A well-insulated home is more airtight. Proper ventilation will improve air quality reducing condensation and mould.
What difference will I notice with new ventilation?
Proper ventilation ensures that fresh air from outside comes into your home. This does not mean that your home will be colder as a result, but that the air heated in your home will not be harmful for your health. You may be able to hear air coming in through the vents, which is normal.
Blocking up vents puts you and anyone in your home at risk of carbon monoxide poisoning. It also means that the air you are breathing in your home could be harming you. Breathing in damp air is very dangerous, especially for people with chronic respiratory conditions.
This work may involve drilling and coring holes in walls and ceilings to create a passage for the ducting.
Any ducting that passes through ‘cold’ spaces (like a cold roof attic) will need to be insulated to optimise the efficiency of the system.
Mechanical Ventilation with Heat Recovery
Mechanical ventilation with heat recovery recovers heat from extracted air and uses it to pre-warm the replacement fresh air from outside of the dwelling.
Mechanical ventilation with heat recovery consists of two independent ducted airflows, each with its own fan. The extract fan extracts the stale humid air from the wet rooms (bathrooms, kitchen, utility, etc.) and passes it over a heat exchange matrix – where it recovers around 80 per cent of the heat from the stale air – before discharging it to the outside. The second fan draws fresh air from outside, filters it to get rid of pollution and airborne allergens, then passes it over the heat exchange matrix in order to supply pre-warmed fresh air to all the living areas and bedrooms.
The ducting will tend to be 100mm to 150mm in diameter, depending on the size of the house. The warmed incoming air also needs to be insulated, to make sure the heat gets to the right place, which could increase the diameter to 250mm.