If your air conditioning unit is turning on and off constantly it is doing what is called Short Cycling.
A unit that is short cycling can cause wear and tear on a unit leading to expensive repair cost.
A electricity bill will also be higher since a compressor in a air conditioner uses more power when it starts.
Air conditioners compressors run more efficiently after they have been running for a few minutes as compared to first starting up.
Some factors that can be the cause are refrigerant levels, thermostats, over sized units, or homes that are not well insulated.
Thermostats Set with a Larger Differential Range
One of the things often over looked is a thermostats differential range which is the temperature a thermostat will turn a unit on or off.
Many thermostats have a +-1 to +-3 degree thermostat differential range.
For example a thermostat with a +-1 degree differential set at 70 degrees will turn off an air conditioner at 69 degrees and on at 71 degrees.
This works fine in a home that is well insulated, properly running and sized to a home.
But what about a home that may need to be better insulated or have over sized units?
A thermostat with a wider differential range can help save on wear and tear of components and electricity cost.
Ideally solving the core of the problem is the best option but it can be expensive to replace a air condition unit or add more insulation to a home.
If you are having problems with a short cycling unit than talking to a HVAC technician would be the first step.
If you have the money to solve the core problem than this is the best option.
For a cheap and easy, short time solution using a wider differential range thermostat can work in a pinch.
You may already have a thermostat that can change the temperature on off range.
To see if it is capable Google it or finds its manual and check what setting it has.
Here is a thermostat has that has a wide differential range.
Lux Products TX9600TS Universal 7-Day Programmable Touch Screen Thermostat
A differential range thermostat can help a short cycling air conditioner greatly by giving it a wider temperature range for starting and stopping.
The root cause of the short cycling should be identified and a plan to fix it should be done.
For a quick, cheap and easy short term solution the right thermostat can help greatly.