[blazar]

The hydronic floor system that we put into our house has tremendous efficiency and long term cost of ownership is very good. This is a great way to generally heat your home and make your floor a bit warmer. Coupled with foam insulation, it makes for very inexpensive and very comfortable living in the winter. The cost of initial install in a new house build is definitely pricey however.

These issues aside, my system came with 5 two-wire thermostats. One wire leads to R and the other to W on the simple thermostats they provide. This is all well and good except I wanted Hydronic floor control with my Control4 Thermostats.

So here is the step by step process I went through to achieve this:
1. You will need a "common" power wire from the circuit board of your floor heating system. This is fairly easy, especially if they wired your thermostats with at least 4-conductor wire. If not, then you are screwed and have to run new wire to your thermostats... this could be really easy or really hard. In my case I had the extra wire, and I wired it to the common lead off my control board. You turn off the "power stealing" feature of the thermostat.

2. So I thought it would be that simple... Red wire to R, White wire to W1, and C to the common lead on my control4 thermostat. This is in fact the correct way to wire the thermostat. In fact, the control4 manual says it will work with heated floor systems. However, as soon as my relay clicked in the thermostat to activate the valve to my heated floor zone, the thermostat would turn off. Just to be sure it just wasn't this brand of thermostat, I checked a honeywell wifi thermostat and it did the same thing. After some research it turns out that sometimes when a valve closes, you might actually steal all the power leaving none for the thermostat... it appears this is what was going on more or less.

3. Next step: buy an isolation transformer circuit. Here is a 3 zone version for your reference. I have 5 zones so I bought two boards.

SKU:IR882 Brand: Argo

The instruction sheet made it very easy to setup up this circuit in between my thermostat and my hydronic floor controller board. You do need to do some wiring but there is no soldering involved since it is all screw-tight connectors.

4. Now the control4 thermostats work great and I can now coordinate my AC/cooling/forced air heating with my heated floor while also coordinating with outside air temperature. I find that outside temperature is a better variable to decide if the heated floor should be on. Once that is settled you can be sure that the AC/cooling is definitely off any time the heated floor is on. Really the point is to be able to set a temperature that you like and keep the house that temp the whole year round while not overlapping the cooling and heating systems and consequently wasting money.


This project can reasonably be done by a DIY with some basic understanding of wiring and electricity safety. Otherwise, just have your hydronic floor folks put the isolation transformer in for you. Your control4 person can take care of the thermostat integration.

Honestly I think the hydronic floor circuit should come with high quality isolation relays... I have no idea why they don't since there is no real downside.

For those building a new hydronic floor, seriously consider putting the thermostat boxes at the control board and do remote thermostat wires. This will give you a cleaner install and nobody can mess with the system. Place the thermostat wires for the AC system along the same zones as the heated floor. Also put the hydronic thermostats and the AC thermostats together so that they coordinate better without overlap (where both systems are on and fighting each-other).


For the most part, I feel that home AC equipment is antiquated from the control perspective. They should all be IP controlled as far as I'm concerned. A nice Cat6 cable to your thermostats and interconnectivity between AC, hydronic floor, etc would be the most plug and play. I suppose this won't happen any time soon.

 

[SMHarman]

There is a new control4 thermostat coming out imminently.

 

[bigbarney]

Really the point is to be able to set a temperature that you like and keep the house that temp the whole year round while not overlapping the cooling and heating systems and consequently wasting money.

That's actually not the case most of the time, especially in colder climates. In the Winter time you're dressed in pants, shirt and even sometimes a sweater while in the Summer you're in shorts and a T shirt. We run the house at 68 in the Winter and about 71 in the Summer. Not to mention humidity is a huge factor in "feeling" hot or cold and that changes pretty drastically from Summer to Winter (depending on where you live)

At any rate, unless you live in someplace like Florida where the weather doesn't change too drastically from season to season, rarely will some one run the same temperatures in Summer as in Winter.

