Founder | BPI® Energy Auditor Certified Professional
Proper ventilation is the key to a fresh-smelling home and a healthy family. It also allows for a comfortable environment, increasing energy efficiency and reducing your heating and cooling costs.
Ready to learn more about healthy ventilation? This article should give you a solid understanding of how home ventilation occurs and what you can do to improve the health, energy efficiency, and comfort of your family and home.
How Does Home Ventilation Occur?
Your home receives ventilation in four ways: through doors and windows, openings in the structure, spot ventilation, and whole-house systems, such as HVAC systems.
Doors and Windows
Doors, windows, and skylights are probably your first thought when it comes to home ventilation.
While opening doors and windows is inefficient for homes that rely on electricity for heating and cooling, the practice does come with some perks.
Take Germany as an example. Lüften, known to us as home ventilation, is the act of opening windows in the mornings and evenings to allow air circulation.
Many Germans are in the habit of opening windows in their home for at least five minutes, twice daily, even in the coldest stretches of winter.
This procedure allows trapped, stale, air-conditioned air to dissipate, replaced with nature’s fresh air from the exterior microbiome.
Americans would also be wise to adopt this practice, which alleviates odors, mold, other fungi, and bacteria from homes.
Small Openings in the Structure
While we like to think that our homes are so tightly built that they’re waterproof, this simply isn’t true.
All joints in homes have some degree of a gap through which air can pass in and out. The floor, walls, and ceilings also have micro gaps. Windows, doorways, and skylights, especially in older homes, are good sources of a draft.
The pipes, cords, lines, and ventilation ducts that run in and out of homes likely have small gaps in the seal, resulting in more ventilation.
While these gaps are minimal, they can hugely improve home air quality.
Spot Ventilation
Bathroom and kitchen exhaust fans are considered spot ventilation.
These vents are intended to carry kitchen and bathroom fumes and odors outdoors and move some outside air back into the home.
HVAC Units and Whole House Systems
Your heating and cooling units naturally ventilate your home with new air, as do whole-house ventilation systems.
To learn more about heating and cooling units and how to prevent heat loss, click here.
Attic Vents
Attic vents and air ducts can be energy-loss culprits via air ventilation.
Some attics have intentionally placed vents to prevent mold growth and allow some heat to escape the building.
Other lofts are attempted to be sealed but still have significant holes or gaps in them, usually around the ductwork or lines that run in and out of the attic.
Crawl Spaces
While crawl spaces are recommended to be as close to airtight as possible to prevent mold and entry by insects and other critters, not all of them are. And not all crawl spaces have insulation, either.
Crawlspaces lacking adequate ventilation can cause significant issues for your home, especially in the form of excess moisture, humidity, and the posed threat of mold or mildew.
Water vapor in crawl spaces can seep up from below into subfloors, floors, or even the entire home. The air ventilating through this area is unsafe and usually smells stagnant, moldy, or otherwise unpleasant.
Understanding Whole-House Ventilation Systems
Unlike natural ventilation which occurs when air moves in and out of the home through cracks and openings like windows and doors, whole-house ventilation occurs through a system of ducts and fans. These ducts and fans circulate air throughout the home mechanically.
There are basically three types of whole-house ventilation systems, as discussed below:
Exhaust-Only Ventilation
It works by depressurizing a home to exhaust the spent air.
Once the spent air is exhausted, it’s replaced by air seeping into the home through natural ventilation like cracks and openings.
Exhaust-only ventilation relies on a centrally-placed fan that collects stale air and sends it out of the house through exhaust pipes. The fan is connected to ductwork that runs into the rooms where air pollutants are mostly generated.
A point worth noting is that an exhaust-only ventilation system is suitable in colder regions. Using this system in hotter regions makes your house susceptible to condensation and moisture damage due to the depressurization processes.
The table below summarizes the pros and cons of exhaust-only ventilation:
| Pros | Cons |
| Efficient in cold climates | Unsuitable for hot and humid climates |
| Simple to use | Can result in back drifting |
| Relatively inexpensive | High heating and cooling costs |
| Can bring air pollutants into the home |
Supply-Only Ventilation
This ventilation pressurizes homes using fans. The process forces exterior air into the house while air leaks through the shell, cracks, and fan ducts.
It also uses a centrally-placed fan with ductwork running to the different rooms. A fresh air inlet pipe sends exterior fresh air into the fan for distribution across the building.
Supply-only ventilation systems are ideal for warmer climates. This is because the pressurization process can create moisture and condensation indoors in cold areas.
