Whether central air in a hot environment or a heating system in a cold environment, you most certainly can seal all penetrations {in practice, we've encountered very few contractors who seem able to do this}, insulate the ductwork and leave the mechanical unit to function in a space that is sufficiently warmer or cooler than the conditioned space to impact its performance. 

In terms of preference, ofcourse closer to LA or NYC is great but if that's not possible, then will any day prefer cooler places -including mountains- than hot and humid florida.

Pay attention to the architecture the cooler more vintage looking homes the hipsters go nuts for.

It is amazing how well a lake house can rent in the cooler and cold months too.

If so a fan set to push down warmer air in winter and draw up cooler air in summer might help too.

I am waiting for cooler weather.

As Mike M mentioned, when there's high humidity outside that air is coming under your house, and then contacting cooler surfaces in the crawlspace.

Also, bigger is not always better in terms of fan capacity or CFM.  

Most the parks stay open till 11 or 12 midnight and it’s a lot cooler and less crowded in the evenings so leave the wife and kids at the pool in the hotel during the day and hit the parks at night.

I inherited tenants who are on month to month lease when are purchased multiple SFR in central valley CA about 6 months back and after purchase I pass on Sewer and water bill to them (old landlord was paying for that too )I have two question :They currently pay $650 as rent and going rent in area is $850 and rental demand is high and I checked there is no rent control in city, what is good way to increase rent and how much (I am planning to increase rent by $75 to 100 and indirectly I already increased by $50 in sewer and water bill as I mentioned above).These is a lease clause where I need to maintain swamp cooler installed on roof , I want to remove that clause too, what best way to approach this, so I am in compliance.Additional note : these tenants are on month to month lease but living for over 3 years and ent in that area is increasing consistently.