I was reviewing a couple of prior posts on this topic and there is not much consensus on how much damage is to much damage.
We’ve basically been reporting it’s damaged and should be serviced/repaired/replaced as needed when it’s deteriorated.
Attached is a photo for the budget for its replacement of the unit, when it has minor damage, but not deteriorated.
Morning, Stephen. Hope this post finds you well.
To answer your question, “How much damage is to much damage to condenser fins?” I would simply report on the type of damage and damage percentile. From there refer to the professional.
Heavily bent or damaged condenser or evaporator coil fins restrict air flow. Efficiency is overall affected with much damage although many units keep on functioning heating and cooling.
By the looks of it, A: A small dog marked it’s spot. B: Top center ding. Stone damage from the lawn mower. C: Lower fin marks. Lawn mower contact/mechanical damage.
Observation: Very small percentage of bent cooling fins. Light mechanical damage to cooling fins.
No adverse conditions observed.
Recommend: A licensed HVAC contractor maintenance the HVAC unit next cooling or heating season. Typical maintenance item.
*Note: Bent condenser and evaporator coil fins can be been successfully straightened with radiator fin comb kits.
PS: Allstar ALL10680 Radiator Fin Comb Kit
Have you asked the 90 Day Widget Master how much damage is present before the 90 Day Widget would disclaim it as a pre-existing condition and not cover it?
That sounds good, Stephen. 
This is a performance question. The SOP says we do not measure performance of the AC.
IV. The inspector is not required to:
- determine the uniformity, temperature, flow, balance, distribution, size, capacity, BTU, or supply adequacy of the cooling system.
Visual damage to condenser fins should be noted and left at that. If the system ran that’s as far as you go. If you start diagnosing, even if your qualified, you’re setting yourself up for an unhappy client.
I completely agree with that statement. You never know what the HVAC tech might recommend and there’s no sense in upsetting your client with possible misinformation.
Extensive or minor - damage is damage.
Definitely, Bob! Excellent advice.
I agree with Bob - cite the observation and recommend the proper expert to repair it.
Also, that damage could have possibly been from a pressure washer… but it’s not our job to determine the why or when, just the what. 
Moot point, Emmanuel. Pre-existing damage is covered under a warranty. It is up to the purchaser to pursue wannaty or accept condition. Read the OP’s post.
Moring, Marc. Hope this post finds you well.
That narrative might me a tad over the top.
Bent fins are not an adverse issue persay. Here is a link for a HVAC company.
Although your condenser may seem to be functioning properly, the coils have AC fins which typically become bent with normal use over time.
Marc, no use needlessly exposing undue liability.
Keep well.
Robert
Hey Robbie!
You are entitled to an opinion that smells like a soft inspection.
Replace the condenser unit. 
Robert, from the first paragraph of your link: https://coolguystx.com/ac-fins-bent-or-damaged/
“Although your condenser may seem to be functioning properly, the coils have AC fins which typically become bent with normal use over time. The longer you neglect bent AC fins, the more it may restrict your air flow or other functionalities of the system. This may lead to higher operating costs or even premature parts failure.”
And that pic does not show bent fins - they are damaged/smashed
As a past HVAC contractor … “The fins on the exterior A/C condensor are bent, damaged and/or missing at a few (or many) spots. This has the potential to affect the units cooling performance OR expose the freon lines to further damage … ALL of which can decrease the units cooling ability OR safe lifespan. We recommend having a competent HVAC contractor evaluate the unit and repair as needed. Depending on the outcome of the HVAC contractors evaluation, it would be prudent to Budget for replacement and/or unexpected repairs OR consider upgrading and replacing the unit now”.
OK, I just got off the phone with Carrier tech support asking about damage and the possibility of combing out fins pressed flat by impact. They said there is no answer that’s true for all situations. The damage really needs to be evaluated by an HVAC service tech.
In a report, It’s a bad idea to go further than to state damage to minor, moderate or widespread portions of the condenser. And don’t call it minor, moderate, or severe damage, because that would mean that you had evaluated the severity of the damage and you’d be liable for the accuracy of your evaluation. If you specify “moderate” damage and it turns out to need replacement, you may be buying them a new condenser for $1,000 or more.
Basically… what Bob and Dan said.
Inspectors do that all the time. I agree, however.
I do it with a number of things Simon, but not that particular one. Minor, moderate, or severe corrosion is fine, for example.
I wouldn’t hesitate to call this severe roof damage!
Kenton, you deal killer, you!
Haha! Just trying to scare off the clients!
