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Green drive is good news for installers

With renewable energy continuing to dominate the HVAC agenda, H&V News looks at the business opportunities this is providing

Regardless of the size of business, it is now impossible for installers and contractors to avoid the renewable energy debate, as the need to reduce carbon footprint gathers momentum.

Hoval managing director Adrian Walker finds it is now very common for projects to use a range of different combinations of CHP, biomass and fossil-fuel boilers, solar thermal and heat pumps, as clients look to cut carbon emissions and tap into government incentives.

“While all of this is clearly desirable, it actually presents building services engineers with an increasingly complex situation,” he says.

“Beyond the familiar engineering imperatives, it is now necessary to address extraneous issues such as planning permission, the client’s desire for ‘green’ credentials and the potential revenue stream from the RHI.”

The challenge is to take all of these factors into account while ensuring the system integrates and controls the various heat sources in the most efficient way. This can only be achieved through a good understanding of the characteristics of each heat source, says Mr Walker.

“I would therefore urge anyone involved in the specification or installation of low-carbon heat sources to ensure they have that understanding, or can call on specialist advice when it’s needed.

“Without that, we’re in danger of failing to deliver the best solutions to our industry’s customers,” he concludes.

Usage reduction focus

Daikin UK’s Scott McGavin agrees that building managers need to make more economies in their energy budgets. Today’s climate control systems are already highly energy efficient, so the focus is to cut usage, he says.

“The answer is through the use of intelligent control systems. Controls can both reduce usage of climate control systems and improve energy efficiency.”

The key is to avoid the end-user noticing any reduction in comfort levels, while also allowing them to control their environment.

Systems should be flexible to allow building managers to set parameters and take away energy-saving demands on individuals, potentially cutting usage by about 35 per cent, Mr McGavin continues. “For example, if a control is set to switch off a climate control system when a room is unoccupied, or a window or door is left open, then energy wastage is reduced automatically.”

When used with passive infrared (PIR), it can detect both room or zone occupancy and activity levels. This is a particular advantage for applications such as hotel rooms. “If we imagine a hotel guest turning down the heat when they return to the room in the evening and then waking up cold in the night to turn the heat back up, we can see that when this is multiplied many times over, it is possible to make extensive energy savings with an intelligent control system,” says Mr McGavin.

Different paths

Armstrong Integrated sustainable design director Steve Cooper says the practice of including renewable energy solutions under one heading may be useful for the general public, but it is extremely misleading from a technical viewpoint.

“Each renewable technology has had a completely separate development path,” he says. The focus of development teams has been on achieving feasibility for their equipment, placing integration with others as a secondary consideration, but these need to be integrated within projects.

“This creates both a challenge and an opportunity. As a number of our previous projects have shown us, there are significant carbon reduction opportunities arising from harnessing multiple technologies. But in order to achieve them, system designers must first overcome issues around effective integration.”

Optimum operating temperatures of the different technologies vary significantly, so without effective integration there will be operational trade-offs that undermine, or possibly completely negate, the potential savings.

“Best practice involves using well-proven solutions so that the efficiency of the system is not compromised in order to accommodate onsite generation capability,” says Mr Cooper.

Easy transition

Vaillant commercial director (UK and Ireland) Dave Lacey says that most installers should not find it difficult to embrace renewable energy technology if they utilise the training available.

Once they have ensured a property is properly insulated, the installer can concentrate on using the best solution and successfully marry it with conventional technology to ensure the full quota of required warmth is provided.

Solar thermal can be integrated relatively easily into an existing system and can provide all the hot water required in warmer months, with a contribution of 50-60 per cent of annual hot water needs, he states. 

Unless the current boiler is a modern condensing model, it is worth considering replacing this. Upgrading the entire system can save up to a third on domestic heating bills in the longer term, says Mr Lacey. 

When fitting a heat pump, care must be taken to ensure that the property is suitable, especially when retrofitting. The boiler is usually removed to make space for the heat pump unit to deliver heat to radiators or underfloor heating. This will need to be discussed with the customer as part of the planning process. 

Successful integration will also depend on its being well controlled and much of this will hinge on the homeowner using the controls correctly. Installers should always make sure their customers understand these. Weather compensation should also be considered, as this allows a condensing boiler to work in condensing mode most of the time, says Mr Lacey.

