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4 Ways to Manage the Stack Effect and Improve Indoor Air Quality

Stack Effect illustration.

If you’re trying to improve the air quality in your home, there’s a lot of things you can try—CO2 monitoring, switching to natural cleaners, replacing air filters, and opening windows. All are worthwhile, but none of these can address one of the biggest causes of poor air quality: the “Stack Effect.”

On its own, the Stack Effect isn’t an issue. It’s just a naturally recurring phenomenon in which air cycles upward from the lowest level of your home (usually your crawl space or basement foundation) to the uppermost level. However, if mold and moisture are down in the lowest levels of your home, the Stack Effect distributes them throughout the rest of your home.

If you have a wet, moldy crawl space, the Stack Effect is going to foil any hope you have of achieving better indoor air quality. If you want to breathe easier (literally), crawl space encapsulation is how you do it.

What Is the Stack Effect?

stack effect cgi

The term “Stack Effect” refers to the natural cycle of air warming up inside your home and rising from bottom to top. It’s a natural phenomenon that happens in virtually every home.  

It works like this:

  • Because the warm air in your home is lighter than cool air, it rises (like in a hot air balloon) to its uppermost levels.
  • Once it reaches the top of the building, it escapes out of any little opening it can find.
  • As the air escapes outdoors, it creates a negative pressure difference (the force at play when drinking through a straw) along the entire height of your home from bottom to top.
  • At the lowest levels of your home, the negative pressure draws in air from outside to replace the air that has escaped.
  • The cycle repeats.

Why the Stack Effect Matters

The Stack Effect isn’t just inconvenient; it can pose a number of very big problems:

  • It can ruin your indoor air quality by spreading mold spores throughout your entire home.
  • Exposure to mold spores can lead to minor to severe allergic reactions and recurring health issues among people with pre-existing conditions.
  • Finally, it can raise your energy bills by 15-25%.

Not only does the stack effect impact your home negatively, but it can also have a detrimental effect on your home’s efficiency and the health of your loved ones. You can resolve this issue with the help of a crawl space professional near you.

Addressing 4 Key Factors of the Stack Effect 

We’ve explained how the Stack Effect works, so now we want to break it down into 4 key factors. Understanding these factors of the Stack Effect can help you prioritize how you want to address the the negative results. For us

1. Outdoor vs. Indoor Temperature

The Stack Effect works on your home in different ways during different times of the year. Why? Because the temperature of the air inside your home is either warmer (during winter) or colder (during summer) than the air outside of it.

  • During winter, the air is cooler, so when it enters your crawl space, it warms up, rises, and escapes at a faster rate. The result of this is a rapid loss of heating.
  • During summer, the air getting into your crawl space is already quite hot, so when it rises it also compounds. This means that your home isn’t cooling off as fast.

If you don’t have measures in place that regulate against the extremes of outdoor temperatures, your home will either be hotter or colder than normal and your HVAC system will overcompensate for it. In some cases, your bills could be 15-25% higher than they otherwise would. What you need is a simple solution that insulates your crawl space against either cold or hot air.

2. Entrances and Exits for Air

The Stack Effect needs an entrance and an exit, usually at the crawl space or basement (entrance) and the attic (exit). The issue often lies with open crawl space vents. Open crawl space vents allow air and moisture to enter into your crawl space and feed mold. From your crawl space, the Stack Effect can spread mold throughout the entirety of your home. This is true even in one-story homes where the air doesn’t travel far.

You’re likely to see mold issues get worse if the crawl space vents remain open. 

stack effect

3. The Upward Movement of Warm Air

We’ve covered this already, but it bears repeating: warm air, being lighter than cold air, rises upward. When air, especially cold air, comes into your house, it will warm up in your crawl space or basement, rise higher, and draw cold air up along with it. So, in extreme temperatures at either end of the scale, your home will struggle.

Your HVAC system is really important to managing the flow of air in your home. Keep it updated and in good condition.

  • The Problem: Unmanageable Airflow
  • The Solution: Maintain Your HVAC System

4. The Movement of Airborne Particles

Because 50% of the air in your home comes from the crawl space, the air quality in your entire home largely depends on the air quality below it. If your crawl space is full of moisture, the air coming up from it may carry tiny particles like mold spores, dust mites, and pest droppings which will spread across your home.

In this case, you’re going to need two things: something to seal out moisture from getting into your crawl space, and a way to clean the air of particles so they can’t spread through your entire home.

We now have a crawl space to be proud of and feel very secure that we will not have any future problems. Pauline and I will not hesitate in recommending your company to anybody. We thank you for your services.

~ Burt and Pauline S., Williamsburg, VA

Call Crawl Space Repair Expert Near You Today!

The Stack Effect can have a very detrimental impact on indoor air quality and energy efficiency. The good news is that you can do something about it.

Call in a trusted crawl space repair expert near you!

If you live in the Mid-Atlantic and you suspect that your crawl space is causing mold and air quality issues throughout your home, choose JES Foundation Repair, the region’s leading crawl space encapsulation experts! Schedule your FREE crawl inspection and same-day estimate in the form below!

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