Benefits of MVHR systems for New Build projects

Michelle Sharp, Group Communications Manager at Zehnder Group UK, explains why MVHR (mechanical heat recovery and ventilation) systems are the right choice for New Build projects with benefits for developers and homeowners.

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.

Passivhaus Standard

With MVHR systems as part of the build, big savings in energy bills can be achieved. This is essential if Passivhaus Standard is required. For example, Zehnder worked on a Passive House social housing development at Knight’s Place in Exeter that resulted in a remarkable annual energy bill of just £18.00 per household.

However, even if actual PassiveHaus Standard is not required, a MVHR system is still the choice for a perfectly balanced solution for any modern, energy-efficient home, especially for New Build

Fabric first approach

Build a 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 homeowners will breathe, the quality of that air and how comfortable that air makes the home throughout the year. A sealed house design will win the energy-efficiency agenda, but ventilation needs to be an integral element of its overall design. An energy-efficient modern home needs a whole house ventilation system to contribute to the delivery of good indoor air quality.

Whole house comfort

MVHR is a whole house system that provides continuous ventilation 24 hours a day 365 days a year, working to maintain and deliver fresh air. It comprises a centrally-mounted unit which is located in a cupboard, loft or ceiling void, and which is connected to each room via a ducting network, with air supplied to or extracted from rooms via simple ceiling or wall grilles. Ventilation is balanced – extract and supply – so always a consistent level of fresh air.

Year-round comfort

• Winter: Heat exchanger in an MVHR system works to ensure that the fresh filtered air entering the building is tempered – making for a comfortable home and of course, energy efficiency savings. The frost protection in most units also protected from the extremities of winter weather.
• Summer: MVHR unit also plays its part in the summer – constantly monitoring the outdoor air temperature so that it can automatically make a decision to keep the indoor environment more comfortable. In summer, recovering heat isn’t necessary and will lead to discomfort and this is where the summer bypass is utilised to allow fresh air in, without tempering the air. The fresh air will give the perception of cooling to the home and tenant by circulating the air.

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 96%!

Health advantages

MVHR provides continuous year-round ventilation which prevent issues such as mould or condensation occurring. MVHR provides fresh filtered air to dwellings – good indoor air quality is essential for health and wellbeing and air is passed through replaceable filters in the unit. This is especially important with the increased density planning guidelines for homes and brownfield developments. MVHR is also an advantage where homes are situated close to industrial estates, on flight paths and near to busy roads which may have poor external air quality levels.

Specification advice

Heat Recovery Ventilation is detailed in Part F of the Building Regulations for airflow rates, and contributes to efficiency via Part L, in SAP calculations. The decision isn’t a difficult one on the basis of energy performance, health and comfort but does require more thought than an extractor fan! This means that design and specification is crucial and it means that it ventilation should be part of the design process

Manufacturers such as Zehnder provide an expert design service to ensure that the great results from MVHR are easily and reliably achievable.

ComfoAir Q range of MVHR units provide whole house system solutions.

Zehnder Group UK Ltd
Unit 4, Watchmoor Point
Camberley
Surrey
GU15 3AD
UK

01276 605800

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