How to ventilate a room without windows when painting

Painting is something I have always loved to do. I love how it enables you to quickly change how a room looks. Even something as simple as painting the ceiling and walls the same color can transform the entire feel of the room.

While modern paints, even enamels, are much safer compared to toxic chemical-filled paints of the past, ventilation while painting is still extremely important.

Luckily there is a way to ventilate almost any type of room. Even basements without any windows. I am positive that you will find a solution that will help you from this list.

Turn On The Range Hood

The Range Hood is probably the most powerful exhaust fan in your house. In my experience, it will keep the air so clean that you won’t even smell the paint fumes.

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.

Since range hoods are designed to exhaust a very large amount of air in a short period they are perfect for exhausting paint fumes.

It will help even if the room you are painting is in the other side of the house.

If the room you are painting happens not to be the kitchen, one might wonder how a range hood will get rid of the paint fumes? There is a very simple trick that can be used to ventilate any room in the house with the range hood.

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 a window in the room that is being painted
4. Open all doors that are between the kitchen and the room that is being painted

Doing this will enable you to ventilate a room that is on the opposite side of the house from the kitchen. Closing all other openings to the outside will force air to enter the house via the open window in the room that is being painted.

This will very efficiently ventilate the room where the open window is.

Note: This method will not work if the house is not airtight. However, most modern buildings are sufficiently airtight to make this work.

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.

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. 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.

Bathroom Exhaust Fan

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

As mentioned before, an average range hood is about 500 CFM. An average bathroom fan will move about 5 times less air compared to that (100CFM)

This means that the ventilation could not be sufficient to ventilate the room that is being painted. However, it will be considerably better than just opening up the window. Since the air will be moving from the window to the bathroom fan the fresh air will circulate better throughout the room.

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.

Turn The Whole House Ventilation Up

Most modern buildings 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 house.

Since this type of system is meant to be running constantly, the air volume it will move 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(but not impossible) 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.

How to increase the effect of the central ventilation system

Since the ventilation system is likely distributing air among all rooms of the building, the amount of air that reaches the room you are painting will not enough. There are a couple of steps that will increase the ventilation of one room.

• If possible close air vents in other rooms (but only while painting as leaving them closed can negatively affect your HVAC system). This will force more air into the room that is being painted
• Turn the ventilation system all the way up
• Open a window in the room that is being painted
• Keep the door closed

Use An Inline Fan With A Duct In Confined Spaces

Say you are painting a room without any windows and no air vents. How is it possible to ventilate this kind of space?

Easy!

A cheap inline fan(amazon link) combined with a Flexi duct(amazon link) will efficiently ventilate any room of the house. I understand this is more hassle than just turning on the range hood as we discussed earlier. But there is a big upside to using this system.

By using a range hood or a bathroom fan to ventilate the painted room, paint fumes are pulled through the entire house. Not so good if someone else is home.

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

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

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 🙂

Box/Floor Fan

A box fan in front of an open window will move a massive amount of air. A 20″ fan will move about 2000 cubic feet of air per minute. In most cases, this is too much painting, luckily most box fans have different speed settings. So you can select a lower setting if the outside temp is low to keep the room warmer.

But if the outdoor temperature is mild, there is no downside to more ventilation. Using a 20″ box fan(amazon link) will guarantee that the paint fumes are exhausted out of the house before you breathe them in.

How to Set It Up?

• Open a window in the room that is being painted
• Place the box fan on the window sill, make sure it is blowing air out otherwise the fumes are blown into other rooms of the house.
• Open a window in another room*
• Open the door between those two rooms

*This will drastically improve the ventilation. Doing this will draw fresh air from the other room’s window and it will be distributed evenly in the room that is being painted. By opening only the window in the room that is being painted the area in front of the window will be ventilated well, but not the entire room. Opening the second window is especially important if the room is large.

I have found a box fan to be by far the most effective way to ventilate rooms when doing renovations, 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 I did not have to wear a respirator the entire day.

Open Two Windows

Natural ventilation by opening two or more windows will create a cross draft that will ventilate the room. However, this type of ventilation is the least controllable. The amount of ventilation will be largely controlled by the wind speed and direction.

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.

Every home should have a bathroom fan, at least turn that on to make sure that there is some air moving, even if there is no wind.

Ventilation, while very important is only part of safe painting practice. There are other things that must be kept in mind to ensure safety during, and after painting is ensured.

Schedule Painting Dry Warm Days

Painting in the middle of the winter, or rainy season will make it very difficult to keep windows open for an extended period of time. This makes ventilating the rooms that much harder. Even using fans to ventilate the room will bring in freezing air from the outside.

Scheduling the painting project for a dry/warm period will make everything SO much easier. Not only will working in the cold suck, 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 more before applying the second coat of paint.

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. 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 which breathing problems, pregnant women and children should be especially careful.

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

2-3 days following painting keep ventilating the room even if nobody is in the room. This will speed up the drying process and will reduce the risk of chemicals leeching into other rooms of the house. There is always some amount of air moving between different rooms of the house.

It is best to set up* a box fan 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.

*make sure to set it up so it blows air out of the window.

Use A Low/Zero VOC Paint

VOC stands for Volatile Organic Compound. Most of the VOCs are released when the paint cures during the first couple of days, this is why it is vital to avoid them during this period. IF you are smelling the fresh paint smell, what you are really smelling are the volatile organic compounds in the air.

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 anincreasing amount 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 all combined in a poorly ventilated space, this is where problems arise and people 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 to 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. However, most people paint their rooms every 10 years or so, so divide the difference in price by 10 and 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.

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 do thefollowing-

• Pour paint out of the paint can and close the lid immediately
• Use clean mixing sticks
• When storing the paint for longer periods keep it in a cool place with the lid completely secured

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 help 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 I realized how useless the disposable dust mask was. If you consider that the half mask will last for years, it will be much cheaper in the long run compared to disposable masks.

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

Note: Do not buy no-name filters or 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 the only thing protecting your health.

Using this mask you will not smell anything. The rubber will seal perfectly against your face 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 nearly puked 🙂

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. Range hoods and bathroom fans can be used to aid ventilation provided they are not ductless. A box/floor fan pointed out of the window is the most efficient way to ventilate the room since they will move the largest amount of air. Opening several windows will create a cross draft that can be sufficient when there is enough wind.

It is best to paint during warm/dry periods, this will make leaving the windows open much easier. The freshly painted room should be avoided for 2-3 days after painting.

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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