WEBVTT Kind: captions Language: en 00:00:00.049 --> 00:00:07.566 I completely shut off my heat when it was -11 degrees Fahrenheit outside for an entire 24 hours 00:00:07.566 --> 00:00:09.456 in order to prove a point: 00:00:09.456 --> 00:00:17.599 my home’s heating system, a furnace which was installed and specced for the structure by professioanls in the HVAC industry, 00:00:17.599 --> 00:00:20.837 is way too big for my home! 00:00:20.837 --> 00:00:23.021 Why did it get installed? 00:00:23.021 --> 00:00:30.943 I can only speculate, but it means that my current heating system absolutely should not be considered as any kind of baseline 00:00:30.943 --> 00:00:33.438 when it comes time to replace it. 00:00:33.438 --> 00:00:36.669 And many of you are probably in that same boat. 00:00:36.669 --> 00:00:40.429 If you are looking to make a change to your home’s heating and cooling system, 00:00:40.429 --> 00:00:44.669 especially if that change is moving from one heating technology to another, 00:00:44.669 --> 00:00:50.629 it pays to find out what heating and cooling capacity you actually need for your home. 00:00:50.629 --> 00:00:53.765 And the good news is that it’s not that hard anymore. 00:00:53.765 --> 00:01:00.500 Before we get to that, though, this is a tweaked and condensed version of a longer video on my main channel. 00:01:00.500 --> 00:01:03.955 If you’d like some additional context and plenty more runtime 00:01:03.955 --> 00:01:08.229 you can check that out there or through the link in the description. 00:01:08.229 --> 00:01:10.440 And I’d like to begin this version 00:01:10.440 --> 00:01:14.680 by letting you in on a secret the industry doesn’t want you to know. 00:01:15.076 --> 00:01:17.810 I’m not really joking, despite the cliche. 00:01:18.000 --> 00:01:19.295 Here goes: 00:01:19.295 --> 00:01:22.989 those fancy heat pumps they keep talking about on the news? 00:01:22.989 --> 00:01:25.219 Well it turns out, those heat pumps … 00:01:25.219 --> 00:01:27.719 ARE JUST AIR CONDITIONERS! 00:01:27.719 --> 00:01:29.425 That’s all they are. 00:01:29.425 --> 00:01:37.784 They’re just air conditioners equipped with an extra valve which allows them to operate in reverse to produce heating in addition to cooling. 00:01:37.784 --> 00:01:39.986 That's all that a heat pump is! 00:01:39.986 --> 00:01:45.159 Everyone in the HVAC industry knows this, at least I sure hope they do, 00:01:45.159 --> 00:01:49.590 but because heat pumps are hyped up right now and people are interested in them, 00:01:49.590 --> 00:01:57.726 in areas where they haven't been common they are often painted as fancier and more exotic machines than they really are. 00:01:57.726 --> 00:02:05.780 The only truly new things on the scene are cold-climate heat pumps which operate efficiently even in very cold weather, 00:02:05.780 --> 00:02:09.211 but those just have little tweaks to the underlying technology 00:02:09.211 --> 00:02:16.138 and are not fundamentally different from the commodity equipment that’s been getting installed the world over for decades. 00:02:16.138 --> 00:02:20.269 So watch out for price gouging - it’s rampant right now. 00:02:20.269 --> 00:02:28.114 And for reference, poke around on HVAC wholesale sites to get an idea of how much more a heat pump system should cost 00:02:28.114 --> 00:02:31.330 compared to a new furnace and air conditioner. 00:02:31.330 --> 00:02:34.910 You’ll quickly find out it’s not much at all. 00:02:34.910 --> 00:02:37.791 If you already have an air conditioner and furnace, 00:02:37.791 --> 00:02:45.809 the most expensive and frankly only different task when installing a heat pump is running a new circuit for backup resistive heating. 00:02:45.809 --> 00:02:51.459 And that’s not always even necessary anymore depending on your local climate or your backup heat source. 00:02:51.459 --> 00:02:54.879 There’s a lot of nuance here which I’m skipping over for time, 00:02:54.879 --> 00:03:02.850 but bottom line, $20,000 quotes to install a heat pump are ridiculous outside weird circumstances. 