Most thermostats with an "automatic" feature (switches from AC to heat on its own) have a 2 degree differential between switching to avoid fighting between the AC and the heat, and most people find that to be an acceptable degree of separation.

 

[blazar]

That's actually not the case most of the time, especially in colder climates. In the Winter time you're dressed in pants, shirt and even sometimes a sweater while in the Summer you're in shorts and a T shirt. We run the house at 68 in the Winter and about 71 in the Summer. Not to mention humidity is a huge factor in "feeling" hot or cold and that changes pretty drastically from Summer to Winter (depending on where you live)

At any rate, unless you live in someplace like Florida where the weather doesn't change too drastically from season to season, rarely will some one run the same temperatures in Summer as in Winter.

Most thermostats with an "automatic" feature (switches from AC to heat on its own) have a 2 degree differential between switching to avoid fighting between the AC and the heat, and most people find that to be an acceptable degree of separation.

Yes, I plan to actually have the system adjust based on outside temperature as well since that is often the variable that seems to effect subjective comfort in our area. We live in a low humidity area for most of the year so this isn't much of a factor.

For us, when it is hot out, we actually need to turn the temp down lower on the thermostats by a few degrees compared to when it is cold outside. I am basically planning on setting up a different temperature threshold program based on the outside temp. I am not sure exactly what outside temp threshold to pick yet without a little experimentation. Our day/night temp variability is very wide so think it will help to adjust based on outside temp.

 

[blazar]

There is a new control4 thermostat coming out imminently.

the trouble with the control4 thermostat that is coming out is the retail price of $350 for a thermostat that does nothing special compared to others on the market. It is simply too little too late. The honeywell wifi thermostat for $180 retail does everything and more, offering outdoor temps/humidity based off the internet and indoor also humidity. It is less clear if third party drivers for control4 integration will actually allow you to use the outdoor temp and humidity data.

Cosmetically there is nothing "wrong" with the new control4 thermostats, but they lack any whiz-bang features or cosmetics. The Nest is a pretty looking thing although it seems annoying to navigate with it.

Remember that when you sell a house, the Nest thermostat "looks cool" and makes the buyer think that the house has been "upgraded"

I believe the "future" of thermostats is to have all of the thermostat relays sitting at your HVAC unit while being controlled wirelessly via your "apple TV" or equivalent device. The thermometer itself would be wireless and mounted hidden from plain sight somewhere. The actual thermostat design that is out now is a throwback to mercury switches. The new HVAC systems should throw out that whole concept and simply add remote wired/wireless thermometers and homekit support. I would envision that you just plug your wireless thermometer into an extra electric outlet somewhere.

At the very least, control4 should have just made all their thermostats built into their touch control panels. This way the damn thing could perform double duty... These home automation company design decisions continue to boggle the mind.

 

[SMHarman]

You talk about the industrial design of the thermostats. If you are in a situation like gut reno or New construction where you can hide them in closets and use remote sensors that embed in the walls or ceilings the design of the wall wart does not matter.

 

[bigbarney]

I believe the "future" of thermostats is to have all of the thermostat relays sitting at your HVAC unit while being controlled wirelessly via your "apple TV" or equivalent device. The thermometer itself would be wireless and mounted hidden from plain sight somewhere. The actual thermostat design that is out now is a throwback to mercury switches. The new HVAC systems should throw out that whole concept and simply add remote wired/wireless thermometers and homekit support. I would envision that you just plug your wireless thermometer into an extra electric outlet somewhere.