Pros
- Simple to install
- Inexpensive
- Suitable for hot and mixed climates
- Minimum outdoor air pollutants
- Allows for better control
- Excellent outdoor air dehumidification
Cons
- Can cause moisture and condensation in cold climates
- Does not remove moisture from the oncoming air
- Higher heating and cooling costs
Balanced Ventilation Systems
Unlike the first two types of whole-house ventilation systems, balanced doesn’t employ pressurization and depressurization. Instead, it brings in fresh external air while expelling the polluted indoor air. This is an excellent process to prevent indoor air pollution.
Due to its operation, a balanced ventilation system is the most preferred. It has two fan systems and two duct systems.
The first fan and duct system supplies fresh air into the home. Meanwhile, the second fan and duct system expels stale air from the building. As a result, it’s ideal for all climates.
Pros
- Eliminates pressurization and depressurization
- Facilitates proper air flow
- Ideal for all climates
Cons
- It’s costly
- Doesn’t remove moisture from the oncoming air
- Higher heating and cooling costs
Why Does Your Home Need Ventilation?
Proper ventilation ensures that moisture, odors, gasses, pollutants, dust, and other particles don’t reach unpleasant or dangerous levels in your house.
While opening your doors and windows can bring on ventilation, it can also welcome other outdoor air sources of pollution inside.
So opening doors and windows isn’t always the only or even best solution when it comes to improving air quality in your home.
Is An Airtight Home the Solution?
Your home needs ventilation for air quality. However, while ventilation can be helpful in some instances, it can be problematic in others.
Air ventilation through cracks and gaps in your home is more likely to carry dust and allergens, which is not ideal.
Are you wondering how to keep dust out of your home? Read this handy guide for cleaning tips, advice, and prevention.
Most homes with moisture and mold have these issues because of unsealed floors and wet crawl spaces. Allowing the air that has been stagnating under your house in a swampy mess to “breathe” back into your home is unclean, smelly, and potentially dangerous.
Because of the abovementioned issues, it’s wise to choose a tight, sealed home and then employ proper air quality measures. For more on techniques for improving the airtightness of your home, check out this article.
A heat recovery ventilator or an energy recovery ventilator is a great way to circulate fresh air while maintaining low energy costs.
Is Ventilation The Best Way to Protect Your Home From Air Pollution?
While proper ventilation is an excellent method for improving air quality, proactive pollution prevention is the best way to keep your home smelling and feeling fresh.
For instance, you can’t ventilate your home into good health if people smoke or vape inside or near its entrances.
What Happens If Your Home Doesn’t Have Enough Ventilation
Energy Efficiency Will Increase
While energy efficiency is essential, too much efficiency can be dangerous and cause many other health risks listed below.
Poor ventilation can cause your home to retain heat and conditioned air at exceptionally high rates, contributing to more affordable electricity or energy bills. Therefore, while desired, efficiency should be used within moderation.
Pollution Builds Up
Everyone should be aware of the dangers of pollution. However, those with lung conditions, increased risks of infection, or overall poor health are at more significant risks of damage when it comes to pollution.
Home pollution caused by poor ventilation can include:
- Asbestos
- Cleaning supply chemicals and fumes
- Perfumes, hair products, makeup, and other beauty products
- Building product chemicals
- Paint product chemicals and fumes
- Dustmites, and dustmite droppings
- Formaldehyde
- Lead
- Nitrogen dioxide
- Carbon monoxide
- Pen dander
- Radon
- Volatile Organic Compounds
- Candle fumes
- Smoke from smokers or residential wood burning
- Cockroaches and cockroach droppings
Carbon Monoxide Becomes a Serious Threat
Carbon monoxide is created by household appliances, especially in instances where fuel doesn’t completely burn.
Cookers, gas fireplaces, boilers, central heating units, water heaters, and open-flame fires all emit traces of carbon monoxide.
In addition, unvented gas heaters are hazardous, creating unsafe levels of carbon monoxide within the home.
Radon Increases, Especially In the Western US
While radon can be found throughout North America, it is especially prevalent in houses in the Rocky Mountains and Great Plains.
Radon is a byproduct of decaying uranium, common in highly mineralized areas, especially the Rocky Mountains.
Radon can be found in the soil everywhere and may radiate through the ground into crawl spaces, where it eventually seeps into the home.
Radon can be primarily concentrated in homes with natural springs or well water. Because radon can linger in water, when the water is introduced into the house through the faucet, radon gasses escape into rooms of the home.
