Need direction in choosing products

[Otto]

Hi,
I am in the early stages of trying to put tgether a system to control my hydronic heating, here's what I have in mind:
I have 20 zones for which there are wall thermostats and HW valves. I would like to have a central panel (hopefully something LCD/ touch screen), from which I could view the space temps and enter setpoints.
Is there a control panel like that? And if so, how would it connect with compatible thermostats in the rooms? I prefer wired to wireless, so do these devices communicate over a LAN? I'm still trying to grasp what's available and what it's all capable of, any and all help will be very much appreciated.

 

[signal15]

Hi,
I am in the early stages of trying to put tgether a system to control my hydronic heating, here's what I have in mind:
I have 20 zones for which there are wall thermostats and HW valves. I would like to have a central panel (hopefully something LCD/ touch screen), from which I could view the space temps and enter setpoints.
Is there a control panel like that? And if so, how would it connect with compatible thermostats in the rooms? I prefer wired to wireless, so do these devices communicate over a LAN? I'm still trying to grasp what's available and what it's all capable of, any and all help will be very much appreciated.

Here's the problem, for hydronic in-floor heating (I'm assuming yours is in-floor, and not air heat exchangers), you have to worry about the thermal mass of the floor. Using a regular thermostat with hydronic heat presents a problem:
1. Heat turns on, and shuts off when the setpoint reaches a certain level
2. Because of the thermal mass of the floor, it continues radiating heat into the room and the temp skyrockets past the setpoint
3. Room cools down to a degree or two below the setpoint, and the cycle repeats.

It's a huge waste of energy, it's annoying, and it makes the room uncomfortable. This is why you need to get thermostats that can estimate the thermal mass of the floor based on how long it takes the room to heat up and cool down. Some have temp sensors that go into the floor to help them, but some just do it based on air temp. Then, they turn on every 15 or 20 minutes for a period of time that is calculated by them to ensure the temperature remains relatively constant within the room.

I use Aube thermostats for mine (TH-135's) and they run about $45 each. There are terminals on the back that you can hook into an automation system relay to make it switch between night and day settings, but you cannot remotely control the temperature by single degree increments. You may want to contact them and see if they have a solution for you. I'm VERY happy with how they perform. I have mine set to turn on every 20 mins (the other option is 15 mins) and it keeps the room within 1/2 degree of my setpoint, and it saves energy.

If you're talking about air heat exchangers, then you don't really have to worry about thermal mass, and can probably use just about anything.

 

[personalt]

I use tekmar controls for my hydronic heat. They use floor temp sensors to figure all that stuff out. Really nice controls, especially if you have a modulating boiler.

I use a tekmar scene switch 480 to internface alarm with HVAC. I can pick from a few scenes from the 480. I have it set up for home, away(short term), and vacation.

The also make a gateway, part 482 that can be interfaced by some 3rd party automation systems.
http://www.tekmarcontrols.com/literature/acrobat/p535web.pdf