Thank you for your comments. The system is not a lousy design. It is quite well done in accordance with industry standards. The only mistake we are aware of is the variable speed control. The contractor needed help and received bad information from a vendor. This approach to circulation is not a common practice, but is beleived by some to be a better approach. No ones grandmother had a system doing it this way. Nor are most current installations. Generally speaking heating systems contractors ignore things like electrical energy cost and focus only on the boiler. This approach addresses one aspect of that and eliminates a bypass valve that can become noisy and an approach that dumps more heat into the boiler room. I know how other systems are designed and built. The contractor (and he is a good one) knows how systems are designed and built and how to do it.
I feel that the attacks on the system design are both uncalled for and incorrect. I came here for help. I would still like that help. I do not need attacks and sniping.
I apologise if I have not made the problem clear.
Problem:
1 - I have a 0-10 V or 20 ma signal from a SENSOR that represents differential pressure across the heating manifold.
2 - The pump that generates the pressure IS a variable speed pump controlled by 0-10 or 20 ma interface. It reaches full speed with all zones calling for heat.
3 - I need a controller to
Harold
I feel that the attacks on the system design are both uncalled for and incorrect. I came here for help. I would still like that help. I do not need attacks and sniping.
I apologise if I have not made the problem clear.
Problem:
1 - I have a 0-10 V or 20 ma signal from a SENSOR that represents differential pressure across the heating manifold.
2 - The pump that generates the pressure IS a variable speed pump controlled by 0-10 or 20 ma interface. It reaches full speed with all zones calling for heat.
3 - I need a controller to
a - start and stop the pump based on an external "heat demand" signal.
b - Control the speed of the pump to maintain a constant pressure across the manifold as zone vlaves open and close.
Thank you for your help and courtesy,b - Control the speed of the pump to maintain a constant pressure across the manifold as zone vlaves open and close.
Harold