The post was put in the lounge section with the disclaimer that it wasn’t an automation question...rather a question to a group of DIYers that tend to have unique solutions for common problems.
I may have not explained the setup well enough. While there are dedicated hot water circulation systems that have a dedicated return line to the hot water tank, the retrofit hot water circulation systems actually push water back the cold lines to the hot water tank to achieve the circulation.
I’m pretty convinced that there is a benefit but only if there are enough of the thermostatic valves that allow coverage to get the main lines.
Now as a total solution against freezing....probably not, especially in places that get extreme cold but for a place like Houston I’d suspect that even a little warm water moving through the cold lines would keep a pile from bursting.
So. While this might not be definitive, for the cost to add a few more thermostatic valves on outside sinks.....it’s worth the gamble and as a minimum if get hot water in those areas much quicker.
Appreciate all the replies and debate.
Cheers.
Mac.
I think Texans really need to ask some hard questions about their utility systems and the redundancy they have built into them. In Canada we use linepack and other storage solutions to provide a buffer in case demand exceeds supply capability from the wells. Every gas well in Canada could shut down for weeks and our system would still function. Canada is a big country so we have lots of line we can pack, but Texas is a large state and I would also be surprised if your natural gas grid is not tied into the national grid to allow for major disruptions in well capacity. The technology to prevent what you are talking about has existed for 30+ years, you need to ask some hard questions of your utility providers and regulators. https://www.aga.org/natural-gas/delivery/how-does-the-natural-gas-delivery-system-work-/
Some old 100 year weather events may turn out to be the new 50 or 30 year weather events. The times (and the climate) are a' changin'.
I love this thread, so timely for me as we're doing some work at the far end of our house that will include some new plumbing. Getting hot water there is an eternal wait. I'm going to talk w/the plumber about adding a recirc system that we can connect via smart plug and turn it on when we're going to need hot water at that end of the house.
That is actually a really good idea for a somewhat difficult automation to create. A residential recirculation pump is going to draw between 30-60 watts (depending on the model), so why not have it off when you don't need it. Obviously turning the pump on and off is easy enough with HE, but when it should run and when it shouldn't could become a somewhat complex rule. Be interested to see what you come up with.
Several recirculating pumps already come with a dial timer for scheduling when the pump runs, HE could obviously out do that.
I chuckle to myself when folks talk about 20, 50 , 100 year events. The earth is billions of years old but somehow we think predictions can be made from a 100 year history.
My plumber was going to charge 700 to install one. I did it myself for 200. It’s on a smart plug and I created 3 simple automations for an hour each. 26 w when powered.
Cheers
Mac.
I had an occasion to work with Boeing company in Seattle. Noticing a lot of equipment was air powered I asked how large their compressed air storage tank was. The answer I received:
We have no storage tank. The 4 inch 10 mile pipe out to the Boeing Airfield was enough
I've read of mixing in some hot water for toilets to avoid condensation in the hot, humid summertime. Flushing your money down the drain, but still, it's a mess on the humid days. (This is in a house w/o A/C.)
I'm actually just going to set up a very simple automation using two apps and a manual initiation. We don't really have any consistent schedule for showering, so the automation needs to have a manual start:
Wife or I want to shower, press a button in the bathroom that turns on the plug the pump is connected to, Pump starts up.
After necessary number of minutes to have warm water available (we'll determine the timing testing time-to-warm at different times in AM and PM) the Auto-Off app will turn off the plug the pump is connected to.
Don't tell anyone, but I might have a bulb in the bathroom flash red a few times when the pump plug is turned off using "The Flasher" app, to make it obvious that hot water is now available. Wife will predictably say "Oh, that's silly, I can just look at my watch." I will predictably respond "Well sure, but isn't the flashing red light cool?!"
I'm mostly a DIY guy, but since the plumber will be here anyway doing all the other work, I'm going to be lazy and add it into his list. The cost will get lost in all the other work on the remodel so I won't feel the pain directly.
I described the setup and benefits to my wife tonight it had crazy high WAF! I desperately need to build up my WAF savings account after all the issues w/Z-Wave on the C7 from last year severely depleted it.
Probably not on our list...though now that you mention it, things have gotten more humid over the past several years, driven by above normal sea surface temperatures on the coast in summer, and increased fog at night. In 2018 a local beach set a temperature record for anywhere along the southern California coast, with a sea surface temperature of 81 degrees! Downright toasty! Nothing like the humidity I grew up with on the east coast (thank goodness), but still annoying,
Trying to think of the Rule(s) I would have to create that would correctly anticipate when I or my wife are going to use hot water, have the rule be accurate 80%+ of the time. For me, this would be exceptionally difficult. Activating the pump based on a button press would greatly simplify this automation. I guess it's all about making it work they way you want. Have fun!
