1. 11 September 2018
The most acceptable method of water heating for Badock – a University of Bristol Hall of Residence.
A Thermal and Financial Model
Naomi Knight - University of Bristol

2. 11 September 2018
Background
Hot water accounts for 18% of domestic energy use in the UK.
Halls of Residence are unique
University of Bristol target - 38% reduction in emissions.

3. 11 September 2018
Aims and Objectives
Find the cheapest method of heating water in Badock Hall of Residence, with consideration of the environmental impact of the system.
Objectives:
Undertake site visit to identify current systems and suitability for alternate systems.
Produce thermal model of the current system and a solar thermal system.
Produce financial model of both systems
Compare results with those of Yingpei Gao

4. 09 May 2016
Current System
Simple schematic of current electric immersion heater system.

5. Current System (2) System with WWHR and insulation Current system
11 September 2018
Current System (2)
System with WWHR and insulation
Current
system
Varying tank temperature over the course of the day for different system configurations

6. 09 May 2016
Solar Thermal
Varying tank temperature over the course of the day for different system configurations

7. Solar Thermal (2) Data set Find time Panel and HX heat addition
09 May 2016
Solar Thermal (2)
Data set
Find time
Panel and HX heat addition
Electricity and heat loss
Left: simple flow chart of thermal matlab model, Above: Stratified tank model, water returns via manifold diffuser.
Mass and Heat balance for tank

8. 09 May 2016
Solar Thermal (3)
Monthly solar fractions for each system. 33% - 41% annual solar fraction - increases to 35% % for PV pumping.

9. Includes energy tariffs – FIT and RHI - and maintenance costs.
09 May 2016
Financial Model
Includes energy tariffs – FIT and RHI - and maintenance costs.
Solar thermal ROIs £102, 000 and £146,000. (Highest ROI for small FPC system with PV pump.)
ASHP ROI £200,000.

10. Financial Model (2) Do nothing scenario ASHP
09 May 2016
Financial Model (2)
Do nothing scenario
ASHP
Annual cost of each system configuration, including amortised CAPEX and predicted maintenance costs.

11. Environmental Impact Gas emissions higher than grid emissions ASHP
09 May 2016
Environmental Impact
Gas emissions higher than grid emissions
ASHP
Annual CO2 emissions for each system, 70% reduction for solar thermal and 90% reduction for ASHP.

12. 09 May 2016
Conclusions
Mitsubishi ASHP is the recommended heating method. (Limited)
Potential for solar thermal
Worst possible outcome – is do nothing.

13. Thank you d Any Questions?
09 May 2016
Thank you d Any Questions?