City Road District

This project entails the provision of 100 No. apartments, split over two blocks, at 259 City Road, Islington, London EC1V 1JE

The heat is produced in the Energy Centre which is located in the basement and is distributed from a low loss header to serve each block.

The bespoke energy centre is situated in the lower basement containing 1 no. Combined Heat & Power (CHP) generating unit, 2 No. fully modulating condensing gas boiler comprising, 1 no. twin head primary pump, 4 no. shunt pumps, primary pressurisation units c/w expansion vessel. Each piece of plant was finely engineered to produce significantly greater efficiencies and enhanced pollution control. The CHP flue which comprises of insulated stainless steel twin walled stacks, runs approximately 50m vertically terminating above block 1 roof.

There is an emergency stop button installed on the wall at the boiler room entrance. This will shut off the gas supply, shut down the CHP and all pumps. To reset turn the button in the direction shown on the button. This will restore plant operation.

Operation of the gas boiler is regulated by its controller which is located on the rear of the boiler. Unison control is incorporated which steps each boiler module on in turn at its lowest rate, and then modulates all boiler modules simultaneously to higher rates to match the system load. This method of sequencing offers higher operating efficiencies, taking advantage of the higher part load efficiencies available at low firing rates. Temperature output is controlled by the same controller based on weather compensation.

Pumps serving the district heating system are controlled by self contained variable speed drives and are designed and set to maintain constant pressure. Automatic change over of the pump heads is controlled by the integrated speed drives and is set to change duty every 24 hours.

The degasser and pressurising unit constantly monitors the system pressure and is set to maintain operating pressure of 8.0bar.

Boiler room piping is made of medium grade seamless steel pipes. Piping up to DN50 has threaded connections and above DN50 welded and flanged connections.

Vertical distribution piping in the risers is made of medium grade seamless steel pipes. Piping up to DN50 has threaded connections and above DN50 Grinell connections.

Horizontal distribution piping on each floor is made of Uponor 5-Layer plastic pipe. All fittings and connections are crimped type.