00:03:02.850 --> 00:03:05.666 But this video isn’t so much about price gouging, 00:03:05.666 --> 00:03:11.319 it’s about figuring out how much of a heat pump (or other heating system) you actually need. 00:03:11.319 --> 00:03:15.055 I live in a fairly new townhome in the Chicago area. 00:03:15.055 --> 00:03:21.050 Because it was built to recent codes and I'm sharing walls with neighbors, it’s pretty energy efficient. 00:03:21.050 --> 00:03:25.239 Yet whoever specced its heating system was apparently not given the memo! 00:03:25.239 --> 00:03:31.880 It’s been equipped with a bog-standard 60,000 BTU/hr furnace and 2-ton air conditioner. 00:03:32.038 --> 00:03:36.716 The air conditioner, miraculously, is actually close to right-on-the-money. 00:03:36.716 --> 00:03:39.319 But the furnace is way too effin' big! 00:03:39.319 --> 00:03:42.694 It is barely running even in extreme cold. 00:03:42.694 --> 00:03:44.105 How do I know that? 00:03:44.290 --> 00:03:50.690 Eyes and ears are pretty helpful here but even more helpful is the fact that I have a smart thermostat. 00:03:50.690 --> 00:03:57.695 Since I have a simple singe-stage heating system which is only ever heating at its full output or not heating at all, 00:03:57.695 --> 00:04:05.264 a log of how much time it spent heating in a day could be used to determine how much heating output it actually produced that day. 00:04:05.766 --> 00:04:11.495 And wouldn’t ya know it, the smart thermostat logs what it tells the furnace to do over the course of a day 00:04:11.495 --> 00:04:15.591 and my user account retains that data for well over a year. 00:04:15.591 --> 00:04:18.567 So with a quick look in my thermostat’s app 00:04:18.567 --> 00:04:22.848 (but not the Nest app, the Google Home app… don’t get me started) 00:04:22.848 --> 00:04:26.960 I can look back in time to see what it did on any particular day. 00:04:26.960 --> 00:04:28.250 So let’s do that. 00:04:28.250 --> 00:04:31.472 Here’s what a typical winter day looks like weather-wise: 00:04:31.472 --> 00:04:36.740 January 5th was a cloudy day with the temperature hovering right around freezing point. 00:04:36.740 --> 00:04:42.657 With essentially no help from the sun, my furnace was providing the only heat to keep the house warm 00:04:42.657 --> 00:04:46.820 and it needed to run for 3 hours and 10 minutes total. 00:04:46.820 --> 00:04:51.644 That right there makes it obvious the furnace is much bigger than it needs to be, 00:04:51.644 --> 00:04:54.000 but this is Chicago. 00:04:54.000 --> 00:04:56.437 It gets a lot colder than just freezing. 00:04:56.437 --> 00:04:58.720 Like two Christmases ago. 00:04:58.720 --> 00:05:06.000 December 23rd 2022 started out at a balmy -8 degrees (which is -22 for those who speak Metric). 00:05:06.000 --> 00:05:08.525 Despite it being that frigid, though, 00:05:08.525 --> 00:05:12.250 the furnace only ran for 6 hours total. 00:05:12.250 --> 00:05:16.238 6 hours of 24 in the day is only 25% 00:05:16.238 --> 00:05:19.480 (or 1/4th for those of you that speak fractions). 00:05:19.480 --> 00:05:27.562 Running only a quarter of the time in weather like that suggests the furnace is in fact four times larger than it needs to be. 00:05:28.222 --> 00:05:30.435 Now, I wasn’t home that day. 00:05:30.435 --> 00:05:37.137 That’s good in that there weren’t any other sources of heat like cooking appliances or hot water usage to skew the data, 00:05:37.137 --> 00:05:42.940 but it’s bad in that the set point was only 62 degrees and not what I normally keep it at. 00:05:42.940 --> 00:05:46.732 Since it can get a bit colder than -8 degrees ‘round these parts 00:05:46.732 --> 00:05:50.369 and since normally I keep it a little warmer when I’m at home, 00:05:50.369 --> 00:05:55.780 I’ll go ahead and fudge that and say my furnace is 3 times oversized. 00:05:55.780 --> 00:05:59.500 Since my current system produces 60,000 BTU/hr, 00:05:59.500 --> 00:06:05.169 then apparently I only really need 20,000 BTU/hr of heating available. 00:06:05.169 --> 00:06:09.679 Which, in heat pump speak, is not even two tons. 00:06:09.679 --> 00:06:12.130 That’s pretty wild. 00:06:12.130 --> 00:06:17.840 If that’s true, then I actually need about the same heating output in the dead of winter 00:06:17.840 --> 00:06:21.428 as I need cooling output in the hottest parts of summer. 00:06:21.428 --> 00:06:25.740 Which, admittedly, feels kinda wrong. 