MVHR stands for Mechanical Ventilation with Heat Recovery, which is a system that helps to ventilate a building while recovering heat from the exhaust air to pre-heat the incoming fresh air. They will look similar to the pictures above. Here are the steps to identify an MVHR unit:

1. The MVHR unit will have two ducts connected to it, one for the supply air (fresh air) and the other for the exhaust air (stale air).

Test

1. Typically smaller than an MVHR. Approximately 300 x 300mm.
2. Usually located on a ceiling or in a ceiling void.