I'm sure you're right. It's quite a while since I was comparing the 2 systems (the house took over a year to build and we were originally quoted before construction began) so my memory is probably faulty on GEN III.
Shrug. There's a lot of hype in all the manufacturer's claims but the basic claim for fully variable compressors makes sense: If your outdoor unit is operating from 0% of capacity to 100% on demand it has to be more efficient/economical than a unit that must continually pump out 100%. It also means a 'soft' start, which I understand also cuts down power usage.
Makes sense but I would wonder what happens to efficiency on those occasions when you do want the whole house cooled/heated. It's going to happen sometimes. I think I'd rather have a bigger unit than needed than make the external unit work harder.
I'm a bit confused here. Do you mean you have no need for individual temperature control in each zone, i.e., you are happy to have a single temp set at the master controller? Different things suit different families I guess but I think that defeats the purpose of these systems. While (with Actron at least) you only have a +/- 3 degree range in which you can set temps individually in each zone that seems to me to be a critical benefit. In real life different people have different comfort levels, different rooms have a need for different temps -- cooler in a 'work' zone like a study, warmer in a living area for example. Being able to have a study at say 22 degrees and the living room at 24/25 makes a huge difference in comfort levels. I take the view that I don't live next to the master controller and I don't want to get up and adjust it just to change the temp where I happen to be. Or get into arguments about what's 'too cold, too warm, just right'.
More importantly, I don't want to have to rely on a system to be precise/smart enough to put sufficient air in individual zones to ensure an even temperature throughout the house. One of the big problems with 'standard' air-con systems is their inability to cope with maintaining even temps. A western facing room always ends up hotter than rooms on the south for example. Both GEN III and ESP Ultima are systems designed to get around that problem. My gut tells me that an individual sensor/controller in each room, a la Ultima, is going to be more accurate than any other way.
IFIRC the GEN III does have the ability to control temps in individual zones but with the addition of some 'extra' device/controller (VAT-V or something?). If that capability is not included in the price you mentioned then it doesn't seem as good a value as it did. I suspect you could do 8 fully controlled zones with Actron for about the same price.
Yes, that's right. The Actron fans are fully variable. You can actually see it on the zone controls, which have a 'fan' graphic that slowly drops back from full to zero as the set temps are reached. Also, the zone fans are not controlled by ceiling motors but are fully controlled via the external unit. I think I've got that right. if I understand this system correctly that means that the fans are fully utilising the variable compressor system, which, as you say, indicates improved efficiency. It also means there is no noise from ceiling motors, not a big issue but helpful.
I sound like I'm a salesman for Actron hey. I'm not but I am impressed with it.