1 00:00:00,080 --> 00:00:06,056 When you live in a cold place like I do, these  whole home humidifiers are great. 2 00:00:06,056 --> 00:00:11,080 Which is why it's such a shame that they're also so terrible. 3 00:00:11,080 --> 00:00:12,874 What do I mean by that? 4 00:00:12,874 --> 00:00:17,006 Well, if you've got one of these or you are looking into getting one, 5 00:00:17,006 --> 00:00:22,052 you should be aware that they need much more attention from you than you might expect. 6 00:00:22,052 --> 00:00:29,385 Not only can these rather easily fail in such a way that can cause catastrophic damage to your home's heating system, 7 00:00:29,385 --> 00:00:36,159 but they can also cause significant damage to your home itself if you simply let them run unattended. 8 00:00:36,159 --> 00:00:38,376 See, the thing that makes them great - 9 00:00:38,376 --> 00:00:43,994 the ability to add lots of moisture to the air very quickly without you having to do anything 10 00:00:43,994 --> 00:00:49,199 - also makes them a problem when the temperature outside gets very cold. 11 00:00:49,199 --> 00:00:56,264 But today, I am going to fix that problem by giving it just a little more smarts than it had before. 12 00:00:56,264 --> 00:00:58,487 First though, a little backstory. 13 00:00:58,487 --> 00:01:02,805 In 2021, I made a video on freestanding humidifiers, 14 00:01:02,805 --> 00:01:08,754 and the comments were filled with folks wondering why I didn't talk about centrally ducted humidifiers like this one 15 00:01:08,754 --> 00:01:11,119 beyond a basic mention. 16 00:01:11,119 --> 00:01:16,604 Well, partly that's because back then I was living in a different home and I didn't have one of these. 17 00:01:16,604 --> 00:01:21,061 But the bigger reason was that if you want to add a humidifier, 18 00:01:21,061 --> 00:01:27,992 it's a lot easier and cheaper to buy one that you just plop somewhere and fill with water. 19 00:01:27,992 --> 00:01:32,744 Many of them are large enough to work just fine as a whole-home humidifier. 20 00:01:32,744 --> 00:01:37,004 Plus, freestanding units don't care what kind of heating system you have. 21 00:01:37,004 --> 00:01:41,884 So, if your home is heated with radiators  or some other kind of ductless heating system, 22 00:01:41,884 --> 00:01:43,574 like certain kinds of heat pump, 23 00:01:43,574 --> 00:01:45,530 those will work fine. 24 00:01:45,530 --> 00:01:51,092 The humidifier I'm talking about today requires both a centrally ducted heating system 25 00:01:51,092 --> 00:01:54,125 and a plumbed connection to a water line. 26 00:01:54,125 --> 00:01:57,850 So, it's not universal and it's much more involved. 27 00:01:57,850 --> 00:02:04,800 And as I already said, these things come with significant risks that you really need to be aware of and monitoring. 28 00:02:04,800 --> 00:02:10,055 I'll explain those shortly, but let's start with a quick overview of what this thing is. 29 00:02:10,055 --> 00:02:14,729 There are several types of these things on the market, but most of them are similar to this one. 30 00:02:14,729 --> 00:02:21,230 Inside is simply a fan which blows air through this wet pad made of absorbent material. 31 00:02:21,230 --> 00:02:26,670 The whole thing is mounted to a giant hole cut into my HVAC system's duct work. 32 00:02:26,670 --> 00:02:32,225 And when it's running, the fan draws in some of the air coming up from the furnace through the sides here 33 00:02:32,225 --> 00:02:37,883 and then forces it through that wet pad where it will absorb moisture before rejoining the airstream 34 00:02:37,883 --> 00:02:40,150 and getting distributed throughout my home. 35 00:02:40,150 --> 00:02:42,249 It's quite a simple device. 36 00:02:42,249 --> 00:02:44,365 Where's the water coming from? 37 00:02:44,365 --> 00:02:46,272 It's coming from right here. 38 00:02:46,272 --> 00:02:53,052 When the humidifier is running, this solenoid valve opens and a small but steady stream of water is fed through this line 39 00:02:53,052 --> 00:02:58,171 and up to this nozzle where it's then distributed  through these drip holes and onto the pad. 40 00:02:58,171 --> 00:03:00,443 That makes the pad soaking wet. 41 00:03:00,443 --> 00:03:05,197 And in fact, once it's saturated, you'll see a trickle of water coming out the bottom. 42 00:03:05,197 --> 00:03:10,520 The valve is deliberately letting more water through than the air going through the pad can absorb. 43 00:03:10,520 --> 00:03:14,322 So, you invariably end up with some wasted water. 44 00:03:14,322 --> 00:03:17,331 I couldn't tell you exactly how much water is being lost here, 45 00:03:17,331 --> 00:03:23,215 but I can tell you I have never noticed an increase in my water bill between heating and cooling seasons. 46 00:03:23,215 --> 00:03:25,048 So, it's not that much. 47 00:03:25,048 --> 00:03:30,514 But if you're concerned about that, there are water-saving models available which don't work like this one does. 48 00:03:30,514 --> 00:03:34,119 But, they have other considerations which I'm not going to be getting into today. 49 00:03:34,119 --> 00:03:41,261 Since the pad is essentially always soaking wet, it gets pretty gross and needs regular replacement. 50 00:03:41,261 --> 00:03:47,430 How often you'll need to do that depends largely on your water hardness and how large your home is. 51 00:03:47,430 --> 00:03:50,843 I have a fairly small home, so this thing doesn't run that much 52 00:03:50,843 --> 00:03:55,094 and I can usually get away with changing it at the start of each heating season. 53 00:03:55,094 --> 00:04:00,548 But even still, this is what last year's pad looks like. 54 00:04:00,548 --> 00:04:06,583 It used to be white and now it's pink and crunchy because of all the calcium it's filled with. 55 00:04:06,583 --> 00:04:08,691 Delicious! 56 00:04:08,691 --> 00:04:12,414 But it can be much worse than simply getting a little gross. 