=================================================================

You can pretty much do that already with the Honeywell Prestige 2 IAQ (redlink) thermostat. It's completely wireless (with exception to the 24volt supply). It communicates with a wireless control module located at your furnace. All the wires that normally connect to the thermostat instead connect to the control module and the module connects to the thermostat wirelessly. You only have to feed the thermostat 2 wires (24 volts). That can come from the furnace transformer or from any plug in wall transformer

The thermostat and control module operate on what's called REDLINK (a honeywell wireless technology) which allows you to add indoor and outdoor wireless temp/humidity sensors. You can use one remote indoor sensor located anywhere in the house, or you can use up to six indoor remote sensors spread all over the house and the IAQ will average all the temperatures for more even heat through the house.

The system also comes with 2 additional temperature probes which constantly measures DELTA T (the difference between intake and output of the furnace). Each furnace stage is supposed to put out a certain temperature and if a stage fails then the probes pick up on it and send you a warning. Delta T will also change if your furnace filter is dirty or your blower motor is not up to speed and you will get an alert.

With the internet gateway added, you have full control on your cell phone or computer. You can even add a redlink wireless remote and control the system like you would control your tv with any remote.

Unlike the Nest it comes with several extra sets of programmable contacts which you can use for alert systems if your sump pump over flows or similar.

There is not one but rather THREE very detailed logs that the thermostat keeps. The logs are in XML format so you can transfer them to computer and place them on a spreadsheet. The first log is your performance log which logs ALL varibles every 20 minutes or so... indoor temp, outdoor temp, delta T, humidity... yadda yadda.... pretty detailed. The second log is your alert log which keeps a log of any alerts sent out, warnings, or failures. The third log is the change log which logs any changes you make on the thermostat.

The thermostat has two different modes of operation... residential and commercial... each one having their own pros/cons (the comercial mode for example can operate on downloadable holiday shedule... etc) so it would be up to you on how you want to set it up.

Unlike the Nest, the IAQ displays almost all information on one screen so you don't have to touch it... time, date, indoor temp and humidiy, outdoor temp and humidity, running mode, etc. The display back ground color can be changed to better match the paint on your wall.... or because it's wireless you can mount it in a hidden place of your choice.

If you want a REAL thermostat then look at the IAQ and forget these other rather consumerish deals.

 

[blazar]

=================================================================

You can pretty much do that already with the Honeywell Prestige 2 IAQ (redlink) thermostat. It's completely wireless (with exception to the 24volt supply). It communicates with a wireless control module located at your furnace. All the wires that normally connect to the thermostat instead connect to the control module and the module connects to the thermostat wirelessly. You only have to feed the thermostat 2 wires (24 volts). That can come from the furnace transformer or from any plug in wall transformer

The thermostat and control module operate on what's called REDLINK (a honeywell wireless technology) which allows you to add indoor and outdoor wireless temp/humidity sensors. You can use one remote indoor sensor located anywhere in the house, or you can use up to six indoor remote sensors spread all over the house and the IAQ will average all the temperatures for more even heat through the house.

The system also comes with 2 additional temperature probes which constantly measures DELTA T (the difference between intake and output of the furnace). Each furnace stage is supposed to put out a certain temperature and if a stage fails then the probes pick up on it and send you a warning. Delta T will also change if your furnace filter is dirty or your blower motor is not up to speed and you will get an alert.

With the internet gateway added, you have full control on your cell phone or computer. You can even add a redlink wireless remote and control the system like you would control your tv with any remote.

Unlike the Nest it comes with several extra sets of programmable contacts which you can use for alert systems if your sump pump over flows or similar.

There is not one but rather THREE very detailed logs that the thermostat keeps. The logs are in XML format so you can transfer them to computer and place them on a spreadsheet. The first log is your performance log which logs ALL varibles every 20 minutes or so... indoor temp, outdoor temp, delta T, humidity... yadda yadda.... pretty detailed. The second log is your alert log which keeps a log of any alerts sent out, warnings, or failures. The third log is the change log which logs any changes you make on the thermostat.

The thermostat has two different modes of operation... residential and commercial... each one having their own pros/cons (the comercial mode for example can operate on downloadable holiday shedule... etc) so it would be up to you on how you want to set it up.

