Mears FM

Mears FM
Malloy Court


Molloy Court – Operated by Mears FM
28x 2 bedroom 2 story dwellings
(2 dwellings on electrical storage heating – 26 dwellings on de-centralized plant)

Original installation consisted of three natural gas fired wall hung condensing boilers and one floor mounted CHP and local BMS, primary flow and return pipework, some underground, wet system standard radiator panels, TRV and controller, hot water cylinders.


  • Retrofit two apartments from electric storage heating connecting to the wet system district network.
  • Monitor and establish all errors in metering/billing system in relation to cost against revenue.
  • Retrofit BMS from the basic on/off to a remotely monitored and controlled system, interfacing with clients existing BMS module at their head offices.
    Develop supply chain maintenance program with specialist manufacturer for the on-site renewable equipment.
  • Modify and improve performance of the primary plant and upgrade the internal secondary equipment so as to introduce maximum efficiencies.

The primary challenges in this project were the space restriction in respect of the plant room. The secondary challenge related to weather conditions as the primary equipment was so unreliable it was considered to be critical works and therefore work was undertaken mid-winter. The two apartments were due to be occupied and so had to be retrofitted whilst tenants were moving in.

Subsequently we found that the original installation had maintainable sections of the network only accessible through a tenants living area and in to the loft space.

The district pipework had been incorrectly sized, oversized in places and undersized in others and it was necessary to replace and modify these sections.


Our appointment was as a result of a site survey, inspection and detailed report on potential savings of energy production costs.

We began the project by installing a mobile temporary plantroom, using up one car park space as agreed with the on-site representative.

To avoid unnecessary environmental and cost issues with fuel oil deliveries, we re-routed the primary gas main and ran temporary boilers on the client’s main gas supply, so the client did not have additional costs and the tenants were billed as normal.

Down time to re-route, connect and commission the temporary plant equipment was 7 hours, performed between 09.00 and 16.00. Temperature with in the network dropped to 44°C from 12.30 and we were back to full temporary operating temperature 78°C by 16.30.

We cut into the primary flow and return within the plant room, then ran flexible heating hoses to the temporary plant, enabling us to switch between primary and temporary with no disruption following the initial 7 hours down time.

We then retrofitted the two apartments, removed all redundant equipment and installed the new wet system, using TRV standard radiator panels based on flow temperatures of 60/70°C and designed to provide return temperatures of 40/50° – winter/summer settings.

All apartments were modified to run and operate within the same delta T parameters.

Our team was able to work quickly and safely on the primary plant as all the equipment was isolated from the heat source.

The existing plant equipment was removed and inspected for suitability, equipment not redundant was built in to the new system.

Our design partners requested a buffer vessel/thermal store form part of the design and installation, the BMS configure to operate with winter/summer settings and an intelligent controller monitoring external weather conditions as well as demand on the system.

As the site was occupied throughout the works, we held weekly tenant/contractor meetings updating the tenants on potential disruptions and where possible working with them to avoid any supply issues. This was made rather more difficult as two of the tenants were night shift workers.

We set up a back-to-back maintenance contract for specialist support direct from supply chain partners regarding the CHP and BMS.

As we had discovered sections of the network which were incorrectly sized we liaised with our specialist engineers, allowing them the time to draw up the pipe calculation, provide detailed drawings of the network modification and then incorporate these changes into their drawings.

By bringing knowledge and experience to the client, they were better able to make better informed decisions, allowing us to improve the performance of the entire project.

Operational benefits

The installation modifications enabled a better use of the space, the pipework modification ensured correct balance of the network and the BMS intelligent controllers enabled efficiency savings of 40% on the gas use against heat production.

Monitoring and metering of the energy production against actual energy use has enabled the client to adjust their standing charge allowing the small network losses to be covered.

Maintainable sections of the network previously in the tenants loft space were all moved to allow access externally.

By implementing contracts with our supply partners we have ensured a continued performance warranty with the client and have improved the client’s reputation with their tenants.

Cost benefits

The recommendations of our supply chain partnership specialists enable us to control overheads, which allows for the highest quality at the optimum cost.

Financial savings were made by:

  • Specifying the correct size of primary equipment
  • Correctly maintaining primary equipment
  • Education of tenants
  • Live monitoring with responsive measures being applied
Bedford College
Sandwell Homes