Easy to keep the pump off when nobody is home or when we are sleeping, this in itself would keep the pump off for about 60% of the time. This in itself might be good enough, as opposed to trying to get more accurate. Your idea of a button press makes it super efficient, if you don't mind pressing the button.
As I may have mentioned before, my family, wife in particular LOVES buttons. She just likes to feel like she's in control of what's happening. Even when it's less efficient, she has asked me to change automations that work perfectly w/out intervention, just so she can control them via button. Gave up a while back on this...she is loveable so many all other ways.
Picos are great if you don’t mind spending the money on the bridge. Easy to create a rule to activate the smart plug from a button press.
You could also use a Inovelli or Zooz with scene control and have a double or tripe tap to activate.
I find that setting up the system on a standard schedule works well as we get up at the same time.
You could also use a motion sensor to trigger a set duration for the re circ system.
That’s the beauty of Hubitat. Triggering it has almost unlimited options.
Mac
You can't predict; however, for realistic requirement to cost trades (cost vs performance vs environment) Historically, the 100 year model works well for infrastructure and building requirements definition. No, we can not actually predict the future accurately for 100 years, but we need to define these needs.
That being said, what has happened in Texas is due to multiple reasons and no technology is perfect:
Wind power equipment was not installed to the environment encountered this week (although it could have).
Traditional power equipment was not winterized to the extreme environment (again it could have been).
Population growth in Texas putting the grid capacity below reserve above peak parameters. This impacted both generation and transmission systems. (Example last summer where during peak times we we near total peak consumption.)
US environment controls requiring early retirement of some power plants (to $$ to maintain to new standards).
Worst: Transmission infrastructure was not fully maintained/updated causing full power outage to a significant number of homes. (The rolling blackouts were sad; however, the total power outage areas were tragic.)
(Note that I call out the wind-power equipment separately. It is the newest equipment on the grid with a very high (85% or so) failure rate. We should see if it was actually procured, built, and installed to requirements at the time of installation. The same would be true to any NEW traditional plants that have come on line since 1989 and had problems.)
In theory I agree, however in practice it doesn't seem to work very well. IMHO
I will guess at least some of the folks in control in Texas will pass this off at a 100 year event so there is no need to make any significant changes.
For other's its just plain greed coupled with the lack of accountability, with a little stupidity thrown in.
Kind of an aside...
When I was looking to purchase my current home, a real estate agent showed me a building lot where a builder was planning to build homes. The sales pitch was the land was very flat, had good soil and was right near a small river. I asked agent if they knew what a flood plain was. The response I received was one of ... no clue. I never went back to see if they finally developed there. I hope they didn't but my guess is there are a whole neighborhood on that land.
In addition too often current "standards" are driven by mfg lobbying. My current pet peeve are arc-fault circuit breakers. Again IMHO this was a product looking for a market. The mfg lobbied the NEC to make them a requirement....wow.
Hey, me too. I've got a couple now tripping for no reason. It used to be it only tripped when you plugged in the vacuum cleaner. I hear they got more plans for GFI circuit breakers.
So here's what I did and it works remarkably well. Pump does not run if we are away. It will automatically run every 45 minutes for about 3 minutes (enough time to get warm water upstairs to the sinks that use it). I also have both upstairs bathrooms on smart switches. The master is motion sensor so it requires no input, but the other is not. If any of the lights come on in the bathrooms upstairs, and it has been at least 30 minutes since the pump ran, it will run for 3 minutes and shutoff. This way, if you go to the bathroom it usually takes a minute after turning the lights on. This gives it enough time for the water to be at least warm and not painfully cold to use.
I also have it preheat in the morning before my alarm goes off (alarm is tied into Hubitat), so I have hot water ready for my morning shower.
Yeah it is not a perfect system, but I think it works good for us. The likely hood of us going in the bathroom and not going to the bathroom is low, aside from mornings getting ready. Though the water is already been ran because of the showers. It may be a little wasteful in terms of it running when it is not needed, but in all honesty that's a reasonable convenience.
I would love to add a circulation pump for my hot water. In my house the boiler is at one end of the basement and the mostly used baths are on the 2nd floor 2/3 the house away from the boiler. Making adding the copper return not practical.
Hum.. maybe the return could be copper tubing? I'll have to reconsider.
