AIR CONDITIONERS AND HEATPUMPS
Air Conditioning is one of those modern marvels that has truly made summer time not just bearable, but enjoyable. That is when it's working right. When it's not, not only is Momma not happy, nobody's happy.
The biggest killer is dirt. A dirty air filter and/or indoor coil literally suffocates the system. Picture stuffing a dirty sock in your mouth, and being asked to run a marathon, and see how long you last. A dirty outdoor coil is like putting a parka on, and running that same marathon in August. You might last a few miles, but you definitely wont last the full marathon, and neither will your A/C.
One myth, is the A/C makes cold air. No, it just moves 'heat' from one area to another. It picks up heat inside, and moves it outside, leaving cooler air inside.
A heatpump does the same thing, except it can run in reverse, and bring heat from the outside to the inside during the winter. No matter how cold it is outside, it can get colder, and the air coming out of your heatpump outside proves it. You can literally feel the difference with your hand while its running.
In the last 20 years we've had a lot of changes in the industry. We now have different refrigerants being used. High efficiency units, and a barrage of different controls. One thing hasn't changed, and one has become exceedingly more important then ever.
No matter what fancy this or that, your system has, if it isn't sized properly you are not going to be happy when it's 100* out. Secondly, if its not installed with the utmost care, and skill the unit just will not last regardless of the brand. It's really like pushing a fat guy to run a marathon, and not expecting him to have a heart attack.