Energy performance gap assessment and Post Occupancy Evaluation of UCL Cruciform Library / Main outcomes
By ucqbvko, on 12 November 2015
This update includes the main results of my dissertation research regarding UCL Cruciform Library. The most important outcomes of the methodology used, including hygrothermal monitoring, occupant comfort surveys, dynamic thermal modelling and Carbon Buzz are presented.
After the monitoring period (6-20/7/2015), the results extracted from the Hobo data loggers were analysed. The most important findings are summarized below:

Hygrothermal monitoring plan
the average internal temperature in the majority of spaces (excluding computer clusters – average of 24 degrees Celcius) fluctuates between 21 and 22 degrees Celcius, really close to the external one (average of 18.9 degrees Celcius).
the average internal relative humidity in the majority of spaces fluctuates between 51 and 55%, falling inside the acceptable range of 40-70% according to CIBSE Guide A (2006).

Average temperature (degrees Celcius) recorded in each space of Cruciform hub

Average relative humidity (%) recorded in each space of Cruciform Hub
Regarding the BUS survey that was conducted during the week 20-27/7/2015 (sample of 56 students), the most important issues are summarized below:
- internal low temperatures
- natural ventilation not existent at present
- need for more working spaces, personal computers and facilities for practicing
- some spaces (mainly the entrance) are noisy
- lack of natural lighting
Dynamic thermal modelling (IES VE software) / Design energy performance
The model was simulated on IES VE software, trying to make it as similar as possible to what the designers had proposed.
Meter readings _ Data obtained from Carbon Culture Platform / Actual energy performance
The actual energy consumption of the library was calculated using data from Carbon Culture Platform resulting in a value of 765.3 MWh.
Estimation of the performance gap
As demonstrated in the graph below, the actual energy performance is 59% higher than the estimated one.
Performance gap factor (actual energy use / design energy use) : 2.49
CARBON BUZZ Platform – Comparison to CIBSE TM46 benchmarks
Carbon Buzz is a collaborative research platform that was launched by the Royal Institute of British Architects (RIBA) in collaboration with the Chartered Institution of Building Services Engineers (CIBSE) in 2008 (http://www.carbonbuzz.org/), enabling designers to compare calculated and real energy use for their buildings. This initiative emerged from the need to manage CO2 emissions from buildings.
Next update….
Conclusions of the research
Recommendations to UCL Estates
Further research
Vasiliki Kontopoulou
Supervisor: Anna Mavrogianni
In collaboration with
UCL Estates: Joanna Marshall – Cook
Green UCL: Alex Green