Fancy new thermostat

[BigV]

Cool!

[Flint]

Reliant Energy now offering the Nest thermostat in Texas.

http://gigaom.com/cleantech/nest-sco...deal-in-texas/

Just saw the ad--it ran 9am Sunday morning during the Olympics.

[Clodfobble]

Yeah, I've been hearing ads on the radio, and I thought, "Hey, that's glatt's friend!"

[Flint]

I was telling everybody in the house this morning-- "Hey! I know a guy who knows the guy who invented that!"

[glatt]

And they knew a guy who knew a guy who knew the dude who invented it. I hope they were suitably in awe.

(My brother didn't invent it. Just wrote some code.)

But I'm pleased that it's getting some attention in Texas. Hopefully, for my brother, the advertising will lead to sales and profits.

[glatt]

Another update to the Nest thread. We're just coming off a winter of heating, and I can report on how the Nest did. We used less fuel than we did last winter. And this winter was colder on average than last winter was. The Nest saved energy compared to the previous programmable thermostat we had.

I was confused by this, because I thought we had the previous thermostat set up just right. I didn't understand how the Nest was saving us fuel. It turns out that the Nest was able to learn how long it took for our radiators to heat the house and how long they continued to heat the house after the thermostat shut the heat off. Previously, we would call for a certain temperature, and the old thermostat would run the boiler until that temperature was satisfied. Then it would shut the boiler off. The hot water would continue to circulate through the radiators, and the house would get hotter than the temperature we asked for. If we had programmed the heat to turn off when we left the house in the morning, the house would still be toasty for a hour or so after we left.

With the Nest, it learns how long it takes to heat the place up, and how long the radiators will coast, still heating the house, and it runs the heat for a shorter amount of time to just give us what we ask for.

I don't notice any less comfort. In fact, I felt like it was warmer in the house. So the Nest is giving us the heat we want, when we want it. And isn't heating an empty house.

You probably want numbers, but I don't have the bills in front of me. But we easily used fewer therms this winter than we did last winter.

[Pete Zicato]

That sounds like a big advantage if you've got steam heat.

Nifty.

[xoxoxoBruce]

In the olde days when fuel was cheap, the thermostat would shut down the fire and circulator at the set temperature so there was little overshoot. That wasted a whole lot of heat that was in the boiler, and would just drift up the chimney. So common practice became to keep the circulator running to dump that heat into the living space instead.

With big olde boilers that could be several degrees of overshoot, I lived one place where it would overshoot five degrees. But newer smaller boilers, usually only overshoot a couple degrees.

Having a thermostat that can predict that, so it hits the right temperature at the right time, is the cat's ass.

[ZenGum]

That is clever. Nice work, twenty-first century.

[glatt]

Our boiler is really old and we don't have a circulation pump, so the water moves by convection. It's a masterpiece of plumbing, with the pipes sloped just so. But what this means is that the water doesn't start to circulate through the radiators until it gets fairly hot. The safety shutoff at the boiler is set at 180 degrees F, so it never actually boils the water. By the time the hot water reaches the radiators, they are hot, but not so hot you would get burned. I'll sit on the kitchen radiator as it is getting hot but when it's at full temperature I can't sit on it for more than about 10 seconds or so before it get uncomfortable. I'd guess they are 120 degrees or so. I've never measured them.

Anyway, I think the lack of a circulator pump means that we have pretty significant overshoot. Easily 5 degrees. Maybe even 6-7 degrees. The Nest keeps the overshoot under control.

[xoxoxoBruce]

Ah yes, that's exactly the type of system I had where I said it would overshoot 5 degrees. An old coal fired boiler converted to oil, with an octopus of asbestos covered piping. I can remember a roommate sitting on the kitchen radiator in his bathrobe eating breakfast, and suddenly jumping up when he realized how hot it was getting.

[Clodfobble]

Austin Energy is now offering an $85 rebate to anyone who installs a Nest thermostat. Unfortunately, we're not on city utilities, but maybe our energy company will get on board soon.

[glatt]

My brother has been complaining about how busy he has been in advance of the Christmas season, but wouldn't say why. Nest has now revealed why.

They just came out with a fancy and expensive smoke detector.

$130

It's a smoke and carbon monoxide detector which sounds an alarm and also gives voice information about why it's going off. It will give you a mild warning at first if smoke or CO levels are rising but are not at an emergency level. If you are burning toast, and it goes off, you can disable the alarm with a wave of the hand. It connects wirelessly with your Nest thermostat to act as an additional temperature and motion sensor for the thermostat, and it will also connect with your smart phone to send alerts if something is going on in your house when you are not there. If you have multiple smoke detectors, they connect to each other wirelessly and will all go off at the same time if one goes off. You will get a message on your phone when the battery is getting low so you can change it before it starts chirping at you. I think you can monitor stuff on your phone like CO levels in the house over time. That would be interesting.

Seems to me that the batteries will wear out faster with all that wireless activity. But they claim the batteries are designed for "multi year" use. And there is a hardwired version.

The sensors it has: Photoelectric smoke sensor, Carbon monoxide sensor, Heat sensor, Three activity sensors, Ambient light sensor, Humidity sensor

[xoxoxoBruce]

The batteries are $20, or less, for a half dozen.
But if they are tied together and all go off together, I won't know where the problem is unless I buy a smart phone... or call the NSA.

[glatt]

But they'll tell you where the problem is. The message will be something like "fire in the hallway - evacuate" (It's a voice and an alarm.)