Excellence in Engineering


The Portman Estate

Crofton Design has been working with The Portman Estate on the regeneration of their Georgian Portfolio in Mayfair.

As part of their commitment to carbon reduction we have been developing schemes that can be retro-fitted into existing historic buildings and a pilot at 21/22 Montagu Street is currently being installed. Crofton will monitor the scheme for two years after completion to test its effectiveness and will use as a benchmark for future installations.

The scheme incorporates a central heat generation plant with common thermal storage which allows the application of solar thermal systems and micro combined heat and power.

The solar thermal installation utilises evacuated tube collectors and distribution to the common thermal store.  The evacuated tube collectors maximise the collection of solar energy even when the air temperature is low.
If the sun is shining a useful contribution to the energy balance of the building can be made. The system concept allow that the solar energy is utilised for both space heating and for the generation of domestic hot water, thus further enhancing the benefit from the solar installation.

In conjunction with the solar thermal collection “micro” combined heat and power (CHP) is employed.  

Finally, gas fired condensing boiler plant completes the heat source plant.  Again these feed into the common thermal storage.  High temperature differentials are utilised on the landlords distribution to minimise pipe sizing, and to ensure that low return temperatures onto the boiler plant keep them in condensing mode at all times.

These low return temperatures also allow the solar thermal system to make a useful  contribution even when temperatures are quite low (around 30ºC to 40ºC).

Within the apartments plate heat exchanger installations draw heat from the landlord’s distribution to serve the requirements of heating and domestic hot water service.

Tom Fitton, Project Manager at The Portman Estate commented;
“Crofton has not been afraid to get stuck in to the more challenging aspects of working with our historic buildings. For example, one solution to introduce micro CHP will produce heat and electricity simultaneously and will result in running cost savings. Their commitment to delivering low-carbon engineering solutions has resulted in cost savings without compromising the integrity of the properties”.