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6 Ways to Ventilate a Room While Painting (4 additional tips to keep you safe)

I love how painting a room changes its look and feel so drastically. But I hate the smell! I think my body identifies it as a potentially toxic substance and sends out warnings. While modern paints are safer than paints of the past, ventilation while painting is still crucial. Luckily there’re so many ways to achieve the ventilation.


Latex, acrylic, and bathroom paints (water-based) require at least 24 hours of ventilation after painting. Oil-based paints (like enamel), require at least 48-72 hours, with 72 being the recommended duration according to the EPA and other such organizations. Ventilate longer if sensitive people are present.

Why You Need to Ventilate While/After Painting

Although foul smells can be quite annoying, they often indicate danger, such as toxic gas, rotten food, or something burning. 

Paint fumes may not smell awful, but their scent is strong and can be considered a warning to us that volatile organic compounds (VOCs) are being released during the drying process.

These VOCs are released through degassing. This is the process whereby gases escape from a substance during the drying or curing process. Furniture treated or coated with certain chemicals and paints will continue to degas or off-gas, even when they are dry.

The danger in VOCs stems from the fact that many of them are considered to be carcinogens or cancer-causing chemicals. Carcinogenic VOCs include benzene, methylene chloride, and more. 

Brief exposure to these carcinogens will not cause cancer, but extended exposure over the years can.

In addition, repeated exposure to all VOCs related to painting, not just the carcinogenic ones, has been linked with the development of asthma and allergies.

While painting your house might be considered low-risk in terms of developing chronic conditions related to VOC exposure, there are enough adverse health effects linked to short-term exposure to warrant proper care when painting.

Man on a ladder painting the ceiling with white paint

Short-term effects of VOCs include dizziness and bad headaches. The fumes can also be especially dangerous for children, the elderly, and those with compromised immune systems.

Through passive ventilation (just letting the fumes linger and eventually dissipate) most paints can take 14-24 weeks to completely off-gas. So, long after the paint is dry, it can still release harmful chemicals into the air.

As a result, painting your house can end up presenting conditions for longer exposure.  

To avoid dangerous levels of VOCs, active ventilation should be used to remove the dangerous substances quickly and efficiently.

Post-Painting Ventilation Duration

Unfortunately, there is not an all-encompassing recommended time for all kinds of paints. To find how long you should ventilate after painting, the type of paint must be considered. 

Latex and Acrylic (Water-Based) Paints

Latex and acrylic paints are both water-based paints.

Acrylic paint is known as a universal paint because it can be used on all types of surfaces and is a very common paint that is used inside of the home. It is known for its fast-drying and matte finish.

Latex paint is also fast-drying and has a matte finish. However, while acrylic paint can go most places in the home and is popular to paint walls with, latex paint is most often used to paint drywall and wood, specifically.

The main difference between the two is that latex paint lacks a significant chemical base. This means that it can be easily cleaned with soap and water and releases fewer fumes than acrylic or other paints, but it also means that it is less durable and has a lower-quality finish. 

Despite these differences, because latex and acrylic paint are both water-based paints, they release significantly fewer VOCs than oil-based paints. 

Typically, the levels of VOCs will be sufficiently low if you actively ventilate a room or space for at least 24 hours after you begin painting with latex and acrylic paint.

However, if there are young children, elderly people, or immunocompromised people in your home, it is wise to ventilate even longer, for up to 72 hours

It is especially important to follow these recommendations if the room in question is a bedroom since sleeping in a newly painted room involves high amounts of exposure to paint fumes.

Here Are the Most Effective Ways to Ventilate the Room While/After Painting

1. Turn on the Range Hood

The range hood is probably the most powerful exhaust fan in your house. Sometimes, it is so powerful that it necessitates the provision of makeup air.

In my experience, turning the range hood on will work so effectively that you won’t even smell the paint fumes. This is because they are typically designed to remove large amounts of air at a time, so the smell has very little opportunity to build up.

