Performance of Energy Sources in Building Services Applications: Assessment

Session 6 Paper 4, CIBSE Technical Symposium, Liverpool John Moores University, Liverpool
11-12 April 2013

The Building and Engineering Services Association (B&ES) have instructed Earp Consulting Limited (ECL) to produce a series of best practice guides for the integration of renewable energy sources into building services applications within the UK.

The use of renewable energy sources to augment or replace traditional energy sources for buildings has brought with it a unique set of challenges for the building services engineer. The results of the early deployment of these systems has been mixed, with large variances in performance. Many of the issues surrounding these early installations centre around the lack of detailed analysis of the system performance characteristics when the system is supplied with energy from sources whose efficiency varies with more than just the load served. Ensuring that each item installed in the building provides best “value” at the lowest carbon cost can be challenging.

This paper reviews the issues surrounding the analysis of the “total building services system” and develops a methodology for the evaluation of all renewable technologies on a common basis. This then allows the interaction of the technologies to be modelled along with control system strategies.

This approach has been used to develop a series of integrator guides to provide the building services engineer with:

• An accepted method of assessing the performance of the different energy source solutions, traditional and renewable, allowing comparative studies and regulation compliance checks.
• An accepted method of assessing the effects of energy saving options in a modular manner to parts or all of the overall system.
• An accepted method of evaluating the effects of different integration techniques and optimised control system strategies.
• An accepted method of reporting the performance of the different energy source solutions and energy saving options.
• An accepted method of commissioning and maintaining the systems for ongoing optimum performance.

These guides use established practice calculation techniques to model the performance of systems in a modular manner. The summation of the modules to form effective and efficient systems can then be evaluated to predict performance over the analysis period.

By adopting established calculation techniques the guides allow designers to use methods with which they are familiar to model the performance of systems and present their results in accordance with European and UK standards.
This paper presents an example of the methodology applied to a simple heating system with an air to water heating only heat pump application.