Source: AP

When Jennifer Byrne, owner and technician at Comfy Heating and Cooling, gets a call to come and fix a relatively new air conditioning system, one of the first questions she asks is if the house has just been remodeled. 

Here in West Philadelphia, Byrne has found shoddy renovations where installers skip steps such as pressure testing after installation. That can result in ice buildup and leaks of the chemicals that cool, called refrigerants.

“This problem is extremely frequent around here. Usually people tell you they bought a house that was flipped and all kinds of things are wrong, like the AC is freezing,” Byrne said, referring to the ice buildup.

Read more: Refrigeration chemicals are a nightmare for the climate. Experts say alternatives must spread fast