Richard Betts, managing director of RABScreen, discusses the importance of airflow in hospital heating and cooling systems
Airflow is the single-most-critical element in the correct operation of all air heating and cooling systems.
Accurate cooling or heating analysis cannot be performed, system performance cannot be measured, and the servicing or commissioning process will be compromised if airflow is anything but correct
Yet most systems do not have the correct airflow, and, as a result, compressors overheat, fans blow hot air, and the heat exchangers at their heart cannot provide the capacity and comfort that manufacturers built and designed into them.
Accurate cooling or heating analysis cannot be performed, system performance cannot be measured, and the servicing or commissioning process will be compromised if airflow is anything but correct, just ask any HVAC manufacturer.
We heat and cool air, humidify it, dehumidify it, clean it, move it, supply it, return it, and try to monitor it.
And all of these processes are jeopardised if the designed airflow to the system is restricted.
The recent economic climate has caused nationwide cutbacks on staffing and budgets and fewer staff on site means a reduced capacity for maintenance and servicing. Hospitals, in particular, are finding they have fewer estates and facilities staff and many services are now outsourced.
But any breakdown of heating and cooling systems within a healthcare environment can have a major impact on services, and the wellbeing of staff and patients.
Measuring, monitoring and maintaining correct airflow should be the first step when servicing equipment - it is the key component for proper equipment operation
The objectives of any maintenance team are very simple: to achieve adequate building cooling or heating; to minimise labour time and maximise efficiencies; to reduce downtime breakdowns; and to maintain customer satisfaction.
Measuring, monitoring and maintaining correct airflow should be the first step when servicing equipment - it is the key component for proper equipment operation.
And energy consumption is dramatically increased when compressors and fans have to work harder to maintain design output, and this means big money is needlessly vanishing into thin air.
Also, if an expensive compressor needs to be changed and the technician has not fully determined why it failed, the new compressor is sure to fail for the very same reasons. Indeed, compressors installed by service technicians fail at 6-7 times the rate of original equipment.
Key to specification is that systems provide adequate building cooling or heating; minimise labour time and maximise efficiencies
In most regions of the UK, pollen is a major contributor to the fouling of cooling equipment.
This, combined with general debris caused by foliage, refuse, and other airborne particulates, can have a significant impact on the day-to-day running of the equipment.
It has always been very difficult to add filtration to cooling equipment (water and dry air cooled), small condensers and cooling towers. Yet external filtration products now offer the ideal solution to air intake debris, contaminated coils and clogged cooling tower sumps.
These screens are easily fitted externally and prevent contaminates in the air entering the system. This saves money by extending the life of disposable filters, saves as much as 30% of input energy on chiller coils and saves labour by reducing cleaning and chemical use.
It pays dividends to keep HVAC airways clean as, by doing so, it reduces energy consumption considerably; reduces the regular maintenance needed on cooling systems; and increases the efficiency of the equipment ensuring its long life well into the future
As a result, the typical return on investment of fitting these filters, take RABScreen’s air intake screens as an example, is less than six months.
These screens are a black engineered mesh, which is heavy duty and high abrasion resistant and incoming debris held in place on the mesh is easily removed by vacuum, brush or washing during regular maintenance.
During the summer months coil cleaning, changing of internal air filters, and general HVAC maintenance must be carried out more frequently, consuming much of the engineering team’s routine programmed maintenance schedule.
Similarly, the correct monitoring of airflow through cooling towers will help to minimise the risk of decaying debris such as insects, seeds and pollen forming a nutrient source for the Legionella bacteria.
As I have said, it pays dividends to keep HVAC airways clean as, by doing so, it reduces energy consumption considerably; reduces the regular maintenance needed on cooling systems; and increases the efficiency of the equipment ensuring its long life well into the future.