The Future of Heat

Significant changes to Building Regulations are likely to take place in 2018 to raise domestic boiler installation efficiency. How can you stay ahead of the curve? Chris Yates, Managing Director at Johnson & Starley, discusses...

In December 2016, the government ran  a consultation entitled Heat in Buildings – the Future of Heat. The purpose of the consultation was to ask views on options the government proposed for raising domestic boiler installation efficiency. The aim was to bring in measures that  reduced energy bills for tenants, giving more choice of ways to heat homes but also support the government’s targets to reduce greenhouse gas emissions through to 2050.   Gas boilers play a huge part in our heating industry accounting for around 1.5 million being installed every year.  The UK is by far the largest boiler market in Europe and the proposals do show that the government does recognise how big an impact these appliances make.

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When you also consider that currently there is no requirement for a room thermostat to be fitted when a condensing boiler is replaced, demonstrates that good practice is not currently being adopted and most importantly, tenants are likely to be paying more than they need to for their heating.  Thankfully, one of the proposed changes to the Building Regulations is that any system that has a replacement boiler, not just new systems, should have control over the time the heating is on and the temperature at which it operates. I think this is a great move, and long overdue, as it should start to improve the consumer behaviour and more importantly, reduce running costs and emissions.  If a thermostat is not fitted, the boiler often has to work at full output which is actually when it is operating at its lowest efficiency and in many cases, may not be condensing.

So, what are the options that are likely to come into force in 2018 and will probably be published later this year?

For all gas boiler installations, landlords will need to have installed a condensing boiler which has been a requirement since April 2005.  Gas boilers are likely to be with us for many years to come much work is being done to introduce green gases into the network be it biomethane, synthetic natural gas, in other words shale, and hydrogen or more likely, a hydrogen blend with natural gas.

Although gas looks to have a long future ahead of it, it is very important to ensure the boiler installations are as efficient as possible but without putting significant additional cost onto the property owner that they may decide to repair the appliance rather than replacing it.  In addition, the tenant must be able to get the full benefit from the measure without it relying too much on their behaviour.  In other words, the benefit occurs with little intervention for the tenant.

So what else has been considered by government? Well, apart from wanting the boiler to be 92% efficient, which is virtually all gas condensing boilers, you will probably need to fit at least one of the following measures:
• Passive Flue gas heat recovery
• Load/weather compensation
• Smart control

Let's take one of these in turn and look at what this means in practice, particularly the Passive Flue Gas Heat Recovery.
Passive Flue Gas Heat recovery is a technology that has been around for many years now and is certainly evolving into a variety of different options that the property owner can consider.  So, what does it do? Well it rather ingenuously extracts waste heat from the products combustion, in other words, flue gases, and this is then used to preheat the domestic hot water which in turn raises the efficiency of the boiler due to it having to do less work. They are called passive as they do not need any additional electricity to operate the device.  Some designs have a summer store which enables it to recover heat from the space heating production and used to later offset the heat required for providing domestic hot water although there is debate as to how effective this is.

The first Johnson & Starley model was a large box on top of our boiler which meant that it was restricted as to where the boiler is positioned and also added additional installation time. Most importantly, it increased the cost of the boiler by around £500 exc VAT. This is often why people think that Passive Flue Gas Heat Recovery is an expensive option and creates extra installation work.

That may have been the case in the past but not now. Four years ago we introduced our Johnson & Starley QuanTec fully integrated Passive Flue Gas Heat Recovery boiler with an output of 28 kW, exactly the same size as our 30 kW model.  How does it do it? It has two additional coils at the back of the heat exchanger that are used to preheat the incoming mains cold water. In addition, it is less than £200 additional cost over our 30kW boiler and with savings to the tenant of up to £100 a year, depending on usage, payback is dramatically reduced.  It also gives an added benefit of the household as pluming is significantly reduced when heating for hot water due to more heat being recovered from the flue gases, lowering the temperature when leaving the flue, making them close to ambient temperature. Finally, it doesn't take any longer to fit our boiler so no additional installation costs are incurred.  Tenants also will not even know it has been fitted as it always operates when there is demand for hot water apart from getting ‘passive’ benefits

The next option is load/weather compensation. This suggests to the boiler that the radiator circulating temperatures need to increase when the house is cold. The warmer house, the cooler the radiator enabling the boiler to run more efficiently due to the low temperature it needs to heat the property. The cost of such unit is about £75 plus installation costs exc VAT.

Weather compensation then adds a further £45 exc VAT to enable the sensor to be fitted outside the property to measure temperature. The advantage with this type of system is that it enables the boiler to anticipate what the heating demand will be, earlier than if you just relied on the temperature sensor inside the property. Not many types of this system are installed in the UK but they do enable improvements in how the boiler responds. 

Finally, it looks as if smart controls are going to figure much more strongly in the decision-making for boiler replacement. In recent years this has been a big growth area as tenants like the appeal of mobile phone apps to control the heating.  Further enhancements would be to add thermostatic radiator valves.  Thermostats alone can be around £250 exc VAT so not cheap but if it encourages users to take more control of reducing energy costs that arguably it is a good thing.

So, significant changes to Building Regulations are likely to take place in 2018 but I think government have made some good practical proposals to help tenants and householders to reduce costs.