57 00:04:12,414 --> 00:04:16,459 Remember that thing I said about these needing much more attention than you might expect? 58 00:04:16,459 --> 00:04:21,241 Well, one day I heard the water valve open, but I didn't hear the fan start up. 59 00:04:21,241 --> 00:04:30,068 And that was because the pad had started to deteriorate and part of it fell forward and into the fan blades, holding them stationary. 60 00:04:30,068 --> 00:04:36,874 I'm honestly quite lucky that it didn't cause any damage to my furnace because the water valve was still open and getting it wet. 61 00:04:36,874 --> 00:04:43,544 So, the pad's detached section leaning at a wonky angle could easily have started dripping water down into the furnace. 62 00:04:43,544 --> 00:04:50,789 And when I was a little kid, my mom and dad had that exact thing happen which fried the furnace's control board. 63 00:04:50,789 --> 00:04:53,460 So, yeah, these are not set and forget - 64 00:04:53,460 --> 00:04:58,804 you really need to be cognizant of their operation and  needs and should be checking on it regularly. 65 00:04:59,520 --> 00:05:04,221 But anyway, you'll notice that the water line  is being fed by my water heater. 66 00:05:04,221 --> 00:05:09,972 This style of humidifier generally works better when the water  which is saturating the pad is hot. 67 00:05:09,972 --> 00:05:16,329 In fact, the manufacturer claims it needs hot water  if you're going to use this humidifier... 68 00:05:16,329 --> 00:05:19,007 Well, hold on. That part comes later. 69 00:05:19,007 --> 00:05:26,168 Now, since this is just a fan that grabs some air from the duct, gets it moist, and then puts it back into the duct, 70 00:05:26,168 --> 00:05:31,389 it relies on the furnace pushing air through the duct work in order to distribute its work 71 00:05:31,389 --> 00:05:34,769 and actually increase the humidity in my home. 72 00:05:34,769 --> 00:05:41,196 And that means if it were for some reason  running when the furnace's blower wasn't, 73 00:05:41,196 --> 00:05:44,238 well, it would pretty quickly cause a problem. 74 00:05:44,238 --> 00:05:52,012 The air in that duct work would get extremely humid and water would start condensing onto things which ought not get wet. 75 00:05:52,012 --> 00:05:54,430 Luckily, there's an easy solution to that: 76 00:05:54,430 --> 00:06:00,277 only power this thing up if the furnace is running and blowing air through the ducts. 77 00:06:00,277 --> 00:06:03,535 That water valve is powered by 24 volts AC, 78 00:06:03,535 --> 00:06:10,602 the same power that your furnace or air handler produces to send through your thermostat wiring for control signaling. 79 00:06:10,602 --> 00:06:15,528 The humidifier is also plugged into 120 volt line voltage for its fan motor, 80 00:06:15,528 --> 00:06:21,988 but the fan is controlled via a current sensing relay which detects that the water valve is open. 81 00:06:21,988 --> 00:06:25,911 So if the water valve is open, the fan will run. 82 00:06:25,911 --> 00:06:34,294 This ultimately means if you wire that water valve across the common wire and the heat signal wire coming from the thermostat, 83 00:06:34,294 --> 00:06:40,499 then the humidifier will only be able to operate when your thermostat is calling for heat. 84 00:06:40,499 --> 00:06:45,123 This setup not only ensures the blower will be running when the humidifier is on, 85 00:06:45,123 --> 00:06:49,254 but it also means the humidifier  won't run during a cooling call. 86 00:06:49,254 --> 00:06:53,721 So, if you forget to switch it off at the end of the heating season, it's no big deal. 87 00:06:53,721 --> 00:06:57,687 But the humidifier can't simply run whenever the heat's on. 88 00:06:57,687 --> 00:07:04,607 That would likely result in over-humidification, which could be uncomfortable or even cause mold issues. 89 00:07:04,607 --> 00:07:11,738 So rather than hook the water valve to the furnace directly, its power wire goes through this humidistat. 90 00:07:11,738 --> 00:07:13,505 This is a fully analog doodad 91 00:07:13,505 --> 00:07:20,547 which sits in the return air stream and closes a switch when the humidity is lower than your desired set point. 92 00:07:20,547 --> 00:07:27,167 So long as that switch is closed and the thermostat is calling for heat, then the humidifier will run. 93 00:07:27,167 --> 00:07:32,273 But once the humidifier has elevated humidity  to your set point, that switch will open 94 00:07:32,273 --> 00:07:36,672 and the humidifier will shut off even if the heat is still running. 95 00:07:36,672 --> 00:07:39,872 It's a very simple control setup, but it works great! 96 00:07:39,872 --> 00:07:42,188 Except for when it doesn't. 97 00:07:42,188 --> 00:07:50,110 First of all, you may remember from a previous video of mine that my home's furnace is oversized by nearly a factor of four. 98 00:07:50,110 --> 00:07:54,888 This means on most days, it only runs for two, maybe 3 hours. 99 00:07:54,888 --> 00:07:59,729 And that's not enough time for the humidifier to actually be effective. 100 00:07:59,729 --> 00:08:04,580 That's a problem specific to my home, but it was very annoying. 101 00:08:04,580 --> 00:08:12,344 I couldn't get the indoor humidity to even touch 40% when I wanted it closer to 45 or even 50. 102 00:08:12,344 --> 00:08:15,359 However, there was a fix for this issue. 103 00:08:15,359 --> 00:08:22,704 Instead of hooking the humidifier's water valve  to the heat signal wire, I changed it to the fan signal wire. 104 00:08:22,704 --> 00:08:27,976 This meant the humidifier was able  to run so long as my thermostat was calling for the blower fan. 105 00:08:27,976 --> 00:08:34,560 And by setting a fan schedule on my thermostat, which ensured the fan ran for 15 minutes every hour, 106 00:08:34,560 --> 00:08:37,937 my humidifier was actually able to do its job. 107 00:08:37,937 --> 00:08:43,184 And for the last couple of years, I've been enjoying delightfully moist air in the winter, 108 00:08:43,184 --> 00:08:46,453 nice and comfy and free of static shocks. 