Household Thermostat with Remote Temp Sensor

In My Humble Opinion
1

I’ve got an HVAC challenge at my place that I hope somebody can help with. I have a dual zone system, each with a typical 5-1-1 day 4-interval-per-day programmable thermostat controlling a typical modern electric furnace + external condenser forced air AC system.

The problem is the thermostat for one zone is located in a rarely-used room that’s much more exposed to solar heat and winter cool than the other rooms we use a lot more. As a result it doesn’t matter what temp we set the thermostat to, the temp control in the rooms that matter sucks.

To add to the challenge, it’s very much impractical to rewire the place to move the thermostat to the room we care about most. Don’t ask.

I *think *my ideal solution is to have the thermostat wired in right where it is, but to also have some sort of remote temp sensor(s) in other room(s) that communicate wirelessly (Wifi, Bluetooth, whatever) back to the wired base. Which will control the heat/cool based on the remote temp input(s), not its own ambient temp.

My problem is I can’t find this.

[rant on]
I can find thousands of thermostats that have wifi remote so I can reset my thermostat’s target temp from across the planet. I don’t need that. I need it to manage the actual temp in a room 10 feet from where the damned wired base is.

I can find thermostats that cost $300 as part of some “smart home” crap. I don’t need that. I affirmatively don’t want it. Go away.

I can find thermostats that “learn my habits.” Hell, *I *don’t know my habits and I’ve lived with me for nearly 60 years. I hardly think some stupid fuzzy logic chip can discover the pattern to a life that’s affirmatively deliberately pattern-free.

Amazon’s search is designed to sell stuff, so any mention of “remote” along with “thermostat” brings in every remote controlled device they sell. Including quadcopter drones, tvs, garage door openers, barbeques, fans, and dog shock collars. They might even have remote controlled sex toys in the list, but I gave up scrolling after page 15 of 200.
[rant off]

So is there anyone here who’s seen this device or who’s an HVAC guru and knows whether this exists? Looking for manufacturer, model line, part number, whatever. Somebody has to have thought of this idea; it isn’t rocket science.

Or any suggestions to achieve the same result via a different method. We’ve done as much as we can with air balance, window treatments, etc. to try to bias the results in thermostat room to give the right results in the important room. Any other suggestions are welcome.

Mucho thanks in advance.

2

I had exactly your problem. Here was the only solution I found.

  1. It is not cheap.

  2. The main module (which goes on the wall where your current thermostat sits) is big and fairly industrial looking.

3

14 minutes flat. Thank you.

4

I believe we had one of those on the zoned system at our previous house (three zones). The main module was actually mounted on the furnace/air handler in the basement. Wireless controllers were mounted on the wall in the three zones but were mobile.

5

I found some other similar options by googling “thermostat with remote sensor”. One that I quickly found (didn’t read anything about it, just noticed that it came it a bit cheaper than the above option) was this and this (together).

Something else you might want to try before dropping a ton of money on this is to just put something opaque over the t-stat since you mentioned that the sun is on it. I know it won’t help if that part of the house gets hotter or cooler first due to system balance issue, but at least it help keep the sun off of it.

6

Great finds. thank you.

Good idea. But …

The issue isn’t that the sun shines directly on the thermostat. It’s that the thermostat room is small, has big windows and low ventilation, and is on the exposed treeless sunny side of the house. So the room gets hot and stays hot since the place is built of concrete with huge thermal mass. Meanwhile, the room(s) we care about are large, on the shady side, and exposed to the prevailing breeze. The net effect, particularly in late afternoon and post-sunset, is the AC is blasting like mad to cool the solar sauna while the rest of the house descends into the shivery expen$$ive 60s.

But just bumping the desired temp doesn’t work, because by midnight the temps in the carious rooms have slowly equalized. The time-of-day programmability features don’t have the resolution to track that slow equalization very well.

7

Something I tried (and it never quite worked) to deal with a bedroom in the back of my house that was always very very cold was to get a t-stat that would randomly cycle the (furnace) fan on and off through out the day in an attempt to keep temp equalized. You could try letting the furnace fan run for a few hours or a day to see if that helps and, if it does see about getting a t-stat that does that. Most new ones have that capaility. But, as I said, it really never did that trick. Everything I tried to warm that room up, short of cranking the temp in the entire house waaay up didn’t do anything to overcome the drafty window, no sun ever hitting that corner of the house and possibly some bad insulation over there.
In the end, I just stuck a small space heater in it. That did that trick. It was $50, I can turn it on a half hour before my daughter goes to bed and set it to turn off an hour after she falls asleep and all is well. However, I don’t have any issues in summer, so that’s good.

