MVHR (Mechanical ventilation with heat recovery) is a whole dwelling ventilation system that supplies and extracts air continuously at a low rate with the facility to be boosted as required meeting Building Regulations Part F . The unit is normally installed in the loft space or cupboard and rigid ducting supplies fresh filtered air to the habitable rooms and extracts stale polluted air from the ‘wet’ rooms. Supply and extract diffusers are fitted to the ceilings and are adjusted to balance the system. The unit incorporates a heat exchanger that tempers the incoming air before it is delivered to the habitable rooms.
The system can be controlled to boost speed when moisture is being generated (by bathing or cooking for instance) either
- Manually via single or multiple switches
- Automatically, typically via humidity or other sensors
These should be located in or near the wet rooms. Background ventilators in windows are not required with this system. For housebuilders, energy efficiency is still the most important specification factor when it comes to ventilation as they seek the most cost-effective way to achieve carbon reductions and reduce dwelling emission rates (DER). Specifying an MVHR unit that boasts low energy usage and high thermal efficiency is key to reducing a home’s DER. As consumers have become more informed of the health implications of Indoor Air Quality, MVHR is coming to the fore as a key ventilation solution.
“The Future of Indoor Air Quality in UK Homes and its Impact on Health”, a recent report by Professor Hazim Awbi, at The University of Reading, states the health risks associated with poorly ventilated homes in no uncertain terms. The research cites MVHR as the most cost-effective solution for achieving an energy-efficient air exchange rate and a healthy environment for building occupants.
Mechanical Ventilation with Heat Recovery (MVHR) is a centralised ventilation solution that simultaneously supplies fresh filtered air into and extracts stake, moist air out of a dwelling. As a result, it is a very effective way of maintaining the indoor air quality of a property MVHR is particularly favoured in New Build because it is not only a very effective way of meeting the Building Regulations Part F but a method of introducing fresh air into a sealed-up building is key to maintain the fabric of the building The unit is usually installed in the loft or a cupboard. Air is extracted and supplied across the property via ducting whilst diffusers are fitted to the ceilings and are adjusted to balance the system.
Xpelair Natural Air range of MVHR units is specifically designed for dwellings of between 1 and 5 bedrooms. The units operate in a low-speed (trickle) mode to ensure continuous ventilation but can be boosted either via a remote switch or automatically via an integral humidity sensor. This means that the extract rate will increase when the unit detects higher humidity as a result of, for instance, showering or cooking.