Air Handlers and Preventive Maintenance
All mechanical equipment needs attention from time to time to prevent equipment breakdowns and to keep the equipment running at optimum efficiency. This includes air handlers also. In many cases an air handler is made up of several components including the air handler cabinet itself, a blower to move air, a coil or possibly two coils, and some air handlers have controls inside of them especially light commercial and residential air handlers. A package unit will have all the components in one package including the air handler inside of it. The air handler can be combined with a gas or oil furnace in one unit. The air handler is usually attached to both the supply and return duct work and sometimes it houses the filters. It is important that the air handler (or air handlers if you own more than one) receive attention from time by a qualified HVAC technician. This means that you should have a regular maintenance schedule for your air handling unit (AHU) equipment.
The Air Handler Cabinet
The air handler cabinet is made of sheet metal and simply acts as a duct to guide the air through and to protect the air handler components and to protect people from the air handler components. Depending on the manufacturer will depend on the color of the unit. Trane air handlers are usually green, Carrier air handlers are usually gray, Goodman, Janitrol, and York air handlers are usually brown (as many manufacturers use brown). Commercial air handlers are usually unpainted sheet metal especially McQuay but Carrier, York, and Trane will paint their commercial equipment before shipping. It simply depends on the manufacturer and what they decided to use to paint their equipment before shipping. Hopefully you can use this as a guide if there is no identifying information on the equipment. Sometimes the identifying information for air handlers are hidden on the inside of the cabinet but it is not recommended to open the air handler cabinet unless you are a trained HVAC professional.
The Air Handler Blower
All air handling units have a blower located inside the air handler cabinet. The air handler blower has a motor that drives it. Some air handing unit blowers are direct drive and some are belt driven. Many light commercial and residential blowers are direct driven by the motor while many commercial air handling units are belt driven by the blower motor. Some motors require regular maintenance in the form of oil or grease. All these air handling unit blower motors, whether they are commercial or residential, have high voltage running to them which can be potentially dangerous. The other danger involved with checking these air handler blower motors is they are moving parts when energized and can cause serious injury. It is recommended in commercial applications to replace the belts at least every ninety days. A qualified HVAC technician should perform this air handler maintenance.
The Air Handler Coils
The air handler coils should be checked for dirt and debris which may have been sucked into the air handler inadvertently. Some air handlers have the filters inside them before the coils. It is a good time to change the filters when making this check. Any dirt or debris on the coil(s) should be removed immediately as these things will impede air flow through the air handler and throughout the entire system as a whole. A blocked air handler coil can also cause serious mechanical issues especially for DX cooling applications. The air filter should catch most of the dust and debris but it always good practice to check the air handler coils to be sure nothing is impeding air flow. Some air handlers can have up to three coils inside them. These are usually commercial air handlers with a cooling coil, a hot water coil for heat, and a reheat coil for dehumidification purposes. All coils should be inspected for any blockage including algae growth. Again, a qualified HVAC technician can handle all the air handler maintenance checks on your air handler coils safely and efficiently.
The Air Handler Control Panel
The air handler control panel has a lot of electrical components inside it. Electricity can be very hazardous so it is recommended that a qualified HVAC technician perform the air handler maintenance checks on the air handling unit control components. The air handling unit maintenance checks on an air handler control panel comprise of looking for loose connection with wiring, loose line voltage connections, burned or corroded wiring and connections, pitted or scared contacts on contactors and relays, and take amperage readings on the main air handler components to make sure there is normal operation. Capacitors can also be tested to make sure they are within the proper ratings as specified by the manufacturer. These entire tests or your air handling unit(s) should be performed by a qualified HVAC Technician.
These basic AHU (Air Handling Unit) checks can save you money on your HVAC energy budget, save you discomfort from unexpected air handler breakdowns, and add longevity to the air handling unit equipment for years to come.
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