That sounds normal. A system that is too large for a house will turn on,
cool the house quickly and turn off quickly. Every turn on and turn off
shortens the life time of an ac. In a perfect world it would be sized to
run forever keeping the house at the right temperature and never turn off.
Of course the outside temperature is always changing so that a perfectly
sized ac system is impossible to design. That is why they have multistage
systems. In any case your thermostat idea is forcing it on and off often
and it would fail prematurely.


"Jim" wrote in message
...
Art wrote:
Short cycling a ac wears it out. Bad idea.


For the sake of clarification define short cycling? Only very hot days it
is not uncommon for my scroll compressor to run for say 90 minutes, shut
down, then come back on 10-15 minutes later.