This project is the second of 2 large commercial office buildings with design by NDY. This building is 21 floors with 350,000 square feet of office space.
Challenges and solutions
While many new or refurbished office buildings employ 4-pipe air source heat pumps with heat recovery for fully-electric heating and cooling, this site can take advantage of both district heating and cooling.
All space heating, domestic hot water and cooling is provided via heat exchangers in heating and cooling substations at basement level to connect into nearby district infrastructure.
A particular challenge overcome in both buildings was to develop a design and controls strategy to ensure sufficiently low return water temperatures back to the district heating infrastructure, to help the district network maintain plant efficiency.
Domestic hot water design was particularly challenging to ensure temperatures high enough for comfort and legionella control, but low enough for the network, even in periods of limited use.
Remaining electrification challenges on this project, and others, is eliminating the use of diesel in life safety systems such as the fire sprinkler pump, wet riser pump and life safety generator where batteries are unsuitable.
We liaised with equipment suppliers for the use of HVO diesel. Where possible on other projects, our team has managed to design-out such systems by using multiple independent electricity supplies from the electrical network to provide the necessary redundancy.