00:06:25.740 --> 00:06:31.621 In the winter, I have to fight an 80 or 85 degree temperature differential in those arctic blasts 00:06:31.621 --> 00:06:39.288 but we rarely ever crack 100 degrees in the summer and most of the time we are only fighting a 15 or 20 degree differential. 00:06:39.288 --> 00:06:42.690 But, well, the data doesn’t lie. 00:06:42.690 --> 00:06:45.789 However, there are some reasons to be cautious. 00:06:45.789 --> 00:06:50.567 Firstly, while my furnace is rated for 60,000 BTU per hour, 00:06:50.567 --> 00:06:58.461 that’s actually it’s input rating - it only releases 92 percent of the heat energy in the gas it’s burning into my home 00:06:58.461 --> 00:07:00.400 (the rest is wasted in the exhaust), 00:07:00.400 --> 00:07:03.898 so in reality it’s output is slightly less. 00:07:03.898 --> 00:07:08.369 But that’s presuming it’s working correctly, which I don’t have a way to confirm. 00:07:08.369 --> 00:07:12.212 It could be outputting more heat than it’s designed to. 00:07:12.212 --> 00:07:19.543 There are also two other minor sources of data fuzziness which reduce the accuracy of a data-logging thermostat. 00:07:19.543 --> 00:07:24.082 The raw energy content of natural gas varies somewhat from day to day, 00:07:24.082 --> 00:07:31.720 so even if I knew for a fact that my furnace were operating perfectly, its actual heat output won’t be quite consistent. 00:07:32.116 --> 00:07:35.858 Also, the thermostat logs how long it calls for heat, 00:07:35.858 --> 00:07:41.443 but at every start-up, there’s actually a delay while the furnace goes through its ignition sequence 00:07:41.443 --> 00:07:45.569 so the thermostat is slightly overreporting total energy output. 00:07:45.569 --> 00:07:53.777 Now, to be clear, these little sources of error are little and unlikely to amount to much, plus two of them work in my favor anyway. 00:07:53.777 --> 00:07:59.426 But it does mean that my 20,000 BTU/hr conclusion probably isn’t perfect, 00:07:59.426 --> 00:08:03.629 especially because I fudged it a bit to account for not being home. 00:08:03.629 --> 00:08:08.169 I still know my furnace is wildly oversized no matter what, 00:08:08.169 --> 00:08:13.020 but I wanted to know exactly what sort of heat I needed in extreme weather. 00:08:13.522 --> 00:08:16.056 And I knew a trick to find out: 00:08:16.056 --> 00:08:17.965 Just get a bunch of space heaters. 00:08:18.229 --> 00:08:20.508 See, since heat is heat 00:08:20.508 --> 00:08:23.765 you can convert between units as much as you like. 00:08:23.765 --> 00:08:29.096 20,000 BTU/hr is equivalent to 5.86 kW. 00:08:29.096 --> 00:08:33.702 And an ordinary space heater like this can pump out 1.5 kW. 00:08:33.702 --> 00:08:37.577 So assuming my thermostat data and math are correct, 00:08:37.577 --> 00:08:42.490 simply running four space heaters on high (which would produce 6 kilowatts of heat) 00:08:42.490 --> 00:08:49.256 should actually provide more than enough heat to keep my home warm even in the most extreme weather we ever get. 00:08:49.256 --> 00:08:50.830 So… 00:08:50.830 --> 00:08:53.721 I thought, why not just wait for some extreme weather 00:08:53.721 --> 00:08:55.583 and then try that and see if it works? 00:08:55.583 --> 00:08:57.003 So I did! 00:08:57.003 --> 00:08:59.913 But - I used more than four heaters. 00:08:59.913 --> 00:09:02.576 And the setup was rather involved. 00:09:02.576 --> 00:09:04.181 And pretty risky. 00:09:04.181 --> 00:09:07.843 So first let me just say, don’t try this yourself. 00:09:07.843 --> 00:09:12.171 I took a number of big risks designing and performing this test. 00:09:12.171 --> 00:09:15.178 I could have ended up with frozen pipes if I wasn’t careful, 00:09:15.178 --> 00:09:22.808 and I put myself at risk of a fire using the space heaters, particularly because getting enough heat distributed in enough places 00:09:22.808 --> 00:09:27.298 required the use of extension cords, splitters, power strips, and even 00:09:27.298 --> 00:09:28.602 Christmas lights. 00:09:29.499 --> 00:09:30.616 Yeah. 00:09:30.616 --> 00:09:35.275 To save on time I’m not going into all the considerations I had to make for the test - 00:09:35.275 --> 00:09:38.926 you can check out the main channel video if you want more of those details. 