What is Mechanical Ventilation with Heat Recovery (MVHR)?

Due to Government legislation and building requirements, new homes are required to be built with very low leakage rates to make them more energy efficient. However, an air tight property can result in poor indoor air quality because condensation and pollutants from cooking, cleaning and bathing will remain trapped inside the building. This is where Mechanical Ventilation with Heat Recovery (MVHR) systems comes in. MVHR systems provide the entire home with all-year-round ventilation; they remove condensation and pollutants from inside the property, therefore, improving the indoor air quality, whilst recovering the heat that would otherwise be lost outside. These systems are great at reducing dust and allergen levels within the home.

How does MVHR work?

MVHR is fast becoming the most common method of ventilation for the whole house for new build properties because it is a proven low-energy, highly efficient ventilation method. The MVHR system works by combining the air supply with the air extract in one unit. Stale air with high moisture content is extracted from ‘wet’ areas such as kitchens and bathrooms and passed through the MVHR system to produce filtered air, which is then delivered into the living areas of the property. As the old extracted air passes through the system the heat from the stale air is recovered via a heat exchanger which is then used to temper the fresh, filtered air.

 

Benefits of MVHR 

-          MVHR systems can be designed to suit every size and type of property from small apartments to homes with up to seven wet rooms which enable you to save money and space.

-          The systems have very low noise levels which is an essential feature because the MVHR systems are continuously running to provide ventilation for your home.

-          MVHR systems can save you money in the long term because they require very low running costs therefore giving you significant energy savings.

-          They are lightweight, compact and very easy to install.

-          MVHR systems dramatically reduce the allergen and dust levels within your low leakage, energy efficient home providing your property with fresh, filtered air.

-          The heat recovery from the air enables a steady heat delivery and reduces the amount of heat lost.

-          The heat delivered through this ventilation system removes the need for radiators as the filtered air is tempered from the heat recovered from the original stale air.

-          Installing an MVHR system will help you to achieve a high score in SAP Q, and to comply with Building Regulations Part F & L.

 

MVHR considerations
 

-          Can’t use in properties that use open fires, the room must have a sealed stove.

-          The initial cost of the installation compare to some alternatives is relatively expensive, however, it is cost neutral after 4 years.

-          The efficiency of the system relies heavily on the air tightness of the building. This is why new low-leakage, high energy efficiency builds are the best properties for MVHR system installation.

-          Filter replacements are required every 9 -12 months.

 

Article written by Optiheat Renewables – Devon based experts in the design, installation and maintenance of MVHR and other renewable heating systems to homes in Devon and Cornwall