"Our thermostat sucks!"

[Andrew]

Hi everyone,

 

Must say I'm kinda pleased at my wife's irritation with our current thermostat (we have two but more on that later).

 

What a great opportunity to justify replacing our thermostat(s)... : )   .....we have upstairs and downstairs heating and cooling units, so I'd likely be replacing both. We have forced air.

 

We have the ISY994iZw unit.

 

So, therefore... I'm looking for recommendations for anyone who might have an Insteon or Z-Wave thermostat installed.

 

Also, any common pitfalls?

 

thanks,

Andrew

[paulbates]

Hi Andrew

 

I suggest coming up with basic requirements first; what is it that you don't have in your current thermostat that you want addressed with a new one? To me, functionality trumps which connection type (zwave vs insteon). 

 

Others can provide feedback based on you saying "I want xxx", and "I don't want yyyy"

 

Paul

[Andrew]

Hi Paul,

 

Easy -

 

I'd like it to:

 

1) Be accurate

2) Be easily programmable

3) Be reasonably versatile (7 day)

 

Our two current thermostats are different; the one upstairs is a very old (1989) Honeywell that isn't even close to being accurate.

The downstairs thermostat is a newer Honeywell, but unfortunately can't seem to accurately tell the temperature either. That said, it's fairly easy to program.

 

As far as it being wireless - no, it doesn't have to be, but it would be nice to be able to log energy use, if any allow that. Also, control remotely

 

thanks,

Andrew

[paulbates]

Andrew

About how old are the furnaces?

 

 

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[larryllix]

Hi Paul,

 

Easy -

 

I'd like it to:

 

1) Be accurate

2) Be easily programmable

3) Be reasonably versatile (7 day)

 

Our two current thermostats are different; the one upstairs is a very old (1989) Honeywell that isn't even close to being accurate.

The downstairs thermostat is a newer Honeywell, but unfortunately can't seem to accurately tell the temperature either. That said, it's fairly easy to program.

 

As far as it being wireless - no, it doesn't have to be, but it would be nice to be able to log energy use, if any allow that. Also, control remotely

 

thanks,

Andrew

How about Intelligent recovery? You need intelligent setback and intelligent recovery.

After having a few thermostats with intelligent recovery I found  it never worked very well after sudden weather changes and warming the house up always used the desired temperature "arrival" time but the setback always had to be predicted and adjusted seasonally. After much confusion during years of usage I always turned the option off.

 

How about 0.5 F accuracy of setting? If you switch to C and it only supports 0.5C setting resolution  or 0.5C sensing resolution you can get some heat waves where the temperature varies too much before cycling. This is not usually a problem when heavy heating is required but in mild season where small amount of heat are required can be annoying..

 

How about multiple heating zones? Do you have separate zones in say main and basement and would like the thermostats to co-ordinate between them or by ISY intervention? Logging of usage or cycles?

 

How about outside temperature sensing? You can see what to wear outside from your thermostat and thermostat can predict "how hard to hit the heat cycle", avoiding temperature swings.

 

Pulse width modulation is a newer technique to cycle furnaces to make the house temperature  have less swings as in above.

 

Fan cycling. Nice feature on higher tech units to be able to circulate your house air about 3:00 am when it starts to get stuffy from human exhalation in closed rooms.

 

Have an HRV to control/cycle for oxygen or humidity control?

[paulbates]

You might be a candidate for the 2441th from Insteon. The reason I ask about the furnace's age is that some older furnaces cause the 2441th problems.

 

 

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[xKing]

C-wire availability is the factor as well

[stusviews]

We've been happy using the Insteon 2441TH thermostats as mentioned by paulbates (#6). We have one for each zone as well as a few wireless thermostats. Both temperature and humidity can be calibrated, they're  easily programmed (both features manually) and can be controlled using the ISY. The Insteon thermostat should work with any HVAC that uses 24VAC (virtually all do) no matter how old.

 

xKing makes an important point. You need at least 5 wires at the thermostat if you have both heating and cooling. There is a workaround if you have only 4 wires at the thermostat that requires an Add-a-Wire kit.

[Andrew]

Thanks everyone!! Responses below.

 

Andrew
About how old are the furnaces?


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Hi Paul-

 

One (upstairs) is original - 1989. The one downstairs was replaced, but I forget how long ago... possibly 10-12 years. I could try to find the model numbers if that helps.

 

How about Intelligent recovery? You need intelligent setback and intelligent recovery.

After having a few thermostats with intelligent recovery I found  it never worked very well after sudden weather changes and warming the house up always used the desired temperature "arrival" time but the setback always had to be predicted and adjusted seasonally. After much confusion during years of usage I always turned the option off.

 

How about 0.5 F accuracy of setting? If you switch to C and it only supports 0.5C setting resolution  or 0.5C sensing resolution you can get some heat waves where the temperature varies too much before cycling. This is not usually a problem when heavy heating is required but in mild season where small amount of heat are required can be annoying..

