how to create positive air pressure in your house

Learning how to create positive air pressure in your house is crucial, and thankfully, it does not have to be very tricky.

Air pressure in your property is essentially the difference in pressure between the outside and inside of your home.

With that difference in mind, you can decide whether you have negative or positive air pressure in house.  

And considering how beneficial positive pressure can be, it is natural to ask how to create positive air pressure in a room or house.

You can create positive air pressure by bringing in more air from the outside through vents, air conditioners, ERVs, etc. 

Understanding More about Air Pressure in Your House

understanding air pressure in your house

There are good reasons to be aware of the air pressure in your home. Managing the pressure in a home will improve the quality of the air circulating in it.

And this makes it a cozier, healthier home for its occupants and good for maintaining the structure of the house.

Understanding more about the air pressure in your home is important. And there are quite a few concepts to learn here. 

Positive Air Pressure

A positive pressure is created when more air is being brought into the home than is being expelled. 

Any home appliance that forces air inside, such as a vent, air conditioner, or heater, might contribute to this change.

While a building’s positive air pressure helps keep polluted outside air from seeping inside, too much positive pressure can lead to air leaks and a drop in indoor air quality

Negative Air Pressure

negative air pressure

When more air is being evacuated from the home than is being supplied, the result is negative air pressure.

Exhaust fans in places like kitchens and bathrooms can create areas of negative air pressure, which in turn draws in outdoor air and lowers indoor air quality. 

Balanced Air Pressure

When the inflow of air into the home is the same as the outflow of air from home, the air pressure inside is considered to be balanced.

One way to do this is mechanical ventilation systems that supply a constant flow of fresh air while simultaneously expelling stale air.

Fact: Placing a fan close to an open window helps bring outside air into your home to improve the air pressure. 

Positive or Negative Air Pressure: Which is Better?

A positive pressure indoors is higher than the air pressure outside, a negative indoor pressure is lower.

A positive pressure will keep bacteria, pollens, mold spores and pollutants out of the house, whereas a negative pressure will keep such things in.

positive or negative air pressure

This makes creating a positive pressure seem the better option for homeowners especially in warmer temperatures when the positive pressure keeps humid hot air out of the building.

Although negative pressure is more often used in research and industry to avoid contaminating the environment outside.

In a house, a negative pressure exhaust system blows air out, pulling more in to replace it through holes or cracks in the building with obvious implications for its structural integrity.

There are other ways negative pressure can cause problems. 

Signs of a Negative Air Pressure

sings of a negative air pressure

In poorly built or badly maintained houses a negative pressure is easy to detect;

  • Stale air
  • Condensation, dampness, mold and mildew
  • Poor heating, cold spots and drafts
  • Respiratory issues including headaches
  • Doors slam or are difficult to open
  • Smoking appliances and fireplaces, extractor fans not working
  • Higher energy use and bigger bills 

Signs of a Positive Air Pressure

signs of a positive air pressure

You will likely feel more comfortable in a house with slightly positive pressure. The atmosphere feels less oppressive.

There is:

  • No excess humidity
  • No excess heat
  • A comfortable airflow
  • Better heating efficiency
  • Lower energy bills
  • General good health

An important Consideration

Energy costs in the home may rise or fall depending on the air pressure.

For instance, negative air pressure can suck in outdoor air, increasing the expense of heating or cooling the home.

Similarly, positive pressure can increase energy usage by driving conditioned air out of the house.

Fact: Take steps to lower emissions from stoves and fireplaces, and store cleaning products and chemicals properly to maintain a balanced air pressure. 

How to Create Positive Air Pressure in Your House

good ventilation house

All new build homes are designed to encourage a slightly positive air pressure with natural ventilation through specialized vents that manage the flow.

To create positive pressure there needs to be a slight imbalance, with more air entering the house than leaving it.

This creates a pull of air through the building. 

Rely on Vents for Positive Pressure

It is important that all the vents are kept in good working order and free from obstruction, dust or debris.

For a positive pressure to develop the air must be able to draw through the house to only exit via exhaust vents.

When a vent is blocked, the air will be forced out via small cracks and gaps by the air pressure behind it.

This creates pockets of differing pressures that can undermine the structure of the house. 

Preventing Lost Air for Positive Pressure

positive air pressure through windows

It is vital to keep your home airtight to be able to create positive air pressure.

As well as the potential for damage, especially around windows and door frames, homes that leak air cannot create or maintain positive pressure.

One place air frequently escapes to via badly fitting pipes and ducts, is attics and crawlspaces.

Air lost in this way is often the root cause of negative pressure.

Air in the home is lost in other ways as well, such as:

  • Poor insulation
  • Extractor oven hoods
  • Dryers

In high winds, the inside and outside air pressures create significant forces as they meet and try to equalize and this causes damage, particularly to the roof.

A sealed house becomes a sealed pressure system, which is unaffected by the pressure outside. 

Positive Pressure through ERV Technology

Most homes can be fitted with an energy recovery ventilator, an ERV.

And interestingly, many homeowners manage their units using Smart technology and maintain positive air pressure in the house.

When paired with a smart thermostat, ERV can control all aspects of the air flow into the home.

panel of energy recovery ventilator

It’s a way to bring air inside in a controlled manner.

And it also helps to regulate the temperature, humidity, and quality of the air that enters and circulates through the house.

As the air is drawn in, the ERV filters it, removing dust, pollen, and any other unwanted airborne particles for clean air.

An ERV also monitors the outside conditions including the air pressure and air quality.

It only brings in the air when conditions are favorable, such as when the humidity is low.

Fact: Using an ERV is an effective way to keep the air pressure positive by preventing outside air from finding a way in, keeping the ambient temperature comfortable. 

Positive Pressure through Temperature Regulation

You can create positive air pressure by paying attention to temperature regulation in your house.

Experts remind us that both positive and negative pressure induces stress on a building.

positive pressure through temperature regulation

Each can force air leakage, although the impact this has varies depending on the temperature and humidity levels. 

In short, the greater the differences in temperature between the inside and outside of the home, the greater the cause for concern.

Air Pressure in Summer

Negative pressure in summer, for instance, will pull the warm air in, and with no exit, the house will become stuffy and too warm for comfort.

Condensation will form on cool surfaces causing water damage.

Air Pressure in Winter

In winter, with negative pressure, the house will draw in the cold outside air in anyway it can, leaving the house feeling damp and expensive to heat with cold spots and drafts.

In winter, even positive pressure can cause problems, which is why systems such as the energy recovery ventilator are popular among homeowners.

Fact: When the difference in temperatures between inside and outside are at extremes and warm, moist air is forced out of the house, often causing mold or wood rot.


Learning how to create positive air pressure in your house can help you enjoy several benefits.

It improves your overall health and even protects your property from structural damage.

You can take various steps to ensure positive air pressure in your house, like using air conditioning systems and checking vents for flow.

Similarly, using ERV is beneficial and so is keeping an eye on temperature fluctuations in your house.