02.02.2010

Dry cycling of gas boilers can waste a great deal of energy, even when BMS optimisation is in use. Installing gas boiler load optimisation controls can reduce this waste and help boilers run more efficiently.

Building engineers, energy and facilities managers tend to overlook that many gas boilers waste energy through dry cycling when they are not actively contributing to the building heating and hot water demand. It is often thought that existing building management systems (BMS) and building energy management systems (BEMS) are optimising the boilers to remove dry cycling. However, the BMS is optimising the building not the individual boilers.

The system should therefore be optimised through intelligent analysis of each gas boiler’s flow and return water temperatures. to reduce energy costs and carbon emissions. This can be achieved by retro-fitting bespoke ‘intelligent gas boiler load optimisation’ controls.

Such a system also needs to work in harmony with existing BMS/BEMS and other temperature controls, and also be fully adaptive to changing load demands such as weather compensation and/or building optimisation controls.

Why does dry cycling occur?

Over 80% of commercial gas boilers are oversized for their application, which is the cause of dry cycling. When a gas boiler is standing idle it acts like a giant radiator, losing energy in the form heat to its surroundings. Even a modern, well insulated gas boiler will typically lose 1-2% of its heat through radiated heat loss.

Additionally, draught within the flue system may draw cooler air through the gas boiler, potentially adding a further 2-5% heat loss. The need to cleanse the combustion chamber is also accentuated each time a pressure jet burner fires, known as ‘standing losses’. Inevitably, these standing losses will cause the gas boiler to fire unnecessarily to overcome the heat losses while the gas boiler is idle and wasting energy.

Reduce your gas consumption by up to 25% through gas boiler optimization

Intelligent gas boiler load optimisation has the ability to recognise and identify dry cycling by constantly monitoring the boiler’s thermal response to changing loads every ten seconds.
By analysing each individual gas boiler’s temperature profiles, dry cycling can be identified and rectified by gas boiler load optimisation controls. In this respect, gas boiler load optimisation controls are not trying to replicate the function of a BMS or BEMS. In fact, they complement and harmonise with the existing controls to deliver additional energy cost savings and carbon emission reductions with low capital costs.

The savings and payback periods delivered by intelligent gas boiler load optimisation will vary. However, independent verification has shown that typical savings of between 10-25% are achieved.

Gas Boiler optimisation - how Envido can help

Envido can carry out a full review of your gas boiler to identify when and where you are wasting energy.

We can install technology that simply clips onto the side of your boiler and solves this problem - cutting your gas bill and your carbon footprint significantly.

Based upon established technology, our products are proven to reduce carbon emissions and energy consumption by up to 25 percent with typical paybacks in under 2 years.

Upgrades or installations of energy-saving equipment can be paid for with no upfront capital expenditure through Enhanced Capital Allowances. Visit our Grants and Funding pages for more information on other payment options.

> Contact us for a no-obligation discussion with a member of our team for more information on how our technology can help improve the energy efficiency of your gas boiler(s)

> Click here to find out more about our gas boiler optimization service