Money Well Spent?

After last year’s pilot scheme more homes across Northern Ireland are to benefit from the launch of a new £12 million boiler scrappage scheme starting in September. The pilot scheme last summer saw almost 1,700 boilers replaced with new A-rated highly-efficient models.

In the main I welcome this initiative but is it the best way to address and improve domestic energy use?

Detailing and assessing individual energy use in the home cannot in my view be a simple one-fix solution; it’s more difficult than that. The replacement boilers are certainly efficient if installed, controlled and utilised correctly.

But are we guilty of just ticking boxes that state that having £12 million spent on new boilers is a sea change in energy use? Surely we need to make sure that any home receiving a new boiler is insulated to a high standard and that the glazing is modern i.e. doubled glazed and the rest of the property reasonably air tight.

If not then most of the advantage from the new boilers will simply be lost heating the existing rooms that lose heat quickly. Insulation for every home to a high standard should be the first and only move before any heating device improvement is considered.

In my view “get it warm and keep it warm” is the mantra. In my opinion continual tinkering won’t properly address domestic energy use or greatly improve the costs for homeowners.

There needs to be a consistent and whole house assessment method established and adhered to, that identifies individual needs and tailors improvements to suit site requirements.

High insulation levels should always be the key element before changing any heating device.

Replacing boilers, oil or gas is governed by legalisation and hopefully this important part is being adhered to by all the industry installers fitting the replacement units.

Heating systems should be designed to match the heating needs of the buildings in which they are installed, using recognised methods such as those described in the CHeSS standards.

They should be installed in accordance with relevant safety regulations, as well as manufacturers’ instructions, the Benchmark scheme, building regulations, the Domestic Heating Compliance Guide and British Standards.

The specifications list only the principal components of a heating system affecting energy efficiency.

Other components will be required, such as radiators, circulator pumps cisterns (feed and expansion tanks), and motorised valves. All components must be selected and sized correctly. Replacement boilers are rarely sized correctly, oversized boilers cost more to purchase and generally operate less efficiently resulting in higher running costs and increased emissions to the atmosphere.

In sizing the heating device the ‘whole house’ procedure can provide the installer with a simple but reasonably accurate method of sizing which is both quick and easy to use.

The ‘whole house’ procedure can be found free of charge at http://www.boilers.org.uk.

This method is aimed at typical dwelling types found in the UK, the method should be used for gas, oil and LPG boilers up to 25 kW and not used for combination boilers or solid fuel heating systems.

Minimum standards of efficiency are required by law for most boiler types. UK building regulations requires a higher performance than the EU Boiler Efficiency Directive (17) but best practice requires boilers of even higher efficiency to be selected. The efficiency of the heating system has a major impact on running costs and the associated CO2 emissions. Boiler efficiency depends upon:
• Fuel type and quality
• Boiler type and design, correctly sized/rated to the individual home or building
• The boiler load based against known or possible weather conditions
• Boiler and radiator sizing relative to the design heat load using SAP, Whole House Method or DHCG
• Minimum system controls as stated in CHeSS standards CE51, CE54, CE30 and the DHCG
• Controlled flow and return temperatures, less is best • Installation and commissioning report and system hand over to the customer (legal requirement)
• System free of sludge and scale, flushed before commissioning
• Regular servicing and maintenance The standards set out minimum controls which must be part of the system before handover occurs i.e. if the boiler is to be changed the installer must assess the system pre change for the minimum controls and explain to the customer that unless the missing controls (if any) are part of the system then the boiler change cannot be started. This element is generally ignored by the industry and building control.

CHeSS standards clearly set out the minimum level of control on any heating system:

A time switch is an electrical switch operated by a clock to control either space heating or hot water, or both together but not independently.

A full programmer allows the time settings for space heating and hot water to be fully independent.

A room thermostat measures the air temperature within the building and switches on and off the space heating. A fixed temperature may be set by the user.

A programmable room thermostat is a combined time switch and room thermostat which allows the user to set different periods with different target temperatures for space heating, usually in a daily or weekly cycle. Some models also allow time control of hot water, so can replace a full programmer.

A cylinder thermostat measures the temperature of the hot water cylinder and switches on and off the water heating.

A TRV (thermostatic radiator valve) has an air temperature sensor which is used to control the heat output from the radiator by adjusting water flow.

Storage, hot water cylinders also have minimum levels of compliance

All of these controls have to be considered or in line with CHeSS standards must be installed before or with the heating boiler i.e. Programmer, Room stat, Cylinder Stat and TRV’s are a legal minimum requirement to meet standards. The system should also be fully explained and demonstrated to the customer so that low cost utilisation can be achieved.

Is it money well spent when we fail to recognise all energy treatment needs?