Looking for a more sensitive thermostat

[Mr. Austerity]

here ya go, a high dollar one that looks purty and it's smart....

Probably won't work any better than what you have but the economy needs the money, buy one.

[CraigT]

There is a secondary menu you can bring up by holding down two buttons at the same time where you can choose H1, H2, or H3, C1, C2, or C3. H1 C1 gives the shortest cyles, both running and non-running, for Heating and Cooling and coversely H3 C3 gives the longest cycles. Both elctronic thermostats I've owned had these sub menus.

What difference would it make what kind of heating and cooling I have. The system is functioning properly, just not the way I want it to. My heating and cooling bills are relatively low for the size of the house and temps are pretty consistant in every room. I am not going to spend $10,000 to replace my HVAC when all I want is a $100 thermostat. They built varying amounts of sesitivaty into thermostats so as to suit different people's comfort levels, I just want a little more cycling than the average person.

No.

No.

Is it in a secluded corner where it can't get a good

No

It is not multi-speed.

I am not looking for something wild and crazy. I'm just asking for a little more of an adjustment than the amount that the average thermostat provides.

[CraigT]

This might be something I would be interested in. Thank You.

[CraigT]

Yes, slightly more stable temps. I am not looking for anything drastic. Like I said, most electronic thermostats have adjustments for sesitivity, I just want one setting more sensitive than the most sensitive setting I have had in the past. I'm really not sure what the settings H1, H2, or H3 mean exactly when it comes to temp. swings. If H1 allows a .5F swing and H2 allows for a 1F swing and H3 allows for a 1.5F swing then I guess what I'm looking for is something less than .5F If H1 means 1F swing, H2 means

1.25F swing, and H3 means a 1.5F swing, I guess I'm looking for a setting which allows for a swing of less than 1F.

I have to believe that there has to be some variation between the manufacturers of thermostats and that there is one out there more suited to me or maybe one with much greater control, but not to the point of causing damage to the system.

[Twayne]

You talk a lot about "settings", but what settings? Various (and most) thermosats have a hysterisis control and an on/off temperature setting. The cycle setting is right n the thermostat and the other temp on/off settings are in the furnace. I can't help but wonder if you aren't shot-gunning t here when the answer is rght in front of you if you look at the right access points.

HTH,

Twayne`

[Vic Smith]

Know what you mean. I don't like short cycling either. Especially noticeable when temps are very low. The Honeywell I have has a 3 degree swing range, but even set at 3 degrees it acts at about 1-to 1.5 degrees. Seems the thermostat manufacturers go for comfort to avoid complaints. Ran across this that somebody mentioned in a forum.

Supposedly can be set with up to 8 degree swing, but make sure.

--Vic

[mike]

There's a gradient across the room due to losses on the outside walls. There's a gradient top to bottom due to stratification. The air coming out of the heater vent is a LOT hotter than the setpoint. There's infiltration. You probably have a single point temperature measurement for the whole house. Given all this, I'd be AMAZED if you could tell the difference between .5 and 1.0 degrees hysteresis in the thermostat. Methinks you're addressing the wrong problem.

I think the Honeywell VisionPro 8800 will do what you ask. I just don't think it will solve your problem.

[dpb]

...

You read him wardsback...he does want very short cycling.

--

[cjt]

Is the wall behind it sealed? If not, cold air can travel through the wall space and dramatically affect thermostat operation.

[Vic Smith]

Then I take it it back I said whatever. (-:

--Vic

[Steve Barker]

sounds like your system is too big. You might explore having the blower speed turned down.

[JIMMIE]

My brother has a similar problem. I told hime get rid of the freakin' jalousy windows. They may as well be open for all the good they are doing. Be cautious of HVAC guys who dont consider how your home is insulated.

Jimmie

[Home Guy]

Well, if you gave the make/model numbers of these thermostats, we could obtain the documentation for them on the web and figure out what the H1/C1 settings correspond to in terms of actual degrees (C or F).

Different systems (particularly heating systems) have different time-constants and different abilities to inject heat into your living space. We are talking about a feedback loop between the thermostat and the furnace (or heat-source) and you seem to have a problem about the responsiveness or over-shoot/under-shoot of this feedback loop.

So, you have a pretty basic furnace (a "builder's furnace") which is what the contractor was able to pull off the back of someone's truck and throw into the basement.

I'm going to guess that you're not the original owner of the house, and now that you've been living in it for 6 months you don't like how the HVAC system is working compared to your last house.

Go to home despot or Lowes or some other hardware store and browse through the thermostats and look for one that specifically lets you set the span or hysteresis IN TERMS OF DEGREES C or F and not some unknown parameter or value.

You might also want to do this:

Go and buy a $10 indoor digital thermometer that can track the MIN and MAX temperature and display it to you at the push of a button. Set this thermometer on the coffee table next to your favorite arm chair, wait a few hours and hit the RESET button, and leave it alone for a few days. After that, check what it recorded for the Min and Max temperature and come back here and post those numbers.

If those numbers are Min: 66 / Max: 74, then yes, you have a problem. If the numbers are 69/71, then I'd say what are you complaining about.

One final question: Have you programmed your current thermostat to turn down the temperature during the night (say, from midnight to 6 am) to something like 65 or 66, and then raise the temp up to 68 or 70 during the day?

[gregz]

Cycles per hour is not something I would like to have. The number of cycles has nothing in common with temperature controlled lab experiments, and might only have to do with efficiency, where too many cycles is a bit less efficient.

You have to read up on thermostats. Most I have used go to a minimum one degree sensitivity. That's only a start. Some have learning modes so the unit actually functions as a true PID controller that initially learns the needed curve to avoid overshoots, and really good ones adds fuzzy logic to add needed programing as it ages. The specs on most furnace stats tell little. I do think some honeywell thermostats do indeed act smart. Drafts and placement on walls trick the thermostat so that needs to be addressed. Multiple zone sensors as well as personal portable remote sensors make temperature more personal and more accurate. The size of the source of heat or cold unit will change the time constants, and of course best to size properly. Even though. The thermostat, say is going to go plus and minus degree adjustment, a good one will be measuring tenths of a degree resolution to make computations.

Greg

[gregz]

I was looking for an example of one specifying PID controller. Here

[1001110010001]

Who cares about a thermostat? I'm looking for a "more sensitive" WOMAN!

[1001110010001]

Who cares about a thermostat? I'm looking for a "more sensitive" WOMAN!

[micky]

Okay, conservative. Thanks for the advice.

[trader4]

I asked the same thing many posts ago too. It's remarkable that we don't have the most basic info, which is exactly how big the objectionable swings are. If it's 69/70, I doubt any thermostat is going to fix the problem. If it's 69/72, then any digital thermostat will likely do much better or there is a problem other than the thermostat. And that is assuming the temp fluctuations are at the thermostat. If they are in a room remote from the thermostat, then it's very likely not a problem that any thermostat is going to fix. Essentially he's asking for a thermostat capable of holding temp range X, without telling us what X is.

[trader4]

Wouldn't it be a good idea to RTFM?

Still waiting to hear:

A - Exactly what is the objectionable temp swing, ie .5 deg or 3 deg?

B - Is it that swing measured at the thermostat or somewhere else in the house?