Renewable tech take-up

Following the launch of the £15m Renewable Heat Premium Payment scheme, householders can claim up to £1,250 towards the cost of installing renewable heating systems, Kensa Heat Pumps reminds readers.

The RHPP will support up to 25,000 installations, focused on homes not heated by mains gas.   Kensa managing director Simon Lomax says: “A £1,250 grant will help to stimulate interest in the technology. It should also be made clear that any qualifying domestic installation that receives the Premium Payment will still be eligible for the full RHI tariff due to start in October 2012.”

Calor head of innovation and policy Paul Riding says the fuel source is the logical starting point when considering carbon cutting off the mains gas grid. For example, switching from oil or electric heating to a condensing LPG boiler will immediately reduce carbon emissions. LPG is also an extremely versatile fuel which can provide for all the hot water, heating and catering needs of any building.

Taking it a step further, LPG-fuelled combined heat and power can be over 90 per cent efficient in its use of energy. For every hour CHP is in operation, there is a potential further cost saving, making it the ideal technology to reduce both carbon emissions and energy costs.

LPG is also the perfect partner for renewable technologies. For example, solar thermal collectors, which are more effective in the spring and summer months, can be supplemented by a high-efficiency LPG boiler. Biomass boilers, supported by LPG, can also be an ideal solution when a local sustainable source of woodland is available, says Mr Riding.

A touch of the flue

Ravenheat managing director Louis Pickersgill points to the benefits of using a flue gas heat recovery device (FGHRD), assisting homeowners to gain a rapid return on investment when replacing their boiler.

This recycles the latent heat gases, normally expelled into the atmosphere, to preheat the incoming water for domestic hot water use. Those currently on the market work in different ways, but all reduce carbon footprint and save money, he states.

Adopting a FGHRD is also an important step on the road to a renewable future. “We, as an industry, should be focused on educating homeowners, landlords and specifiers that affordable and manageable steps can be taken to improve energy efficiency and save money immediately,” says Mr Pickersgill.

Smith’s Environmental Products sales and marketing director Jim Bennett says that while the RHI and RHPP will encourage people to learn more about renewable heat generators, it is equally important that systems are looked at as a whole – including the heat emitter.

“While homeowners are probably aware of heat pumps and solar technology, they are less aware that using fan convectors alongside renewable technology can keep heating costs and carbon emissions to a minimum,” he says.

Utilising simple and proven technology to put heat where required, when required, fan convectors are suitable for use in both existing and newly built domestic or small commercial properties. 

They also have low water content, using a heat exchanger that holds just 5 per cent of the water required for an equivalent output radiator. This allows the premises to heat up (and cool down) faster, he states. Fan convectors are also able to run at low water temperatures, making them ideal for use with carbon-cutting technologies.

As renewable energy systems operating at low water temperatures continue to grow in popularity, end-users and installers need to be made more aware of fan convectors and their carbon cutting credentials, says Mr Bennett.

Renew pressure

Jaga Heating Products commercial manager Paul Kingswell says HVAC engineers are under great pressure to use environmentally friendly heat sources and, alongside these, an equally sustainable heating delivery system is required.

Positioned as modern, eco-friendly alternatives to the traditional large, steel-panel models, today’s intelligent radiators operate with 90 per cent less water.

This lower thermal mass, particularly when twinned with convector fans, means modern radiators can cope perfectly with the low flow temperature of 35 deg C to 38 deg C typically produced by heat pumps, and highlights an end to the practice of having to use over-sized conventional radiators.

Same-size heating

Purmo sales and marketing director Chris Edwards agrees that radiators can be run at lower water temperatures, complementing renewable technologies, without needing to be significantly larger in proportion.

“When combined with better insulation in properties, they can be specified at about the sizes that we are already used to,” he says. “Turning down the heat will help not only to cut carbon footprints but also lower bills for end-users, who are now facing 18 per cent rises in domestic fuel costs.”

With lower water content, newer radiators are more energy efficient, he states, and old models are 100 per cent recyclable. “We’ve also maintained a lot of manufacture in the UK and can make products for the same costs as we could abroad, and the carbon footprint attached to each radiator is far less as a result,” he says.

While underfloor heating is excellent in the right setting, cover it with thick carpeting and heat is lost into the floor. Radiators, in contrast, emit all their heat into the air space and circulate it quickly, avoiding stratification and providing maximum comfort, says Mr Edwards.