Using a whole-house fan for purer air is possible, but first you need to understand the dangers of poor air quality and how ventilation can help.
What are the Main Causes of Poor Indoor Air?Air quality is often associated with the outdoors, but inside there can be many contaminants that harm the overall quality of your air as well. From typical dust to pet dander to scary-sounding chemicals, you may be quite surprised to learn what’s floating around on your indoor air.
One of the most common sources of indoor air pollution is combustible material, including oil, gas, kerosene, coal, wood, tobacco, and candles. Basically, anything that burns in the home puts out a small amount of contamination; overtime, these small doses can become significant problems.
Cleaning supplies and paint cans off-gas chemicals into the air in your home. Building materials are also sources of air pollution and reduced air quality. Old insulation is still an issue for many homes, as it can leak asbestos chemicals into the air. Even cabinetry and furniture made of certain processed-wood products can leak chemicals, including volatile organic chemicals, or “VOCs.”
Biological pollutants can also exist, even in the cleanest homes. By biological, we mean anything that is living, including mold, viruses, bacteria, and pests. This classification also includes household pets like cats and dogs, as they can shed dander, creating significant issues for people with pet allergies. Insects such as roaches can also contribute biological air pollutants, as they shed body parts that are so small and light they become airborne.
Indoor particulate matter, which is a mixture of solid and liquid particles suspended in the air, can also be a major contributor to poor indoor air quality. Particles that are extremely small are a special concern for homeowners, as tiny particles can be inhaled, leading to significant health issues in the future.
Carbon monoxide is another chemical that can be particularly frightening. This colorless, odorless gas can come from many sources, including tobacco smoke, heaters, chimneys, and stoves. This chemical disrupts a person’s bloodstream and nervous system, leading to symptoms that range from general sluggishness to nausea and headaches. In extremely high concentrations, carbon monoxide can even be fatal.
These are just a few of the indoor air pollutants that can cause significant health issues.
Health Impacts of Poor Air QualitySo, what does it all mean?
Why does it matter if a chemical is leaking from wood furniture or if there is mold in the basement?
What are the real-world consequences of these issues?
While the exact health impacts will depend on the specific pollutant itself, as well as personal reactions and pollutant concentrations, there are plenty of studies that demonstrate the connection between poor air quality and poor overall health.
Mental illness, for example, has been linked to poor air quality. A study from Korea found that long-term exposure to air pollution was connected to potential mental health disorders, including depression and suicide. The study did not research the cause of this connection, but merely established that the connection exists.
Children’s asthma is another health issue that has been connected to air pollution, specifically damp buildings, which are prone to mold. A comprehensive article from Environmental Health Perspectives published in 2014 (which was an update of a 2000 article) looked at numerous studies and determined that indoor exposure to damp environments increases the chances of childhood asthma.
How severely and frequently a person is affected by air pollution depends on many factors, including age and preexisting conditions, as well as individual sensitivity, which can vary completely from one person to another. Some people, for example, tend to react to biological sources of air pollution, while another person, for unknown reasons, has little to no reaction.
The immediate effects, of course, vary depending on the contaminant, but they often resemble colds or diseases caused by viruses, which makes diagnosis difficult. Therefore, you have to pay attention to the circumstances of a symptom. Take note of the time and location when symptoms tend to occur; if you notice a pattern, it may be that indoor air in a certain place or during a specific time is the cause.
Long-term effects, however, can be more difficult to spot. Many symptoms are only noticed years after exposure, and they can include respiratory issues, heart disease, and even cancer. While many short-term symptoms are mere annoyances, long-term symptoms can be debilitating and even cause death. For these reasons and more, it’s important to maintain healthy air in your home, and it often starts with understanding the current quality of air in your house.
Measuring Air Quality in the HomeAfter learning about the health effects of air pollution, you might be ready to make the moves that will keep you and your family safe. But where to start?
Logically, the best starting point is to test the air that currently exists in your home, and you can do that by testing and measuring for indoor air pollution.
Unfortunately, there is really no reliable testing method that will cover all of the contaminants that could be in your home; you’ll have to test for different pollutants in different ways. For example, you’ll need a kit that tests for particulate matter, another for lead, another for volatile organic chemicals, and so on.
However, testing for each pollutant costs money, and it wouldn’t be financially prudent to test for each and every possible contaminant. For this reason, it helps to know exactly what chemicals you should test for. It helps, in other words, to have a specific contaminant in mind. You need to approach the problem like a sleuth, looking for clues that might tell you if you should test for one contaminant or another. For example, if you feel like there are lots of dust in the home, you should probably test for particulate matter. If you have relatively new paint on the walls or new furniture with wood preservatives, it would be wise to test for VOCs, which are often released by these materials.
There are various kits that can be used to test for different contaminants, and they will vary in pricing depending on many different factors. HomeAdvisor, a source for home-improvement information, says that the typical range for air-quality testing is between $283 and $547.
With information from air testing, you can start to make targeted changes that improve the overall quality of the air in your home. One of these changes may be increasing ventilation in the home through a whole-house fan.
But first, let’s see if ventilation really matters for improving indoor air quality.
Whole House Fan for Purer Air
Does Ventilation Lead to Better Air?Whether or not you find pollutants in the home, increasing ventilation may be a great way to improve the overall quality of the air. If there is not enough air coming into your home, you can have a wide range of pollutants that start to accumulate, creating many of the health problems that we discussed above.
Homes are generally designed to be as air-tight as possible, which is great for keeping warm or cool air inside, but terrible when it comes to indoor air pollution. Unfortunately, by trapping air in the home, energy efficiency is often at odds with indoor air quality.
