people walking at the desert during day

Smart blinds, cooling, sprinklers and dealing extreme heat

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OK, well, Seattle just suffered a historic three days of high temperatures (in June?) of over 100F. Portland hit a record 117F. To give you a sense of how hot that is, the Las Vegas record is 117F/48C so that is awesomely high. So what can you do in this kind of temperature. In Seattle, the record was 108F which broke the 105 record in July 2009. So it is hard to know what the statistics hold, but 2020 and 2016 were the two hottest years on record globally.

So, what’s a person to do given this is happening and you don’t have the air conditioning, well here is some advice (for folks like us who have lived without A/C) for those circumstances where there is low humidity and the temperature falls in the evening (think desert temperatures). For instance, here, the high was 108F but the low that night was 76F.

  1. Get up early and when the temperatures fall (if you are lucky, although in Asia, oftentimes the temperature just stays at 90F/90% humidity where this won’t work). But in the Northwest, although it was down to 72F at 4AM is the time to get up and open all the windows to get the house as cool as possible.
  2. Then as the temperatures rise, you can begin to close up the East side where the heat is going to be. We like to close up the rooms on that side too.
  3. For these incredibly hot days, going lower is good. As an example, the basement stayed a static 75F and our garage which is in the shade and has a strange double roof with 2 feet of air stayed 72F the whole time (although humidity there bumped to 72% and the PM2.5 really climbed as the cars just ooze chemical junk. Yuck!)
  4. Basically, you want to seal the rooms and these act like insulation for the rooms you are living in.
  5. We ended up in our only room at the Northwest corner of the house (and then the basement because soil is a great insulator) that happens to be shaded and with that trick, the temperatures there never got about about 80F which is pretty amazing given it was nearly 30 degrees hotter outside.
  6. Finally, water is an incredibly effective coolant particularly when it is dry. So a little water spritzing and a jump in a pool work really well. I tried this experiment working outside and then periodically dunking.

Longer term things to think about

Well, it does seem like things are getting warmer, so what are some things that you can do longer term:

