Hello, MyGreenKC community! We hope you’re all staying cool and comfortable despite the recent heatwave. Over the past week, we’ve experienced sweltering temperatures of up to 100°F, coupled with a staggering 125° dew point.

The humidity was off the charts, often pushing the dew point into the mid-80s. With these extreme conditions, many of us encountered condensation issues, whether on the vents, walls, or other surfaces of our homes. This is often a sign of a weakness in the insulation or air barrier. In this blog, we’ll dive into the science behind condensation, the role of air conditioning and insulation, and compare summer and winter condensation issues.

The Science of Condensation

Condensation occurs when water vapor in the air cools down and turns into liquid water.

This is influenced by the dew point, which is the temperature at which air becomes saturated with moisture and water vapor begins to condense into liquid water. When the surface temperature of an object (e.g., a vent, wall, or window) falls below the dew point of the surrounding air, condensation will form on that surface.

Latent Heat and Air Conditioning

Latent heat is the energy required to change a substance from one state to another without changing its temperature.

For water, this includes the latent heat of evaporation and the latent heat of condensation (or vaporization). It takes about 970.4 BTUs (British Thermal Units) of energy to evaporate one pound of water, and the same amount of energy is released when one pound of water vapor condenses back into liquid water.

An essential function of air conditioning is to remove humidity from the air, which involves converting water vapor into liquid water. This process not only cools the air but also helps to reduce the indoor humidity level. So, if you have your air conditioner set at 70°F and there’s an 85°F dew point outside, a leaky home will likely result in condensation issues. And here’s a little joke for you: if you don’t have enough “inches” upstairs (in your attic insulation), you might have a higher propensity for condensation issues. Ha ha!

Summer vs. Winter Condensation

Summer condensation often appears on cool surfaces, like air vents or walls,

where there is a weakness in the insulation or air barrier. In contrast, winter condensation usually occurs when the surface temperature of a window or wall is below the dew point inside the house. In both cases, the moisture from the inside condenses on the cooler surface, but the causes and solutions may differ.

Conclusion

Proper insulation and a well-sealed home are key to preventing condensation issues in both summer and winter. At MyGreenKC, we specialize in helping you improve your home’s insulation and air barrier to keep you comfortable year-round. Contact us today for a consultation and say goodbye to condensation woes!

Remember, if you’re dealing with condensation, it’s not just about the heat—it’s also about what’s hidden in the humidity. Stay cool and dry, everyone!