Sample Works

In this example a client relied upon directly heated calorifiers close coupled to a pumped circuit operating on a 24Hr basis. Local thermostatic control was achieved with immersion type thermostats which satisfied Health & Safety requirements of storage at 60°C and distribution at 50°C.

When the system failed, due to its extended operational period, we were requested to consider the matter and engineer a solution. An occupied building required reinstatement of services as soon as practically possible and therefore the project was split into two distinct phases. In Phase 1 the single-phase elements were replaced with three-phase items and a new controls strategy maximised the benefits of off-peak electrical charges. This produced operational savings of £800/month.

With the system back in operation Phase 2 provided the staged replacement of the pumped circuit with local water heaters [typically rated at 3Kw with a 15L capacity and therefore exempt of the definition ‘Controlled Service’ & the Regulation G3]. Once completed the pumped circuit was decommissioned. This produced additional savings of £1300/month.

Project 2

In this example an Air Conditioning Inspection was undertaken on a modern office building converted some time previously for multi-occupancy usage. Initial inspections confirmed that Hitachi Heat Pumps units, in both split and twin-split configurations[common pipework preventing separation of individual units], were installed in addition to conventional perimeter heating, from central plant, to serve an envisaged original open plan layout. The resultant combination gave rise to cross controlling between the air-conditioning units; in the twin-split configuration cassettes from the condensing unit were not always serving the same area within the building, or between the air-conditioning equipment and the central plant. A lack of effective maintenance, the filters within the cassettes were so blocked that no airflow was evident and the outdoor unit’s required full chemical treatments, completed the obvious areas of concern.

Our recommendations for the works were as follows:

• Conduct a full maintenance regime ensuring compliance with both F-Gas & Ozone Depleting Regulations as applicable.

• To enable the remote controllers time clock only for pre-heating of the building, 22°C as suggested in CIBSE Guide A, prior to occupancy thereby maximising on the benefits provided by the heat pumps and reducing the loadings on central plant.

• Central plant controller to be reconfigured to provide staged operation of plant.

• An optimiser to be fitted to the central plant.

With the exception of direct costs associated with the supply and fitment of the optimiser all remaining works are low cost yet yield significant savings, which themselves will provide significant emission reductions, a factor which will only be enhanced if the optimiser is also incorporated.

Project 3

This is an example that in some respects we would not rather list and yet amply demonstrates the problems facing the sector with finishing skills for which no accredited engineer would admit responsibility. The initial problems concerned a lack of performance from the plant which was visually confirmed as leakage from the flare connections!

Recommendations were produced but the photographs say so much more than we could!!