Unlike the Nest, the IAQ displays almost all information on one screen so you don't have to touch it... time, date, indoor temp and humidiy, outdoor temp and humidity, running mode, etc. The display back ground color can be changed to better match the paint on your wall.... or because it's wireless you can mount it in a hidden place of your choice.

If you want a REAL thermostat then look at the IAQ and forget these other rather consumerish deals.

nice, those look like very useful long term advancements. I think the pricing on all this should really improve with standardization across the industry. We need a unified IP protocol for HVAC data that should be defined by the biggest players (like honeywell) in this market. Unfortunately each company is still doing its own proprietary thing which has been the achilles heel of the consumer electronics market for a long time. In many ways, the industry as a whole is up to its usual shenanigans which makes it harder for consumers to make clear cut choices/purchases.

I understand the profit motive and the need to keep competitors at bay, but these are the very strategies that lead ultimately to customers going to disruptor companies like Apple and Google. Consumer IT simply is not the strong suit of so many HVAC and CE corporations.

This is especially true of consumer electronics which also do not have a unified IP based control protocol... but instead a bunch of obscure codes without a standard driver model.

In a "perfect world" there would be no need for Crestron or Control4 based on current technological limitations. I would say implementation of available technologies is still behind by about 15-20 years compared to what the technology has been capable of for a long time.

 

[bigbarney]

Unfortunately each company is still doing its own proprietary thing which has been the achilles heel of the consumer electronics market for a long time. In many ways, the industry as a whole is up to its usual shenanigans which makes it harder for consumers to make clear cut choices/purchases.

I understand the profit motive and the need to keep competitors at bay, but these are the very strategies that lead ultimately to customers going to disruptor companies like Apple and Google. Consumer IT simply is not the strong suit of so many HVAC and CE corporations.

Well, that can be looked at as good or bad depending on the angle. I have a DSC alarm and a Honeywell thermostat and at first I was bit angry at having to use two different apps for control, but it's kind of a blessing in disguise... if one system goes down you can still control the other. It's the common parts which weakens the entire concept. Your internet connection for example. That made me think a bit. If systems remain independent from one another... is that such a bad thing? The other thing to think about is security. If the system is all common then once a hacker is in... then they're into EVERYTHING.

I'm slowly learning the benefits of separate systems and after considering it all carefully enough, I'm not sure I would want a single common control circuit.

 

[blazar]

Well, that can be looked at as good or bad depending on the angle. I have a DSC alarm and a Honeywell thermostat and at first I was bit angry at having to use two different apps for control, but it's kind of a blessing in disguise... if one system goes down you can still control the other. It's the common parts which weakens the entire concept. Your internet connection for example. That made me think a bit. If systems remain independent from one another... is that such a bad thing? The other thing to think about is security. If the system is all common then once a hacker is in... then they're into EVERYTHING.

I'm slowly learning the benefits of separate systems and after considering it all carefully enough, I'm not sure I would want a single common control circuit.

Yep great points of course but it is quite interesting what combinations of automation can occur when everything is integrated. On the other hand, most of these items can be self automated via weather and user location data and will provide perhaps 90% of the benefits without compromising security.

 

[stefuel]

What's interesting about all this is you will be told how much gas or oil you will save with all these additional controls. No one ever talks about how much electricity is wasted and the amount of wear and tear on the equipment. Hydronic systems of any type that are modulating just sit there on low fire with all zone valves open and pumps running for hours on end. You're putting a lot of hours on the boiler, pumps and zone valves which will mean more repairs and electricity use. I'm not convinced with all things considered in that there is that much of a saving.

 

[SMHarman]

But many things have their use measured in cycles. Wear is not turning it on but off and on.

A boiler/furnace on low is not expanding and contracting for example.

