Smart Thermostat w/Wired Remote Sensors

[Matthew Strongin]

As you know, I also work in tech and do not want gadgets in my house (except for my TV and AppleTV) but did you not get the memo (aka email) which stated the robots are taking over?

I welcome the robots. My concern is potential points of vulnerability and I don't put a ton of stock in the security of rushed to market, low cost, connected smart home devices. Plus, like both you and Thomas mentioned, I spend my day immersed in solving tech problems and when I go home I just want stuff to be simple and not remind me of work.

[Matthew Strongin]

Is this common in East Coast US cities?

It is in Miami, but the source is different. Despite being below sea level, it often feels like we're in close proximity to the surface of the sun.

[monadnocky]

It is in Miami, but the source is different. Despite being below sea level, it often feels like we're in close proximity to the surface of the sun.

Let's see.... if the mystery heat in Boston and NYC comes from Hell, that must place Miami in Satan's armpit, heat- and humidity-wise.

[davids]

Radiant heat is also nice because it self-regulates. Radiant heat transfer is proportional to the temperature difference to the fourth power so as the rest of the room gets closer to the radiant surface’s temperature, the heat transfer strongly decreases. And vice versa.

But a radiant floor is tough in a bedroom, because you don’t “see” the radiant surface when you’re in bed, and the bed hides most of that surface. This is why a radiant ceiling is boss for a bedroom.

Don’t sweat the four zones. Each zone needs a temp sensor in it. Watch the zones that could use a fast-acting response, like entries or somewhere that can see a big influx of cold air. Or a kitchen where people and cooking activity could quickly add a whole bunch of heat. These will be a challenge. Radiant heat is like a little tugboat that bumps a big thermal ship in the right direction.

And, controls suck. They’re way too complicated and cost way too much. I just put in a Nest (actually two, one at my kid’s house as well). I’m pleased, it’s a simple interface with a whole bunch of learning inside.

How much your system will need to adjust depends on two things. Usage, is the house unoccupied for significant amounts of time? If so it needs to set back. And the prime mover. If it’s a fossil-fuel fired boiler then it likes to be fired up and run at full throttle. If it’s an air-source heat pump, it’s like a long-distance cyclist. Keep the needle out of the red and apply the effort in a thin, even coat.

TH is my HVAC guru (even when I ignore him), and I'm so happy to get his take on radiant heating. We're planning it for our master bathroom when that gets redone, but aside from that it's forced air at my house.

As far as the zones - hey, I wish we had zones. Each of our 3 floors is a different climate during both winter and summer. It's especially noticeable on the 3rd floor during the warmer months. We just replaced the skylight blinds with room-darkening shades and I'm hoping that helps keep it cooler up there. We'll see. Someday that floor may get a nice wall-mount AC unit.

As far as your controls... Our thermostat lets us set four distinct customizable periods for each day of the week. We go with morning, daytime, evening and nighttime. As we live there full time that works really well for us, and neither of us feels any need for a control that would let us manage setting over the Internet. Since you guys, Jorn, are going to be going back & forth irregularly, the remote management could be very nice.

And finally - 4 separate thermostats? Yeah, it would be nice if they made a single unit that allowed you to select a zone and then play with its settings. It seems like an obvious product, huh? Maybe it has to do with controlling multiple furnace/ac systems?

Also, am I the only one that thinks "smart" systems are concerning? Maybe that's because I work in tech or maybe that's odd since I work in tech, but I want as few components in my house connected to the internet as possible. And things like smart devices aren't exactly models of security.

I don't like them.
I don't like talking to computers.
I don't like the idea that computers are listening to me speak.
And I don't like that a computer, tied to my home, would know I'm not at home.

[zachateseverything]

I welcome the robots. My concern is potential points of vulnerability and I don't put a ton of stock in the security of rushed to market, low cost, connected smart home devices. Plus, like both you and Thomas mentioned, I spend my day immersed in solving tech problems and when I go home I just want stuff to be simple and not remind me of work.

I get the concern. From my standpoint, if something doesn't have a camera, microphone, or access to my personal or financial info I'm not too concerned about it being connected to wifi. Like, I have a couple smart light switches and will probably get a Nest thermostat at some point. Having something that's controllable and programmable via my cellphone is useful. Mostly I just want to be able to turn on a couple lights and turn down the heat if I'm out of the house for a trip. But if the devices got compromised, what would they do? Screw with the dimmers until they got bored?