00:09:38.926 --> 00:09:45.445 But the bottom line was I had about 6,500 watts of resistive heat distributed throughout my home. 00:09:45.445 --> 00:09:52.092 The heat sources were powered through digital temperature controllers so I could properly maintain a consistent temperature with them, 00:09:52.092 --> 00:10:00.120 and they were all metered through energy monitors so I could total up how much energy was actually used during the test. 00:10:00.120 --> 00:10:03.825 I set up each temperature controller to maintain the same temperature band 00:10:03.825 --> 00:10:08.275 that my furnace normally does in each room when set to 69 degrees, 00:10:08.275 --> 00:10:14.259 and with the setup finalized and in-place, all that was left to do now was reset the energy monitors, 00:10:14.259 --> 00:10:15.944 turn on all those heaters, 00:10:15.944 --> 00:10:17.973 and shut off the furnace. 00:10:17.973 --> 00:10:19.787 So that’s what I did. 00:10:19.787 --> 00:10:28.250 The test began at 8 AM on January 14th when the outside temperature was -11°F (or -24 Celsius). 00:10:28.250 --> 00:10:32.378 With the furnace disabled, the heaters would have to hold their own. 00:10:32.378 --> 00:10:36.687 Before long the temperature controllers had switched them all on but then - 00:10:36.687 --> 00:10:39.070 they all started going off. 00:10:39.070 --> 00:10:42.956 This meant that the heaters were sufficient to raise the indoor temperature 00:10:42.956 --> 00:10:46.700 despite it being 80 degrees colder outside than inside. 00:10:46.700 --> 00:10:52.089 So clearly, that 6.5kW of heat on tap was more than enough. 00:10:52.089 --> 00:10:58.665 And 24 hours later, the heaters had used a grand total of 110.76 kWh, 00:10:58.665 --> 00:11:06.530 representing an average power draw of only 4.61 kW or 15,729 BTU/hr. 00:11:08.166 --> 00:11:12.680 Now, the whole 24 hour span included some sources of noise. 00:11:12.680 --> 00:11:17.978 For one, it was a bright sunny day during the test so the sun was helping to heat my home a bit, 00:11:17.978 --> 00:11:23.029 and I did prepare food which added some heat not accounted for by the meters. 00:11:23.029 --> 00:11:27.489 However, I was taking readings from all of the meters every four hours, 00:11:27.489 --> 00:11:34.697 and between 8PM (long after I made dinner and the sun had set) and 8AM the next day (just after sunrise), 00:11:34.697 --> 00:11:38.504 the heaters used 61.38 kWh 00:11:38.504 --> 00:11:47.277 representing a continuous draw of 5.115 kW, or 17,452 BTU/hr. 00:11:47.277 --> 00:11:53.102 The outdoor temperature during that period was fluctuating between -9 and -11 degrees, 00:11:53.102 --> 00:11:57.582 which is just a teensy bit warmer than the coldest temps we typically experience. 00:11:58.215 --> 00:12:00.013 So - there we go. 00:12:00.013 --> 00:12:01.296 That’s the number. 00:12:01.296 --> 00:12:11.337 17,452 BTU/hr is the actual heating load of my home when it’s -10 outside and about 70 inside. 00:12:11.337 --> 00:12:15.698 Which means that sure enough, my furnace is triple oversized. 00:12:15.698 --> 00:12:18.039 Actually a bit more than that. 00:12:18.039 --> 00:12:21.788 For me and my home, this is excellent news! 00:12:21.788 --> 00:12:26.676 Because I’m in a townhome which was built assuming everything that could be gas would be gas, 00:12:26.676 --> 00:12:30.420 I only have 100A electrical service which is limiting. 00:12:30.420 --> 00:12:41.019 But even using resistive heat, as I did in the test, I only need just a hair over 5 kW to stay warm which is only a 20A electrical load. 00:12:41.019 --> 00:12:46.940 A heat pump will use even less power so long as it can operate with a coefficient of performance above 1, 00:12:46.940 --> 00:12:51.394 which these cold climate heat pumps can do well into negative temperatures. 00:12:51.394 --> 00:13:00.436 So when it comes time to replace my furnace, a 2-ton heat pump (which can normally produce 24,000 BTU/hr or 7 kW of heat) 00:13:00.436 --> 00:13:07.964 will be just fine and 5kW of backup heat strips will be more than enough to supplement the heat pump when required 00:13:07.964 --> 00:13:12.000 or even function as my only heat source in an emergency. 