Queenswood School GSHP
Client: Queenswood School
Services: Technical Survey & Options Appraisal
Renewables: Ground Source Heat Pump (GSHP)
Technical Assessment & Review
Queenswood School consists of 23 buildings built over the course of the last century. This school was looking to reduce their gas usage for the heating and domestic hot water. A Ground Source Heat Pump (GSHP) was identified as the most suitable technology.
Starting with a measured onsite survey we could assess fabric heat losses, ventilation heat losses, hot water demands, system losses and thermal response. A heat loss model can be produced based on the design day conditions.
Dynamic Thermal Analysis
We created a comprehensive thermal model of the property using IES-VE, allowing us to conduct multiple simulations with a high level of accuracy, down to a 10-minute resolution. This level of detail is extremely important for building with varying occupancy levels.
This allows the contribution from solar thermal to be maximised as the daily contribution can be stored for use in evening or next day.
It takes some time to get the quality and level of detail in the model correct, but it is fundamental to the value of the output for all the work that follows.
Heat Load Modelling
Conventional ‘steady state’ calculations for heat load tend to oversize the heating plant requirement. As they have limited parameters and tend not to consider previous operating periods.
Put simply, the building may already have some heat from the day before, rather than assuming you are heating it up from cold every day.
We used the IES model of the site heat demands based on the annual occupancy patterns and type of activity, the heat and hot water demand.
Ground SourceHeat Pump Sizing
We provided detailed specifications for Ground Source Heat Pumps to provide space heating and hot water.
An estimation for the borehole size and area needed, along with the number of boreholes, was given. A borehole array map was created to determine the interaction between boreholes and how much energy is being taken from the ground.
Other checks were done such as an analysis of ground temperature with the GSHP implemented to ensure no excess heat is drained from the ground.