IMHO the AC was a nice addition in hot SoCal & the Southern tier of states (or northern in muggy summers for that matter) - especially when I was driving my non-AC'ed 73 914-2.0 to a meeting in a suit in 90+ degree weather!
The Porsche factory didn't offer AC on either 911/912 nor 914 lines, but recognized that the US market demanded that it be available as an option. When the 914 was produced, Porsche had just stepped up from having their vaunted sports cars being sold in a corner of VW dealerships, to "graduating" to separate Porsche+Audi dealerships - gradumatation if you prefer!
Similarly, small volume auto producers like Porsche routinely contracted out for the optional equipment which they could not provide, then offered them as add-ons at their dealerships - this included such basics as Radios/Stereo Decks & AC. While some on here look at these dealer options with their noses in the air about them "not being factory" - the reality was that at that time almost all auto makers - including the Big 3 - sent far more "stripped" cars out of the factory than loaded ones, then allowed the dealers to equip them up at the showroom to meet the customers' desires & needs - than they sent out fully loaded cars.
In fact, Toyota broke marketing ground & expanded their foothold in the US market during the 70's by offering their cars as all essentially fully loaded, which forced the Big 3 & others to start better equipping their cars from the factory, and stop niggling the customer on all those options for extra cost. After all, the extra cost options were the dealers bred-n-butter by usually being sold at huge mark-ups of 100% or more. So dealers LOVED options & bemoaned their slow reduction with better equipped cars from the factory.
Today, many on here are either unaware or forget these facts of automotive history. As late as the late-80's VW was still selling "radio ready" Vanagons with dealers selling OP radios/decks (OP = Over Priced, not "Ocean Pacific" in this case); nor was the AC in them from the factoryt, but a later add-on. We bought our 88 Westy radio ready - got a great Sony AM/FM/Cassette unit for 1/2 the price of the POS dealer Becker unit, and it had AS added at & by the Westfalia Werk - not by VW itself (although a VW engineered & approved AC unit nontheless).
The funny thing is, that I don't hear the 911 folks complaining nor downgrading the dealer AC'ed 911 models, like the 914 guys seem to here. Yes, a shoddy installation is not a great thing, nor is adding more spots for rust to start on non-rust preventative treatment cars, but still ...... I'm just saying!! You don't see 911, 912, 930 nor 914 guys complaining about & ripping out their radios & antennas because most of them were dealer installed!<_<
That all said - yes, your 72 is indeed a special 914 for having the AC since most did not - particularly if it is one of the 2 dealer sold &
Porsche factory approved AC systems (both designed by the same guy BTW). The VPC (Volkswagen Products Corp. division of VW of America - VoA was the Porsche importer & servicer in the early days back then), and DPD (don't recall what the initials stood for).
You can differentiate the 2 as follows:
VPC - rectangular evaporator unit in front trunk with spare on top requiring the tire board to sit higher, and the under dash fan/vent/control unit has the dials offset to the right of the stock air/heat slider controls in the center of the dash. On 73-76 914s with the shortened Center Console, the 3 gauges are flat mounted in a triangular pattern.
DPD - has a conical evaporator shroud over which the spare can fit inverted (i.e.: shiny side up - in non-ac 914s they sit shiny side down), with the under dash fan/vent/control unit's dials centered under the fresh air/heat dash sliders. On 73-76 914s with the shortened Center Console, the 3 gauges are angled to the driver mounted in a linear pattern.
If yours was so equipped by the selling dealer with one of those two, then IMHO you should keep it. If it's not currently functional, then you can either look into having it rebuilt, or look at one of the units designed by the VPC/DPD designer which AA sells, to see if it can be retrofitted into the original DPD or VPC in your 914, so you get the benefit of better performance due to a better compressor with less HP drain, running on R134 & gets colder (although the cockpit is a small box to cool to start with).
Here is a 72 MY dealer options & accessories catalog FYI - & I'm including the 911 section too, so you can see that both were treated equally in terms of AC & other dealer added options.
Click to view attachment Click to view attachment Click to view attachment Click to view attachment .... continued ....