building opportunities for business improving the building services LOW CARBON DOMESTIC RETROFIT EDITION 1, September 2011 7 John Willoughby European Union European Regional Development Fund Investing in your future improving the building services 7.1 Introduction . .3 7.2 Ventilation . .4 7.3 Heating and hot water . .8 7.4 Electric power . .12 This guide provides information on business opportunities associated with building services in low carbon domestic retrofi t. It covers: 7.5 Summary of business opportunities . .13 • ventilation 7.6 Next steps . .15 • heating and hot water services • electric power. It is building services that are actually responsible for using the energy in the home. Often they are given insuffi cient thought and left to installers, which can result in inappropriate, oversized and poorly controlled solutions. As a dwelling becomes better insulated and more airtight, the reduced load should result in simpler building services solutions. But the opposite seems to be happening; building services are becoming more complicated and diffi cult to understand – both for the designer or builder and for the householder. See Guide 6 for more information on reducing air leakage in retrofi t. Wind turbines are unlikely to Photovoltaic panels supply make an impact unless the site renewable electricity is very windy Efficient hot water production Solar panels can give a good needs careful planning supply of hot water in summer Waste water heat recovery is Efficient heat recovery ventilation available for showers is one option for good air quality in airtight dwellings Not all modern gas boilers are as efficient as one might think Biomass boilers could have potential but need fuel storage Good, user-friendly controls are essential Water-saving appliances reduce energy and carbon emissions as well Unless the householder understands the systems, the Water recycling gives a sense of potential benefits can be lost security but is unlikely to reduce energy, costs or emissions Ground or air source heat pumps have potential for off-gas-grid Over half of the emissions can properties come from electricity use – efficient lights and appliances are essential Figure 7.1 Building services are becoming more and more complicated. Many people see low carbon solutions purely in terms of bolt-on renewable technologies such as solar panels and wind turbines. Some of these technologies have a role to play but need to be evaluated in terms of the overall package of improvement measures. Disclaimer: While every eff ort has been made to trace and acknowledge all copyright and trademark holders, we would like to apologise should there be any errors or omissions. 2 building opportunities for business GUIDE 7: improving the building services Business Opportunity 7.1 Introduction Integrating the technologies together can be a complex task and there are many This guide provides information on business opportunities associated with building opportunities for engineers services in low carbon domestic retrofi t. It covers: and technicians, designers • ventilation and installers to satisfy the • heating and hot water services demand for a holistic approach to designing, installing and • electric power. maintaining the low carbon It is building services that are actually responsible for using the energy in the home. building services. Often they are given insuffi cient thought and left to installers, which can result in inappropriate, oversized and poorly controlled solutions. As a dwelling becomes better insulated and more airtight, the reduced load should result in simpler building services solutions. But the opposite seems to be happening; building services are becoming more complicated and diffi cult to understand – both for the designer or builder and for the householder. See Guide 6 for more information on reducing air leakage in retrofi t. Wind turbines are unlikely to Photovoltaic panels supply make an impact unless the site renewable electricity is very windy Efficient hot water production Solar panels can give a good needs careful planning supply of hot water in summer Waste water heat recovery is Efficient heat recovery ventilation available for showers is one option for good air quality in airtight dwellings Not all modern gas boilers are as efficient as one might think Biomass boilers could have potential but need fuel storage Good, user-friendly controls are essential Water-saving appliances reduce energy and carbon emissions as well Unless the householder understands the systems, the Water recycling gives a sense of potential benefits can be lost security but is unlikely to reduce energy, costs or emissions Ground or air source heat pumps have potential for off-gas-grid Over half of the emissions can properties come from electricity use – efficient lights and appliances are essential Figure 7.1 Building services are becoming more and more complicated. Many people see low carbon solutions purely in terms of bolt-on renewable technologies such as solar panels and wind turbines. Some of these technologies have a role to play but need to be evaluated in terms of the overall package of improvement measures. 