Drivers for refurbishment Is existing plant inefficient?
Do labour resources for reactive works exceed resources for planned maintenance?
Are there changes in the building use or extension of the building?
Are there changes in envirnomental policy/ legislation?
Health and safety concerns?
Identify type of heating system, distribution routes. Understand how the system works. How does the heating system perform? Review O&M manuals, BMS historical data
Evaluate existing heating loads and effectiveness of controls
Evaluate the constraints relating to the existing heating system, the building and the proposed refurbishment
Undertake condition survey. Refer to BSRIA Guide AG4/ 2000 and CIBSE Guide M
Look at the potential to improve the thermal performance of the building and reduce the heat load (e.g. improved double glazing, improved insulation)
Decide on the level of refurbishment
Boilers, flues, flue dilution system, controls, primary and secondary hot water circulation pumps, commisioning valves, pressurisation unit, HWS calorifiers, primary and secondary hot water distribution pipework, heat emitters, oil storage facilities, ventilation and combustion air supply systems, general condition of the boiler house, electrical distribution systems
Minor refurbishment Implement planned activities
Major refurbishment
See separate process flow chart (Figure 3.2)
Complete refurbishment Design as for new build
Figure 1: AM14 decision flowchart for refurbishing (Source: CIBSE AM14)
re-commissioning. Beyond this, a total refurbishment is one where the building might be undergoing a major structural change or a complete replacement of the heating systems. Some potential key constraints on the refurbishment process are highlighted – such as a lack of record drawings and equipment schedules, and issues around the integration of new systems and controls into existing ones. AM14 does not present a set of specific
solutions but highlights areas that need careful consideration when assessing the practicality and viability of a refurbishment project. New approaches to systems design will often mean that additional space is needed. For example, biomass systems will require storage and access for delivery
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that, in the case of replacing existing oil fired systems, may simply be a matter of reorientation of the existing areas. However, replacing or augmenting electrical or gas systems could entail a whole additional set of delivery, storage and chimney requirements. Consequential constraints are
included, such as the need to determine the operational changes when using condensing boilers on a traditional heating system to maintain heating outputs. The manual is mindful that in many refurb projects the heating requirement for the building is likely to be reduced when fabric and air leakage improvements are made, so compensating for a reduction in heat distribution capacity through lower flow and return water temperatures.
AM14 focuses on information that is essential for the proper evaluation, design and operation of the systems for the designer and building operator
February 2012 CIBSE Journal 39
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