109 00:08:46,453 --> 00:08:51,974 This scenario is why the manufacturer  wants this thing hooked to hot water. 110 00:08:51,974 --> 00:08:59,581 If it's running during a heating call, the air the humidifier is taking from the furnace and blowing past the pad will be hot, 111 00:08:59,581 --> 00:09:02,081 which will help water to evaporate. 112 00:09:02,081 --> 00:09:09,141 But if it's running during a fan call, that air is only at room temperature and the water won't evaporate as quickly. 113 00:09:10,390 --> 00:09:15,201 Honestly though, I have a hunch it would actually work fine if it  were hooked up to cold water, 114 00:09:15,201 --> 00:09:22,864 and the real reason they want it hooked to hot water is to minimize the cooling which would occur as water evaporates. 115 00:09:22,864 --> 00:09:28,981 This thing is basically a swamp cooler and it will  drop the temperature of the air leaving the vents if it's running. 116 00:09:28,981 --> 00:09:35,782 But if the pad is soaked in hot water, that cooling effect is diminished somewhat and possibly even eliminated. 117 00:09:35,782 --> 00:09:37,584 But anyway, that's not important. 118 00:09:37,584 --> 00:09:42,001 What is important is this little note you may have spotted on the humidistat. 119 00:09:42,001 --> 00:09:47,873 This thing wants you to turn the humidity set point down as the outdoor temperature falls. 120 00:09:47,873 --> 00:09:54,722 This is because the colder it is outside, the colder the inside surface of your walls and windows becomes 121 00:09:54,722 --> 00:09:57,731 and that will encourage condensation. 122 00:09:57,731 --> 00:10:02,433 This could simply be an inconvenience - maybe you'll have some water puddling on window sills. 123 00:10:02,433 --> 00:10:07,042 But it could also lead to mold growth inside your exterior walls. 124 00:10:07,327 --> 00:10:11,091 And you don't want that, which is why it has this helpful little note. 125 00:10:11,091 --> 00:10:14,676 There's just one small problem with notes like this, though. 126 00:10:14,676 --> 00:10:20,146 You're lucky if people read them, and you're even luckier if people remember about them. 127 00:10:20,146 --> 00:10:23,819 I'm a people and I have forgotten about this several times. 128 00:10:23,819 --> 00:10:29,900 Usually what happens is the temperature plummets overnight and when I get up, the windows are soaking wet. 129 00:10:29,900 --> 00:10:32,806 So then I go downstairs to the furnace closet - 130 00:10:32,806 --> 00:10:35,000 quick reminder for you homebuilders out there, 131 00:10:35,000 --> 00:10:36,946 this can all just go in a closet! 132 00:10:36,946 --> 00:10:39,893 It never has to go in an attic. 133 00:10:39,893 --> 00:10:42,836 If you're doing that, you suck at planning! 134 00:10:42,836 --> 00:10:48,477 And I promise everybody out there, the 20 square feet or so taken up by this stuff in the floor plan 135 00:10:48,477 --> 00:10:52,733 is absolutely worth being able to get at it without a ladder. 136 00:10:52,733 --> 00:10:53,892 Priorities, man. 137 00:10:53,892 --> 00:10:55,107 Get some! 138 00:10:55,856 --> 00:11:00,941 As I was saying, I go downstairs to the furnace closet, turn this down, and then when the cold snap is over, 139 00:11:00,941 --> 00:11:03,958 I'll wonder why it's not as comfortable as I'd like it to be before remembering, 140 00:11:03,958 --> 00:11:07,793 "Oh right, I turned the humidistat down" and then I turn it back up. 141 00:11:07,793 --> 00:11:14,370 Given all that hassle, it sure would be nice if there were humidistats out there that were aware of the outdoor temperature 142 00:11:14,370 --> 00:11:20,332 and could automatically adjust the indoor humidity set point down during those cold snaps. 143 00:11:20,332 --> 00:11:22,648 Oh, wait. Those exist! 144 00:11:22,648 --> 00:11:29,453 But, well gosh darn it, they're going to need a wire run to an outdoor temperature sensor. 145 00:11:29,453 --> 00:11:33,772 And this furnace closet is pretty much in the dead center of my home. 146 00:11:33,772 --> 00:11:35,786 So, that's gonna be annoying. 147 00:11:35,786 --> 00:11:42,310 The easiest thing to do would be to run a wire across the garage and maybe slip it past the garage door seal, 148 00:11:42,310 --> 00:11:50,863 but I didn't like that idea, and I really didn't like the idea of drilling holes in walls or having random wires going all over the place. 149 00:11:50,863 --> 00:11:53,367 I've lived in my home for over three years now 150 00:11:53,367 --> 00:11:59,200 and have been lamenting the difficulty of installing an outdoor temp sensor for a better humidistat the whole time. 151 00:11:59,200 --> 00:12:05,120 And then about two weeks ago, I finally remembered about that  pipe that brings in outside air for the furnace. 152 00:12:05,680 --> 00:12:09,485 Yeah, this pipe here, it goes all the way outside. 153 00:12:09,485 --> 00:12:15,822 The point of this is to allow the furnace to have combustion air without creating negative pressure in the building. 154 00:12:15,822 --> 00:12:21,717 When this panel is closed up, the combustion section of this furnace is effectively outdoors. 155 00:12:21,717 --> 00:12:27,000 It draws in fresh air through here, which brings in enough oxygen to set some methane on fire 156 00:12:27,000 --> 00:12:31,043 and then pushes the exhaust gases out this other pipe. 157 00:12:31,043 --> 00:12:36,945 And uh well, I could have just run  the outdoor sensor wire through this pipe the whole time. 158 00:12:37,980 --> 00:12:40,319 Yeah, better late than never! 159 00:12:40,319 --> 00:12:46,927 Now, quick note, some of the fancier thermostats out there are able to control a humidifier directly. 