But I'm less enthused about installing a listening device in my own home. I also try my best to minimize the number of places that have my credit card or bank account info stored. I'm already on a televangelists mailing list for life because someone stole my credit card number and donated $1 to "the cause."

[thollandpe]

If you have conduits carrying molten lava or hellfire through your living space, there ain’t no reason you can’t throw an inch or three of fiberglass pipe insulation over them. Then they’ll keep most of the Btus to themselves.

Unfortunately yes, wildly overheating spaces, especially in mild weather, is often a feature of steam heat. There are things you can do, but fewer and fewer people seem to understand steam these days.

And also unfortunate is that the response to overheating, opening the windows, likely exacerbates the problem. Stack effect – think of the building as a giant air pump. Cold, dense air leaks in on the lower levels, expands as it’s heated, rises, and leaks out the upper levels. When the windows are opened the airflow increases, and often carries more cold air in across a thermostat on the lower level. Vicious cycle. Chain reaction.



Fixing this monumental waste of energy, and corresponding cause of discomfort, should be on somebody’s radar. Certainly makes more sense than building another pipeline to bring more gas, to burn and make more heat, and pump it through a building to overheat people who are already too hot, and make ice dams to ruin the roof.

PS Jorn, one of the routines you want is “optimum start/stop”. Even with all the thermal mass, you will need to start morning warmup sooner but you can start coasting earlier. Another is “outdoor air reset”. I have not done this with radiant, but it’s worth asking if you can reduce the water temperature in milder weather.

[Mark Kelly]

He said each zone gets its own thermostat. So we'll have four thermostats on the wall, one for each of the zones.

The sensors are in whatever room each zone is in, but the thermostats will be together on the wall in a line, albeit out of the way and fairly unobtrusive. But really? Four thermostats?

He's going to check on multi-zone thermostats.

In industrial control it is general practice to use individual controllers at low levels of complexity and a single screen multipoint system at higher levels. Four points is low level.

Then again, this is based on historical practice: embedded PLC systems used to cost a bomb. These days a single touchscreen multipoint system is doable for well south of $500 (not including the sensors, armoured industrial sensors are relatively expensive but your domestic sensors are cheap as chips). If you can handle some simple programming, Velocio can set you up with everything you need.

[j44ke]

...

Also, am I the only one that thinks "smart" systems are concerning? Maybe that's because I work in tech or maybe that's odd since I work in tech, but I want as few components in my house connected to the internet as possible. And things like smart devices aren't exactly models of security.

No you are not. The thermostat spec'd by the HVAC guy has smart features, but it is no way as intrusive as some of the "smarter" devices that use "learning" features to track your movements around the house and schedule the application of heat accordingly. Most of these smart devices either use remote motion/temperature sensors to figure out where the people are in the house and then respond accordingly with heat or cool. Some devices, instead of using remote sensors, track the movements of your phone around the house. Geofencing it is called I believe. So when your phone goes into the living room, the thermostat directs resources there. And the learning aspect uses an algorithm to predict your movements, so over time your cumulative patterns of movement through the house drive the application of heat/cool to those areas.

All of this information has the possibility of being sold as data that then results in your receiving marketing on living room furniture, bath products, or even medical products at certain times of the year.

Fortunately, radiant floor heating is, as Todd says, "a little tugboat that bumps a big thermal ship" - it just doesn't react quickly enough to work with any of those smart programs. If radiant heating is told to react to your movement from the bedroom to the living room, that reaction will be accomplished in approximately 8-12 hours. Radiant floors are best operated by figuring out a temp that generally works for all times of the day, and (depending on climate) either sticking with that level or augmenting with smaller more reactive heating/cooling methods like split units or other machinery. The smart feature work best with forced air heat/cool, electric baseboards and possibly modern radiators that can be controlled with automated valves - forms of heat/cool production that allow relatively quick redirection.

Because the house won't be our primary residence, mostly what we need is a way to communicate with the heating system while we are away. We need to be able to check temps to be assured of proper function, adjust the temp down if we forget to do so before leaving and adjust it up if the weather forecast predicts a hard freeze. We also have heat/cool split units in each zone run by two "suitcases" outside. They will likely be used only as needed as "fill-in" on days when the radiant needs a little help as it comes up to temp or dog days of summer when there is no breeze to speak of.

I am realizing, based on what Todd said, that zones will actually be important for more than just keeping my wife comfortable. I think every room will have its thermal fingerprint, so there will eventually be minor temperature differences between the 4 zones. But again, with radiant heat, it will take a while to get those dialed in.

[j44ke]

...

