First-time poster here. I have been following SuperHouse for a while now. I’m trying to automate my central heating/cooling system (York) ) by replacing my old thermostat. I was just wondering what options are there that can support zones. I have looked at Nest and Ecobee, but not sure if they can support zones without major rewiring. At the moment I have manual switch that changes zones to upstairs / downstairs. I have attached a few pictures of my controller wiring. Thank you for your help.
Hey! Welcome to the rabbit hole!
I have some experience in the HVAC world but am not totally up on all the latest and greatest of the controllers. It looks like your zone control is not connected in any way to the thermostat? The connections to that are pretty bog standard stuff. It is very possible to do thermostat automation but the zone control adds complexity to the mix. Are you looking to change out the whole thing for a DIY thermostat setup or looking to find a unit that does zoned control that is “smart”?
It looks like your zone control is not connected in any way to the thermostat?
No, I don’t believe so just a 3 way switch.
Are you looking to change out the whole thing for a DIY thermostat setup or looking to find a unit that does zoned control that is “smart”?
I’m looking for a of the shelf thermostat that can combine zone control and thermostat in to one unit. The goal is to have something nice looking and to connect to HomeAssistant. DIY using sonoff as zone control is not out of the question.
One option for some zone control is just to use 2 spinoffs. Or if your looking for a somewhat more permeant solution you could go down the path of an arduino controlling relays In a switchboard. And control that via mqtt
That would open the door for. Future controls like lights etc
I was looking around at zoned thermostats and they want serious dough for them There are a number of things that a zoned thermostat is supposed to do. One is to read the temp of each zone and provide heating/cooling as required to that zone independently from the others. More sophisticated systems will allow for independent temps for each zone. So the downstairs can be set to one temp and upstairs can be set to a different temp. The actual creation of the project is above my knowledge level since my coding abilities are not to that level yet but you would need a base control module ( a D1mini would work well) and a relay board for zone control. The upstairs and downstairs zones need some sort of temp sensors if you want automatic zone control. I am assuming that you could probably use the voltage on the existing lines to power these devices but it might require rectification as some furnaces use AC voltage instead of DC voltage.
Have a look at http://www.smarttemp.com.au, I have no association with them apart from having one of their controls for my home, which has 5 zones. It works well.
So I have been wanting to setup Zone Control in my home in the US for a while. I even went as far as installing baffles in the air ducts in my home to control with Raspberry pi cpu and Ardunio for connections. Now I have come across smart vents. That you can use to easily zone each room.
so far there are several options out there to choose from but I was wondering if anyone already has any experience using these as of yet?
If not I will be more than happy to start the reviewing process.
@Cadavissr31 I did a LOT of reading on the smart vents and from a HVAC POV… don’t do it. The main reason is that a heating system ducting is (supposed to be) made properly and created with air flow, restriction, temp loss and many other factors involved. Many people think, “If I am not using that room, I don’t have to pay to heat it so I will close off the vent in there and only heat the parts of the house that i want heated/cooled.” The heater will generate too much back pressure because it’s designed for a specific CFM and that causes issues with overheating the coil/plenum or too little air flow over the a/c coil and you get freeze ups. Efficiency goes out the window. You want unrestricted air flow through your system. It is better to have a smaller CFM system with zoneing or a multi-speed fan and smart zone control to make sure the fan speed is optimal for need. HVAC is one of those things that if it isn’t designed specifically for the outcome, it will not function properly for the structure. It is best to “smart up” your existing system’s controller but not mess with the actual design of the ducting. I have found that basic integration into automation schemes for HVAC can be done with an off the shelf controller smoother than with a DIY system but that is because I don’t want to reinvent the wheel. For most systems, all the controller does is turn it on or off and maybe run a temp profile for different times of day. Simple and already done in a ton of dependable ways. If you have in floor/ceiling radiant, oil heat, solar, goethermal, there are other things you can geek out on simply for monitoring but it’s still a basic control system. The best monitoring you can do is fuel oil tank level monitoring.
@Guru_Of_Nothing
Thank you for your input. You seem to understand the HVAC systems so I will ask you. If I am putting in induction fans in the duct work that are activated upon the activation of a limit switch triggered by the opening of the vent, would that help offset the back pressure?
Also I have a room addition on the house that was not there when the HVAC system was put in. This is the area where your statement above makes since of the situation that I am dealing with in my home.
I know the function and am actually certified for air conditioning but the engineering part I know just enough to be dangerous. The key to proper function is calculated flow. The fan size, speed and what not is calculated for a specific target CFM of air flow at each vent. They may change duct sizes along the path to change flow or restriction or to manipulate the pressure at each vent. When they add on to a system, they rarely add flow to it, just volume of duct. Putting in fans to move the air along only works if there is enough restriction to be overcome to make that flow valuable. Most of the time, it isn’t. You can do some manipulating of the air handler itself (the body of the heater/air conditioner) like variable speed fan drive (VFD) to speed up or slow down the fan to control CFM but that is only good if you have a way to throttle the hot or cold output of the guts of your handler. Again, not enough air flow, overheat the hot parts or freeze up of the coil for a/c. HVAC is not something that you can really easily tweak up or down. These systems really need to be changed from the ground up to have total control of their function. Not saying you can’t play with it as they are not hyper sensitive but as you do play with it, keep an eye out for the effects those modifications are having on the handler. The hot side is not quite as sensitive as the cold side (if you have a/c as part of your handler).
Basically, the box is designed to do (x) cfm flow wide open. Each vent is calculated at (y) cfm flow wide open. The totals of the vents needs to be roughly the same as the flow of the box (x=y). There are also ducting restriction calibrations in that as well but they are not huge unless the ducting takes lots of corners or has lots of small feeder ducts from the main. You can close down a couple and still get acceptable flow. You can’t however auto-vent everything and let them control room temp. The fan will always blow the same speed unless it is a VFD and way smarter than a normal residential handler. You need to make sure your box temps in the handler stay close to what was designed with all the vents open after you have made modifications. And remember, you dont have temp readings and compensation in every room unless you put it there. Cycle times are important too. If you have electric heat in the handler, that can be turned on and off instantly. Gas or oil heat has a cool down time that has to be considered. That creates temp swings in small spaces.
There are a number of things that a zoned thermostat is supposed to do. One is to read the temp of each zone and provide heating/cooling as required to that zone independently from the others. More sophisticated systems will allow for independent temps for each zone. So the downstairs can be set to one temp and upstairs can be set to a different temp. The actual creation of the project is above my knowledge level since my coding abilities are not to that level yet but you would need a base control module ( a D1mini would work well) and a relay board for zone control. The upstairs and downstairs zones need some sort of temp sensors if you want automatic zone control. I am assuming that you could probably use the voltage on the existing lines to power these devices but it might require rectification as some furnaces use AC voltage instead of DC voltage.