Proper Home Ventilation Keeps Your Home’s Indoor Air Quality Healthy

Published on: January 15, 2014

Much like your heating and cooling, home ventilation is one of those things you might not give much thought to until something goes wrong. Unlike problems with your heat and A/C, though, poor home ventilation isn’t always immediately noticeable. Not ventilating your home sufficiently will leave you with issues including dry skin, headaches and fatigue, as well as lingering odors and humidity and mold problems.

In the Southeast U.S, humidity issues are a particular concern. Despite the consequences, lack of ventilation is a common problem. Today’s homes are often tightly air sealed to help maintain indoor temperatures and humidity levels as well as keep pollen, car exhaust and other air contaminants out. Although this improves the home’s energy efficiency, it all but cuts off airflow between the indoors and outdoors. To make up for this loss of air circulation, you may need to add additional ventilation.

Benefits of Home Ventilation

Sufficient airflow in your home gives you more than just fresher-smelling air. Your health, safety and comfort will all improve and you’ll see lower energy bills, too.

  • Better indoor air quality — In a home without good airflow, the air feels stagnant. Odors from the kitchen and bathroom tend to hang around. Pollen, mold spores and dust mites accumulate and aggravate allergies and asthma. Chemical pollutants are also a concern. Furniture, paint and other items emit volatile organic compounds (VOCs) such as formaldehyde and benzene. Without sufficient home ventilation, these build up in your home’s air and, with long-term exposure, may affect your health.
  • Less risk of  carbon monoxide exposure — Combustion appliances, such as gas and oil stoves and water heaters, must be properly ventilated. Without good ventilation, exhaust fumes containing carbon monoxide (CO) can build up in your home and pose a threat to your health and safety. Low-grade carbon monoxide exposure can cause headaches, trouble concentrating, tiredness and mood disturbances. Because these are easily mistaken for symptoms of other illnesses, you may not realize lack of home ventilation is a contributing factor. As if that weren’t bad enough, exhaust fumes are also combustible and a build up in your home is a fire risk.
  • Fewer mold issues — While an efficient air filter can do a lot to cut down on the mold spores in your home, it’s nearly impossible to keep these spores out entirely. With good air filtration and ventilation, however, mold spores don’t have a chance to take hold. Without this ventilation, the spores aren’t removed, so they have a chance to settle and grow. Insufficient ventilation also contributes to excess humidity and condensation on your widows and pipes. Stagnant, humid air creates the perfect conditions for mold. Once mold starts growing, it produces spores that can aggravate allergies and asthma, and aren’t great for your health overall. Install proper ventilation and you’ll greatly reduce the chances of mold developing in your home.
  • A longer life span for your home — High humidity and mold problems are bad not just for your health, but for your home’s health, too. On a cosmetic level, excess humidity can cause wallpaper and paint to peel, leave water stains on walls and ceilings, and warp wood flooring. More serious problems occur when moisture buildup in your home allows mold to develop inside your walls, under flooring, above ceiling tiles and in other out-of-the-way spots. Once established, this mold rots the wood and drywall and can cause serious structural damage. Improving your ventilation prevents this damaging moisture build up.
  • Greater energy savings — A muggy, poorly ventilated home feels hotter than a home with good airflow. Without good home ventilation, you’ll find yourself turning up the air conditioning in attempt to get comfortable. That runs up your energy bills unnecessarily. To compound matters, high humidity levels also force your air conditioner to work harder, use even more energy and further increase your cooling bills. In winter, something similar happens. If excess humidity is present, it can make you feel clammy and chilly, so you’ll need to turn your heat up more to feel warm enough. Better ventilation helps with both problems, improving your comfort and saving you money year around.

Finding the Right Home Ventilation

No single type of ventilation is perfect for every home, but some are generally favored over others. If your home could use more airflow, get familiar with the ventilation systems available so you’ll have an idea of where to start.

Natural Ventilation

Also called accidental ventilation, this type of ventilation comes through tiny cracks around your doors, windows, plumbing and wiring penetrations, and other areas. In homes built before the early 1960s, these little cracks and gaps were left intentionally to allow airflow through the home. If you have an older home, unless it’s been professionally air sealed, you probably still have some natural ventilation. Homes built within the last 10 to 20 years or so are usually well air sealed and don’t have this airflow.

Although air leaks do work to get fresh air in, they cause more problems than they solve. Because there’s no way to control or filter the air going out and coming in, air leaks let in contaminants and humid air from outdoors. They can also cause air pressure imbalances that draw combustion appliance exhaust fumes into your living space.

Ultimately, natural ventilation is best avoided. If you have a drafty home, call in a heating and cooling professional to perform an energy audit. This review will pinpoint where you’re losing conditioned air. Once you identify the leaks, you can use caulk and weatherstripping to seal them.

Spot Ventilation

Most building codes require this ventilation type, which involves small exhaust fans that draw out moist air and odors. These fans are usually found in the kitchen and bathrooms. Range hoods are also a type of spot ventilation.

When exhaust fans like these vent outdoors, they do a decent job of clearing the air in a limited area. The problem is many don’t vent outdoors. Instead, they merely pass the air through a filter and return it to your home. The filter captures larger debris particles, such as cooking grease particles, but it does next to nothing against finer contaminants or humidity.

In the hot and humid southeast U.S., exhaust fans worsen humidity problems when overused. If your home lacks sufficient airflow, you’re likely to end up overusing the exhaust fans simply because they’re all you have.

While spot ventilation has its place, you may need more than this to improve your indoor air quality and control your home’s humidity levels.

Whole-House Ventilation

For healthy airflow in every room of your home, whole-house ventilation is an option worth considering. These ventilation systems use one or more fans to bring in fresh air or let out stale air, and a duct system to conduct air to and from different parts of your home.

Unlike natural ventilation, they let you control the airflow in your home and give you a chance to filter out air contaminants.

Whole-house ventilation systems come in three main forms:

  • Supply-only — Often the best choice for the Southeast’s warm climate, this ventilation system uses an intake vent to pull in fresh air from outdoors and distribute it through your duct system. The system can use your heating and cooling system’s ducts or a separate ventilation-only duct system. If the ventilation system is connected to your regular ductwork, the incoming air can be dehumidified before being distributed. On the down side, supply-only systems rely on air leaks in your home to let out stale air, although spot ventilation fans also help.
  • Exhaust-only — These systems use fans to draw out stale air but rely on air leakage or open windows to let in fresh air. Because they’re liable to let in hot, humid outdoor air, they’re best avoided in warm climates.
  • Balanced — Balanced systems use both an intake vent to bring in fresh air and exhaust vents to let out stale air. HRV (heat recovery ventilation) and ERV (energy recovery ventilation) are the most common types of balanced systems. Although ERVs can work well in some Southeast homes, they’re not always suitable for our warm, humid climate.

Don’t Forget the Attic

Because building codes generally require it, most attics are fitted with a single roof vent and individual soffit vents at a minimum. These reduce the accumulation of moisture that can cause insulation, wood, drywall and other material to deteriorate. The attic ventilation your home was built with may not be ideal, though. Many homes fare best with continuous ridge-and-soffit ventilation. A heating and cooling expert can help you decide which system will work best for your attic.

For trustworthy, professional guidance finding the home ventilation systems that work best for your needs and budget, visit us at A/C Southeast. With our Find a Contractor service, it’s easy to find a local professional who can work with you to optimize your ventilation.