3 improving the building services Business Opportunities Options for ventilation are 7.2 Ventilation complex and poorly understood. There is an opportunity for We spend a great deal of time indoors in the company of many indoor pollutants (see Figure 7.2). Ventilation has a key role to play in diluting and removing these people to give impartial advice pollutants. Air tightness is a prerequisite of a low energy retrofi t but if a house is on strategies for air sealing made airtight without an adequate ventilation system, it can be an unhealthy place to and design and installation of live. Conversely, installing ventilation systems in leaky houses can add to heat losses effi cient ventilation systems. and carbon emissions. It is important to build tight and ventilate right. Odour The supply chain for Pa rti cu components associated with la 2 te O s advanced retrofit is currently C , P o underdeveloped in this country. l le An opportunity exists to n develop quieter decentralised whole-house extract systems M o e i and Passive Stack Ventilation n s t o u z (PSV) techniques to the r e O retrofit market. B a c t The current range of single-room e e r k ventilators has low-powered fans ia o a n m and effi cient heat exchangers. d s m co i c An opportunity exists to develop te ba s To units that are quieter and have VO de Cs, Formaldehy improved airfl ow. Figure 7.2 Sources of pollution in the home. Ventilation options Most homes in the United Kingdom rely on uncontrolled infi ltration for background ventilation. Windows are opened or extract fans are used for intermittent purge ventilation. When air tightness issues have been addressed, a more controllable ventilation system should be considered. Options include: whole-house extract, passive stack ventilation, heat recovery room ventilators, hybrid heat recovery systems and whole-house heat recovery ventilation systems. Mechanical extract ventilation (MEV) In airtight houses air quality can be improved by using a continuous extract system. Air is taken from the wet rooms and trickle vents are used to admit fresh air into living rooms and bedrooms (see Figure 7.3). Extract rates can be boosted with switches or presence detectors. Further improvements can be made by using low-watt fans and humidity-controlled trickle vents. The preferred option is a single central extract fan unit with ducts to the wet rooms. If the air tightness of the house is being improved, it is important to provide suffi cient trickle ventilators for fresh air supply – one in each window head may not be enough – and it may be necessary to fi t some ventilators in walls. Good quality humidity-controlled trickle ventilators should be used; poor quality ones often leak air even when they are closed. 4 building opportunities for business GUIDE 7: improving the building services Business Opportunities 1. Warm air from wet rooms... Mechanical ventilation with heat 2. ...is extracted by a central fan and exhausted from recovery (MVHR) systems are the building. Passive relatively unusual in the United infrared sensors (PIRs) or pushbuttons can be used Kingdom. In new build their to boost extract rates in design needs to be painstaking. different areas. 2 In retrofi t the design, planning 3. Fresh air is drawn into dry and installation is even more rooms via trickle vents which can be humidity challenging. There are many controlled. opportunities for services off ering the design, supply and 1 3 installation of effi cient, low- power MVHR systems. An opportunity exists to develop training and accreditation for mechanical ventilation installers. An opportunity exists to develop a suite of MVHR products Figure 7.3 Mechanical extract ventilation. designed for the retrofi t market. Decentralised mechanical extract ventilation (DMEV) An opportunity exists to A new range of fans has become available which are intended to be installed in each wet off er integrated planned room and to run continuously. These systems are referred to as “Decentralised whole- maintenance services for MVHR house extract”. Where centralised whole-house systems can be diffi cult to integrate systems as part of an overall into a retrofi t, decentralised fans may be a simpler solution. These decentralised units maintenance package. can be window or wall fans, or can be ducted. It is unlikely that wall or window fans would be quiet enough to be left running continuously so ducted systems with silencers might be the preferred solution. Secondary opportunities Passive stack ventilation (PSV) exist to carry out training of maintenance technicians and Passive stack ventilation has the ability to ventilate the house without the use of develop systems such as online electric fans. Ducts link the bathrooms and kitchens to terminals on the ridge of the maintenance records (like the roof.