Air-con sensor

Engineers at Purdue University have developed a sensor-based system that indicates when air conditioners are low on refrigerant, preventing the units from working overtime.

The new system could be used in automotive air conditioners, which tend to leak refrigerant more than other types of units, and for household central air-conditioning units, according to James Braun, a professor of mechanical engineering at the university.

Maintaining the proper amount of refrigerant in a system saves energy because air conditioners low on refrigerant must operate longer to achieve the same degree of cooling as properly charged units.

‘Not only does the energy efficiency go down, but you also reduce the lifetime of the unit because it has to work harder, causing parts to wear out faster,’ Braun said.

‘It’s also very time consuming and costly to have a technician check the refrigerant and charge it up to specification.

‘To accurately learn how much charge is in the system, you have to remove all of the refrigerant and weigh it, a procedure that requires a vacuum pump and is quite time consuming.’