  1. Insulation and thermopane and sealed windows. It’s counterintuitive, but insulation really helps in the summer as well as the winter. Get as much as you can.
  2. Attic fan. We can’t do this because of what our roof is, but having an attic fan really helps lower temperatures. Attics can be really, really hot and these can be automatically controlled. Some are really cool, like being solar-powered. Even if you have A/C, these are great units to cool the 150F air up there. And if you are DYI inclined, you can set it up with ESP8266 which is a 3 channel relay that can control a 2-speed attic fan, but you probably really want an
  3. Get heat-insulating honeycomb blinds. OK, this is another thing that you can do which are blinds that come down automatically and which are heat reflecting. The so-called honeycomb blinds look less bulky than classic metal or wood and are better insulating, but you can’t turn them halfway to get some light, so they are great for insulation or as a secondary set behind regular curtains. And if you care about insulation, the more cells the better. Also, you can get them in lightening or blackout. Obviously the latter is better as a second set to sleep better and insulate more.
  4. Make them smart. So if you get blinds, then you have making them smart blinds. That’s a cool idea where they will go down automatically as things heat up. So Ikea makes a vertical blind system in widths from 28 to 48″ wide that have motors at the top. Pretty inexpensive at $148 or so. They have a controller, but with one of their Zigbee boxes, you can make it work with HomeKit. The big limitation is that they are most 74″ long, so if you have really big floor to ceiling windows they won’t work. They are battery powered though, so you have to put new batteries in. If you already have blinds, then Soma makes a bunch of battery powered actuators that can automatically turn vertical blinds. the Soma Tilt 2 works on horizontals and the Soma Shades 2 works on anything with a chain on it. Finally at the high end, you can get the Lutron Serenas which have really long lasting batteries or you can get it with a 12V wall wart too or even a power distributor if you can into the walls for say new construction. They are also custom made, so you get exactly the right length and about 10x more expensive than Ikea 🙂 but they will exactly fit and that does matter.
  5. Temperature sensors, with the new generation of smart sensors, we have a Kaiterra (and are getting the Eve Room) are great solutions. They are pretty expensive, but since they tie into Homekit, they are secure and private. They will give you a real-time feed in terms of temperature, so if you have sensitive stuff like wine for instance, you can be safe knowing it is stored properly. Buying these is a little complicated, but the Kaiterra Laser Egg comes in three flavors. The Laser Egg is $149 and measures PM2.5 and temperature. The Kaiterra Egg+Chemical also measures TVOC (think alcohol) and junk like that for $199. Then for places where you have gas or other bad stuff, the Kaiterra Egg+CO2 is $199 and measures that dangerous gas. One nice thing about these devices is that they have rechargeable batteries and connect to wall power, so you never need to change out batteries (which I always forget!). For most folks if money is no object, I would say the Kaiterra Egg +CO2 makes the most sense if you don’t have CO detectors now (everyone should :-). Finally not on the Eve Room is that it is indoor and Bluetooth, but because it also uses Thread, if you have an HomePod mini around, you are more likely to connect to it (otherwise it falls back to Bluetooth). The thing doesn’t have CO2, but does have TVOC at $180 for two of them.
  6. Scale up your A/C. If you have it, then you are going to need a lot more tonnage if these temperatures keep rising, so might be a good time to think about that. In the example, we are marked as Zone 4 so low-temperature needs, but if you believe things are getting worse (one rule of thumb is to look down 300 miles towards the equator and that is what you have to plan for), you bump up a region. As an example, if you have say 1,500 square feet per floor, then in Zone 4 in typical temperatures you would need a 2.5-ton unit. But if you think it’s getting hotter, then you will need more like 3 tons. An aside, 1 ton means you A/C can cool 12,000 BTUs per hour and that means that you can cool 12,000 pounds of water by one degree per hour. Note that 5 tons is the residential limit, so if you need more, you install multiple units in tandem. Note that if you do buy a unit that is “too big” then it will cycle rapidly and you lose efficiency, but you are ready for the really bad days. The old school way is square footage * 30 is the rough BTUs you need and then subtract a ton for most cooler regions. Or leave it on if you are in hot climates (like yesterday). So, 1,500 x 30 = 45,000 is 3.75 tons so if you worried about the hot, then you need a 3-4 ton unit, otherwise, subtract one and you need a 2.5-3 ton unit in typical climates. And if you are really doing this, have them do a Manual-J analysis. More complex analysis is ((House sq.ft. x 25) / 12,000) – 0.5) and you can see it is just different factors. One thing about the multiplier is the SEIR rating which is basically how well insulated you have and then the subtraction is a rough way to also adjust it.
  7. Get a mister for your air conditioner. This is not going to work everywhere. First of all, if it is really dry hot and you have soft water (no minerals and not too humid so you don’t get mold forming, but the temperate Seattle, it can work well, it is supposed to improve efficiency by making the input air moist. A really clever design by cool’n save make it possible with a flapper that mechanically opens the misters just by the air pressure. So no electronics at all. YOu do have to remove it I the winter, but a decent solution. It does require that you have water near your A/C, so you need to connect it to a garden hose (with a Y-connector as it doesn’t draw much water at all).
  8. Get a smart sprinkler system. If it is hot, then you need this kind of thing to keep your plants alive. The new ones are HomeKit enabled as well, so you can see what is going on. It is apparently pretty easy to install, you just replace your current unit and they have a set of wire pairs (8-zones or 16-zone) and you plug them into this thing. If you have rain sensors, it does the same. The Rachio Sweet 16 for instance is $280 and the Sweet 8 is $180 and the Rainmachine Pro 16 is $220 (and also doesn’t store anything in the cloud and is all local). There are lots of installation issues with these and most seem related to of course flaky WiFi. So the Rainmachine Pro 16 might be the best choice since it has a dedicated Ethernet port and you can always hook up a real WiFi Access point if you need it. Finally right now it is just $169 at Rainmachine, so not a bad deal for 16 zones. There is also a Rainmachine HD, but the reviews say that the connections are quite a bit smaller and harder to stick into the device. Just make sure that you note which zone you are moving from so you can port the controls from your old one to your new one.
  9. Get a mister for patio area. This again works if it is the dry heat, but for $22 from Redtron, you get a hose with misters every few feet and you basically mount them above you and it sprays keeping you cool. Way easier than dunking all the time. You probably also want a Y-connector and something like the Eve Aqua water controller, so you can turn them on and off remotely. If you are doing this, you probably don’t want a 2-way splitter since the Eve will be crooked, so get a 4-way and it will be nice and straight. Finally, if you do have a sprinkler system, one trick is that you can take one of the zones and add the mister wire above then when it is hot, you can use it as a mister, so you don’t need to a dedicated hose system.

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