This may be something you know already, but if you want to run an air conditioner economically, you need to understand something called "latent heat of vaporization". Humidity is the big energy sucker when running air conditioning. I seem to recall you live in a very humid climate, so I thought I'd mention this.

Many people in humid climates make the hugely expensive mistake of opening their windows when the temperature drops but while the "wet bulb" (dewpoint) temperature remains high.

In order for the airconditioner to do it's thing, it needs to condense the water vapor out of the air passing over the evaporator. Since the evaporator coil is going to be down in the 40-50 degree range, it's going to condense water vapor out until the dew point reaches this level. This takes an extraordinary amount of energy because water has a very high latent heat of vaporization (which is the heat required to move from liquid to vapor state, or vice versa). This is one reason why steam engines and steam turbines are so effective -- steam holds a shitload of energy.

When you turn on the air conditioner on a hot & humid day, it will run pretty much until it dehumidifies the air close to the dewpoint corresponding to the evaporator temperature. Then it will cool down the air to the temperature you set (these things actually happen simultaneously). After the air is dry, it takes relatively little energy to keep it cool. It's condensing out all that water vapor that takes a ton of energy.

So the worst thing you can do is close the windows at 85 degrees and 70 degree dewpoint, and turn on the AC, then at night when the temperature drops to 75 degrees (but the dewpoint is still in the high 60's) open the windows and let all that water vapor in. Now the AC has to dehumidify that air again.

If you turn it on and leave it on, then you don't need a very big air conditioner. You only need one that can keep up with the heat entering the building. It may take a long time to cool down if you have a smaller unit, but it will be able to maintain the temperature *unless* you open the windows and let in all the humidity. Then the poor little AC unit is going to work itself to death constantly condensing water vapor.

I turn on my AC in early summer and turn it off in the fall because I live in a very humid climate.

If you're only worried about 6 weeks, I'd strongly encourage you to read up on latent heat, then turn it on and LEAVE it on for the whole 6 weeks. It's much cheaper to do it this way.

Temperature is not the measurement that matters in most heat removal -- enthalpy is, and water vapor content is the critical factor in enthalpy of air.

Jim