Drafty windows are one of the root causes of high energy bills and inconsistent indoor temperatures, allowing up to 20% of heat to escape your home. Air infiltration is the introduction of outside air that flows into your home, and one of its entry points is through inefficient windows. This leads to your HVAC system working in overdrive, as your energy bills steadily increase throughout the seasons.

While it’s nearly impossible to eliminate 100% of air infiltration through your windows, there are energy efficient window options that can reduce drafts almost completely.

How Does Air Infiltration Enter the Home Through Your Windows?

There are several entry points of air infiltration through drafty windows. As you can see from the following diagram, airflow enters your home through the sash, the sash meeting the rail, the sash parameter, and the sill.

Air Infiltration Windows in Boston, MA


Inefficient window design and poor quality installation can result in air infiltration, drafty windows, and high energy bills. If you’re experiencing unwanted drafts and high energy bills in your home, the good news is that you don’t have to fight an endless battle with your thermostat.

The Key to Fixing Drafty Windows (For Good)

The truth is that outdated and drafty windows should be upgraded with high quality replacement windows in Boston. Over time, windows can lose their ability to block out air infiltration, and seal repair or new caulking serves as a Band-Aid approach. Caulk is generally used for cracks and openings between stationary house components such as around door and window frames, and weather-stripping is used to seal components that move, such as doors and operable windows.

Coastal Windows & Exteriors reduces drafts significantly with our industry leading energy efficient windows. This type of window design isolates air infiltration hot spots and seals them off minimizing energy loss.

dura sill window design

When you get your windows installed by Coastal Windows & Exteriors, they will be 23 times more airtight than the industry average CFM rating—specifically compared to residential wood double hung windows. Our windows only allow .01 CFM of air leakage per minute which is equivalent to less than .8 soda cans of air per minute, while competitors such as Pella and Andersen windows allow .12 to .30 CFM per minute which is equivalent to 24 soda cans of air per minute.

To put our windows’ performance into perspective, it would take a combined 23 windows from Coastal to leak the same amount of air as 1 window from our major competitors. This means that Coastal’s windows are more efficient at blocking air infiltration while keeping your energy bills as low as possible—and the proof is in our CFM numbers.

Drastically Minimize Window Drafts with Coastal Windows & Exteriors

Don’t suffer another minute from air infiltration and drafty windows. Coastal Windows & Exteriors provides top-of-the-line replacement windows for New England homeowners, and we strive to help you create a more comfortable home.

If you have any questions about air infiltration, drafty windows, or other home improvement projects, get in touch with us today by calling 978-817-7072 or e-mail svanderbilt@mycoastalwindows.com with your questions.