Rex Nye, from independent builders merchant D.W Nye, explains how good ventilation improves energy efficiency and boosts health, as well as the products you can sell to assist it.

As winter sets in, it’s only natural that we spend more time tucked up inside our cosy homes. In fact, we spend 90% of our time indoors, but health experts say poor air quality in the home could be bad for our health.

Indoor air can be up to 10 times more polluted than outdoor air. Smoking, gas cookers, faulty boilers and heaters can all lead to poor air quality, which has been linked to respiratory problems. Meanwhile, lack of circulating air can cause condensation, leading to damp and mould problems. Aside from looking unsightly, mould spores can cause health issues, such as nasal congestion, reduced lung function and chronic conditions including asthma and allergies.

Ventilation is the key to both health and energy conservation. For centuries, homes without ventilation never developed problems, so why go to extra expense and effort to ventilate our homes today? Unlike today’s homes, old houses didn’t have insulation in the walls, so fresh air could enter through the gaps, cracks and holes. Also, building materials were mostly produced using natural products, whereas many of today’s building and decorating materials contain chemicals that may be harmful to health.

Good ventilation benefits

Most houses are so draughty they’re impossible to heat, or they’re so well-sealed that the air becomes stale. The ideal balance is to make sure air can travel freely in and out of your property without wasting money by letting heat escape.

Try these quick fixes to ventilate your home naturally:

• Make sure you open the door and windows in the kitchen when you’re cooking to allow odours and gases to escape. If you have one, turn on the extractor fan too.

• Always open the window when you’re having a bath or shower to prevent build-up of mould. If there’s an extractor fan, leave it on for at least half an hour after bathing to allow steam to escape.

• Don’t hang clothes over radiators as this creates mould spores, which can quickly become airborne. If you must dry clothes inside, hang them on a clothes horse and open a window to ventilate the room.

• Aim to air your home as often as you can. In winter, opening windows three times a day will make a real difference to the air quality in your home.

• If your windows have vents, leave them open to allow stale air to escape and fresh air in. Don’t worry about cold air - leaving vents open will make little difference to the temperature in the house. Adding vents is a simple, relatively inexpensive way to ventilate your home and will help prevent problems such as dry rot and mould. Try Timloc Flyscreen Plastic Louvre Vent, £3.28, or Plastic Air Bricks, £1.46, both from

Professional ventilation

Many modern ventilation systems are capable of removing dust particles and other allergens, as well as improving indoor air quality. These include Heat Recovery Units, which maintain stable humidity levels, removing condensation and mould. Stale air is drawn out as it passes over a heat exchanger, which recovers the heat from the outgoing air in order to warm the incoming fresh air.

Passive ventilation uses the natural buoyancy of hot air and wind to encourage airflow through the property. The positioning of vents is important to make use of positive pressure from wind to encourage air movement through the house.

Passive Stack Ventilation uses natural forces to ventilate a house by installing stacks and ducts which draw warm, moist air through grilles from a bathroom or kitchen and out through the roof.

Positive Input Ventilation works by drawing in fresh, filtered air via a unit that’s usually installed in the loft. The units control humidity levels and remove indoor air pollutants, such as carbon monoxide and radon gas.