00:13:12.000 --> 00:13:15.352 But my experiment, although it was extremely valuable, 00:13:15.352 --> 00:13:17.733 was also absurd. 00:13:17.733 --> 00:13:23.993 It is not a thing anybody should do and the good news is - nobody has to! 00:13:23.993 --> 00:13:27.771 You might find this hard to believe, but those scientists? 00:13:27.771 --> 00:13:33.474 The've figured out the thermal properties of the materials we use to build our homes! 00:13:33.474 --> 00:13:37.975 Insulation has an R-value which tells you its resistance to heat transfer. 00:13:37.975 --> 00:13:47.130 Windows have R-values, too - plus low-e coatings on the glass help reduce solar heating in the summer and reduce radiant losses in the winter. 00:13:47.130 --> 00:13:50.282 The materials on the exterior of the home have an influence, too - 00:13:50.282 --> 00:13:53.138 and we know all this information. 00:13:53.138 --> 00:13:55.962 To tie it all together into something useful, 00:13:55.962 --> 00:14:03.460 there are these tools out there called measuring tapes which allow us to gauge the size of walls and windows. 00:14:03.460 --> 00:14:06.620 If you actually take the time to assess these variables, 00:14:06.620 --> 00:14:16.043 you can perform a load calculation which will tell you how much heating (and cooling) your home actually needs depending on how it was built. 00:14:16.043 --> 00:14:19.070 Now, I am not here to show you how to do one. 00:14:19.070 --> 00:14:25.385 It’s not that complicated - you’re essentially just finding the total area of your home’s exterior surfaces 00:14:25.385 --> 00:14:28.149 (taking note of window and door dimensions, too), 00:14:28.149 --> 00:14:32.399 then plugging that information along with their R-values into a spreadsheet 00:14:32.399 --> 00:14:35.549 (and don’t forget to count the ceiling and floors, too). 00:14:35.549 --> 00:14:38.250 But it is pretty tedious. 00:14:38.250 --> 00:14:42.245 Still, for grins and giggles, I did one for my home. 00:14:42.245 --> 00:14:45.121 I used on online Manual J calculator 00:14:45.121 --> 00:14:50.318 (manual-J is essentially the industry standard for how to do a block load calculation) 00:14:50.318 --> 00:14:54.378 and after inputting all my measurements, it told me that I would need… 00:14:54.378 --> 00:15:03.348 19,000 BTU/hr of heating with an outdoor temperature of -15 and an indoor setpoint of 70 degrees. 00:15:03.348 --> 00:15:07.119 That’s within spitting distance of what my experiment just showed, 00:15:07.119 --> 00:15:15.580 and since it was a little warmer during the test than -15, coming in a tad higher than my experiment makes perfect sense. 00:15:15.580 --> 00:15:20.470 So rest assured those calculations do, indeed, work. 00:15:20.470 --> 00:15:24.913 If someone had actually done that calculation (and believed its results) 00:15:24.913 --> 00:15:29.849 they would never have put a 60,000 BTU/hr furnace in my home. 00:15:29.849 --> 00:15:33.260 That's just way more than my home needs. 00:15:33.260 --> 00:15:36.606 But I can feel your trepidation coming through the screen - 00:15:36.606 --> 00:15:41.521 why would I conclude that having just enough heat would be… enough? 00:15:42.000 --> 00:15:45.990 Well, enough is by definition enough. 00:15:45.990 --> 00:15:49.321 When a heating system is properly sized to a given home, 00:15:49.321 --> 00:15:57.429 then when the weather outside gets frightful, the heating system will need to run nonstop, and that is actually normal. 00:15:57.429 --> 00:16:01.420 There’s a concept called design temperature which is important here. 00:16:01.420 --> 00:16:06.800 Where I live, -15 outside is about the coldest we ever experience. 00:16:06.800 --> 00:16:12.872 And 70 degrees inside is the warmest I’d ever need my primary heating system to keep the house. 00:16:12.872 --> 00:16:19.624 Those are my design temperatures: the absolute worst conditions a heating system should expect to fight, 00:16:19.624 --> 00:16:23.385 and they only show up once or twice a year - if that. 00:16:23.385 --> 00:16:30.571 There isn’t actually a need to have any more heat capacity available than what the design temperatures dictate - 00:16:30.571 --> 00:16:35.184 especially when, even if the weather happens to dip below the design temp, 00:16:35.184 --> 00:16:38.874 a wide variety of simple supplemental heat sources, 00:16:38.874 --> 00:16:41.388 such as all those space heaters I now own, 00:16:41.388 --> 00:16:43.690 are available to fill the gap. 00:16:43.690 --> 00:16:49.436 But actually sizing heating systems appropriately seemingly never happens. 