Cooling Questions
- Does the refrigerant in my air conditioner need to be changed?
- If it is not a refrigerant charge problem, what else may be causing my air conditioner not to cool well?
- What temperature (how cold) should the air supply be?
- What would cause my air conditioner to "freeze up" with ice?
- Indoor and outdoor temperatures may be too cold.
- Evaporator air recirculation is possible due to poor or improper installation.
- Dirty filters.
- Supply air louvers may be shut off.
- Inadequate or damaged ducting (if so equipped).
- Dirty or plugged cooling (evaporator) coils.
- Electrical problems, faulty thermostat, inoperative freeze thermistor, welded relay.
- My air conditioner does not cool like it did when it was new. What should we check?
- The filters could be dirty. This is a very probable cause and can be easily corrected by washing the filters with detergent and water, then replacing them when they dry.
- The evaporator coil could be covered with lint, dirt or other debris. Dirt will reduce the air flow and slow down the heat transfer from the air to the refrigerant. If this condition exists, you should contact an Authorized Service Center to have the condenser cleaned.
- Condenser coil could be coated with dirt, leaves or lint. The coil may even be damaged by hail or you may have backed into an overhead structure, smashing the coil fins. When the condenser air flow is obstructed, the air conditioner's internal pressures and temperatures go up and the transfer of heat to the outside air is hampered. The condenser coil may be washed out with a garden hose or blown out with compressed air. Be sure to remove all electrical power and protect the fan motor and electrical controls from getting wet.
- The condenser air flow could be recirculating. Make sure the path of air flow into and out of the air conditioner is not obstructed. Some people mount storage pods near the air conditioner, which may obstruct air flow.
- The heat gain (the transfer of outside heat to the interior living area of your vehicle) may be greater than the ability of the air conditioner to remove it. Several factors influence heat gain, including the outside temperature and humidity, length of the vehicle, type of vehicle, insulation value, slide outs and the number of windows. The air conditioner capacity may be too small for the application.
- How can I tell if my air conditioner is cooling to the best of its ability?
- Start the air conditioning unit and allow it to run for at least 1/2 hour - possibly longer if it is warm outside.
- With a standard analog or digital thermometer, measure the temperature of the air immediately entering the return air grille of the air conditioner.
- Subtract from this temperature the temperature of the air immediately leaving the supply air louvers. If it is a ducted air conditioner, use the closest discharge register and make sure the temperature sensing device is measuring supply air temperature only.
- An air conditioner that is performing to its design specifications should have a temperature difference of approximately 16° to 22°. Slightly lower temperature differences are possible under extremely humid conditions, as the unit will have to run longer to remove moisture from the air.
- Temperature differences greater than 22° are possible in warm, dry weather.
No. Refrigerant will not become old or wear out. It will last the lifetime of the air conditioner.
It could be any number of things or a combination of several. Please refer to Questions 3, 4, 5 & 6 in this section for details.
Unfortunately, there is not an easy answer to this question. The supply air temperature will vary somewhat proportionally with the temperature of the air being pulled through the return air grille(s) of the air conditioner. Additionally, the outdoor air temperature, humidity, air volume and even proper air conditioning maintenance all have an effect on the air conditioner supply air temperature.
To answer this question, we must understand air conditioner capacities are rated primarily by their ability to transfer heat from the inside of your vehicle to the outside air. Your air conditioner may freeze up if it fails to pick up or transfer this heat for any of the following reasons:
In the following instances, you should seek professional service at one of our Authorized Service Centers:
For additional information, please see Question 1 in the Maintenance Section, as well as Questions 5 & 6 in this section.
There are several possible answers to this question:
After proper air flow has been determined satisfactory and the coil surfaces have been checked and cleaned, the following cooling performance test may be run. Check the air temperature drop across the evaporator coil as follows: