Trouble Locating The T-Stat.

[stevenjr]

Trouble Locating The T-Stat

Hi, Im an Licenced Electrician working on my own house and doing the rough-in Im having trouble locating the T-Stat. I already roughed this in and was approved by the AHJ, well the
Electrical AHJ. I can still make changes and have it re-inspected.

See photo attachment

Photo Link :
http://i228.photobucket.com/albums/ee238/sje98/T-StatLocation.jpg

Here is the problem HVAC Crew located 2nd new return duct under the Hall closet about 24 x8. Maybe I should say built into the lower section of the hall closet. There are other metal round returns in the ceiling as well that they installed.
The Hvac Crew wants to put the T-Stat just 5 feet from it into the living room\ hall entry point .but about 3.5 feet above is a supply duct. This supply duct is just about over the T-Stat ( about 18" in front of it and 2 feet to the right) Im thinking system will cycle off to soon because of the supply duct above it. The other inside wall is taken up by a flat screen tv 2 feet from that is another supply duct in the ceiling.

There is no other place to put this T-stat other than the two locations in the photo. The is also Stairway in the photo that goes down to the finished basement from this hallway where I located the T-stat.

What is the best location for good air flow, and not dead air space .

If the Hvac Guys are correct the I will move it. I only placed The t-Stat There because No one got back to me on the location of where the T-stat goes, so I took my best guess just to get this electrical inspected and turned on for the The hvac guys to install and test the equipment. I figured I could move this stuff later if needed.

[canesfanforlife]

I think you should look into having your HVAC contractor put in a wireless t-stat. Then you could move it where ever or whenever you want. Very handy.

[crstephens83]

I personally don't like the look of the wireless t-stat, Get yourself a honeywell touchscreen t-stat and add a remote sensor and locate it in the return duct! Than you can put the t-stat anywhere and not have to worry about false readings. All you have to do is run another t-stat wire to the return duct from the t-stat location, you can even wire two sensors in series and have two locations that are being sensed, the t-stat will average the two readings!

[dj3901783]

Can't go wrong with CrStephens idea. I've seen t-stats close to supply ducts before and the only time I see a problem is when the air is directed straight towards the t-stat. With that placement just because as to which register you use. I usually mount the t-stat on an adjacent wall of where the a/h is or basically having the t-stat facing the a/h or return air below the a/h.

[stevenjr]

crstephens83,

I have a honeywell Th8320U 1008 . Looks like a Dual Heat or 3 heat unit and Cool. Also has a heat pump and conventionl connections on it. Would this work ?
I have not looked up the PDF from honeywell on this yet. just went out to my truck after I read your post and pulled it out of my glove compartment. It was given to by a demolition contractor on a job I had to remove the three phase power connections from some large AC units. I was thinking about the wireless, but there could be RF interferance at 2.4 GH some microwaves interfere on that Freq, though I never seen it happen.

I like your Idea on this . this would solve some problems , save me another inspection fee, and no heated debates with the Hvac Crew. I do very little Hvac these days mostly the big 3 phase power hook up for commercial jobs.

[stevenjr]

Looks Like this unit honeywell Th8330 has the remote sensor .
Remote Indoor Sensor for the VisionPRO line.

Spectification
• Used to sense temperature if the thermostat is installed in a poor temperature sensing location.
• Small remote temperature sensor to match any room decor.
• Easy to install and use.
• Factory calibrated; no field calibration required.
• Works with a maximum 200 foot wire run.

$ 53.00 from honeywell's site

This is the only remote sensor I could find for this unit. did not see an option for a sensor in the duct work . or is this it. other than the Outdoor Temp Sensor.

[crstephens83]

yeah that is the t-stat that I was talking about! If you read the instructions it will tell you how to wire in the sensors. You will need to talk to a local supplier and find out if they make a duct sensor for that t-stat. I have myself used the regular sensor and mounted it in the duct, but it is a little costly for mounting in the duct. also the t-stat will need to be programmed for the remote sensor in the installers programming menu!

[stevenjr]

crstephens83

Great, thanks for the information. I went down to my local Heating and AC Supply place. their going to order the kit for me abot $ 108.00 for the two that mount in the duct work. honeywell did not list the sensors that mount in the duct work on the web site. but the heating contrator wearhouse has them in there order book. It seems there are two differnt type sensors. thanks again crstephens83 and eveyone else for the professional advice. The Hvac Crew took off $50.00 off the 7,500 bill for the T-Stat. wow... now I can fill my service truck gas tank half way.

[flange]

So if you put the tstat in the return air in the basement, wouldnt you have a problem with ac season, when all of the cool air will tend to drop to the basement and cause your stat to be satisfied even when upstairs is not? and the converse in winter?

[crstephens83]

well that is the downfall to having a two story, you will never be completely satisfied unless it is zoned properly, or two units, but if the two sensors are wired in series than you will get a happy medium between the two sensed locations

[zip605]

I've got my remote sensor located in the return drop. A few inches prior to the filter. In the basement. During the summer, the basement will be about 65-68 degrees. If I don't keep the fan circulating all the time, the stat will never call for cooling.

I don't remember what happens in the winter, but it's not what you want.

I keep the fan circulating all the time (Rheem Mod - variable speed), so I'm not overly concerned about the electric usage. The constant air movement helps even out the temps in my 2-story. Everything works well, but only if the fan keeps going.