160 00:12:46,927 --> 00:12:51,626 I don't have one of those - I just have a basic Nest which irritates me for several reasons, 161 00:12:51,626 --> 00:12:55,036 but mostly works and I somewhat begrudgingly put up with. 162 00:12:55,036 --> 00:13:01,834 Luckily, the people who built my home were kind enough to not cheap out and actually ran seven conductor thermostat wire 163 00:13:01,834 --> 00:13:04,559 between my furnace and the thermostat. 164 00:13:04,559 --> 00:13:09,734 And this means I could upgrade to a fancier Nest or some other smart thermostat 165 00:13:09,734 --> 00:13:15,660 which knows the outside temperature through the internet and then allowed it to control the humidifier. 166 00:13:15,660 --> 00:13:20,303 But quite frankly, I am trusting internet-based solutions less and less these days. 167 00:13:20,303 --> 00:13:22,715 So, I decided not to go that route. 168 00:13:22,715 --> 00:13:26,384 Instead, I searched for a new dedicated humidistat. 169 00:13:26,384 --> 00:13:31,829 And then I discovered, wow, this is a much rarer product than I imagined. 170 00:13:31,829 --> 00:13:33,879 I mean, in hindsight, I kind of get it. 171 00:13:33,879 --> 00:13:37,110 When you buy a humidifier, it's going to come with one of these. 172 00:13:37,110 --> 00:13:42,409 But my humidifier apparently came with this dumb one, and I want a smarter one. 173 00:13:42,409 --> 00:13:49,022 And since apparently nobody but specialty supply houses stocks these things, off to Amazon I went. 174 00:13:49,022 --> 00:13:52,821 I found this Honeywell model as well as this Aprilaire model 175 00:13:52,821 --> 00:13:56,346 and this suspicious clone of the Aprilaire model. 176 00:13:56,346 --> 00:14:02,519 Since I have an Aprilaire 700 series and this claims to be compatible with that humidifier, 177 00:14:02,519 --> 00:14:06,183 I figured I'll just get the Aprilaire 60 humidity control. 178 00:14:06,183 --> 00:14:07,677 So I did. 179 00:14:07,677 --> 00:14:15,165 Annoyingly, the product listing gave no information on how long the outdoor air temperature sensor wire was. 180 00:14:15,165 --> 00:14:22,434 I'd need about 30 feet of wire and I figured it would be reasonable for them to include perhaps 50 feet of wire. 181 00:14:22,434 --> 00:14:25,595 But nope, it was about 2 feet long. 182 00:14:25,595 --> 00:14:29,065 No big deal. I have a soldering iron and I know how to use it. 183 00:14:29,065 --> 00:14:32,508 So, the first step was to run a wire through that pipe. 184 00:14:32,508 --> 00:14:39,089 I made a stop at everybody's favorite suspiciously cheap tool store and got myself a suspiciously cheap 50-ft fishtape. 185 00:14:39,089 --> 00:14:42,567 I'm sorry, no, it's a 50 Fish T ape. 186 00:14:43,459 --> 00:14:47,989 I tried to run the fishtape directly  through where the pipe ends inside the furnace, 187 00:14:47,989 --> 00:14:53,295 but I wasn't too hopeful that that would work as there's a lot of bendy bendy in those pipes. 188 00:14:53,295 --> 00:14:55,758 And indeed, it didn't work. 189 00:14:55,758 --> 00:15:00,058 No big deal. I figured I'd just drill a hole in this last 90 here, 190 00:15:00,058 --> 00:15:05,360 which was probably the start of a straight shot  all the way to where the pipe comes out the wall. 191 00:15:05,920 --> 00:15:11,958 After double and triple-checking that I was about  to drill through the intake pipe and not the exhaust pipe, 192 00:15:11,958 --> 00:15:13,247 I made my hole. 193 00:15:13,247 --> 00:15:19,727 And the fishtape went in nice and smooth for a good long while, but then it hit something. 194 00:15:19,727 --> 00:15:23,866 I tried and tried and wiggled and wiggled, but it was just not going to budge. 195 00:15:23,866 --> 00:15:25,816 That was annoying. 196 00:15:25,816 --> 00:15:29,179 But then I remembered  a trick I saw on the internet somewhere. 197 00:15:29,179 --> 00:15:34,835 I took some lightweight twine and tied it to the end of a shopping bag, and then I stuffed it into the pipe. 198 00:15:34,835 --> 00:15:40,879 Then I went outside with my vacuum cleaner,  which had an attachment that fit nearly perfectly into that pipe 199 00:15:40,879 --> 00:15:42,916 and gave it a toot. 200 00:15:42,916 --> 00:15:48,544 I am terribly sorry that I left my mic kit plugged into the camera because there's no sound for this clip, \ 201 00:15:48,544 --> 00:15:51,296 but I'll dub it with what I imagine it sounded like. 202 00:15:51,296 --> 00:15:53,095 [fwbbslrpptty-yoop] 203 00:15:54,000 --> 00:15:58,246 I honestly could not believe how well that worked, but I was sure glad it did. 204 00:15:58,246 --> 00:16:00,767 Too bad I already drilled that hole, I guess. 205 00:16:00,767 --> 00:16:07,860 With the bag and the twine now at the other end of the pipe, I pulled it out and tied a wire to the end of the twine. 206 00:16:07,860 --> 00:16:14,587 I wasn't planning to use speaker wire for this, but since  this pipe is apparently twistier than I realized, 207 00:16:14,587 --> 00:16:17,895 I wanted something relatively thick and strong. 208 00:16:17,895 --> 00:16:21,498 Then I went back inside and started pulling on the twine. 209 00:16:21,498 --> 00:16:24,375 It was going so well, but then... 210 00:16:25,374 --> 00:16:26,132 But! 211 00:16:26,132 --> 00:16:27,648 A Christmas miracle! 212 00:16:27,648 --> 00:16:32,370 It made it past that hole I drilled, and with some picks, I was able to get it out. 213 00:16:32,370 --> 00:16:34,857 Good thing I already drilled that hole, I guess. 214 00:16:34,857 --> 00:16:37,933 I pulled out about 10 ft of wire from that hole, 215 00:16:37,933 --> 00:16:43,926 and then I went outside, cut it to length, and soldered the sensor wire to the new end I just made. 216 00:16:43,926 --> 00:16:51,385 Then I went back inside and pulled the wire back until the sensor was dangling down at the very end of the intake pipe. 217 00:16:51,385 --> 00:16:53,988 And that's where I decided to leave it. 218 00:16:53,988 --> 00:17:00,773 Then I taped the wire in place and made a big ol' booger of silicone to seal up that hole in the pipe. 219 00:17:00,773 --> 00:17:03,988 Now, some of you,  including the writers of the instruction manual, 220 00:17:03,988 --> 00:17:11,966 might be concerned about how close the intake pipe is to the exhaust pipe, but I am confident that this location is fine. 221 00:17:11,966 --> 00:17:18,480 For one, when the furnace is running, it will be drawing fresh air up and through the tube past the sensor, 222 00:17:18,480 --> 00:17:20,725 so the heat from the exhaust shouldn't matter. 