So I'm finally getting my head around my primary/secondary unpressurized system..... Had almost all the things right in my head except for the fact that my system needed another 2 pumps!! BTW...I'm spending the extra money and going with Alphas and hoping they pay off in the long run because I plan on running my system--on a limited basis--through the summer; at least to charge the storage tank to provide DHW.....
So now here's my dilemma... I'm planning on burning hot to charge the storage to as close to 200ºF as I can get and then draw off as needed down to around 120ºF and then recharge etc. So...when the boiler pump is running, the primary loop pump needs to run as well as the pump for the coil in the tank.... That is one issue of control. The second issue is once the boiler is off, the tank is, theoretically, up to temp....the zones--whose pumps are running all the time, also need to tell the primary loop pump to run as well as the tank-circ pump.... At the moment I am planning on using a Tekmar 256 boiler control--per a chat with a Tekmar engineer--to control my main flat panel radiator zone via an Alpha pump. The controller will turn the pump on and off based on outdoor reset, so I won't have to worry about turning the system off on warm days or back on when it gets colder. I think this will be pretty vital on the wacky spring days we can have where there is a 30-40º temperature swing. No need to drain the tank down unnecessarily, or heat up the house when we're all outside enjoying the weather......The temp sensor on the 256 will provide feedback to the unit on what the supply temp is to the mixing valve before the manifold, so I can see from the house whether I need to refire the boiler.
I am also trying to steer clear of a thermostatic control in the house to drive the pumps/zone because our house is so fragmented and the flat panel radiators allow each room to be adjusted individually. We will also be running our wood cookstove during the winter, which currently throws off the thermostats in the house for our propane forced air system.
I'm prepared to let the two circ pumps--primary loop & tank/coil--run all the time--hence the Alphas...but is there a simple/ inexpensive way to control these pumps based on temps, load or ?? This type of system is SO different from a "standard" one where the house calls for heat and the furnace kicks on..... In my system there will be no back up furnace. I will be firing the boiler based on tank temperature readouts provided by probes in bottom and top of tank. In my case I am viewing the Tank as the heat source, not the boiler, and the zone pumps as the "boiler" to be controlled.
Any thoughts? Have I missed something in a previous answer to my puzzlings?
So now here's my dilemma... I'm planning on burning hot to charge the storage to as close to 200ºF as I can get and then draw off as needed down to around 120ºF and then recharge etc. So...when the boiler pump is running, the primary loop pump needs to run as well as the pump for the coil in the tank.... That is one issue of control. The second issue is once the boiler is off, the tank is, theoretically, up to temp....the zones--whose pumps are running all the time, also need to tell the primary loop pump to run as well as the tank-circ pump.... At the moment I am planning on using a Tekmar 256 boiler control--per a chat with a Tekmar engineer--to control my main flat panel radiator zone via an Alpha pump. The controller will turn the pump on and off based on outdoor reset, so I won't have to worry about turning the system off on warm days or back on when it gets colder. I think this will be pretty vital on the wacky spring days we can have where there is a 30-40º temperature swing. No need to drain the tank down unnecessarily, or heat up the house when we're all outside enjoying the weather......The temp sensor on the 256 will provide feedback to the unit on what the supply temp is to the mixing valve before the manifold, so I can see from the house whether I need to refire the boiler.
I am also trying to steer clear of a thermostatic control in the house to drive the pumps/zone because our house is so fragmented and the flat panel radiators allow each room to be adjusted individually. We will also be running our wood cookstove during the winter, which currently throws off the thermostats in the house for our propane forced air system.
I'm prepared to let the two circ pumps--primary loop & tank/coil--run all the time--hence the Alphas...but is there a simple/ inexpensive way to control these pumps based on temps, load or ?? This type of system is SO different from a "standard" one where the house calls for heat and the furnace kicks on..... In my system there will be no back up furnace. I will be firing the boiler based on tank temperature readouts provided by probes in bottom and top of tank. In my case I am viewing the Tank as the heat source, not the boiler, and the zone pumps as the "boiler" to be controlled.
Any thoughts? Have I missed something in a previous answer to my puzzlings?
