Airflow: The most important part of any heating and cooling system?

Airflow is the single most critical element in the correct operation of all air heating and cooling systems. Yet most 

systems do not have the correct airflow.

As a result compressors overheat, fans blow hot air and heat exchangers at their heart cannot provide the capa-

city and comfort that their 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. 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. Fewer staff on site 

means a reduced capacity for maintenance and servicing. However, the objective of any maintenance team 

has not changed.
It is very simple:
•Achieve adequate building cooling or heating.
•Minimise labour time and maximise efficiencies.
•Reduce down time breakdowns.
•Maintain customer satisfaction.  

Highly qualified engineers are wasting hours on the environmentally unfriendly, chemical cleaning of coil fins 

instead of fine tuning and balancing the sensitive air handling systems they are trained to maintain.

Measuring, monitoring and maintaining correct airflow should be the first step when servicing equipment. It is 

the key component for proper equipment operation. Energy consumption is dramatically increased when com-

pressors 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 same reasons. Indeed compressors installed by service technicians 

fail at six to seven times the rate of original equipment.

Difficult
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 upon 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 conden-

sers and cooling towers. Yet products like the RABScreen external filtration now offer the ideal solution to air in-

take 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.  

As a result, the typical return on investment of fitting RABScreen air intake screens is less than six months. 

These air intake screen 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 explained it pays dividends to keep HVAC airways clean as by doing so it reduces energy con-

sumption considerably; it reduces the regular maintenance needed on cooling systems; and increases the

efficiency of the equipment ensuring its long life well into the future.