223 00:17:21,440 --> 00:17:26,481 My water heater exhaust is also in this area,  which could potentially affect it. 224 00:17:26,481 --> 00:17:33,780 But unless I'm actually using hot water, the water heater only comes on for about 5 minutes every few hours or so. 225 00:17:33,780 --> 00:17:36,733 And one day, I want to get a heat pump water heater. 226 00:17:36,733 --> 00:17:43,437 I could have, of course, actually pulled the wire out of the bottom of that pipe and mounted the sensor somewhere if I were concerned, 227 00:17:43,437 --> 00:17:45,335 but I wasn't, so I didn't. 228 00:17:45,335 --> 00:17:50,795 All right, with the outdoor temp sensor in place, it was time to install the new humidistat. 229 00:17:50,795 --> 00:17:56,026 It needs a 3/4 inch hole in the return duct to get a measurement of relative humidity. 230 00:17:56,026 --> 00:18:00,506 And I was hopeful the existing  humidistat would have a similar hole underneath, 231 00:18:00,506 --> 00:18:08,049 but no, that one needed a big old hole cut in  the sheet metal, which now presented me with a problem. 232 00:18:08,049 --> 00:18:13,594 I elected to seal that hole with some  duct tape and mount the new humidistat lower down. 233 00:18:13,594 --> 00:18:20,527 I didn't have a 3/4 inch drill bit, so I simply abused my 1/2 inch drill bit and made this beautiful hole. 234 00:18:20,527 --> 00:18:26,641 But with it mounted here, it will now be able to know the humidity of the air which is entering my furnace. 235 00:18:26,641 --> 00:18:30,598 This is something that I don't quite love about this humidistat. 236 00:18:30,598 --> 00:18:32,907 For my home, it's perfect. 237 00:18:32,907 --> 00:18:36,669 I don't actually have any return ducting at all. 238 00:18:36,669 --> 00:18:43,388 The enclosed bedrooms upstairs have vents installed above the doors which pass air into the hallway. 239 00:18:43,388 --> 00:18:49,251 And the hallway leads to a switchback staircase which goes all the way down to the lower level where the furnace is. 240 00:18:49,251 --> 00:18:55,923 And since the main level is basically one big  room, the staircase itself is the return air path 241 00:18:55,923 --> 00:19:01,116 and all the furnace needs is one giant intake vent at the bottom of the stairs. 242 00:19:01,116 --> 00:19:05,661 That's what's on the other side of the duct I've just attached the control to. 243 00:19:05,661 --> 00:19:12,928 My home's setup means that whenever the furnace blower is running, the humidistat is going to get a pretty accurate reading. 244 00:19:12,928 --> 00:19:19,868 But I can think of plenty of cases where it would be better  for the humidity sensor to be somewhere else. 245 00:19:19,868 --> 00:19:26,956 In those cases, you might be better off getting a  fancier thermostat, which can control a humidifier remotely. 246 00:19:26,956 --> 00:19:31,708 But if your home's HVAC system was  designed reasonably well like mine was, 247 00:19:31,708 --> 00:19:37,232 taking a reading of the air entering the furnace or air handler should work fine. 248 00:19:37,232 --> 00:19:41,029 And with it now mounted, all that was left was the wiring. 249 00:19:41,029 --> 00:19:44,318 Here, things are drastically different than before. 250 00:19:44,318 --> 00:19:49,055 This humidistat has the capability to force the furnace fan to run. 251 00:19:49,055 --> 00:19:55,467 If it hasn't gotten a heating call in an hour, it will kick on the blower so it can stir the air up for a while, 252 00:19:55,467 --> 00:20:02,125 get an accurate humidity reading, and then if it's too low, it will switch the humidifier on and keep the blower running 253 00:20:02,125 --> 00:20:05,287 regardless of what the thermostat's commanding. 254 00:20:05,287 --> 00:20:10,891 This is a pretty neat feature, and it means I can remove the fan schedule from my thermostat. 255 00:20:10,891 --> 00:20:15,019 But it also means this now needs a way to control the furnace. 256 00:20:15,019 --> 00:20:20,179 But in addition to that, it also wants to  know if the thermostat is calling for heat. 257 00:20:20,179 --> 00:20:23,745 So it needs some pretty significant wiring changes. 258 00:20:23,745 --> 00:20:30,157 In fact, it wants to be connected to R and C, giving it a 24 volt power source from the furnace, 259 00:20:30,157 --> 00:20:33,437 W so it can see a heating call in progress, 260 00:20:33,437 --> 00:20:38,640 and it wants me to disconnect the thermostat wire  from the G terminal on the furnace 261 00:20:38,640 --> 00:20:42,494 and instead connect it to the G terminal on the humidistat. 262 00:20:42,494 --> 00:20:50,364 Then I need to run a new G wire called Gf back from the humidistat and land it on the G terminal in the furnace. 263 00:20:50,364 --> 00:20:54,234 This setup is what allows the humidistat to force the furnace blower on, 264 00:20:54,234 --> 00:20:58,906 but it will still pass a fan call from the thermostat through as normal. 265 00:20:58,906 --> 00:21:05,197 And finally, of course, I need to connect the humidifier's control wires to the two H terminals on the board 266 00:21:05,197 --> 00:21:07,663 and the outdoor temperature sensor. 267 00:21:07,663 --> 00:21:12,558 With that done, all that was needed was to turn the furnace back on and test it out. 268 00:21:12,558 --> 00:21:13,855 Hope I didn't blow anything up. 269 00:21:16,567 --> 00:21:21,445 [blower noise in background] I think the outdoor temperature is high enough for it to run 270 00:21:21,445 --> 00:21:24,336 if I turn it to six, but we'll see. 271 00:21:24,836 --> 00:21:25,896 [click] 272 00:21:26,860 --> 00:21:30,939 Uhhh, so the board woke up and the relay definitely clicked 273 00:21:30,939 --> 00:21:35,728 and it's telling me the humidifier is running, but the humidifier is not actually running. 