00:16:49.436 --> 00:16:57.169 The HVAC industry is currently stuck in a habit where they build tremendous amounts of margin into a home’s heating system. 00:16:57.934 --> 00:17:01.721 To be fair to them, there are some good reasons to do that: 00:17:01.721 --> 00:17:06.301 when you only have a single source of heat, then when the weather hits design temps, 00:17:06.301 --> 00:17:15.935 a properly-sized heating system will take a long time to increase the temperature if, say, you’re like me and like to turn the heat down a bit at night. 00:17:15.935 --> 00:17:20.680 But the main reason they’re always going so overboard is that… 00:17:20.680 --> 00:17:22.284 that's easy. 00:17:22.284 --> 00:17:24.996 Particularly when you have gas at your disposal, 00:17:24.996 --> 00:17:31.857 you can just use simple rules of thumb such as a home’s footprint and number of floors to pick out a furnace - 00:17:31.857 --> 00:17:35.490 then choose the next size up, just in case. 00:17:35.490 --> 00:17:42.000 I can all but guarantee that’s how my home ended up with such an oversized heating system. 00:17:42.000 --> 00:17:45.234 But this habit needs to die. 00:17:45.234 --> 00:17:48.650 We’re not gonna be heating our homes with gas forever. 00:17:48.650 --> 00:17:51.684 Pick whatever reason you’d like, there are plenty! 00:17:51.684 --> 00:17:58.579 Heat pumps are in the news so much these days because they allow us to capture ambient heat energy from outside, 00:17:58.579 --> 00:18:01.831 concentrate it, and move it inside. 00:18:01.831 --> 00:18:03.902 That process is so efficient 00:18:03.902 --> 00:18:12.534 that we can end up with 3 or sometimes even 4 times as much energy inside our homes than we spend running the heat pump to collect it. 00:18:12.534 --> 00:18:19.838 That is why they are such a big deal - it’s a way we can get more heat with less energy expenditure, 00:18:19.838 --> 00:18:23.526 and doing more with less is always a good idea. 00:18:23.526 --> 00:18:32.060 For that reason alone, more and more people will be using heat pumps as their primary or possibly only source of heat. 00:18:32.060 --> 00:18:36.430 They just make way too much sense to not use. 00:18:36.430 --> 00:18:38.813 And when speccing a heat pump system, 00:18:38.813 --> 00:18:45.083 actually installing the correct equipment with the correct capacity is very important! 00:18:45.083 --> 00:18:46.853 More than it’s ever been. 00:18:47.144 --> 00:18:50.540 There are a whole bunch of reasons that this is the case. 00:18:50.540 --> 00:18:54.111 For one, heat pumps are electric sources of heating and cooling, 00:18:54.111 --> 00:18:58.750 so larger systems require more electrical capacity to run them. 00:18:58.750 --> 00:19:02.994 Therefore, concluding that you need a bigger heat pump than you actually do 00:19:02.994 --> 00:19:10.970 can come with a whole host of potential headaches including the need to upsize circuits or potentially even get a service upgrade. 00:19:10.970 --> 00:19:14.299 So you absolutely don’t want to go overboard. 00:19:14.669 --> 00:19:20.814 Plus, if you want a backup generator or even a whole home battery system which are getting more and more popular, 00:19:20.814 --> 00:19:26.661 bigger heat pumps will need bigger generators, batteries, transfer switches, and all that jazz. 00:19:26.661 --> 00:19:30.630 Having more than you need can be a legitimate problem. 00:19:30.630 --> 00:19:35.546 Plus, I keep running across folks who have been told by HVAC contractors 00:19:35.546 --> 00:19:40.541 that their home’s current ductwork isn’t big enough to have a heat pump. 00:19:40.541 --> 00:19:52.794 Maybe that’s true, but if that contractor hasn’t done a load calculation or any sort of sanity check on whether the home’s current heating system is actually appropriate, 00:19:52.794 --> 00:19:58.370 then the contractor simply doesn’t have enough information to be making that conclusion. 