Keep in mind that a ductless range hood will not help in this case. While a ductless range hood is OK for filtering small amounts of food odors, it will not filter the air sufficiently when painting.

Obviously, the closer the range hood is to the room that you are painting, the better it will work. However, you can use the range hood to provide relatively effective ventilation in rooms across the house. The next section details how.

How to Ventilate Any Room in the House With a Range Hood

  1. Turn on the range hood, preferably to the highest setting
  2. Make sure that all openings to the outside are closed. This includes all fresh air vents, windows, and doors
  3. Open the windows in the room that is being painted.
  4. Open all doors that are between the kitchen and the room that is being painted

With this setup, you are creating a cross breeze.

The air actively exhausted through the range hood creates negative pressure in the kitchen that must be balanced by drawing new air in. Since the nearest open windows are in the room being painted, this is where the air will come from, creating a flow of fume-y air from the room to the range hood.

You should be able to feel a significant draft coming from the open window. If there is no draft, double-check that all other windows, doors, and vents are closed.

If you do not have an airtight house and the air leaks through gaps and cracks in the exterior and around windows and doors, then this method will be much less effective since air has so many potential entry points.

Consider A Space Heater During The Colder Months

An average range hood will move about 500 cubic feet of air per minute. This means that 500 cubic feet of ice-cold air is entering your house every minute in winter.

An easy way to combat this is to put a space heater (amazon link) in the room that is being painted. This will help keep the room temperature at a comfortable level and the paint dry out faster as well.

Note: the heater cannot provide ventilation.

2. Use the Bathroom Exhaust Fan

A bathroom exhaust fan can be used in the same way as a range hood to ventilate a room that is being painted. However, it will be less effective.

As mentioned before, the average range hood is rated at about 500 CFM. By comparison, the average bathroom fan will be rated around 100 CFM. So, five times less air is moved by the fan each minute.

This means that even if you are painting the bathroom itself, you might still battle some fume buildup. Opening up the bathroom window is definitely still advised but the combination is better than just opening the window alone.

I personally have used a 400 CFM range hood for ventilation while painting, so I can’t say for sure how well a bathroom fan will work. All I can say that the range hood worked very well. I didn’t even have to turn it all the way up for it to be effective.

A bathroom fan can also be used to cool rooms when certain conditions are met.

3. Turn the Whole House Ventilation Up

Most modern houses, particularly in the USA, have some sort of mechanical ventilation system installed other than bathroom fans and range hoods. This is to ensure a steady flow of fresh air into the typically airtight house.

Since this type of system is meant to be running constantly, on normal settings the air volume that the whole house ventilation system will move per minute will be quite small.

What’s more, the air will be distributed evenly among all the rooms in the house. This means that it is difficult to get sufficient ventilation for painting.

A central ventilation system might be enough since modern paints don’t give off so many toxic vapors. Especially low VOC or zero VOC paints. But you can also try adjusting the system to run at a higher rate.

Opening the windows in and around the room being painted for the best effects.

Some people might recommend that you close the vents to all other rooms except for the one being painted. However, this is not a solution. It will not increase the airflow to the room. At least, not enough to justify all the downsides to this practice.

4. Use Inline Fan With Flex Duct In Confined Spaces

A great option for temporary and local ventilation is to set up a length of flex duct (leading from the room being painted to the outside through a door or window) with an inline fan placed within the duct and directed to pull air out of the room and exhaust it outside.

VIVOSUN 4 Inch 195 CFM Inline Duct Ventilation Fan Vent Blower for Grow Tent

You get cheap inline fans (amazon link) and Flexi duct (amazon link) is very affordable and very helpful to have on hand in the garage for multiple reasons.

Note: Try to avoid the aluminum foil ducts as they tend to rip very easily. Especially since you will be stepping over the duct quite often. The duct I linked to is covered in thermoplastic and is much more durable.

While it may seem like a hassle to put this system together, it is a setup that can be very effective in a room with no windows or external doors, such as a basement or storage rooms.