274 00:21:36,656 --> 00:21:38,282 Well... 275 00:21:38,282 --> 00:21:43,289 All right, with the help of a multimeter and some troubleshooting, I have figured out what's going on here. 276 00:21:43,289 --> 00:21:45,709 And now I'm mad! 277 00:21:45,709 --> 00:21:53,567 So, this thing comes with instructions for hooking it up to an Aprilaire 700 series humidifier, which is what I have. 278 00:21:53,567 --> 00:21:57,936 And it has a footnote about if your humidifier was made before 2007 279 00:21:57,936 --> 00:22:01,830 (apparently they've been making them like these forever) there's some difference in the wiring. 280 00:22:01,830 --> 00:22:05,423 Well, this humidifier is definitely newer than that, but it's not working. 281 00:22:05,423 --> 00:22:10,713 Well, it turns out I don't have a 700. I have a 700M. 282 00:22:10,713 --> 00:22:13,554 And you would think, right, the M stands for manual - 283 00:22:13,554 --> 00:22:20,900 the only difference between those models is you get the  manual control, the one that I just replaced, or this digital control. 284 00:22:20,900 --> 00:22:27,338 But in fact, the 700M  gets its 24volts AC externally from the furnace. 285 00:22:27,338 --> 00:22:32,403 And the 700 automatic version has its own 24 volt transformer inside. 286 00:22:32,403 --> 00:22:37,682 And all this is doing is bridging these two contacts through this relay. 287 00:22:37,682 --> 00:22:44,535 But the manual humidifier needs to get 24 volts AC, which is going to be possible with this - 288 00:22:44,535 --> 00:22:48,909 I have to do a little bit of sanity checking to make sure I wire it correctly. 289 00:22:48,909 --> 00:22:55,042 But I'm going to have to jump either R or C over to one side of this 290 00:22:55,042 --> 00:23:02,531 and then basically have that relay send  24 volts up to the humidifier like the original control. 291 00:23:02,531 --> 00:23:08,753 Now, why on earth does Aprilaire choose to distinguish them in this way? 292 00:23:08,753 --> 00:23:10,993 I don't know, but it's really frustrating. 293 00:23:10,993 --> 00:23:17,605 And they clearly don't want people figuring out how to wire this digital version to the manual one 294 00:23:17,605 --> 00:23:19,342 because they just don't even tell you it's possible. 295 00:23:19,342 --> 00:23:21,964 But it's totally possible. This is just a relay. 296 00:23:21,964 --> 00:23:27,182 One of these relays does the humidifier. The other relay forces the furnace fan on. 297 00:23:27,182 --> 00:23:34,768 But they do not give you a wiring diagram for how to use this with the manual model, even though it's completely possible. 298 00:23:35,767 --> 00:23:39,975 [sigh] I've been meaning to make a video on right to repair for a while. 299 00:23:39,975 --> 00:23:44,660 This isn't quite part of that, but man. 300 00:23:44,660 --> 00:23:45,810 This is dumb. 301 00:23:45,810 --> 00:23:48,295 Okay, my modifications are complete. 302 00:23:48,295 --> 00:23:53,993 Now, this is going to look very confusing because I don't have - almost none of these wire colors are correct. 303 00:23:53,993 --> 00:23:57,252 I'm actually using garage door opener sensor wire. 304 00:23:57,252 --> 00:23:59,699 Uh, yeah, but it should work. 305 00:23:59,699 --> 00:24:06,070 Basically, I now have red and blue (this is 24 volts and common) 306 00:24:06,070 --> 00:24:10,746 taken off of the input and then I have a separate lead for them. 307 00:24:10,746 --> 00:24:17,122 So now this thing and the humidifier are wired in parallel. 308 00:24:17,122 --> 00:24:23,505 But the humidifier's return - it's landing on one of the H terminals 309 00:24:23,505 --> 00:24:26,437 and then the other H terminal is coming back to this common point. 310 00:24:26,437 --> 00:24:33,708 So basically the humidifier would run all the time if this relay is closed. 311 00:24:33,708 --> 00:24:37,271 But when the relay is open it shouldn't run. 312 00:24:38,960 --> 00:24:45,435 Now, there's really nothing left to do except  turn this back on and hope for the best. 313 00:24:45,435 --> 00:24:51,434 Now, uh I know it's safe to do this because the  worst thing that would happen 314 00:24:51,434 --> 00:24:55,283 is I will blow the furnace's power supply fuse. 315 00:24:55,283 --> 00:24:58,987 And uh it's probably an automotive fuse, I may even have a spare on hand. 316 00:24:58,987 --> 00:25:02,248 But it will be easy to get a replacement if I need it. 317 00:25:02,248 --> 00:25:07,328 It's part of how I know it's safe for me to be doing this nonsense. 318 00:25:07,328 --> 00:25:11,804 Here is the moment of truth, part two. 319 00:25:16,479 --> 00:25:18,743 Okay, it's on. 320 00:25:18,743 --> 00:25:20,941 We're going blower activation... 321 00:25:23,725 --> 00:25:26,094 I'm going to turn that to on. 322 00:25:26,094 --> 00:25:29,197 Crank this up all the way and hopefully the humidifier comes on. 323 00:25:31,766 --> 00:25:33,149 What is this test? 324 00:25:33,149 --> 00:25:37,042 [clack, hissing, whirring] Oh, well, that works. 325 00:25:37,042 --> 00:25:39,815 And look at that! The humidifier is running! 326 00:25:39,815 --> 00:25:41,453 Now, is the blower actually running? 327 00:25:41,453 --> 00:25:44,034 It's hard to tell when the humidifier is on as well. 328 00:25:44,034 --> 00:25:47,372 Oh, for sure it is. So, that worked correctly. 329 00:25:48,407 --> 00:25:50,760 Want to make sure this actually shuts off now. 330 00:25:50,938 --> 00:25:52,464 [clunk] 331 00:25:52,786 --> 00:25:53,653 Awesome. 332 00:25:53,653 --> 00:26:01,165 With that rather ugly but functional wiring modification, this is now working as I expected it to the whole time. 333 00:26:01,165 --> 00:26:05,588 The humidistat can now energize this relay, which forces the furnace fan to run. 334 00:26:05,588 --> 00:26:10,966 And that allows it to perform its own check of the ambient humidity level on an hourly basis. 