Connexus is a rural housing group focused on providing high-quality affordable housing to the counties of Herefordshire and Shropshire. Within its portfolio, Connexus manages the award-winning Rocks Green shared ownership development of 91 energy efficient properties powered by a woodchip biomass district heating system for heating and hot water.

The challenge

Some 11 years after the development was completed, Zenergi was engaged to evaluate improvements that could be made to the biomass system at Rocks Green to improve its efficiency.

Connexus was spending increasing amounts of time and money managing several issues, including boiler failures, billing issues, and failures with the control systems and heat exchanges in the properties. Residents were concerned about high heating bills, and were experiencing heat being used, even when their heating was switched off to save money.

The solution

Zenergi’s in-depth investigation identified several issues that were impacting the efficiency of the boiler system. Evaluations to replace the biomass system with natural gas boilers in the plant room; natural gas boilers in each property; and air source heat pumps in each property were also provided for consideration.

The decision was made by Connexus to undertake the repair and replacement works that would retain the energy efficiency integrity of the original design from a biomass system that is inherently low carbon. Connexus engaged an organisation to undertake the work and Zenergi was engaged to project manage and oversee it.

The project included replacing the existing heat interface units in each of the 91 properties, repairs to the boilers and improving the connectivity of the system in each property.

The benefits

Once the works were complete, training was provided to residents to ensure optimum operation of the system, along with a guide explaining who to contact should they have an issue with their system. Residents are enjoying warmer homes and are no longer paying for heating they are not using. Zenergi sourced a better value supply contract for the wood chip.

Connexus have more time to focus on their core activities without the drain on resources required by the continued maintenance issues.