Additionally, the fumes are pulled through a contained pipe as opposed to through the breathing air in the house as it is with the range hoods and exhaust fans, this means that there is less chance of you or your family inhaling the fumes on their way out.

The 4″ fan and duct is sufficient if the required ducting distance is not very long. If you need to ventilate the air more than 25 ft away from the fan get the 6″ fan and duct.

By using an inline fan and a duct, you can direct the paint fumes anywhere you like. Provided, of course, you have a long enough duct.

5. Use a Box/Floor Fan

A box fan in front of an open window will move can move large amounts of air. A 20″ fan will move about 2000 cubic feet of air per minute.

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In most cases, this is too much for painting. Luckily, most box fans have different speed settings. So you can select a lower setting.

Using a 20″ box fan (amazon link) will pretty well guarantee that the paint fumes are exhausted out of the house before you breathe them in.

How to Set It Up?

The fan should be pointed facing the window not into the room. While pointing it into the room would pull in fresh air, it would also push the fumes further into your house. You want to force the fume-laden air out.

  1. Open a window in the room that is being painted.
  2. Place the box fan on the window sill (facing out).
  3. Open a window in another room to enhance the ventilation effects. This will allow fresh air to be pulled back into the house to replace the fume-carrying air that is pushed out.
    • Without it, the pressure system in the room can tend towards a vacuum, which slows the rate at which air can leave. Additionally, it allows the whole room to be ventilated better as opposed to just the area nearest the window.
  4. Open the door between those two rooms

I have found a box fan to be by far the most effective way to ventilate rooms when doing renovations in general, not just painting.

I have used a 20″ box fan placed in front of a window when sanding drywall. This creates a large amount of fine dust. The box fan kept the air reasonably clean so that I did not have to wear a respirator the entire day (although wearing the respirator is still the recommended practice).

6. Open Two Windows

Remember the cross breeze that we spoke about in the section on using your range hood to provide ventilation to rooms further from the kitchen? Well, you can create totally natural cross breeze ventilation by simply opening two windows.

The windows should be as across from each other as possible. One should be in or near the room being painted and the other should be as across from the first window as possible with no complete barriers between them (like closed doors).

There is no guarantee of the rate of ventilation with this method, nor can you control the direction of airflow. The air might be pulled from the room through the house and out the far window or it might be pulled out of the window in the room.

The uncontrollable nature of natural ventilation makes it the least desirable. If at all possible consider investing in a box fan. They cost very little and could be used for other purposes during the hot summer months.

Additional Tips to Keep You Safe

Ventilation while you paint is not the only thing to keep in mind if you are trying to minimize your exposure to paint fumes (which you should be trying do!).

Schedule Painting for Dry and Warm Days

Painting in the middle of the winter or during the rainy season will make it very difficult to keep windows open for an extended period of time, thereby making ventilating the rooms that much harder. This eliminates all of the methods listed above if you want to utilize them most effectively.

Not only will working in the cold make you miserable and increase your bills as you try to keep the house as warm as possible, but paint also takes much longer to dry in cold temperatures.

This means that the whole project will take longer since you have to wait longer before applying the second coat of paint.

Scheduling the painting project for a dry and warm period will make everything so much easier.

Avoid Freshly Painted Rooms For 2-3 Days

Depending on which paint is used, there will be toxic fumes in the room for 2-3 days after painting.

If at all possible, it is best to completely avoid freshly painted rooms for a couple of days, regardless of which paint is used. People with breathing problems, pregnant women, and children should be especially careful.

Generally, water based paints emit fewer chemical vapors compared to oil based paints, but they should still be considered dangerous during the drying period.

Keep the ventilation set up and running for 2-3 days following painting, even if nobody is in the room. This will speed up the drying process and reduce the risk of chemicals permeating into other rooms of the house.

It is best to set up a box fan as directed in front of the window of the freshly painted room. This will ensure that no paint fumes are being distributed to the rest of the house.

