You may be surprised to learn that the air inside your home is often far more polluted than the air outside. Combine this with the fact that the average person spends more than 90% of their time indoors, and you’ll quickly realize why poor indoor air quality is such a huge concern. While air filters and purifiers help to combat indoor air pollution, ensuring your home is adequately ventilated can make an even bigger difference. We’ll explain why ventilation is important for air quality and look at different options to help you keep your home properly ventilated.
Passive vs. Mechanical Ventilation
Ventilation is simply the process of pulling stale air out of a building and bringing clean, fresh air into it from outside. Passive ventilation can be achieved by opening windows on different sides of the building to create a through-draft that refreshes the air inside. The majority of older homes also have quite a bit of passive ventilation that happens naturally. This is because the exterior structure or “envelope” in an older building usually isn’t airtight, so there are numerous gaps that allow indoor air to flow out and outdoor air to flow in.
Mechanical ventilation refers to using fans to move air in and out of a building. Bathroom and kitchen exhaust fans are technically a form of mechanical ventilation since they continually draw air in when running and blow it outside through a vent pipe. We say “technically” because exhaust fans don’t pull air in from outside on their own. Instead, they create negative air pressure as they draw air out of the building. This leads to an imbalance between indoor and outdoor air pressure. The imbalance then causes air to flow inside through gaps and holes in the structure, such as around windows and doors or even through chimneys.
Why Having Adequate Ventilation Matters
Even if you have an older home that has quite a bit of passive ventilation, investing in some type of mechanical ventilation can make a huge difference. Without sufficient ventilation, the air inside a building will quickly get quite stale and feel stuffy unless the windows are open. Another extremely common issue in Florida is that buildings can be extremely humid if they don’t have adequate ventilation. This is because people give off quite a bit of moisture when they sweat. Cooking, bathing, doing laundry and running the dishwasher also release moisture into the air and contribute to increased indoor humidity.
A bigger issue is that the air in a building always continually becomes more and more polluted since there are so many different things inside any building that give off pollutants and contaminants. This includes formaldehyde and other potentially carcinogenic volatile organic compounds (VOCs) that occur in furniture, building materials, electronics, cleaning and laundry products, etc.
The many different sources of airborne pollution inside any building account for indoor air being typically two to five times more polluted than outdoor air. The reason is that pollutants are more concentrated indoors than they are outdoors, where they’re more dispersed. This is a major concern since we spend most of our time inside, and exposure to higher concentrations of VOCs and other pollutants can lead to both short- and long-term health issues. Adequate ventilation is so essential because it works to draw airborne pollution outside and brings less polluted air indoors.
An Overview of the Most Common Ventilation Systems
The three most common types of mechanical ventilation are energy recovery ventilators (ERVs), heat recovery ventilators (HRVs) and whole-house fans. A whole-house fan is essentially a much more powerful type of exhaust fan that draws air inside the home up into the attic, where it then gets vented outside. While they are effective, whole-house fans generally aren’t a great option in Florida. That’s because you must have at least a few windows open when the fan is on. If the windows are closed, the fan can end up pulling the exhaust fumes and carbon monoxide produced by gas appliances into the house.
Another issue with using a whole-house fan in Florida is that it will draw lots of moisture into the house through the open windows, which will quickly make it much more humid. It’s never a good idea to use a whole-house fan unless the outdoor temperature is cooler than your desired indoor temperature, so there won’t be that many times that you could use the fan.
ERVs and HRVs are better choices since they use fans installed in an exterior wall to draw air in and out so that you don’t need to have any windows open. You can also program the ventilation unit so that it runs periodically to ensure the stale air is regularly replaced with fresh air from outside. As long as the unit is properly sized, it should be able to completely exchange all the air inside a home within a few hours. That said, you normally need to set the unit so that it runs for around 20 minutes each hour to ensure that your home is sufficiently ventilated and greatly improve your indoor air quality.
The main thing to understand about ERVs and HRVs is that they have an internal heat exchanger that allows them to capture and transfer heat between the outgoing and incoming air. When the incoming air is hotter than the outgoing air, the ventilator captures heat from the outdoor air so that it gets cooled as it comes inside. The opposite happens when the outdoor temperature is cooler, resulting in the incoming air being partially heated. This process is essential since it prevents the system from just drawing lots of hot air in during the summer or making the house cooler in the winter. That means you’ll be able to enjoy all the benefits of adequate ventilation without causing your air conditioning and heating costs to increase. The ventilator also has an internal air filter to ensure that it doesn’t bring lots of allergens like pollen, dust and mold spores into the building.
ERVs are generally considered the much better choice in Florida or any other humid climate. An HRV can only transfer heat between the two air streams, so it will still bring moisture inside and make your home humid. An ERV is better in Florida or any other humid climate since it can also capture moisture. There are several different types of ERVs, but they all work similarly by first removing water vapor from the incoming air and then transferring it to the outgoing air so that it gets vented outside. In colder climates where the winters are drier, an ERV will instead transfer moisture from the outgoing air to the incoming air to help overcome issues with dry winter air.
If you’re searching for ways to overcome indoor air quality issues in your home, Ahoy! Cooling & Heating is ready to help. We’ve been serving the Tampa area since 2010 and offer a wide range of indoor air quality services. We’re also the area’s most trusted source for air conditioning and heating installation, repairs and maintenance.
Contact Ahoy! Cooling & Heating today to schedule a consultation and learn more about how we can help boost the air quality in your home.
