A/C Cleaning Tips

By: Peter Kirtschej, Service Advisor, ABR Wholesalers, Inc.

It’s that time of year again – air conditioning system cleanings are in full swing.  As an HVAC technician, I would like to offer some advice about the air conditioner cleaning process.  When you arrive at the home, talk to the homeowner to see if there are any problems or concerns they may be experiencing with the comfort level in their home. Doing this can help lead you in the right direction if there is a specific problem they are having with their system.  Once you have assessed their comfort level, you can begin the cleaning. 

1.  Set the thermostat for cooling, then put the thermometers in the supply plenum and return plenum to calculate the Delta T.

2.  Hook gauges to the condenser, making sure that the gauges are dedicated to that refrigerant.

3.  Clip the clamp of the thermometer to the suction line to check super heat.

4.  Next, connect the gauges to the condenser - the gauge readings will reveal how the unit is running based on the temperature and pressure chart that is usually located on one of the panels.

5.  The gauge reading may indicate one of the following:

a.  The unit is low on charge

b.  The suction side gauge is low and the liquid line reading is abnormally high.  This would indicate some form of restriction in the refrigeration system.  If the unit has high head pressure, this will cause the compressor to run hotter than it should resulting in over heating the oil in the system.  Because of the overheating, the oil's viscosity will break down causing premature compressor failures.  High head pressure could be caused by one of many issues such as

A dirty air filter

Condenser coil is plugged

Condenser fan motor may not be spinning up to appropriate rpm

Dust and dirt build up on the evaporator coil restricting air flow

Duct work may be undersized for the application

6.  Check the temperature differential between the inlet and the outlet of the filter drier - If the temperature difference is greater than a couple degrees, this could cause potential restriction and should be replaced.

7.  Check the amp draws on the fan motor compressor.

8.  Turn the power off to the condenser and check the capacitor to make sure it has enough microfarads.  Examine the contactor closely, making sure the contacts are not pitted or worn down too much.  When contacts are worn, the surface area of the connection is smaller.  This creates more resistance (more amp draw) and in turn causes more heat and stress on the wires and piece of equipment.

9.  If the contactor looks okay, retighten all the screws on the contactor that may have backed off due to thermal expansion.

10.  Examine the wires going to the condenser to make sure they are not rubbing on anything.

11.  After checking all the components on the condenser, clean the condenser coil, pulling the outer grills or covers and the condenser top and fan motor.  This is a necessary step on most condensers so that the coil can be accessed.

12.  Once you are confident that the coil is clean, reassemble the condenser. If you found something wrong, document the issue.

13.  Check the air filter.

14.  Pull the evaporator coil cover to determine if cleaning the coil may be in order. You can blow out the condensate drain of the coil Using a shop vac or nitrogen.  

15.  Once the air conditioning system is clean, take a good look at the ductwork to determine whether or not the customer needs a duct cleaning.  While you’re doing that, check to see if all the dampers open through the house.

16.  The final step of the air conditioning system cleaning is to have a conversation with the homeowner. Explain any problems that you discovered during the cleaning, and present any recommendations that you may have for those issues or other issues the homeowner is concerned with 

a.  If the homeowner says yes to the repairs, complete them or schedule a follow-up appointment.

b.  If they decline, document everything on your service tickets for the future.

Air conditioning cleanings are a great way to strengthen a customer relationship, identify potential add-on sales, and plant seeds for future sales.  ABR Wholesalers has all the tools you’ll need to save you time and maximize your profits on these cleanings.  For more information, contact ABR today!