335 00:26:10,966 --> 00:26:16,789 If during that check it finds that it's lower than the set point, it will then energize this relay which, 336 00:26:16,789 --> 00:26:23,986 thanks to those horrible jumpers and wire nuts will now send power up to the humidifier's water valve, which will switch it on. 337 00:26:23,986 --> 00:26:27,148 And of course, that will increase the humidity in my home. 338 00:26:27,148 --> 00:26:33,791 But once it reaches the set point, the humidity sensor will detect that, at which point it will turn the humidifier off. 339 00:26:33,791 --> 00:26:37,436 That will all happen regardless of what my thermostat's doing. 340 00:26:37,436 --> 00:26:40,880 If though my thermostat is commanding the heat to run, 341 00:26:40,880 --> 00:26:47,372 the humidistat is now aware of that thanks to the fact that it's hooked up to the W terminal on the furnace board. 342 00:26:47,372 --> 00:26:54,342 So, as before, if the humidity is below the set point, it will close the relay and send power to the humidifier. 343 00:26:54,342 --> 00:26:58,516 And once it's satisfied, it shuts the humidifier off. 344 00:26:58,516 --> 00:27:01,549 Now, none of this is really new. 345 00:27:01,549 --> 00:27:05,132 My old setup with the humidifier connected to the fan terminal 346 00:27:05,132 --> 00:27:11,536 and with my thermostat forcing the fan to run for 15 minutes every hour accomplished the same thing. 347 00:27:11,536 --> 00:27:17,906 See, I also went into my thermostat's programming to make it command the fan during a heating call. 348 00:27:17,906 --> 00:27:25,280 Something that's not necessary for my heating system to work, but which allowed the humidifier to run during a heating call, too. 349 00:27:25,280 --> 00:27:32,026 So, when it comes to the basic functionality of the humidifier, I haven't really changed anything. 350 00:27:32,026 --> 00:27:38,639 But now that this control knows what the outdoor air temperature is, I no longer have to think about that. 351 00:27:38,639 --> 00:27:45,258 It will automatically reduce the humidity set point as the ambient temperature outside falls. 352 00:27:45,258 --> 00:27:51,637 This chart here explains how the humidifier will adjust the set  point based on the outdoor temperature reading. 353 00:27:51,637 --> 00:28:00,613 The recommended setting, five, will allow the humidity to get as high as 45%, but will start lowering it when the outdoor temp is 30° F, 354 00:28:00,613 --> 00:28:03,468 which is just a hair below freezing. 355 00:28:03,468 --> 00:28:10,476 I know that my home can handle 45% at that temperature just fine so I decided to set it to six. 356 00:28:10,476 --> 00:28:14,651 And actually, this is my biggest disappointment with this thing. 357 00:28:14,651 --> 00:28:24,472 I would like setting six to shoot for 50% humidity when it's above freezing outside, but the highest this will ever go is 45%. 358 00:28:24,472 --> 00:28:27,887 That's not a big difference, but I can notice it. 359 00:28:27,887 --> 00:28:35,188 Still, I will happily sacrifice that for the peace of mind that this will automatically reduce its output in those cold snaps. 360 00:28:35,188 --> 00:28:40,598 I haven't had this installed for very long, but my thermostat, which has a hygrometer in there, 361 00:28:40,598 --> 00:28:44,114 is telling me the indoor humidity is hovering around 45%. 362 00:28:44,114 --> 00:28:47,875 So, it's doing its job and seems to be accurate. 363 00:28:47,875 --> 00:28:51,824 Or I guess at least my thermostat agrees with it. 364 00:28:51,824 --> 00:28:53,960 The other thing I don't like about this? 365 00:28:53,960 --> 00:28:58,117 It won't tell me what it thinks the outdoor temperature is. 366 00:28:58,117 --> 00:29:05,528 It should throw an error code if the sensor goes bad, but what if the sensor is simply drifting over time? 367 00:29:05,528 --> 00:29:11,511 I'm not going to know that unless the drift is bad enough to cause it to over- or under-humidify. 368 00:29:11,511 --> 00:29:15,487 Since I've installed this, the outdoor temperature hasn't fallen much below freezing. 369 00:29:15,487 --> 00:29:19,745 So, I'm not even sure yet that it's working as intended. 370 00:29:19,745 --> 00:29:23,594 That's cool since, you know, that's the whole reason I did this. 371 00:29:23,594 --> 00:29:26,542 But, we're supposed to get a cold snap shortly after Christmas, 372 00:29:26,542 --> 00:29:32,034 and I'll do one of those community posts once we've gone through that. And I'll pin a comment here, too. 373 00:29:32,034 --> 00:29:35,149 Aside from the absolute ridiculousness that was 374 00:29:35,149 --> 00:29:42,014 having to figure out my own way to get this Aprilaire humidity controller to work with my Aprilaire humidifier, 375 00:29:42,014 --> 00:29:44,719 I am very happy to have made this upgrade. 376 00:29:44,719 --> 00:29:47,085 But to circle back to the beginning of this video, 377 00:29:47,085 --> 00:29:53,219 while the main point of doing this is to make my humidifier something closer to set-and-forget, 378 00:29:53,219 --> 00:29:56,940 it's still absolutely not set-and-forget. 379 00:29:56,940 --> 00:29:59,819 The potential for leaks is still there. 380 00:29:59,819 --> 00:30:03,877 The potential for a deteriorating water pad is still there. 381 00:30:03,877 --> 00:30:09,215 And while I hope its outdoor temperature sensor will work reliably for years to come, 382 00:30:09,215 --> 00:30:15,942 the potential for too much humidification if it starts drifting in the wrong direction is still there. 383 00:30:15,942 --> 00:30:21,821 I will absolutely still be monitoring my home's humidity level and the function of the humidifier. 384 00:30:21,821 --> 00:30:28,100 And I suggest that anybody out there with one of these things check on it at least monthly and preferably weekly. 