 

[bigbarney]

What's interesting about all this is you will be told how much gas or oil you will save with all these additional controls. No one ever talks about how much electricity is wasted and the amount of wear and tear on the equipment. Hydronic systems of any type that are modulating just sit there on low fire with all zone valves open and pumps running for hours on end. You're putting a lot of hours on the boiler, pumps and zone valves which will mean more repairs and electricity use. I'm not convinced with all things considered in that there is that much of a saving.

Statistics show that Gas fired equipment will actually run for a shorter overall period when reheating a house after an extended shutdown than it would have if simply left on at a steady temperature.

I will agree with you however that the savings involved is vastly over stated. Unbiased government testing shows that there is a savings to be had with set back thermostats but that savings is somewhere around 5 to 15 percent and nowhere NEAR the 30% that some thermostat manufactures are claiming.

Modulating systems are a real double edge sword. They offer a more even heat but they also drink more electricity in doing so. A modulating gas fired forced air furnace for example will have (by nature) MUCH longer running times on the blower fans.

As for controls...it all depends on the system you have. Heat pumps for example need LOTS of control. They can save you a lot of money, but if you don't run them correctly they can also cost you a lot of money. You need controls to lock out the compressor when the temp gets below a certain point, controls to defrost ONLY when defrost is needed, controls to lockout the AUX heat so it doesn't come on prematurely.... etc. Get the right thermostat, and all this is a breeze... get the wrong one and you will have to spend lots of extra money purchasing the separate control modules.

 

[blazar]

We have folks in an out of the house all the time and therefore constant temp is better. Plus we have dramatic day night fluctuations and if the heated floor isnt started early enough it will take too long to heat up in time for your comfort.

Big drop in energy bill was going to a house with foam insulation, the heated floor and two stage ac were just gravy.

 

[stefuel]

"I will agree with you however that the savings involved is vastly over stated. Unbiased government testing shows that there is a savings to be had with set back thermostats but that savings is somewhere around 5 to 15 percent and nowhere NEAR the 30% that some thermostat manufactures are claiming."

Try using a "set back" thermostat on a modulating boiler. People try to use these all the time on modulating hydronic systems that are controlled through the use of a outdoor temp sensor. They allow the house to cool down during the coldest part of the day. Some people will do crazy swings like 10 degrees. Then at lets say 8:00 AM they will try to raise the temp back up 10 degrees. But now the outside temp is starting to rize. The boiler is only going to modulate enough to maintain the house at the given outdoor temp NOT bring it back up. I devised a work around for this for a customer who insisted on using setbacks. I put a cheap digital thermostat centrally located on the first floor. I set it to 2 degrees lower then the daytime temp and disabled the front buttons. That thermostat only controls a DPDT 24 volt relay. One side of the relay is passing the signal from the outdoor reset (thermistor). To the other side of the relay is a FIXED resistor that tells (fools) the boiler into thinking it's zero degrees out thus forcing it to high fire. Any time the whole house themostat senses 2 degrees lower then the daytime set temp, it switches from thermistor to resistor and will go to high fire until it catches up. This is really usefull in situations like power outages. If your power has been out for a day or two and it's only 50 degrees in the house but when the power was restored it was 70 out. Under normal situations the boiler won't even be allowed to come on. For instance a Buderus boiler with a AM10 control on it. It has a "WWSD" (warm weather shut down) setting on it that is factory set to 70 degrees. That house is stuck at 50 degrees until the outside temp drops below 70. With my circuit, that boiler will go to high fire until that house gets to 68 degrees. Then it will switch back to modulation

 

[blazar]

"I will agree with you however that the savings involved is vastly over stated. Unbiased government testing shows that there is a savings to be had with set back thermostats but that savings is somewhere around 5 to 15 percent and nowhere NEAR the 30% that some thermostat manufactures are claiming."

