Freelancers aren’t typically in the business of doing work “pro bono,” but if you’re concerned about the environment and looking for ideas to write about in the lead-up to Earth Day, a new initiative from one heating, cooling, and ventilation (HVAC) service might be worth your attention.

According to ACHRnews.com, Service Experts Heating and Air Conditioning announced that they will be offering a promotional deal for nonprofits in the areas of their service locations, which can be found across 30 states. On Earth Day, April 22, 2016, the company will provide free air conditioning tune-ups for nonprofits and deserving families.

“Heating and air conditioning systems are one of the top users of home energy, consuming up to 50 percent of energy use every month,” said Rob Haines, marketing manager for Service Experts. “Every single tune-up contributes to reducing energy use and cleaner indoor air, and we’re excited about the cumulative positive effect of our free Earth Day tune-ups on the environment.”

It’s estimated that regular heating and air conditioning tune-ups can save up to 30% on a home’s energy bill. Overall, air conditioners use about 5% of all the electricity produced in the United States. Depending on the unit, HVAC filters alone should be replaced once every couple of months or so, according to EnergyStar.gov.

The Precision Air Conditioning Tune-ups that the company is offering have a value between $99 and $139, depending on the market. Service Experts Heating and Air Conditioning is based in Plano, TX, but they have over 90 locations across 30 states. For a full list of the participating locations, check out the story.

Some of the nonprofits the service is already scheduled to help include a Habitat for Humanity office in Baltimore, Serenity House Assisted Living in Ohio, a 48-bed multi-faceted shelter serving at-risk youth due to abuse, neglect, or homelessness called City House in Dallas, and a family in need referred by Trinity Baptist Church in Virginia.