Due to the nature of daily activities that produce moisture: cooking, cleaning and even breathing, it is impossible to completely rid any household of moisture. However, when a house becomes too damp, mould sets in. One of the best ways to combat this unsightly nuisance is to make sure that moisture never has a chance to take hold and become a bigger problem. This can be done with the help of a home ventilation system. If you wish to change and have a CMV installed in your home, follow this guide.
Step 1: placing the valves
The main principle for installing a CMV is to place the valves away from areas where residents spend the most time in order to minimise draughts. Supply air valves in living spaces should be placed far back in the room, near windows and ideally above a radiator. In new houses, supply air valves are often placed above the front door, well away from any furniture. Exhaust valves should be placed directly on the source of moisture and heat, for example on the shower, washing machine or dishwasher, and as high as possible on sloping ceilings.
Step 2: Ventilation system
The ventilation unit itself must be placed in the centre of the area it is to serve. Do not place the unit directly above a living space to avoid noise pollution and make space around it to connect pipes, power supplies and condensate outlets. A front or rear inlet will often be a good choice, if the unit cannot be placed in the loft. If the fan unit is placed in the loft, it should be placed on a firm surface sloping towards the condensate outlet and strong enough to support the weight of the unit and 1-2 people.
Step 3: Air intake and exhaust
The last step in installing a CMV is to establish intake and exhaust ventilation ducts for the façade and roof. Fresh outdoor air enters the house through roof vents or gable vents. Be aware of the pressure drop in the solution you choose and, ideally, always choose one that is one or two figures larger than the main duct. Roof cap vents should be placed at least 3 metres between the fresh air intake and the exhaust air outlet.