Try using a "set back" thermostat on a modulating boiler. People try to use these all the time on modulating hydronic systems that are controlled through the use of a outdoor temp sensor. They allow the house to cool down during the coldest part of the day. Some people will do crazy swings like 10 degrees. Then at lets say 8:00 AM they will try to raise the temp back up 10 degrees. But now the outside temp is starting to rize. The boiler is only going to modulate enough to maintain the house at the given outdoor temp NOT bring it back up. I devised a work around for this for a customer who insisted on using setbacks. I put a cheap digital thermostat centrally located on the first floor. I set it to 2 degrees lower then the daytime temp and disabled the front buttons. That thermostat only controls a DPDT 24 volt relay. One side of the relay is passing the signal from the outdoor reset (thermistor). To the other side of the relay is a FIXED resistor that tells (fools) the boiler into thinking it's zero degrees out thus forcing it to high fire. Any time the whole house themostat senses 2 degrees lower then the daytime set temp, it switches from thermistor to resistor and will go to high fire until it catches up. This is really usefull in situations like power outages. If your power has been out for a day or two and it's only 50 degrees in the house but when the power was restored it was 70 out. Under normal situations the boiler won't even be allowed to come on. For instance a Buderus boiler with a AM10 control on it. It has a "WWSD" (warm weather shut down) setting on it that is factory set to 70 degrees. That house is stuck at 50 degrees until the outside temp drops below 70. With my circuit, that boiler will go to high fire until that house gets to 68 degrees. Then it will switch back to modulation

I am doing something very similar. Im going to use outside temp to program the indoor heated floor.

If outside temp less than 32, heated floor at 74. Outside temp between 32 and 50, heated floor at 72, and above 50 outside, floor off so it doesnt overlap the ac ever.

The forced air heat is set to 60 as backup just in case.

This is being programmed into a control4 setup.

 

[bigbarney]

I am doing something very similar. Im going to use outside temp to program the indoor heated floor.

I'm trying to figure out what your goal is with this. Why would the outdoor temperature be important in adjusting your floor temperature? What happens if the room starts getting too warm? Do you have a secondary stat for room temperature in series so the room doesn't overheat.... or underheat for that matter?

 

[stefuel]

I think you should reconsider this. I'm sure others in the automation industry will argue but IMHO the task of controlling floor temperature should be left to a dedicated controller. A controller that uses carefully calculated heating curves to give your floor what it needs when it needs it. I would use a Tekmar (360) I think coupled with their 3-way motorized valve. Slick as greased goose poop. Add all the sensors you want to monitor it from your HA but let it do it's thing. It also has a warm weather shutdown setting so it won't fight the A/C.

Also, after you've rolled your own system and something fails you won't know what it is without testing each component by it's self. The Teckmar self diagnoses it's self and the components connected to it.

 

[blazar]

Our floor stats came with $2 thermostats... Nothing special but they did a decent job. i just dont want the floor to overlap the regular ac. Outside temp allows me to disable floor heat over an outdoor temp of 50 so that my indoor cooling doesnt cause the floor heat to turn on.

Also i subjectively need higher floor heat settings when it is extremely cold outside. I am not sure why this is the case but every winter it happens. Being able to adjust for temp ranges helps get things subjectively perfect.

 

[stefuel]

Our floor stats came with $2 thermostats... Nothing special but they did a decent job. i just dont want the floor to overlap the regular ac. Outside temp allows me to disable floor heat over an outdoor temp of 50 so that my indoor cooling doesnt cause the floor heat to turn on.

Also i subjectively need higher floor heat settings when it is extremely cold outside. I am not sure why this is the case but every winter it happens. Being able to adjust for temp ranges helps get things subjectively perfect.

I can tell you for sure that your target floor temp of 74 degrees ain't gonna cut it. You're about 25 degrees low.
A dedicated floor controller like the Tekmar 360 will regulate the floor temp automatically based on outside temp and optional inside temp (not to be confused with the inside thermostat). Do a search for the Tekmar 360, Tekmar 741 actuator and Tekmar 710 3-way valve. That's what you need to do it right.