District heating - better service, lower costs

The New Harmood Estate in the London Borough of Camden is a typical public housing development. Built in the 1980s, the site comprises more than 200 dwellings that receive communal hot water and heating via a vast network of pipes. This ageing system connects the properties to a remote, central boiler house.

It was on this estate that Mechanical Services Manager for the Housing Department, John Stow, decided to test-drive his new FLIR Systems ThermaCAM thermal imaging camera.

Readings from the pressurisation unit water meter in the boiler house had told him the New Harmood system was leaking substantial volumes of water.

Without the benefit of site construction plans and in advance of thermography training, he scanned the estate and within half an hour had found the problem.

'I didn't trust it at first,' John explained.

'I thought I might have simply discovered a buried, unlagged pipe'.

'But when the contractor started digging, the major leak was evident'.

'I couldn't believe it had been so simple to find'.

'The crosshair in the viewer made it easy to pinpoint the problem.' Thermal imaging is certainly not a new technology to the Camden Council.

To ensure a high level of service to its tenants as well as to reduce running and maintenance costs, thermal imaging surveys have been regularly out-sourced.

However, whilst this service has been effective at pinpointing problem hotspots, it is not readily available.

With the cost of a thermal imaging camera now very much reduced by comparison with prices prevailing in the mid-nineties, John Stow sought Council funding to bring the service in-house.

It was a move that made a lot financial sense as the Council is responsible for no less than 35,000 properties including 200 district heating systems that serve from 10 to 400+ properties ranging from bed sits to five bedroom properties.

There is no doubt that the problem on the New Harmood Estate could have taken up to a week to resolve if thermal imaging had only been available as an out-sourced service.

In the event, speedy diagnosis resulted in the residents being without a full service for just 18 hours.

Whilst good service delivery to its residents is clearly an important commitment for the London Borough of Camden, so too is the reduction in green house gasses and making sure that best value is achieved from investment.

Reducing energy loss is therefore another key reason for purchasing the thermal imaging camera.

A typical district heating boiler house comprises three or four boilers and associated plant including a pressurisation unit.

If there is a leak anywhere in the piping network on an estate, this unit will continue to pump-in a corresponding top-up to maintain the required pressure.

This in-fill is metered making it immediately obvious there is a leak.

If left unchecked, the continual top-up of raw water promotes scale build-up in the boiler, plate heat exchangers and calorifiers.

This scale build up not only leads to increased energy consumption but may result in premature failure of key plant.

As a result more energy has to be used to maintain the temperature.

Finding leaks fast is therefore of critical importance in cutting these costs and the fundamental reason why the Council purchased a ThermaCAM thermal imaging camera'.

''Although I have concentrated on thermal imaging of pipework, the camera has great potential for wider use,' John Stow explains.

Indeed, the FLIR Systems' ThermaCAM is ideal for air tightness testing, detecting areas prone to mould, assessing flood damage and finding leaks in flat roofs as well as detecting traditional electrical and mechanical hotspots.

One job John Stow already has in mind is thermal imaging heat exchangers.

By creating benchmark images, he plans to grade the scale build-up so that appropriate descale regimes can be implemented, saving labour and costs. Request a free brochure from Flir Systems....