There was a time when the air outside was more polluted than indoor air.

Nowadays, pollutants can be two to five times more concentrated indoors than outdoors. To compound this problem, most people spend up to 90% of their time inside.

Why indoor air quality (IAQ) matters

The air you breath has a huge impact on your wellbeing. Health issues caused by poor IAQ can be immediate or long term depending on the type and concentration of pollutants. Short term symptoms include sore throat, fatigue or headaches. Long term effects include the development of respiratory illnesses and even cancer.

Here are four ways to improve your home's IAQ:

Air cleaners and purifiers

You can clean the air throughout your house or you can deal with it room by room. Whole house air cleaners are placed in the return duct to your furnace. The air first passes through the purifier's filters to remove allergens and pollutants before entering the furnace. Then it gets distributed throughout your home via ductwork.

Alternatively, you can opt for a purifier that takes care of only one room. These units clean more air in that space but the obvious disadvantage is that the rest of the house won't benefit.

UV light

UV light is used in air purifiers to kill bacteria and mold spores so it helps reduce allergens in the home. Depending on the technology used, it can sometimes produce high levels of ozone, which is a pollutant. If you choose to use UV light, consult the manufacturer about the potential for ozone creation.

Natural ventilation

Depending on the weather, you can use natural ventilation to introduce clean air into your home. Open the windows and doors on opposite sides of your home to allow outdoor air to flow through. Be careful if you

Ductwork is a vital part of your home's heating and cooling. Unfortunately, because it's mostly hidden, we tend to forget about it. But ductwork problems can cause high energy bills and issues with heating and cooling.

Here are some issues that ductwork might have and how to deal with them:

Leakage
If your ducts aren't properly airtight, you'll lose air to the surrounding spaces. That means energy loss, since you'll have to turn up your furnace to get a comfortable temperature. You'll also have uncomfortable rooms where there's not enough air to heat (or cool) them.

Finding leaks can be tricky since most of the ductwork is hidden. You can take care of exposed ductwork in the mechanical room, for example. Use a duct sealant like mastic or Underwriter's Laboratories (UL) certified aluminum tape to seal the leak.

Dust, allergen and germ buildup
Ducts can circulate dust throughout your house. This results in poor indoor air quality and can get your family sick. Winter colds are bad enough without dust aggravating your symptoms.

Have professionals clean out your ductwork every few years. The frequency will depend on whether you have allergies, pets or live in a dusty area.

Poor sizing
Air flow distribution depends on ductwork sizing. Even with dampers, ducts must be correctly sized for the amount of air needed to condition a space. Get this wrong and you'll have to deal with discomfort during both seasons.

If you notice some rooms consistently hot in summer and cold in winter, get a professional to assess your duct sizing. You might have to replace and rebalance portions of your ductwork system.

Poor layout
If you have duct runs that are too long, the pressure drops in the system will reduce the amount of air reaching the grilles. Similarly, if the