 

How about multiple heating zones? Do you have separate zones in say main and basement and would like the thermostats to co-ordinate between them or by ISY intervention? Logging of usage or cycles?

 

How about outside temperature sensing? You can see what to wear outside from your thermostat and thermostat can predict "how hard to hit the heat cycle", avoiding temperature swings.

 

Pulse width modulation is a newer technique to cycle furnaces to make the house temperature  have less swings as in above.

 

Fan cycling. Nice feature on higher tech units to be able to circulate your house air about 3:00 am when it starts to get stuffy from human exhalation in closed rooms.

 

Have an HRV to control/cycle for oxygen or humidity control?

 

Hi Larry,

 

Intelligent recovery - not sure. Probably?

 

.5˚ accuracy - sure. I haven't looked into the tolerance of any thermostat we've had.

 

Multiple heating zones: well, we have one upstairs unit and one downstairs unit (none in the basement) and they currently work independently. Logging would be nice but I don't think I need any coordination, specifically, though if it reduces programming somehow, it may be nice.

 

Outside sensing - Maybe but only from the standpoint of prediction. We typically check our phones before getting dressed if we're unsure of the weather.

 

Pulse width: sounds good.

 

Fan cycling: yeah, that sounds good too! I know my downstairs thermostat has a "fan only" setting so that would be great. Upstairs, my thermostat can't do it but I think I could control the fan if the thermostat had the setting.

 

HRV - no idea what that is!

 

You might be a candidate for the 2441th from Insteon. The reason I ask about the furnace's age is that some older furnaces cause the 2441th problems.


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Possibly - I looked it up and thought it was funny that the 1st two bullet points were:

• Plastic
• Imported

Lol....

 

I'm assuming the 1989 unit in the attic may not be the best bet. I'll look into them this afternoon to see if I can find models.

C-wire availability is the factor as well

Hi xKing -

 

Not sure what that is but I'll look it up.

[paulbates]

Andrew

I just replaced two Bryant units from from 1989. The igniters for the gas in these two furnaces would cause the 2441TH to lock up and stop working. It is rare for this to happen but you need to run the furnace in heat mode to know for sure. For me sometimes it took up to seven heat cycles for the problem to show up.

 

You've probably off for the summer already so I wanted you to know that this could happen

 

 

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[paulbates]

The C wire provides power. Typically older Honeywell thermostats were battery-powered and as a result the c wire, which provides power, is not run from the furnace to where the thermostat is installed. Some people install a power supply at the thermostat to get around this.

 

 

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[Teken]

Newer houses have the option to include HRV (Heat Recovery Ventilation) this essentially uses the dirty stale air being exhausted out the house and pre-warms the outside (inbound) air. Doing so allows the furnace to heat / cool air more or less.

 

The only down side to a HRV is the electrical load on the home. So, if you're trying to reduce your energy consumption this vampire load can be quite dramatic on the monthly electrical bill.

 

There are many types and brands of HRV's and some of them operate extremely well. Whereas some other cheaper brands / units are nothing but a energy hog that offers very little air quality differences.

[larryllix]

Newer houses have the option to include HRV (Heat Recovery Ventilation) this essentially uses the dirty stale air being exhausted out the house and pre-warms the outside (inbound) air. Doing so allows the furnace to heat / cool air more or less.

 

The only down side to a HRV is the electrical load on the home. So, if you're trying to reduce your energy consumption this vampire load can be quite dramatic on the monthly electrical bill.

 

There are many types and brands of HRV's and some of them operate extremely well. Whereas some other cheaper brands / units are nothing but a energy hog that offers very little air quality differences.

Mine replaces all the bathroom exhaust fans as well as in the laundry room to control humidity and smells. The fan motors are 1/20 hp or something really small. Southern climates usually have never heard of this (ooops... thanks Teken) as they don't have a vapour tight house with R20-R60 insulation either.

[xKing]

I live in the south (Dallas, TX area) and very interested in a way of mixing in the filtered (darn pollen!) exterior air for cooling. Sometimes it gets down to like 72F outside after a hot day and I would love to use some of that air to cool the house down. Is there a way to do that using the existing closed cycle furnace, install some kind of a damper? 

 

I do NOT want the whole house fan Thanks!

[Teken]

I live in the south (Dallas, TX area) and very interested in a way of mixing in the filtered (darn pollen!) exterior air for cooling. Sometimes it gets down to like 72F outside after a hot day and I would love to use some of that air to cool the house down. Is there a way to do that using the existing closed cycle furnace, install some kind of a damper? 

 

I do NOT want the whole house fan Thanks!

 

If you're talking about a HRV style I don't believe there is a way (normally) to accomplish this with out it actually being a whole house fan / air exchange unit.

 

How exactly would you like this to work in your personal environment though? Are you needing this to bring in cool fresh air only to one room / floor / zone?

[paulbates]

I live in the south (Dallas, TX area) and very interested in a way of mixing in the filtered (darn pollen!) exterior air for cooling. Sometimes it gets down to like 72F outside after a hot day and I would love to use some of that air to cool the house down. Is there a way to do that using the existing closed cycle furnace, install some kind of a damper? 

