Controlling a heating/cooling system

Abstract

In a hydronic heating/cooling system, liquid is led along a main supply pipe ( 1 ) to a supply manifold ( 2 ) and distributed into heating loops ( 3 ). The heating loops ( 3 ) return to a return manifold ( 4 ). At least one of the manifolds ( 2, 4 ) has actuators ( 6 ) for controlling the flow in the heating loops ( 3 ). Actuators with fast operating times are used and valves of the actuators are controlled to close at different times in different heating loops ( 3 ).

1 . A method for controlling a hydronic heating/cooling system in which liquid is led along a main supply pipe to a supply manifold and distributed in the manifold into heating loops, the heating loops returning to a return manifold, and at least one of the manifolds having actuators for controlling the flow in the heating loops, the method comprising using actuators with fast operating times, and preventing the simultaneous closure of actuator valves in different heating loops. 
     
     
         2 . A method according to  claim 1 , wherein the endings of duty cycles are detected and, if two or more duty cycles end substantially simultaneously, a delay is added to at least one duty cycle. 
     
     
         3 . A method according to  claim 2 , wherein the duty cycles are defined to end substantially simultaneously if the difference between the ends of the duty cycles is shorter than an operation time of the actuators. 
     
     
         4 . A method according to  claim 2 , wherein the length of the delay is equal to or longer than the operation time of the actuators. 
     
     
         5 . A method according to  claim 1 , wherein the actuators control the flow in the heating loops on and off such that during a duty cycle the flow is high and between the duty cycles the flow is off. 
     
     
         6 . A method according to  claim 1 , wherein the duty cycles in different heating loops overlap partly. 
     
     
         7 . A hydronic heating/cooling system comprising a main supply pipe, a main return pipe, at least one supply manifold, at least one return manifold, heating loops from the supply manifold to the return manifold, and actuators for controlling the flow in the heating loops arranged to at the supply manifold and/or the return manifold, the actuators having fast operating time and means for preventing the simultaneous closure of actuator valves in different heating loops. 
     
     
         8 . A system according to  claim 7 , comprising the system comprises means for detecting the endings of duty cycles and means for adding a delay to at least one duty cycle if two or more duty cycles end substantially simultaneously. 
     
     
         9 . A system according to  claim 7 , wherein the actuators are arranged to control the flow in the heating loops on and off such that during the duty cycle the flow is high and between the duty cycles the flow is off. 
     
     
         10 . A non-transitory computer-readable medium having encoded thereon software for controlling a hydronic heating/cooling system in which liquid is led along a main pipe to a supply manifold and distributed in the manifold in to heating loops, the heating loops returning to a return manifold, and at least one of the manifolds having actuators for controlling the flow in the heating loops, wherein the software comprises instructions that, when executed by a control unit, cause a control to detect endings of the duty cycles and prevent the simultaneous closure of actuator valves in different heating loops.