It can be a bit complicated, but there are plenty of reliable sources and direct studies that make the case for increased ventilation as a way to reduce air pollution and enhance health in the home. One excellent source is the Indoor Air Quality site created by Berkeley Lab of the University of California. According to a review of papers on ventilation, homes, and health, there are plenty of studies that have found a documentable connection between increased ventilation and improved health. While the report does admit that the findings are “mixed,” over half of the studies found a statistically significant connection between enhanced health benefits and better ventilation. 11 of the 20 studies that were researched found a significant improvement in one of more health outcomes.
The health benefits of ventilation have even been studied in classrooms. A report looked at ventilation in classrooms with the theory that low ventilation may lead to higher concentrations of pollutants. The study looked at 18 naturally-ventilated classrooms in the Netherlands, 12 of which were given increased ventilation, while 6 remained as controls. Data was collected through three weeks. While some airborne factors were not changed, the results provided strong evidence that increasing ventilation is effective at decreasing concentrations of some indoor pollutants. Yes, this study was on classrooms in the Netherlands, and this article talks about your home, but it still demonstrates the importance of ventilation for reducing pollutants inside.
There is a lot of information on the subject, and while more research would certainly be useful, it makes sense that indoor air pollution can be reduced by ventilation. By letting fresh air into the home, you can dilute and remove many of the harmful chemicals, pollutants, and allergens that could be causing trouble for you and your family. For example, the VOCs released by paints and woodworking chemicals are found inside, but they are not found outside (at least not in noticeable concentrations). Therefore, opening the windows and letting fresh air inside will be useful.
Whole House Fan Overview
How a Whole House Fan WorksWhole-house fans are meant to cool a house by providing a cool breeze throughout the home. Used in place of air conditioning, they are most useful when the outside temperature is dry and cooler, and they are often used during summer nights when the air starts to cool; times when it is warm but not so warm that homes need to run the air conditioner. It should be noted that they are different from attic fans, which only move hot air in the attic, and don’t really impact ventilation in the living space.
While they are specifically built for cooling a home, by increasing ventilation these fans may also be useful for creating fresh indoor air. Admittedly, there is no evidence that currently links whole-house fans and air-pollution reduction. However, if ventilation reduces air pollution (which has been demonstrated through scientific research), and whole-house fans provide ventilation, this does not at all seem like a stretch.
A whole-house fan is installed in the ceiling of the top floor of a home. Resting between the top floor and the attic, the fan pulls air from the living space of the house and pushes it into the attic, where it is expelled outside through vents in the attic walls and ceiling.
Unlike air conditioning, to run a whole house fan, you must open windows in the bottom levels of the home, which will allow for a steady stream of air from the ground floor into the attic. The attic must also have proper ventilation space, which will allow the air to be removed from the home.
With this ventilation, hot air is exhausted outward while cool outdoor air is drawn in. This ventilation cools the home with less energy than an air conditioner.
Installation of a Whole-House FanInstallation for a whole-house fan is fairly simple, but if you don’t consider yourself a handy person or have experience with electrical wiring, it may be best to leave this task to the professionals. That said, many people with moderate home improvement experience can handle the project.
To start, you will need to estimate the fan size and attic ventilation that you will need. Start by measuring the interior square footage of your home’s living space, then multiply this number by between a minimum of 2 and up to 3. The result will be the required Cubic Feet per Minute (CFM) that you need from a fan. For example, if you have 3,000 square feet of floor space, you need a fan that moves in the range of 6,000 - 9,000 CFM.
The CFM you choose will generally be based on your budget and your attic ventilation.
To determine the required attic ventilation, take the CFM and divide by 750. This will tell you the total cubic feet of ventilation you need. Using our example above, a 9,000 CFM fan will require 12 cubic feet of attic ventilation. (9,000 / 750 = 12)
Note: If Installing Wires, Work with an ElectricianDepending on the unit you purchase and the nature of your home, you may have to run wires to power the fan. If this is the case, we strongly recommend you work with a professional electrician. Improper wiring can cause a fire, so do not attempt this step on your own!
How Much Does a Whole-House Fan Cost?Whole house fans are generally inexpensive and can be purchased and installed for less than $2,000, in most cases. According to Fixr, a cost-guide website, the national average for whole-house fan installation is between $1,250 and $1,830, which includes the whole house fan, timer, cover, and extra vents. Depending on what you purchase and where you live, you may be able to have a whole-house fan installed for as low as $700, according to their numbers. They also say that on the high end a whole-house fan installation can go over $2,750.
Energy rebates may be available through utility companies and municipalities, which could lead to savings on your purchase and installation.
Tips for Further Enhancing Ventilation in the HomeIncreasing ventilation in your home can have many benefits, including fresher air and the removal of air pollution. It might surprise you to learn that increasing ventilation is quite easy, but it does take diligence and consistency. It’s easy to neglect, but once you get in the habit of increasing ventilation throughout the day, you’ll have better air at all times.
Keeping windows open is clearly the most obvious way to improve ventilation. By simply opening windows all through the house, you allow fresh air to move in while indoor air pollutants can be removed. When you have windows open, keep all of your interior doors open as well, which will allow for the free flow of air from one side of the house to another.
Using your interior exhaust fans can also increase ventilation. Exhaust fans in the bathroom and kitchen help remove odors, and they are also effective for moving air through the home. These fans pull air out and remove it through vents in the ceiling, and while they are generally used to remove smells, smoke, and moisture, they are also important for improving ventilation.
Fans can also help with overall ventilation. Whether they are ceiling fans or box fans, moving air through the home will help keep the pollutants moving, which is especially important if you are using open windows to increase ventilation.