 

I do NOT want the whole house fan Thanks!

 

There are different solutions for this, the general term is "free cooling". I evaluated it when I replaced my 2 furnaces last fall, but it was going to be a big job to go through the foundation of my 1950s house and simply install the unit. My climate conditions in Michigan create a very long season that can take advantage of free cooling, but the cost of installing the unit in my older house far outweighed any savings I would ever see in electricity.

 

I would start with several HVAC contractors in your area for advice / costing.

 

FWIW The Venstar colortouch (T5800, T5900, T7850, T7900) series thermostats can be configured to coordinate control the free cooling unit with AC when you use its external sensor.  

 

Paul

[G W]

I live in the south (Dallas, TX area) and very interested in a way of mixing in the filtered (darn pollen!) exterior air for cooling. Sometimes it gets down to like 72F outside after a hot day and I would love to use some of that air to cool the house down. Is there a way to do that using the existing closed cycle furnace, install some kind of a damper?

 

I do NOT want the whole house fan Thanks!

In Colorado, we use small evaporator cooling systems tied into the main HAVC. This way the air is filtered and it cheaply cools the house.

[larryllix]

One way that works fairly cheaply is to install a power attic vent. You can turn these on at select times drawing in through a passive and filtered vent in the lower house, up through he home and through the attic hatch (power open?) and out the attic. This helps cool your home down much faster as the outside air hits the living parts first and also keep the attic cooler so the ceilings don't radiate that heat at you all night.

 

This also follows the natural convection that your house wants to do in the evening consuming less energy to make it happen. Humidity would be a deterrent for this system.

 

Expect the attic fan motors to last 2-3 years so make sure it is easily replaced without tearing shingles off from the roof. 

[paulbates]

One way that works fairly cheaply is to install a power attic vent. You can turn these on at select times drawing in through a passive and filtered vent in the lower house, up through he home and through the attic hatch (power open?) and out the attic. This helps cool your home down much faster as the outside air hits the living parts first and also keep the attic cooler so the ceilings don't radiate that heat at you all night.

 

This also follows the natural convection that your house wants to do in the evening consuming less energy to make it happen. Humidity would be a deterrent for this system.

 

Expect the attic fan motors to last 2-3 years so make sure it is easily replaced without tearing shingles off from the roof. 

 

I have a modified version of this Larry. The original house from the 50's came with a HHF in the gable and manually operated dampers between the second floor ceiling and the attic.

 

I replaced the original dampers with Tamco 9000 sealed / insulated dampers and a motor. Depending on the conditions and certain windows being open, I can open the dampers and run the gable fan using 2 speeds, or just open the dampers let the warmer air passively rise out of the house on cooler evenings. The dampers seal and insulate impressively during operational months, and a foam block goes in the opening above them in the attic in the winter.

 

Not ideal, but given the retro construction aspect, it was relatively inexpensive. My wife loves the HHF this time of year and the fall.

 

Paul

[xKing]

There are different solutions for this, the general term is "free cooling". I evaluated it when I replaced my 2 furnaces last fall, but it was going to be a big job to go through the foundation of my 1950s house and simply install the unit. My climate conditions in Michigan create a very long season that can take advantage of free cooling, but the cost of installing the unit in my older house far outweighed any savings I would ever see in electricity.

 

I would start with several HVAC contractors in your area for advice / costing.

 

FWIW The Venstar colortouch (T5800, T5900, T7850, T7900) series thermostats can be configured to coordinate control the free cooling unit with AC when you use its external sensor.  

 

Paul

 

 

Thanks, for all your suggestions, guys

 

I'm thinking of something like this:

 

My problem with the traditional "whole house fan":

- need to open windows manually

- incoming air is not filtered and pollen gets sucked into the house

 

My house is 2 story ~2600 sq/ft with 2 HVAC systems (upstairs and downstairs) so I'm still thinking/deciding. Ability to vent the house with the cool FRESH air would be great.

[Teken]

Just so we are all clear because I am taking the image supplied by xKing literally. I know way back in the day before anyone knew what not to do in terms of venting bathroom (humid) air into the attic space.

 

This caused ice damning, mold, rot, etc.

 

All newer houses vent directly to the outside by way of a central exhaust duct work etc. Nobody is really entertaining the idea about venting dirty internal air back into the unconditioned attic are they???

[G W]

That depends on the structure and area of Tera on which the building is located.

[Teken]

That depends on the structure and area of Tera on which the building is located.

For this specific instance lets just say it's a current home that vents to the outside. Nobody is going to vent stale bad (humid) air into the attic, right?

 

 

Ideals are peaceful - History is violent

[paulbates]

My problem with the traditional "whole house fan":

- need to open windows manually

- incoming air is not filtered and pollen gets sucked into the house

 

The other disadvantage of the WHF is the possibility to backdraft hot water heaters' exhaust stack back into the house.  I've not had this problem, but it needs to be evaluated.

[G W]

If the home is in New Mexico, Yes.