8

I have a two-zone system and one of my zones was hard to wire so we set up a wireless thermostat exactly where we wanted it. Not sure if some of the others suggest that or not, but that seems like the better way to go rather that have an additional sensor and a thermostat where you don’t want it.

9

Note: For an electrician or “wired security system” type workman, running wire and moving devices is quite a simple thing.

You also have the option of running an exposed wire like this…

Might want to get a couple of estimates.

10

I asked about this in regard to window mounted ACs. They already have remotes, wondered why the temp sensor wasn’t in the remote where it could be located somewhere practical instead of on the unit itself. What makes those remotes inexpensive is using optical transmission, requiring clear line of sight to the unit. I guess the same problem exists in general for thermostats. Seems like it ought to be something coming along though with Bluetooth or similar technology.

11

The main competitor to Nest, the “smart thermostat”, appears to be Ecobee. The thermostat comes with one remote temp/occupancy sensor, and apparently the ability to add more. Don’t know much about them, though.

12

I don’t know how t-stats with remote sensors communicate, but if you have a window unit with a remote it would be trivial to change it from IR to RF to eliminate the line of site issue*. However, you’ll probably still run into problems where people fall asleep with it under a blanket with them or go to work and it’s sitting in a spot that gets a lot of sun or some other issue that causes it to make the room far cooler than the user wants.
*The TiVo remote uses RF which is really nice. As long as you know where all the buttons are you can keep your arms under your blanket and still operate the remote just fine.

13

I had the same problem as you did and spent months researching the options, waiting for the perfect solution to appear. It sounds like the Ecobee3 is exactly what you’re looking for, provided you like the way it looks (I didn’t). For us, the desired sensor location was pretty close (upstairs, directly above the thermostat) so we got the Venstar with a remote (wired) sensor and had someone fish a wire to the second floor which was cheaper and easier than I expected. If you need to go further than that though, the Ecobee would probably do what you need. You can even use sensors all through the house to average them out if you like.

14

Something like that would work better if it was independent of the remote. Just something designed to be hung on the wall or placed on a shelf at some useful location. Not a bad idea for regular HVAC thermostats. Using more than one in a zone and a little logic could optimize heating/cooling cycles and identify where vents or baseboard dampers should be adjusted. The main problem is battery power. The device could communicate battery levels like my TV remote does, the appliance would have to know to use some default if the thermostat isn’t communicating. I’m sure this kind of thing and many others are on the way to fill the internet of things with content.

15

There’s actually already a few devices on the market that do that. There’s a central system and/or t-stat and each room has it’s own sensor and the vent has a damper. The sensor in each room can, on it’s own, open and close it’s damper as well as call for heat/AC.
The most recent generation I saw will also make sure enough vents are open at any given time to make sure there’s enough air flow across the heat exchange/AC coils to not cause any problems.
They’re simple, in theory, but I don’t think they’re cheap.

16

Sigh, I know I’m going against everything you said, but I just installed an Ecobee3 which includes a remote sensor. It’s a so-called “smart” thermostat and can be set to try to adjust the temperature to where you are. And yes, you can control it via Wifi and “hey Siri!” and your phone, but you don’t have to. And it’s just under two hundred bucks.

17

Another possibility:
Put a thick, dark film on the sauna room windows. I am nocturnal and have foil on the sliding glass door in the bedroom.
Most people balk at foil, but a film (sold AS a temp-reducing film) might be acceptable.

If you do go with a wireless design, you might want to put the controller in the same space as the furnace - as long as the sensor can reach it.
Don’t let the t’stat wires fall into the wall - I made that mistake when I stripped off wallpaper in that hall.
Somebody may want those wires again.

18

Doing some more research, it seems there are many lines of thermostats that move the control “brains”, relays, etc. to a base station box attached on/near the HVAC unit. Then the UI and temp sensor can be located anywhere in the house and connect wirelessly to the base station. And there can be more than one control head feeding the base station.

That’s probably closer to what I really want.

19

Another option, brand-wise is Totaline/Venstar. AFAIK, same devices under different names.

We had a Totaline stat with remote sender and it worked well. The remote had the option of being mounted to a wall or taken from room to room.

20

I installed this Venstar.

It made the house livable. Without it, the temperature swings were enormous.