PS Jorn, one of the routines you want is “optimum start/stop”. Even with all the thermal mass, you will need to start morning warmup sooner but you can start coasting earlier. Another is “outdoor air reset”. I have not done this with radiant, but it’s worth asking if you can reduce the water temperature in milder weather.

Good info. I think this was mentioned, but I'll add it to my notes.

Our apartment building in NYC is single-pipe steam heat. I've replaced and tuned the steam vents on each of the radiators in our apartment, and as a result, we get better heat than floors above and below. I've actually closed the inlet valve on one radiator this year, because we don't need it.

I cannot get any of the other apartments to do anything about their steam valves. They complain about the lack of consistent heat, but when I explain how single-pipe steam heat works and show them the solution, they ask if I can just "turn it up more".

[NYCfixie]

I welcome the robots. My concern is potential points of vulnerability and I don't put a ton of stock in the security of rushed to market, low cost, connected smart home devices. Plus, like both you and Thomas mentioned, I spend my day immersed in solving tech problems and when I go home I just want stuff to be simple and not remind me of work.

Multiple times I have been stuck between an HVAC salesperson, the Facilities Director of a company where I work who wants this type of system installed but simply does not understand the "computer/network" side of it, and a CFO who wants everyone to get along and save lots of money due to the proposed new HVAC system.

In one really bad example (circa 2017) a major HVAC salesperson tells my Facilities Director and CFO that their "wireless mesh" HVAC control system "must" be wired to the internal network, the wireless mesh thermostats will not interfere with the internal wireless network, the HVAC head unit must be open to the internet, and that the head unit is "protected" even though it only uses a simple password. I spent weeks digging through their documentation and used it to finally got one of their senior engineers to admit on a conference call that the mesh wireless "may and often does" interfere with "some" wireless networks and that in a "future patch" they will upgrade the login credentials. I begged our CFO and Facilities company not to use the system but they received a huge rebate from the state so the project was well on its way (maybe involve the Technology Director earlier on next time?)

Needless to say that as soon as they started to install the system it interfered with the internal wireless network and caused employees to complain about dropped connections and dead spots (which did not happen or exist beforehand). And within a few weeks the system got hacked and the temps set to 100 over a long weekend in the summer. I think it took about 2 days to cool the building down when everyone came back on Monday. In the end, they had to "wire" all the thermostats (which cost a small fortune) and I was able to get the entire system off the internal network so if it ever got hacked again there was no chance a hacker could use it as a backdoor into the internal network.

The really funny part for me was when I finally got around to watching Mr Robot on Netflix, this is one of the hacks they used.

[NYCfixie]

And also unfortunate is that the response to overheating, opening the windows, likely exacerbates the problem. Stack effect – think of the building as a giant air pump. Cold, dense air leaks in on the lower levels, expands as it’s heated, rises, and leaks out the upper levels. When the windows are opened the airflow increases, and often carries more cold air in across a thermostat on the lower level. Vicious cycle. Chain reaction.

Incorrect. It's the old lady's that complain to management if their individual apartment is not hotter than hell all year 'round.

And it may sound crazy but many of these older buildings do not have thermostats in every apartment and rarely on every floor.

[davids]

TeeAitch,

What's a "lowels levels"? I want to be sure it gets all the positive pressure it seems to require.

xoxo,

[Ras72]

Jorn, these thermostat/sensors; are they to control the radiant floor or the HVAC?
If they're for the latter are you going with variable refrigerant flow units (VRFs)? If so, I'd go thermostat for each unit.
If not, disregard this post and carry on.

Radiant floor should be controlled at your distribution manifold - balanced by differential temps of supply and return. As said, because of lack of reaction time (thermal mass) a radiant floor should be a seasonal set and forget.

[thollandpe]

TeeAitch,

What's a "lowels levels"? I want to be sure it gets all the positive pressure it seems to require.

xoxo,

Hey, that's bewol the belt!

Davidses, I'd put the radiant heat in the bathroom ceiling. Your skin will "see" more of the ceiling than the floor and be warmer. Your tub or shower enclosure will also be heated. And a heated ceiling is less likely to grow mold and mildew. If you have access to the tub or shower enclosure from below, insulate it!

And regarding your three-story control issue, schedule a MassSave energy audit and ask about a blower door test. That will show you how many leaks you have and help show you where they are. They'll pay for a good chunk of air sealing and insulation. Beat back that stack effect. Get the rebates and incentives.

[NorTX-Dave]

I don't like them.
I don't like talking to computers.
I don't like the idea that computers are listening to me speak.
And I don't like that a computer, tied to my home, would know I'm not at home.

