ENERGY EFFICIENCY

Natural Gas is a wonderful clean-burning fuel, however it is wise to use it in the most efficient way.
Approximately 14% of the available energy in natural gas is in the form of latent energy. To make use of this latent energy special design is required to extract it from the gas.

When a conventional boiler burns gas to heat water the latent heat is lost in the waste flue gases; this is why a boiler flue is normally very hot and needs special installation to avoid being a potential fire hazard. Condensing boilers extract extra energy from the gas supply by utilizing the latent heat energy from the gas that is not available to standard boilers.
Keston condensing boilers are among the most efficient available worldwide and this is demonstrated by using plastic as a flue material rather than steel. The flue temperature is typically 10°C below supply water temperature as the latent heat is condensed out of the gas.

Further energy savings are realized by having the boiler modulate its output to match the heat demand. A microprocessor alters the speed of both the turbo fan and the pump to suit the output required; this means, that only the energy required for the task, is used rather than the fixed output of a conventional boiler.

When a Keston rig is used the full potential energy savings of the system can be realized, for example a 4 x C55 boiler rig can modulate from 12 - 220kW. The savings incurred come from the fact that most of the time a heating system is in operation, only a proportion of its total output is required. An engineer will design a heating system to deliver its total output at its worst case scenario, whereas the majority of the heating is required at average winter temperatures.
The Keston rig controller is smart enough to optimize the boilers to suit the output and can also include weather compensation if required.
 

HOW DO THEY WORK?

The commercial range of Keston wall mounted gas condensing boilers covers outputs from 11kW to 110kW with single boiler units. As with all Keston boilers, each has an extremely high efficiency performance of up to 98% (GCV). Despite their powerful outputs, each unit is designed for wall mounting. Keston Boilers offer complete and cost effective solutions to commercial and industrial heating and in all installations, can offer the highest quality systems. These are very often at much lower costs than a single commercial boiler of equivalent output.

How it Works The Keston uses a high powered combustion blower to deliver a premix of gas and air to a downward firing burner in a high efficiency, single pass heat exchanger. The heat exchanger is made from highly corrosion resistant stainless steel in corrugated cross-flow sections. Hot combustion gases pass across the tubes providing heat to the water system. A modulating shunt pump, (integral to the appliance) will ensure the heat exchanger receives the correct water flow when firing and operates at optimum efficiency. Keston boilers are of low mass and low water content giving a rapid response when there is a call for heat. The design, with its single pass heat exchanger, avoids the complications associated with other condensing boilers. The unit is totally room sealed and requires no ventilation for combustion air to the room or compartment in which it is installed. Keston commercial boilers are exceptionally easy to install and maintain. Prefabricated multiple boiler assemblies are available as an option to assist speedy installation. They are completely environmentally sound with negligible NOx emissions (Class 5 rated) and can save 30% on the heating bill.

Unique Flue System All Keston boilers have the advantage of a small diameter plastic flue system and the commercial range is no exception. For the C40 and C55, the 50mm diameter plastic flue option can be extended up to 15 metres away from the unit. The 75mm diameter plastic flue option can be extended up to 45 metres. For the C90 and C110, the 100mm diameter plastic flue can be extended up to 30 metres in length. All boilers can accommodate vertical or horizontal flue routes and are room-sealed. The usage of low cost plastic pipe for the flue can save thousands of dollars on installation costs when compared to a conventional flue. In refurbishment projects, there is no need for expensive relining of the flue. This system is also ideal for buildings with difficult flue options and particularly listed buildings with various restrictions. Added benefits of the flue flexibility are that the boiler can be sited practically anywhere in the most convenient position and the flue can be terminated in a location where the "plume" generated with a condensing boiler does not cause a visual nuisance.