freon were the culprit. 433 00:23:50,496 --> 00:23:55,191 So, replacement refrigerants were developed like our friend R-134a. 434 00:23:55,191 --> 00:23:58,134 These HFCs don’t harm the ozone layer, 435 00:23:58,134 --> 00:24:02,093 but they are ridiculously potent greenhouse gases. 436 00:24:02,093 --> 00:24:07,217 This here is over 1,400 times better at  trapping heat in the atmosphere 437 00:24:07,217 --> 00:24:09,182 than carbon dioxide. 438 00:24:09,400 --> 00:24:10,090 Great! 439 00:24:10,400 --> 00:24:14,155 Even though in an ideal world it will never leave  the refrigerant loop, 440 00:24:14,155 --> 00:24:17,283 eventually refrigeration systems develop leaks. 441 00:24:17,283 --> 00:24:22,281 If you ever bought one of these to recharge your A/C, that’s why. 442 00:24:22,281 --> 00:24:26,263 So these HFCs are being phased out for newer refrigerants like 443 00:24:26,263 --> 00:24:29,930 2,3,3,3-Tetrafluoropropene 444 00:24:29,930 --> 00:24:34,093 also known as R-1234yf. 445 00:24:34,093 --> 00:24:38,190 This refrigerant has a global warming potential of less  than 1, 446 00:24:38,190 --> 00:24:40,782 so as far as we can tell it’s harmless. 447 00:24:41,040 --> 00:24:44,168 Currently, these new refrigerants are rather  expensive. 448 00:24:44,168 --> 00:24:45,840 And the reason is patently obvious. 449 00:24:46,400 --> 00:24:47,534 It’s patents. 450 00:24:47,534 --> 00:24:50,446 These next-gen refrigerants are protected by patents 451 00:24:50,446 --> 00:24:55,201 and their owners are absodidily OK with exploiting that and hard. 452 00:24:55,201 --> 00:24:57,363 Now, that was once the case for this fella. 453 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. 454 00:25:02,880 --> 00:25:05,101 In some states, anyway. 455 00:25:05,101 --> 00:25:07,864 Perhaps my most radical thought I’ll put forth here 456 00:25:07,864 --> 00:25:09,867 is that patents on things like, 457 00:25:09,867 --> 00:25:10,615 oh I don’t know, 458 00:25:10,615 --> 00:25:14,783 climate-friendly refrigerants that we really need to make a lot more of and fast 459 00:25:14,783 --> 00:25:16,768 should be invalidated. 460 00:25:16,768 --> 00:25:19,874 Maybe we ought to consider some classes of things unpatentable 461 00:25:19,874 --> 00:25:22,878 and instead encourage their development through some sort of prize system 462 00:25:22,878 --> 00:25:25,505 or just develop them publicly from the start 463 00:25:25,505 --> 00:25:27,802 I don’t know just spitballin’ here. 464 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 465 00:25:33,568 --> 00:25:34,995 because we need that! 466 00:25:35,440 --> 00:25:37,517 Then again, there is another option. 467 00:25:37,762 --> 00:25:41,827 Carbon dioxide can actually be used as a refrigerant, 468 00:25:41,827 --> 00:25:45,493 although when you do that it prefers you call it  R-744. 469 00:25:45,955 --> 00:25:47,011 It’s more polite. 470 00:25:47,718 --> 00:25:48,779 Now if you’re wondering, 471 00:25:49,280 --> 00:25:52,768 “Well if that’s possible why haven’t we just  been doing that from the start?” 472 00:25:53,230 --> 00:25:54,000 I’ll tell ya! 473 00:25:54,469 --> 00:25:58,521 The working pressures you need to make carbon dioxide a refrigerant are... 474 00:25:58,521 --> 00:25:59,869 quite high. 475 00:25:59,869 --> 00:26:02,958 Think 1,000+ PSI. 476 00:26:02,958 --> 00:26:07,808 That means the refrigeration equipment needs to be much more robust in order to handle it, 477 00:26:07,808 --> 00:26:09,040 making it more expensive. 478 00:26:09,680 --> 00:26:12,359 More traditional synthetic refrigerants... 479 00:26:13,338 --> 00:26:15,450 that sounds wrong but, yes 480 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. 481 00:26:21,639 --> 00:26:23,832 So right now it’s pick your poison. 482 00:26:23,832 --> 00:26:26,040 Cheap system, expensive gas… 483 00:26:26,040 --> 00:26:28,640 or cheap gas but expensive system. 484 00:26:29,200 --> 00:26:32,720 But anyway, we’ve talked about all  I wanted to talk about heat pumps.   485 00:26:32,720 --> 00:26:34,416 For now, anyway. 486 00:26:34,416 --> 00:26:38,277 I fully expect them to find their way into more and more places, 487 00:26:38,277 --> 00:26:42,133 and I’m sure we’ll address many of their flaws  as time goes on. 488 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, 489 00:26:47,757 --> 00:26:50,489 well golly gee that’d just be neat-o! 490 00:26:50,800 --> 00:26:52,139 I hope we can do it. 491 00:26:52,139 --> 00:26:54,774 But one thing is for sure about the future. 492 00:26:55,100 --> 00:26:57,537 I’m pumped for it. 493 00:26:58,407 --> 00:27:01,069 ♫ geothermally smooth jazz ♫ 494 00:27:01,939 --> 00:27:02,492 I wanna - 495 00:27:02,492 --> 00:27:05,550 [incessant coughing] 496 00:27:05,550 --> 00:27:09,623 And if you had a thermostat which was aware  of its current ... bleugh. 497 00:27:10,575 --> 00:27:13,260 Hoo hoo hoo hoo I skipped a word! 498 00:27:13,260 --> 00:27:15,600 What was that in the script? 499 00:27:15,600 --> 00:27:17,830 Aware of the current COP… 500 00:27:17,830 --> 00:27:20,665 yeah that was just an error and I f.. I s.. I.. I made it! 501 00:27:20,665 --> 00:27:23,949 Turn around. There’s a human sk .. sorry. 502 00:27:23,949 --> 00:27:25,975 [evil laughter] 503 00:27:25,975 --> 00:27:29,920 Even with an entirely fossil-fuel  powered electrical infrastru… 504 00:27:31,200 --> 00:27:34,054 that’s a lot of big words in this one. 505 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! 506 00:27:39,820 --> 00:27:40,759 Aehehehe! 507 00:27:40,759 --> 00:27:44,061 A bore hole can be dug hundreds of  feet below the soil, 508 00:27:44,061 --> 00:27:45,877 and rather than 509 00:27:45,877 --> 00:27:46,416 [rude raspberry] 510 00:27:49,189 --> 00:27:51,476 So, are we pumped? 511 00:27:51,476 --> 00:27:54,000 Are we pumping up the jam? 512 00:27:54,000 --> 00:27:58,154 You know, somebody probably has that job at the Smuckers factory. 513 00:27:58,154 --> 00:28:00,916 And then when the jars get put on pallets? 514 00:28:00,916 --> 00:28:03,509 Those folks always end with jam-packed days.