How Mechanical Ventilation with Heat Recovery (MVHR) Works

How Mechanical Ventilation with Heat Recovery (MVHR) Works

By Ruth MacEachern

Product Manager

Mechanical Ventilation with Heat Recovery (MVHR) systems are designed to provide continuous ventilation while recovering heat from the outgoing stale air. MVHR systems can be fitted to a single room such as EnviroVent HeatSava or be installed to provide a whole house ventilation solution such as the EnviroVent EnergySava range.

They provide an energy efficient form of ventilation that captures the heat from air that is being extracted from the home to warm the incoming air and can help to reduce heating bills.

How MVHR works

MVHR systems consist of two separate airflows: one for extracting stale, moist air from "wet" rooms like kitchens and bathrooms, and another for supplying fresh, filtered air to living spaces. The stale air is extracted and passed through a heat exchanger.

The heat exchanger transfers the heat from the outgoing stale air to the incoming fresh air without mixing the two airflows. This process can recover up to 95% of the heat, significantly reducing the energy required to heat the incoming air.

The pre-warmed, filtered fresh air is then distributed throughout the home via a network of ducts and vents, ensuring a constant supply of clean air while maintaining comfortable indoor temperatures.

How MVHR systems are installed

Whole house MVHR systems require careful planning and professional installation to ensure optimal performance. In most cases, MVHR systems are installed in new build properties or during a full renovation of an existing home.

A ventilation specialist will assess the property to determine the best locations for the MVHR unit and the ductwork. The system must be designed to ensure efficient airflow and heat recovery.

The central unit of the MVHR system is normally installed in the loft where it can be easily accessible for maintenance and filter changes.

The ducts are installed to connect the MVHR unit to the extraction points in wet rooms and the supply vents in living areas. The ducts are insulated to prevent heat loss and condensation.

Once installed, the system is tested to ensure it is working correctly and efficiently. The installer will also provide instructions on how to operate and maintain the system.

Find out more

If you are in the process of building a new home or are about to undertake a major renovation of your property, an MVHR system could be ideal for you. For more information about how MVHR systems work and how they could benefit your home, please contact your local ventilation specialist.