Some things simply don't get better with age.
Take air conditioners – they're one of the hardest working machines in your business, and if they're not operating at maximum efficiency, they can use a lot of extra power and cost you money, as well as creating unnecessary carbon pollution.
Air conditioning technology has made many advances in the past few years, resulting in far more efficient and environmentally-friendly models now being widely available. Check the energy rating label before you buy. The more stars the more energy efficient.