Summary:
Designing a compressed air system for use in a hospital is a complex and challenging task. Not only does it have to meet a plethora of demanding regulations that cover medical devices and medicines, but it must also be energy efficient, cost effective and, above all, totally reliable. These are the challenges facing suppliers but they must be met because only a highly reliable source of absolutely pure breathing air is suitable for hospital patients. There are two very distinct compressed air systems in hospitals that are governed by different standards and regulations around the world. First, there is the medical air used for patients and medical equipment and then there is the technical air that is used for maintenance around the facility. One of the prime requirements of medical devices directive 93/42/EC is that these systems must be separate, which means the air produced by compressors for use in facility tasks cannot be used for patients, and vice versa.
Overview
The highest priority for medical air and its use in hospitals is the safety of the patient. This means that breathing air needs to be available 24 hours a day, seven days a week.
At the core of this reliability is redundancy. The 93/42/ EEC and related regulation stipulates that there needs to be multiple sources of compressed air to ensure that if one compressor is under maintenance and a second fails at the same time then there is a back-up of one or more sources that is able to provide 100 per cent of a hospital’s maximum air requirements. Therefore, it is common practice for installations to have triple or even quadruple systems in place, with each compressor able to feed 100 per cent of the demand.
When designing a system for a hospital, one of the main challenges is to calculate the hospital’s 100 per cent compressed air demand. This is defined as the amount of air that would be required if every conceivable application was being used at the same time – even though this is a situation that would never actually occur. Whether for patient beds or operating theatres, medical compressed air is used in all areas of hospitals and must be readily available at all times. By designing compressed air systems with at least triple redundancy, the risk of failure is virtually ruled out.
