Manual Controls - to start with
My hydronic heating system relies on manual controls for filling, flushing, configuration and isolation. This isn't the most convenient way of operating the system, but it's a simple way to start and it helps reduce opportunities for failure.
With my system, it's generally configured to heat everything in series - furnace heat exchanger and then radiators - so control of the system doesn't hinge so much on changing the configuration of system flow, although this is something I could do.
System control hinges primarily on how much heat is produced by the wood stove and how much heat I extract from the water-to-air heat exchanger with the furnace air plenum. So, manual control is largely a matter of loading wood, regulating air intake to the stove, and turning on and off the "fan only" recirculation mode on the furnace.
The "bells and whistles" of the system will come later, but for now I'm satisfied with manual control as I learn about how well the system can use the heat that I'm extracting from the wood stove insert. My objective is to have a sufficient number of radiators such that I can crank the stove up and distribute sufficient heat through the radiators without overheating the system.
The idea is simply that I want full control over the system until I know for certain what type of automated controls are appropriate. If you see this as designing and building as I go, then you are seeing it as it is.
When I'm certain about what I need in terms of automation, then I'll acquire these components and add them into the system. The problem with doing it now is that the main part of my system - the heat source - is all manual, so much of the automation doesn't make sense to incorporate because I can't automate the heat output of the large fireplace insert.
Therefore, having manual controls is sufficient to start with during my "get acquainted" period.
In the event that I want to isolate a portion of the system or redirect all of the heat to the furnace air plenum heat exchanger, it's a matter of opening and closing manual valves that are easy to access throughout the system. I use ball valves in the system because they are easy to operate, provide visual indication of their status, and they are reliable.
After I know better what I'd like to do with the system to automate it's operation, I'll incorporate temperature switches for turning on pumps, diverting excess system heat, and activating the furnace recirculation mode.
Done with Manual Controls, back to Alternative Energy Sources