Use A Low/Zero VOC Paint

VOC stands for Volatile Organic Compound. The smell of paint is the result of VOCs triggering your sensory system.

Most of the VOCs involved in painting are released when the paint cures during the first couple of days. This is why it is vital to avoid them during this period.

The last couple of decades have drastically increased the safety of building materials that are used in our homes. This is partly because there have been an increasing number of studies showing the harmful effects of the chemicals that are used in building materials.

The problem is, they are often tested in isolation. This means that every material is tested separately. But in a real building, there are dozens of different building materials that all release some amount of toxic chemicals into the air.

When they are combined in a poorly ventilated space, problems can arise and people can get sick.

This has brought on so-called “green” building materials. Low/zero volatile compound paint is one of them.

Not only will the zero VOC paint reduce the number of chemicals in the air during painting, but it will also drastically reduce the number of chemicals in the air years after painting.

Disadvantages of Low/Zero VOC Paint

While they are a great choice for most people, there are some things that must be considered before choosing a zero VOC paint.

  • Higher Cost.

Zero VOC paint costs considerably more compared to regular paint.

Most people paint their rooms every 10 years or so, so the extra cost can be divided by ten. You can see if the cleaner indoor air is worth x dollars a year.

By using this logic, it will not be much more expensive in the long run, if you can live with the other drawbacks of zero VOC paint, then it should be a no-brainer.

Of course, if you don’t have the money up front, the cost per year won’t make a difference.

  • Surface Maintenance.

Ammonia-based cleaning products should be avoided when cleaning surfaces painted with zero VOC paint. Choose high gloss paint for areas that will be cleaned regularly as this will make the task much easier.

  • Paint Shelf Life.

Zero VOC paint does not contain any fungicides and generally fewer preservative chemicals compared to regular paint. This means that the paint itself will go bad much more easily.

It is always wise to leave a small amount of leftover paint for touchups in the future. To make sure that the paint will be still usable after several months or even years, close the lid of the paint can once you have poured some out to use, mix the paint with clean sticks, and store it in a cool place.

Use a High Quality Respirator

For years, I was using those cheap disposable dust masks whenever doing home improvement projects. I would always wonder if they really helped since I could always smell the fumes of whatever I was working with. Also when sanding, my nose was still filled with dust after a long day’s work.

Only after I bought a real respirator did I realize how useless the disposable dust mask was. If you consider that the respirator will last for years, it will be much cheaper in the long run compared to disposable masks.

I highly recommend the 3m 6503QL paired with a 60923 filter (both pictured below). This filter offers the best combination of protection from organic compounds and particles. It’s perfect for all types of home improvement projects.

No products found.

Beware of no-name filters or filters from an unknown seller. There have been cases of counterfeit filters being sold, so it is best to stick to a reputable seller, even if the price is a bit higher. The quality of the filter is protecting your health.

Using this mask, you will not smell anything. The rubber will seal perfectly against your face (those with beards will have a less perfect seal) and the filter will keep the air you breathe in clean.

I remember the first time I used it. I was building a speaker enclosure out of fiberglass and epoxy resin. I really did not notice anything until I took the mask off. Since I was used to the clean air the shock of the strong epoxy resin smell was so strong I felt instantly ill!

Ventilate for the Right Amount of Time

Paints can still release VOCs after they have dried, so make sure that you ventilate the room for long enough.

The ventilation duration can depend on the paint type.

These tips are also applicable for applying waterproofers like Drylok.

Conclusion

Ventilation during and after painting is extremely important. Vented range hoods, vented bathroom fans, temporary inline fans with flex duct, box/floor fans, whole house ventilation systems, and open windows can be used to aid ventilation.

It is best to paint during warm/dry periods as this will make leaving the windows open much easier. You should use a respirator, avoid the room for 2-3 days after painting, and make sure to run the ventilation for a sufficient amount of time after the paint job is complete.

Hopefully this article was helpful. Be sure to vote below and leave feedback, so I can improve the future articles.

Thank you

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