Step 5.1: Hydraulic optimisation

Any optimisation process should begin with looking at the hydraulic circuit as installed. Whatever is possible for a system will differ on a system-to-system basis and require the Hysopt software user to use his/her hydraulic knowledge. What follows are a few general possible improvements to be done, which try to limit constant flow in the system, while also lowering return temperatures to improve boiler efficiency.

Remove overflow by-passes

Either fully remove these by-passes or limit the flow going through by installing either a two-way valve or PICV in front, controlled by the valve based on the required flow.

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Remove or control volume flow over low loss headers

Often placed to ensure a minimum flow over boilers, or to hydraulically separate parts of the building. However, the overflow through this header leads to both constant flow and higher return temperatures.

Depending on the projects the headers could be removed and replaced by a controlled overflow in the circuit to ensure the minimum flow, keep the header but use a control strategy to limit the flow (which can be found in the inspiration library), or simply kept in place if the constant flow is needed for the boilers.

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Remove pumps in series

Often, certainly, when headers are being removed, pumps will end up being placed in serial and hence, should be removed. Hysopt will also show this as a fault during calculations.

Switching from constant to variable flow distribution circuits

Change distribution circuits with 3-way valves to 2-way valves wherever possible.