mouse53
and it is always better to maintain the temp than try to pull it down after sitting all day.

Does not compute. Does the efficiency of the vapor cycle cooling system change, or something? Like, not just fan speeds, but does the pump change speed and do the line pressures adjust to a less efficient value in favor of more rapid cooling, or something? Otherwise, on its own, thermodynamics would dictate that it is not possible for what you said to be true. The greater the difference in heat between inside and outside, the greater the rate of heat transfer. If you let the house heat up during the day, the difference in heat is reduced, and therefore heat transfer is less. Conversely, if you keep the house cool all day while it is hot outside, the heat difference is always greater and therefore the heat transfer is always greater, and therefore you will use a total of more energy while trying to maintain that difference between inside and outside.
If the efficiency of the heater or cooler remains the same, short abrupt temperature changes will be less costly every time.
Off-peak vs on-peak power use could have a significant effect rendering what I said untrue.

STR1D3R_2

Do you unplug your refrigerator when you leave home? My guess is no. When you shut your system down and let the heat and humidity sink in to your home, it not only raises the air temperature of your home but every single molecule within it. Even a wood handrail on your staircase will get saturated with heat and humidity and the ac system will have to work it out with a muuuch longer initial run time. It may not even finish before you shut it down and leave for work the next day. Sure, it will cycle off on air temp but even after the sun sets, everything in the home will still be giving off heat that it stored. Best to set it and forget it. 
 
Dont forget the "R" value in insulation either. There is a purpose it is measured and used in different climates

Great point. 

So cold or not insulation plays a good part on keeping temps on check🤔

STR1D3R_2
Lmao, R value has absolutely EVERYTHING to do with it. 

I'm not sure which part you are failing to understand.
 
Insulation has an affect on the magnitude of difference between the two methods.  But it cannot cause one method to all-of-the-sudden become the better choice instead of the other.  It cannot invert the outcome.  Insulation has a huge affect on the electric bill, yes, but, on its own, has no affect on whether the statement "it is always better to maintain the temp than try to pull it down after sitting all day" is true or false.  That's all I am arguing.  I never said that insulation cannot have a huge affect on the electric bill.  I think you are taking this off-point.
 
Hypothetical example without any on-peak vs off-peak power options:
House with R14 insulation everywhere, keeping your house set at 70F all day: costs $6 per day.
House with R14 insulation everywhere, letting the house warm up to 80F, and then turning on the A/C at 17:00 PM: costs $4 per day.
 
House with R1 insulation everywhere, keeping your house set at 70F all day: costs $15 per day.
House with R1 insulation everywhere, letting the house warm up to 80F, and then turning on the A/C at 17:00 PM: costs $9 per day.
 
House with R1000000 insulation everywhere, keeping your house set at 70F all day: costs $0.50 per day.
House with R1000000 insulation everywhere, letting the house warm up to 80F, and then turning on the A/C at 17:00 PM: costs $0.48 per day.
 
 
 
So, like I said, the insulation has an effect on the magnitude of the savings between one method and the other, but it will not cause one method to all-of-the-sudden swap with the other as the way to save more money.
 
If your cooling bill is high enough that you are concerned about it, odds are that you don't have the greatest insulation.  Therefore, all the more likely that one method instead of the other will net you a significant price difference.
 
So again,

mouse53
and it is always better to maintain the temp than try to pull it down after sitting all day.

wrong.  I would say that it is almost always NOT better....  On-peak vs off-peak power remains a key point (and unknown) to this discussion.

Buying an efficient A/C will be best then?🤔
Or
The A/C system given to the house is not strong enough to cool the entire house at all.
How long has the unit been used?
Which A/C system would you guys recommend?
How many square feet is the house Tweaked lives?🤔

Maybe a better statement would be "Better to maintain a constant temp. depending on...." 
Saying "always sometimes comes around to bite me in the butt.
What I recommend to someone in TX. Fl. AL. would be different from someone in NY. CT. VT.
OP has a 14.5 seer A/C unit, it has to be more efficient then the portable unit he has.
14.5 seer is not bad at all. I remember when they listed 8 seer as " High Efficiency" 
Me, I would use the central A/C and keep it at the warmest comfortable temp, and maybe set it back a few degF when not home.
 
 
atfrico
Buy the highest seer you feel comfortable paying for. There is a point where the price goes up higher than what it is worth.
There is a point at which you will not recover the expense, return on investment.
 
I worked on just about all the brands that were made over 8 years ago.
What I like in order. Carrier, York, Trane, Lennox. Most of the others brands are ok. People like what they are used to working on.
Some of the bigger manufacturer have a 2nd brand like Carrier has Bryant and so on. I liked them too.
 

STR1D3R_2
"it is always better to maintain a conditioned space temp than try to pull it down after sitting all day"
better?

Again, still wrong, for the same reason.
 
Let's make this easier.
 
Let's say that the flow of heat is from the outside to inside.  Let's say that flow of heat is measurable.  Let's say that the greater the difference in temperature between outside and inside, the greater rate at which heat flows from outside to inside.  Ok, that is all factual.  Now, you take that value ... the total amount of energy you used in order to offset that flow of heat ... and that is proportional to how much energy you could potentially save by not trying to force that condition to happen.  So, tonight, you have to cool down your house from 80F to 70F, which uses a lot of energy, but it still uses a total of less energy than it would have if you had tried to force it to maintain 70F.  Why?  As the inside temperature rose relative to the outside temperature, you weren't consuming energy the whole time trying to offset that change.  Therefore, there was less total heat flow into the house, therefore there was less total heat, therefore there was less total energy required to remove that heat.
 
