Nigeria, April 29 -- When Kola Adebayo, an air conditioning technician in Abuja, gets a call to fix a malfunctioning air conditioning system, one of the first questions he asks is if the AC needs servicing or a gas refill.

Mr Adebayo said these problems are persistent in the Nigerian capital. "Usually, people tell you their ACs are not freezing, and it needs servicing or a gas refill," Mr Adebayo said, hauling a piece of equipment.

In Nigeria, air conditioners have become popular as the appliance, once a luxury for the middle class, has become a necessity in an increasingly hot climate.

The cooling sector is governed by regulations that prohibit the release of refrigerant gases into the air, such as by conducting leak tests after repai...