what Ive been led to believe is you want the unit to have enough grunt to cool/heat the space relatively quickly so that it can go into 'maintenance' mode where it 'asks' the compressor for far less to be drawn.
does that make any sense whatsoever?
Well, sort of, but not really. Your HVAC system should be dimensioned to the correct capacity for the room, neither oversized nor undersized. If you under-size it, then it will be running at full power almost all of the time, only dropping out for brief periods, then kicking back in again. So it will use far more power than it needs to, will make far more noise than it needs to, and the life will be shortened considerably: higher maintenance costs, more frequent failures, etc. Plus, the environment in the room won't be stable: the humidity will gradually drop with little to no change in temperature (and perhaps even a RISE in temperature), as the HVAC system slowly fights the latent heat load of the room, then the temperature will suddenly drop as the unit is finally able to take care of the sensible heat load as the room reaches the target, then both temperature and humidity will rise rise quickly when the HVAC turns off, and the cycle repeats. So the room will be too warm and too humid most of the time.
On the other hand, if you over-size the HVAC system, then it will suddenly and drastically blast a powerful gust of freezing dry air into the room, dropping both temperature and humidity very fast, then it will turn off, the temperature and humidity will rise slowly until they reach the level where the unit kicks in again. So you will have wild swings in both temperature and humidity, the room will be too cool and too dry most of the time, and will be uncomfortable. Plus, you will have paid far more than you needed to for the system that is too big for your place, and when it is running, it will consume far more power than it needs to.
The correct way to size an HVAC system is to do the math: Figure out what your latent heat load will be and what your sensible heat load will be (worst case, typical case, and best case), what volume of air you need to move (cubic feet per minute), and the static pressure load that your duct system will impose, and get a system that will be able to handle that. The system should be sized such that when faced with the worst-case (likely on a hot, humid mid-summer's day when you have the room full of hard-playing sweat musicians, with all their instruments and equipment turned on and turned up to eleven, plus beer and pizza), it will still be able to deal with that load when running no more than 80% duty cycle, and also it will still be able to move the correct volume of air when facing the best-case scenario: cool night, with only one person sitting quietly in the room, and minimum gear turned on, it will still be able to deal with that light load while running no less than 20% duty cycle.
That's not so easy to do. It needs some research into the climate conditions, and a good understanding of room occupancy and equipment load, plus some judicious use of typical "rules of thumb" for HVAC systems.
HVAC is a lot more complicated than most people realize.
- Stuart -