We all want to ‘breathe easy’, to have good clean air in our homes. Increasing insulation and reduction of drafts contributes stuffy buildings and overheating.
Modern, energy-efficient homes are sound investments – good environmental credentials, quality build, utilisation of new technologies and lower energy costs – a win win situation for developers, landlords and tenants. When it comes to the indoor climate for a home of this type, there really is only one system that fits the bill. Michelle Sharp, Group Communications Manager at Zehnder Group UK, gives the lowdown on MVHR.
The greatest ongoing living costs for social housing occupants, after food, is for heating and electricity, therefore social housing providers should be investing in modern efficient systems such as Mechanical Ventilation with Heat Recovery that keeps the building well-maintained and keeps the money in the tenants’ back pocket – and in turn keeping houses rented for longer periods of time and reducing the risk of tenant complaint, issue and possible re-housing.
New homes are driven to be built to stringent energy-efficient standards and the choice of heating and ventilation system is crucial to achieve these standards and maintain a good, comfortable indoor environment. At the very top level is Passive House where MVHR systems are a prerequisite part of the build, and where amazing savings in energy bills can be achieved. We recently worked on a Passive House social housing development (Knight’s Place in Exeter – see case study below) that resulted in an annual energy bill of £18.00 per household! However, a home or a MVHR system does not have to be of Passive House standard to be beneficial for developers, landlords and tenants – it’s a perfecetly balanced solution for any modern, energy-efficient home.
So, what are these benefits, how are they realised and why should MVHR be the system of choice new build social housing?
Build the structure well, with practically no air leakage and you will keep the heat in and the energy bills down. There is however the question of air – the air that the occupants will breathe, the quality of that air and how comfortable that air makes the home throughout the year. Going from a leaky house to a sealed house design will win the energy-efficiency agenda, but ventilation then becomes crucial to the home. An energy-efficient modern home needs a whole house ventilation system to contribute to the delivery of good indoor air quality.
Energy Efficiency: MVHR helps reduce the heating demand of a property by recovering heat that would have otherwise have been lost through the traditional ventilation process. There are many different units with varying performances, but this can be up to an outstanding 95%!
The nature of heat recovery also means that it contributes to reducing heating demands in the winter through the heat recovery process – this is a great contribution to the environment and the occupant who is living in the home!
Heat Recovery Ventilation is detailed in Part F of the Building Regulations’ airflow rates, and helps efficiency via Part L, through SAP calculations. The decision isn’t a difficult one on the basis on energy performance, health and comfort. However it is more than an extractor fan and is the very heart of the home and therefore when looking at specifying MVHR you need to focus right from the design stage. Here are some top tips to guide you:
Manufacturers such as Zehnder provide an expert design service to ensure that the great results from MVHR are easily and reliably achievable. All social housing builders, architects, and building engineering services consultants are welcome to contact us for initial, exploratory advice. Whether your project is a new-build or an improvement programme for a modern building, there’s no point in throwing away energy, or making your building more vulnerable to condensation and mould problems when you don’t have to.
Knight’s Place: Setting New Standards for Passive House within the Social Sector
Knights Place Housing is a sustainable social housing development of 18 one and two-bedroom apartments, designed by Gale & Snowden Architects for Exeter City Council. Built with meticulous attention to detail, the two blocks have been designed to strict Passive House standards, which deliver high comfort levels for residents via a mechanical ventilation and heat recovery system (MVHR). This produces consistent internal temperatures and excellent air quality whilst minimizing energy use for heating and cooling, resulting in lower energy bills. Knights Place is amongst the first multi-residential, certified passive houses in the UK.
Outstanding Energy Performance
Commenting on the specification of the products, Principal Mechanical and Renewable Energy Engineer at Gale & Snowden Jason Fitzsimmons explains: “Generally the key issue for passive houses is controlling heat loss through walls and windows. You can insulate but you still have fresh, cold air affecting the interior climate so the heat exchange efficiency rate of an MVHR system is very important.”
Knight’s Place apartments maintain a comfortable temperature of 21ºC year round for residents, with minimal heating required and low running costs. According to the SAP Energy Performance Certificate, dwellings at Knights Place can be heated for as little as £18 a year.
First published 26th April 2016.
|Knight’s Place, Exeter – an example of Passive House standard MVHR||Installing a MVHR system will improve air quality and reduce the risk of health issues.||Michelle Sharp, Group Communications Manager at Zehnder Group UK.|