00:19:58.370 --> 00:20:05.167 Those ducts may be perfectly fine for the heat pump that’s actually appropriate for that home. 00:20:05.167 --> 00:20:10.399 Additionally, and this is something that everyone in the industry should know very well, 00:20:10.399 --> 00:20:15.456 oversizing a heat pump can lead to nasty moisture problems in the summer months: 00:20:15.456 --> 00:20:20.597 if you have too much cooling capacity, the heat pump might short-cycle 00:20:20.597 --> 00:20:25.045 and that means it won’t run long enough to actually dehumidify the air. 00:20:25.045 --> 00:20:30.266 What I personally think the industry needs to get more comfortable with - quickly - is that 00:20:30.266 --> 00:20:36.110 secondary heat sources will become much more common as we transition to heat pumps. 00:20:36.110 --> 00:20:43.179 And those are going to function as the margin that traditionally gets figured into gas-fired systems. 00:20:43.179 --> 00:20:47.910 I mentioned backup heat strips previously - those are just old-fashioned heating elements 00:20:47.910 --> 00:20:51.088 (not unlike the wire elements in these space heaters) 00:20:51.088 --> 00:20:55.027 that get tucked into the air handler to provide additional heat. 00:20:55.027 --> 00:20:58.919 They are often referred to as auxiliary heat or emergency heat. 00:20:58.919 --> 00:21:00.932 And both of those terms are apt: 00:21:00.932 --> 00:21:05.037 the heat strips provide an emergency backup in case the heat pump fails, 00:21:05.037 --> 00:21:12.492 but if the heat pump is working, they can work alongside it to boost the total system output when required. 00:21:12.492 --> 00:21:14.239 If configured correctly, 00:21:14.239 --> 00:21:19.441 then when the temperatures are approaching design conditions and the heat pump is only barely adequate, 00:21:19.441 --> 00:21:23.644 the thermostat can command the heat strips to work alongside the heat pump 00:21:23.644 --> 00:21:29.760 to perhaps double the system output and quickly raise the indoor temperature when requested. 00:21:29.760 --> 00:21:36.532 And even if the temperature dips below design conditions, meaning the heat pump is no longer sufficient on its own, 00:21:36.532 --> 00:21:39.860 modern cold-climate heat pumps don’t just stop pumping. 00:21:39.860 --> 00:21:43.356 They’ll keep on working well into the negative temperatures. 00:21:43.356 --> 00:21:50.749 They probably won't be putting out much heat, but it will be something - so the heat strips won’t be working alone. 00:21:50.749 --> 00:21:56.242 In other words, there is still a margin - it just looks a little different now. 00:21:56.242 --> 00:22:01.719 So to recap - first of all, heat pumps are not magic machines! 00:22:01.719 --> 00:22:05.462 Don't let anyone convince you they're revolutionary technology, 00:22:05.462 --> 00:22:14.283 they’re just reversible air conditioners and they should only cost marginally more than a conventional heating and cooling system to purchase and install, 00:22:14.283 --> 00:22:19.554 with the only major potential hiccup being provisions for backup heating if necessary. 00:22:19.554 --> 00:22:23.684 If you’re getting a $20,000 quote for a central heat pump, 00:22:23.684 --> 00:22:28.657 ask why on Earth it’s so high and what sort of equipment they’ll be installing. 00:22:28.657 --> 00:22:33.289 Then poke around on those wholesale sites to see if their bid makes any sense at all 00:22:33.289 --> 00:22:39.370 or if they’re just playing amateur economist and testing to see just how far they can push what the market will bear. 00:22:40.030 --> 00:22:46.185 For those of you that don't have central heating systems, ductless mini-splits are gonna be great options 00:22:46.185 --> 00:22:50.360 but they are going to be more expensive because they involve more work. 00:22:50.360 --> 00:22:54.558 Still, though, the equipment itself isn’t very expensive 00:22:54.558 --> 00:22:56.814 and the work isn’t really that involved 00:22:56.814 --> 00:23:00.040 (I’ve done it myself and I’m just some schmuck on the Internet) 00:23:00.040 --> 00:23:02.551 so… shop around. 00:23:02.551 --> 00:23:09.968 Second, nobody should ever be sizing replacement equipment based on what is currently installed. 