+++1....but then I probably feel that way because I'm reading Soshanna Zuboff's "The Age of Surveillance Capitalism."

[rwsaunders]

Jorn..check that the tstats are for heating only if you don’t have AC...the model that you linked looks to be for AC and heat. Yes, four tstats are needed to address four zones and I’ll put a plug in for NEST units. I have two in use for the past 4-5 years and I like them. Question for your HVAC guy...do you need four separate WiFi user names and passwords to manage the tstats remotely? That could be a pain....my Nest units are on the same app and identified separately. Some of the units in the market can manage your smoke and CO detectors too...one stop shopping when you’re in the Czech Republic and you want to know what’s going on in upstate NY when Mike Noble is housesitting for you. Lutron makes such a beast and I’m sure that there are others in the game.

https://luxury.lutron.com/en-us/cont...mber=HQWT-T-HW

[davids]

Hey, that's bewol the belt!

Davidses, I'd put the radiant heat in the bathroom ceiling. Your skin will "see" more of the ceiling than the floor and be warmer. Your tub or shower enclosure will also be heated. And a heated ceiling is less likely to grow mold and mildew. If you have access to the tub or shower enclosure from below, insulate it!

And regarding your three-story control issue, schedule a MassSave energy audit and ask about a blower door test. That will show you how many leaks you have and help show you where they are. They'll pay for a good chunk of air sealing and insulation. Beat back that stack effect. Get the rebates and incentives.

We'll have a forced air duct (and exhaust fan too!) in the bathroom ceiling, just like now. I like the idea of adding a warm floor under my aging tootsies as I perform my daily ablutions. And it's cheap in the context of a gut re-do of the bathroom!

I really don't think we've got much of a stack effect in our 1999 house. I can easily create a heat chimney by opening a window on the 3rd floor.

[j44ke]

Jorn, these thermostat/sensors; are they to control the radiant floor or the HVAC?
If they're for the latter are you going with variable refrigerant flow units (VRFs)? If so, I'd go thermostat for each unit.
If not, disregard this post and carry on.

Radiant floor should be controlled at your distribution manifold - balanced by differential temps of supply and return. As said, because of lack of reaction time (thermal mass) a radiant floor should be a seasonal set and forget.

Radiant floor. I realized I've been using HVAC as a stand-in for "heat and cooling" but really, the Honeywell thermostats are running the radiant floors only. The split unit AC's also have heating capacity, but they will be mostly used as an answer to "is it cold in here?" when the radiant is running just fine thank you and then cooling during the dog days of summer or when we have company who don't want to sweat. They each have separate thermostatic control doohickeys. Yes, control at the manifold. Yes, seasonal set and forget.

I'll get all the terms figured out eventually. Until then, definitely ask for translation, as you did!

[j44ke]

Jorn..check that the tstats are for heating only if you don’t have AC...the model that you linked looks to be for AC and heat. Yes, four tstats are needed to address four zones and I’ll put a plug in for NEST units. I have two in use for the past 4-5 years and I like them. Question for your HVAC guy...do you need four separate WiFi user names and passwords to manage the tstats remotely? That could be a pain....my Nest units are on the same app and identified separately. Some of the units in the market can manage your smoke and CO detectors too...one stop shopping when you’re in the Czech Republic and you want to know what’s going on in upstate NY when Mike Noble is housesitting for you. Lutron makes such a beast and I’m sure that there are others in the game.

https://luxury.lutron.com/en-us/cont...mber=HQWT-T-HW

Yes, the thermostats are to be used for heat only. Honeywell makes their stuff installer-customizable - as I understand it - so the guy will disable the functions the thermostats are not performing and things that run counter to the operation of radiant floors, like geofencing. The Honeywell app allows you to add all the devices to the same app, then manage them through the same interface, same log-in. The smoke and CO2 are on our alarm system. I need an app for Mike Noble. Do you know his log-in? So I can turn him on and off remotely.

[thollandpe]

TH is my HVAC guru (even when I ignore him)...

It's the good advice that you just didn't take.

We'll have a forced air duct (and exhaust fan too!) in the bathroom ceiling, just like now. I like the idea of adding a warm floor under my aging tootsies as I perform my daily ablutions. And it's cheap in the context of a gut re-do of the bathroom!

I really don't think we've got much of a stack effect in our 1999 house. I can easily create a heat chimney by opening a window on the 3rd floor.

Assuming your house is tight without getting a blower door test is like assuming your cholesterol is OK without getting your blood drawn.


The irony and the agony.