385 00:30:28,100 --> 00:30:35,199 That I think is the biggest argument for choosing a large freestanding humidifier over one of these things. 386 00:30:35,199 --> 00:30:38,143 Sure, it's annoying to fill those up with water every day or two, 387 00:30:38,143 --> 00:30:44,997 especially considering that you'll need to use a water treatment product with those fill-ups to prevent odors and mold growth. 388 00:30:44,997 --> 00:30:48,068 And of course, they take up space. 389 00:30:48,068 --> 00:30:55,267 But when you have to keep interacting with it in order for it to keep working, you'll be more likely to notice problems. 390 00:30:55,267 --> 00:31:00,890 Plus, if its tank were to start leaking, at most you'll have a few gallons of water on the floor. 391 00:31:00,890 --> 00:31:07,175 This thing's plumbed to full water pressure, which means leaks could be much more catastrophic. 392 00:31:07,175 --> 00:31:11,871 I have a floor drain in this furnace closet, so I'm not too too worried about that. 393 00:31:11,871 --> 00:31:17,462 But still, it could cause major damage to my furnace, and that's not good. 394 00:31:17,462 --> 00:31:23,227 But I must admit, it has been very nice  to have this machine keeping the air comfortable 395 00:31:23,227 --> 00:31:27,220 without having to fill up a weird 2 gallon bottle every couple of days. 396 00:31:27,220 --> 00:31:31,063 And now that the humidistat knows the outdoor air temperature, 397 00:31:31,063 --> 00:31:35,974 I'll be slightly more at peace knowing that I can't forget to turn it down. 398 00:31:35,974 --> 00:31:40,423 I'm still going to be checking on the humidifier every week or so to make sure the fan is spinning 399 00:31:40,423 --> 00:31:42,718 and that there isn't water where there shouldn't be. 400 00:31:42,718 --> 00:31:48,061 Plus, of course, I'll be checking that the controller I installed actually does its job. 401 00:31:48,061 --> 00:31:53,878 Assuming it does, though, this is as close to set-and-forget as you can reasonably make one of these, 402 00:31:53,878 --> 00:31:56,245 and that makes me happy. 403 00:31:57,067 --> 00:31:59,822 ♫ moistenedly smooth jazz ♫ 404 00:32:00,595 --> 00:32:03,624 A few things I didn't mention in the main body of the video: 405 00:32:03,624 --> 00:32:09,561 First, like my old setup, I'll have to remember to turn this off when the weather gets warm. 406 00:32:09,561 --> 00:32:14,611 If I don't, it may try to add humidity when that's the last thing I want. 407 00:32:14,611 --> 00:32:16,309 Yay, Midwest. 408 00:32:16,309 --> 00:32:23,833 Second, at time of filming, I haven't yet verified whether or not it knows the thermostat is commanding the fan. 409 00:32:23,833 --> 00:32:28,269 It should, but I didn't think to actually test that before I got here and shot the talking head. 410 00:32:28,269 --> 00:32:29,579 Here's the answer: 411 00:32:29,579 --> 00:32:35,110 I just confirmed that yes, it does turn on the humidifier when the thermostat gives it a fan call. 412 00:32:35,110 --> 00:32:37,455 So, that is working as I expected. 413 00:32:37,455 --> 00:32:41,538 And third, this thing's humidity sensor does a reasonable job, 414 00:32:41,538 --> 00:32:48,454 but I have noticed that the displayed humidity falls quite  dramatically as soon as I open the door to the furnace closet. 415 00:32:48,454 --> 00:32:52,716 It drops by about 5% even when the blower is running. 416 00:32:52,716 --> 00:32:58,285 This is a bit puzzling to me as it's in the same room that the furnace is pulling air from. 417 00:32:58,285 --> 00:33:02,663 And based on what my thermostat is telling me, it doesn't seem to matter. 418 00:33:02,663 --> 00:33:09,135 But clearly the sensor is being affected by the air around it and not just inside the duct. 419 00:33:09,135 --> 00:33:12,231 That makes complete sense based on this thing's design. 420 00:33:12,231 --> 00:33:18,320 And it would really be improved if it had some sort of remote sensor you could shove deep into the duct. 421 00:33:18,320 --> 00:33:24,109 Plus, that would mean you could mount this control  somewhere it's more visible if you wanted. 422 00:33:24,109 --> 00:33:29,911 I know there are plenty of climates out there where the idea of wanting to add moisture to the air is abhorrent, 423 00:33:29,911 --> 00:33:37,198 but I'm surprised how terrible the options seem to be for central ducted humidifier controls. 424 00:33:37,198 --> 00:33:40,674 They are simple things, yes, but we could be doing so much better. 425 00:33:43,422 --> 00:33:47,256 ...humidistat the whole time and then about 2 weeks later - 426 00:33:47,256 --> 00:33:48,745 oh shoot. 427 00:33:48,745 --> 00:33:53,532 Yeah, it used to be white and now it's pink and chunky fer- 428 00:33:53,532 --> 00:33:55,884 ah, it's crunchy! 429 00:33:55,884 --> 00:33:57,469 Crunchy, not chunky. 430 00:33:57,469 --> 00:33:58,655 Eurgh. 431 00:33:58,655 --> 00:34:04,926 This thing is basically a swamp cooler and will drop the temperature of the air leaving the vents if it's running. 432 00:34:04,926 --> 00:34:07,140 But the pad... 433 00:34:09,520 --> 00:34:11,318 I missed the word if. 434 00:34:12,174 --> 00:34:15,199 Then I taped the wire in place and made a... 435 00:34:15,199 --> 00:34:16,687 ah, farts. 436 00:34:16,687 --> 00:34:19,646 That's what's on the other side of the duct of... 437 00:34:19,646 --> 00:34:20,477 Farts. 438 00:34:20,477 --> 00:34:21,615 Farts!! 439 00:34:23,578 --> 00:34:30,195 So those of you who were looking at that wiring diagram closely might have noticed that it was showing the transformer in the automatic version and how the relay breaks that circuit. 440 00:34:30,195 --> 00:34:35,117 I was so confused by the idea of the transformer not being in the furnace that it didn't even register what the diagram explained. 441 00:34:35,117 --> 00:34:38,242 Sometimes a multimeter brings a faster answer!