This is thermodynamics and Fourier's Law.  This is science.  In a closed system, this will always be true.
 
If the outside is 80F, and the inside is 70F, it requires DOUBLE the amount of energy to maintain that inside temperature, compared to the outside being 80F and the inside being 75F.
 
So, let's say that it takes 16000 BTU an hour to maintain 70F inside while the outside is 80F (k = 1, A = 800, t1 = 80, t2 = 70, s = 0.5).  On the other hand, it takes 8000 BTU an hour to maintain 75F inside while the outside is 80F (k = 1, A = 800, t1 = 80, t2 = 75, s = 0.5).  That alone explains why running the A/C at a higher temperature setting uses less electricity, but it ALSO proves what I am talking about.  BTU/hr is energy, and energy doesn't stop flowing just because you turn the breaker off to your house.  Thermal energy is always flowing whenever there is a difference between two areas.  If you reduce the total amount of thermal energy flow (by allowing the inside temperature to more closely match the outside temperature), the total amount of energy you have to consume in order to bring the temperature back down to 70F IS LESS, because you aren't bleeding off energy to heat loss during the entire day.  The more difference there is between inside temperature and outside temperature, and the longer you maintain that difference, the less efficient the system (this closed system being your house in this example) is as a whole, and the more energy you use in total.
 
The only way this becomes untrue is in a complex environment with other factors and human desires at play.  You want to keep your guitar from bowing? Ok, disregard this practice.  You want to keep your fish and plants happy, ok disregard practice.  So on and so forth.  That doesn't make you right and me wrong, it just makes your decision different than mine.  Or, as I said, if electricity is cheaper earlier in the day, use it while it is available and store it in the thermal mass of your house.  Or, your A/C system has a mode which makes it wildly inefficient when trying to reduce temperature by a large amount, well, all bets are now out the window, aren't they? As far as science is concerned, as long as the price of electricity is maintained constant, the efficiency of the A/C system is maintained relatively the same, and the condition of the home maintained relatively the same, turning on the A/C system only after you can no longer bear the heat will save you money EVERY time, versus leaving the A/C system set to a certain temperature all day.  As far as science is concerned, as long as the price of electricity is maintained constant, the efficiency of the A/C system is maintained relatively the same, and the condition of the home maintained relatively the same, leaving the A/C system set to a certain temperature all day uses a total greater amount of energy because it is constantly trying to offset a greater rate or heat transfer between outside and inside.  Insulation does not affect this proportion, it only affects the magnitude.

Nereus
Who has their thermostat set for 70?

Not me.  But, these are all just values used for comparison purposes.  The exact values are not material to anything more than magnitude.  Proportionality is maintained.  2 BTU/hr vs 4 BTU/hr.  4000 BTU/hr vs 8000 BTU/hr.  The proportion is the same.  Only the magnitude is affected.  Same as for insulation value.  Insulation value does not affect the proportion, only the magnitude.

Nereus
 
Who has their thermostat set for 70? Pretty damn cold.. we have ours set at 77 for both summer a/c and winter heating, seems like a comfortable level. Maybe 75 during summer I could understand..
 

Me, I like my house 69-73f depending how I am feeling.
In the Winter I set it for 67f-68f Some like it hot and some like it cold. In the Winter I add humidity with a humidifier 
 
 
I had a service call in an office building. There were about 9 or 10 women and a couple two or three men there.
Some were saying they were hot, some were cold and a couple people told me they were comfortable please do not change it.
So what to do.I went and got the building Mgr. and he told them. "If you're hot, take some clothes off, cold put their clothes on, comfortable, watch them and laugh."
So we left it as it was, what else could we do. It was about 73f or so in the office at that time.
He then gave me a range 70-75f. If the temp is in that range, leave it alone. If they have a problem, tell them to come see me.
 
I really think we are over thinking this.
A residential home the savings over a year on the cooing is 10% max setting back the temp with a programmable stat.
Running my A/C is about 50$ a month and my electric is expensive, so we are talking 5$ a month. 20$ for the Summer season.
Not a lot of money by today's standards.

atfrico
So running the fan will dissipate the warm air in the house.making it slight colder than outside🤔.

No.  If your windows are closed, and when not considering the outside temperature and the amount of insulation (too complex to form generalities ... see below), running the fan does not remove heat.  It actually increases heat (because the fan uses energy and creates heat), and adds to the total amount of heat in the system. All that the fan does is create airflow which will speed up the rate of heat dissipation from hotter thing (you: 97F) into the cooler thing (the room: 75F).  You feel cooler, but the room gets warmer, faster.  Of course perspiration is an added complexity.
 
The ice on the other hand, is thermal mass.  You stored that energy (or lack of energy) in the ice using your freezer earlier in the day.  Now, that thermal mass is being utilized later in the day.  Not much more to it than that.
 
... "see below" ....  If the outside temperature is cold, yes, running the fan can help cool down your house.  It causes heat to transfer from you faster, to the air; and therefore helps heat transfer from the air faster to the floor, walls and ceiling; and therefore helps promote a greater temperature difference between inside your house and outside your house; and therefore the heat transfers faster from the inside surface of the wall to the outside surface of the wall; and therefore you and your house cool down faster.  So, in that case, yes, running the fan will make it cooler.  But we aren't discussing how to efficiently cool yourself on a cold day.

And again, amp draw is not a constant. When the load is high the amp draw is high, sometimes double or more. This is not theory, it is fact. Also we are talking about tweaks 5 ton 60k btu single stage system without zoning vs his portable.