St Mungo’s, a charity providing housing, health and employment services to homeless people in London and the South, has chosen Mitsubishi Electric’s Ecodan CAHV monobloc air source heat pump boilers for its newly built flats in Spring Gardens, Lewisham.
In line with St Mungo’s environmental values, the charity wanted a cost-efficient community heating and hot water system that used renewable energy and complied with stringent local authority planning requirements. It needed to cope with the different heating loads required by a community heating scheme and deal effectively with regular changes in tenancy and occupied hours.
In addition, tenants required the ability to alter the temperature of their individual flats, whilst allowing St Mungo’s to have full central control of the system.
“As a homelessness charity with a limited budget, we wanted a sustainable solution that would fulfil all of our criteria, giving us control and flexibility without compromising on performance,” said Steve Fabian, Purchasing Manager at St Mungo’s. “The needs of our clients are paramount in whatever we do, so it was also really important for us to achieve our goal of reducing energy costs to our clients.
“In addition, we wanted to reduce the institutional feel of the flats where possible and the individual control units, which allow each resident to set their own preferred temperature is a small but significant part of achieving that goal.”
To achieve all this St Mungo’s called in Waterstone Design, a building services consultancy and tasked them with designing a system that would fulfil all the elements of the challenging brief.
The new system uses three Ecodan CAHV monobloc air source heat pump boilers capable of delivering 129kW at -3°C, with minimal drop off down to -20°C including defrost. The heat pumps provide underfloor heating for all 24 dwellings, supplying hot water requirements through a direct hot water plate heat exchanger to ensure the heat delivery system operating temperatures can be kept as low as possible.
The load requirements for any community heating system are extremely dynamic, but Mitsubishi Electric’s CAHV monobloc systems have been designed to cope with this by allowing the capacity to increase in 0.5kW increments, from 18kW upwards, a level of modulation unprecedented within the heating industry. The units cascade on and off to achieve peak efficiency and ensure even wear and tear throughout their operating life.
Each MCS-approved CAHV monobloc system is hermetically sealed and requires very little maintenance. Two separate refrigerant circuits operate within each unit guaranteeing a 50% back up, whilst offering the benefit of low on-site refrigerant volume.
“We aim to offer innovative support services to our residents, and this new system ideally matches the quality and effectiveness we aspire to across our organisation,” Mr Fabian concluded.