00:23:10.179 --> 00:23:17.348 Depressingly often, what’s there now is oversized up the wazoo and blatantly inappropriate for that home - 00:23:17.348 --> 00:23:20.710 especially when a home is on its fourth or fifth system. 00:23:21.000 --> 00:23:26.049 Imagine how out of control it can get when each installer keeps jumping to the next size 00:23:26.049 --> 00:23:27.442 just in case. 00:23:27.442 --> 00:23:34.857 There are many, many ways to do a sanity check on that equipment but it rarely ever happens. 00:23:34.857 --> 00:23:38.672 Just this past Spring my parents got a cold climate heat pump 00:23:38.672 --> 00:23:46.549 and the sales rep who came out somehow figured they’d need a 5-ton heat pump based on, as far as I can tell, 00:23:46.549 --> 00:23:51.167 nothing but a guess and maybe the output of their old system. 00:23:51.537 --> 00:23:55.043 But had that rep looked at the data from Nest, 00:23:55.043 --> 00:24:00.123 he would have seen that their old system had never run for more than 12 hours in a day 00:24:00.123 --> 00:24:08.440 so it was about double oversized and a three-ton heat pump (the same size as their existing air conditioner) would be sufficient. 00:24:08.651 --> 00:24:14.010 Luckily I was there for this process, showed him that data, and he listened to me. 00:24:14.010 --> 00:24:17.735 And sure enough, their 3-ton heat pump is working just fine 00:24:17.735 --> 00:24:24.000 and the heat strips were only required once this winter, and for just a few hours at that. 00:24:24.000 --> 00:24:26.125 If you’ve got a smart thermostat, 00:24:26.125 --> 00:24:30.489 the historical data it provides can be tremendously useful. 00:24:30.489 --> 00:24:34.576 HVAC professionals really oughta be looking at that data (when it's available), 00:24:34.576 --> 00:24:39.311 And when it's not, they need to be doing proper load calculations! 00:24:39.311 --> 00:24:43.254 That needs to be wayyyy more common than it is right now, and somebody 00:24:43.254 --> 00:24:48.184 (perhaps even the Air Conditioning Contractors of America, the publishers of Manual J) 00:24:48.184 --> 00:24:53.521 should really build a guided tool to help professionals do this quickly. 00:24:53.627 --> 00:24:57.623 Bottom line, the tactics of yesterday are no longer appropriate. 00:24:57.623 --> 00:25:01.940 Everything is changing so habits need to, as well. 00:25:01.940 --> 00:25:08.262 Frankly, if you are in the HVAC business, you could really differentiate yourself from your competitors by 00:25:08.262 --> 00:25:16.490 1) actually investigating the performance of the equipment that’s already there to see if it’s correct, perhaps by looking at thermostat data if available, 00:25:16.490 --> 00:25:22.420 2) performing even just basic load calculations to check that you’re somewhere in the ballpark, 00:25:22.420 --> 00:25:26.551 3) educating your customers on how heat pump systems work 00:25:26.551 --> 00:25:31.236 and how the heat strips help to fill in any gaps and, most importantly, 00:25:31.236 --> 00:25:37.468 4) charging honest prices for heat pumps which will, get this, 00:25:37.468 --> 00:25:40.442 cause you to win all the bids! 00:25:40.442 --> 00:25:45.990 Honestly this industry is ripe for disruption, and it doesn’t need to come from outside. 00:25:45.990 --> 00:25:49.088 One of you just needs to wake up and smell the roses. 00:25:49.088 --> 00:25:51.817 Change is scary, and difficult! 00:25:51.817 --> 00:25:56.360 But one of the great things about heat pumps (and electric technologies in general) 00:25:56.360 --> 00:25:59.352 is that they are incredibly flexible. 00:25:59.352 --> 00:26:02.913 It’s not just fire in a box with air blowing through it, 00:26:02.913 --> 00:26:08.598 it’s a modular toolkit which can be configured in many ways and tailored to any home. 00:26:08.598 --> 00:26:11.577 And they’re only gonna get better and better as time goes on! 00:26:11.577 --> 00:26:18.000 Already they are appropriate in climates like mine which was unheard of not that many years ago. 00:26:18.000 --> 00:26:21.064 So why not learn some new tricks? 00:26:21.064 --> 00:26:23.155 Isn’t that what makes life fun? 00:26:24.238 --> 00:26:27.985 Thanks for watching, and more pumping more now!