It is crucial to test for radon in your air and water. There are a few symptoms of radon exposure: difficulty breathing, tightness in the chest, difficulty speaking, or trouble swallowing.
Indoor Relative Humidity Levels Increase
With unregulated ventilation, you lose control over what enters and exits your home, and that includes moisture.
Ideally, relative humidity levels should remain below fifty percent in your house at all times.
Too much humidity damages the dwelling and your health. Moisture leads to mold, mildew, decay, unpleasant odors, and eventually rotting.
Additionally, dampness can worsen immune functioning and asthma and lead to a sore throat, nasal congestion, sneezing, rhinitis, coughing, and an increased risk of infection.
Always run your bathroom fans when your shower or bathtub is running, ensure your dryer vents are outside correctly, and run dehumidifiers as needed.
Proper Home Shock Ventilation
A rapid and intensive shock ventilation treatment is the best way to quickly and efficiently ventilate a home.
Open every window in your home entirely for three minutes if it’s windy and up to ten minutes if it is not windy.
The key here is to open the windows entirely rather than leave them slightly ajar.
Completely open windows ventilate the whole house in minutes; meanwhile, slightly cracked windows may take two hours or more to ventilate thoroughly.
Much hot air will dissipate during that time, meaning heating the home backup will use significantly more energy than quickly blasting the house with cold air for five minutes or so.
Which Is the Right Ventilation System for Your Home?
Now that you know the different ventilation systems for homes, which one is the right for your needs?
The right ventilation system for your home depends on your budget and climatic conditions.
While exhaust-only and supply-only are the least expensive, they are climate-specific. For instance, exhaust-only ventilation systems are ideal for cold areas and supply-only works best in warm climates.
Although costly, a balanced ventilation system is the best option since it won’t expose your home to moisture build-up and condensation, no matter your climate.
How to Protect You and Your Family’s Health
Open Windows and Doors Regularly
Shock your home. You can ventilate it as often as needed. Some practice this twice a day, while others only utilize this method as part of their monthly cleaning schedule.
It’s a good practice if your home doesn’t run any heating or air-conditioning systems. Otherwise, it’s wasteful and generally should be avoided.
Use Bathroom Exhaust Fans
Always turn your bathroom exhaust fans on when you shower or bathe.
Some people even wire their exhaust fan to their overhead light, alleviating the need to remember it.
While the fan may create an irritating sound, the health issues and mold that it prevents are well worth the sacrifice.
Use Kitchen Exhaust Fans
Kitchen exhaust fans and ventilation systems are helpful for more than whisking away smoke and odors.
Gasses, fumes, and sometimes dangerous inhalants are created when cooking. It’s important to get them out of your home.
If you don’t have an exhaust fan, open a window and use a small, portable fan to create a makeshift venting system.
Check That Combustion Appliances Appropriately Vent Outside
Hire a contractor or check yourself, but please be safe and ensure that these fumes leave your home and do not get trapped inside.
Ensure That Your Dryer Vents Outdoors as Well
Dryer vent hoses come detached from the wall or your dryer surprisingly easily. So, make it a habit to peek behind your dryer to confirm it’s still snugly fashioned to both the wall and the machine.
While you’re at it, clean your lint trap, vacuum out the area near your vent trap, and clean out the dryer duct too. You can save yourself from a severe fire.
Always Use Ventilation When Painting, Sealing, and Staining Indoors
Open windows, run fans, and use air filters or anything you can to rid your home of the fumes of these products.
Test Your Home for Radon
Whether by hiring a professional or using a hardware store kit, just make sure you do it. Here’s a helpful guide from Cancer.org to assist with your home radon test.
Use a Dehumidifier or Humidifier, and Clean it Regularly
While most people need to run a dehumidifier, others need a humidifier, especially if fireplaces or woodstoves heat their homes.
Either way, make sure that your humidifier or dehumidifier has an appropriate filter in place and that the filter is being cleaned or replaced as needed.
Use an Air Filter and Clean it Regularly
Like humidifiers, air filters also require cleanings and changes to keep your home clean, safe, and smelling fresh.
Never Idle Vehicles in Garages, Under Carports, or Near Entrances
The fumes and dangerous gasses can get sucked right into your home, causing an unsafe indoor environment for you and your family.
Use An Energy Recovery Ventilator (ERV) or Heat Recovery Ventilator (HRV)
A heat recovery ventilator works very similarly to an ERV, except it transfers only heat, not any moisture.
For more unique energy-saving methods, you may check out Radiant Floor Heating Design and Small Wind Turbines For Your Home!