London, 2019
Architect: Roz Barr Architects
Area: 650m2
RIBA National Award 2018
RIBA London Award 2018
President's Award UK Church Architecture Awards 2019
The church was previously heated by blowing warm air around the room using electric powered fans housed inside wall mounted convectors.
To heat the church fully by convection, a large volume of room air and the heavy masonry walls needed to be warmed. Warm air heating systems promote internal air currents. The less dense heated air naturally rises out of the occupied zone up to the ceiling and as this air cools, it will drop back down forming downdraughts. To maintain comfort in the room, the heating system needed to operate continuously until the whole volume of air in the room is warmed. Any heater that attempts to heat the whole air volume will use large amounts of energy in the process. Keeping the warm air heaters on for long periods of time did not suit the occupancy pattern of the Church.
We designed a system that prioritises radiant heat transfer which avoids directly heating the whole volume of air inside the church. Copper pipes are embedded within the base of all masonary external walls. Heated water is circulated through the pipes and the walls are continuously heated 24 hours a day during the heating season.
A hot strip is created at the base of the walls which drives convection in the boundary layer between the bulk room air and the wall surface. The warmed walls radiatively heat people and objects inside the space. With this there is no convection in the bulk of the room air, which gives a lower risk of air currents and downdraughts.
Installation of the wall tempering pipework was carefully specified and monitoried during installation to ensure there was a minimal and consistent plaster cover over the embedded pipework.
The result is the walls are now warmed and the bulky convectors have been removed.
The wall tempering system was designed to provide a base level of comfort during general use with the heat generated by the occupants contributing to a warmer envionment for times when the church is busy for events and popular services.
New primary servicing routes were incorporated into existing floor trenches previously used to route pipework for the original gas lighting. These service trenches were re-formed using the collection buckets from sections of standard Aco slot drains butted together. A new timber accessible cover was applied to contrast with the original floor.