AC Condenser Protection - A How To

[Anonymous]

A rock through the open grill into the i3 AC Condenser radiator hard enough to puncture it, is a $1,000 plus repair, as the entire front of the car has to be dismantled to get at the condenser.

The best DIY solution is tp put some hardware cloth, or wire mesh behind the open grill, to protect the condenser, while still allowing air flow.



On the i3, easier said than done. access to the area behind the grill is almost non-existent. You cannot get at it from underneath, and the only access from above is by taking out the frunk box, then there is limited access by pushing open a flexible plastic shield an inch or so. Not ideal.

On top of that, the i3 grill is supported by double-legged 'V' shaped brackets, one leg vertical in the grill, and the other branching off behind the grill at almost a 45 degree angle. Makes mounting a mesh piece directly behind it difficult.

Here is how I did mine. Note that mine is the Rex model, which has a three tiers of openings in the grill - the BEV model has the top opening sealed.

View attachment After 2 r.jpg

First ordered this grill mesh - in powder coated black (they also have it in polished silver).
https://www.ebay.com/itm/CCG-UNIVERSAL-6-x-36-SMALL-HEXAGON-ALUMINUM-GRILL-MESH-SHEET-BLACK-POWDER-COAT/130634416711?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

then created a paper pattern of the grill.



The center of the grill has support brackets exactly 6 inches apart center-to-center. I then cut a 6 inch section out of the exact center of the grill mesh. Idea is to have three grill pieces, which once assembled, have their seams hidden behind the grill support bracket.

View attachment Section 2 r.jpg

... more

 

[Anonymous]

... continue

Doing the right side first, I added wire loops for 'handles' for easy maneuvering,

View attachment Handles r.jpg

Then slid the section in flat through the center of the grill, then worked it upright, and slid it sideways between the V bracket legs, so it would fit flush against the back of the grill, and the squared off end would be right behind the right center bracket. Took a couple of in-and-outs, to trim the rounded end to fit, and so the square end lined up behind the upright, but once I got that, took it out and used it to trim the left side to mirror match. Then in with the right side, and then in with the left side.

To fasten them to the grill support, bent some 22 gauge black jewelry beading wire from a hobby store (Hobby Lobby) into narrow 'fish-hooks'.
View attachment Hook Wire r.jpg

Poke in on one side of the bracket, work the 'hook' end behind the mesh and bracket, to the other side of the bracket, so it pokes back out the mesh on the other side, grab with small needle-nose pliers and pull out the 'hook' end, so you have equal wire poking out on either side of the bracket, then twist the two ends together nice and tight, cut off excess, and tuck the little twisty pigtail against the grill. Once both sides are done and fastened in to at least the far right and far left supports, add the center piece of the grill, and fasten in with the wire the same way.

Once done, it looks all one-piece, almost OEM, and from feet away, it's almost invisible.



Easy, Peasy

 

[IvanRex]

Thank you for sharing

 

[alohart]

Thanks for posting these instructions. I now wish that I had purchased aluminum grill mesh rather than stainless steel woven wire mesh. Aluminum is easier to cut, and unwelded woven wire tends to unravel when cut. Oh, well, I'll make do.

I noticed that your grill is different from the grill on our BEV. Realoem.com lists different part numbers. I assume that your i3 is a REx. Our grill has only 2 horizontal openings whereas yours has 3. The top horizontal opening in your grill is closed off in our grill. It makes sense that a BEV without an ICE to cool would not require as much airflow as a REx. Maybe that's part of the reason why the Cd of a BEV is 0.01 less than that of a REx.

It also appears that a heat exchanger isn't very far behind the grill mesh that you installed (I can easily see it through your mesh grill). The heat exchanger in our BEV is probably 6" behind the grill. Maybe a REx has both an A/C condenser and an ICE radiator, one in front of the other like in regular ICE vehicles. So I have quite a bit of space between the grill and heat exchanger. I should probably take out the frunk box to learn whether access to behind the grill is better than in a REx.

 

[Anonymous]

HI Art
Yes, mine is a Rex. The heat exchanger is at least 6 inches back from the grill in mine as well - optical illusion with the mesh in front makes it look close, when it is not. I looked at stainless mesh as too, but any cost-effective piece the right size was woven, not welded, and I was afraid of it unraveling when cut. And the aluminum easy to cut with simple tin-snips. Aluminum will surface-oxidize slowly in salt air and eventually show some pitting, but not rust away like iron based metal. And powder coated aluminum stands up pretty well long-term.

 

[Seasidenj]

I used another method bought a metal gutter leaf guard from Lowes in black. Cut to the size of the opening and secured it with wire ties from the front. Not too noticeable and was cheep any easy.

 

[TOEd]

Just completed this project. Used black plastic eavestrough screen with 1/4 inch openings. Thank you MKH for the suggestion. Removing frunk did not provide access. So used vacuum cleaner and small tube to suck out leaves/bugs through front grill. Used 6 black zip ties to hold everything in place. Found dental pick to be very helpful in positioning screen and positioning zip ties. Have about 100 feet of plastic screen if anyone needs some. Free for pick up in Toronto Canada if you are nearby.

 

[alohart]

I finally got around to installing A/C condenser protection thanks to MKH's how-to thread. This protects against a low-probability event, debris passing through the grill with enough momentum to puncture the A/C condenser. However, the resulting repair would be expensive which might make installing protection worth doing.

A downside would be reduced air flow through the A/C condenser and coolant radiator. The condenser frontal area is much larger than the open area of the grill, so air flow velocity through the condenser is considerably less than that through the grill even before condenser protection is installed. If I drove in a very hot climate like in Phoenix or Las Vegas, I might decide that the risk of less efficient, poorer performing A/C or of overheating the REx engine or coolant-cooled electronic modules might not be worth taking. I have no idea how to assess these risks. However, driving a BEV in Honolulu where the climate is more moderate, I decided that the risk of installing inexpensive A/C condenser protection was worth taking.

I had already purchased a 1' x 2' (30 cm x 60 cm) piece of woven 304 stainless steel wire mesh, so that's what I used for the protective screen. There are pros and cons associated with woven wire mesh versus the powder-coated stamped aluminum grill mesh that MKH used. This woven wire mesh is 74% open versus 60% open for the grill mesh, so airflow through the A/C condenser and coolant radiator would not be as reduced with woven wire mesh.

Stainless steel should age better than powder-coated aluminum whose coating could be chipped by road debris impacts although in our humid, salty climate, light surface rust could form on stainless steel.

Black aluminum grill mesh is more attractive, is easier to work with, and is dimensionally stable (i.e., it doesn't tend to lose its rectangular shape as does unwelded woven wire mesh). Woven wire mesh is not difficult to cut with metal snips, but the woven wire can unweave unless a border is created. Using needle-nose pliers, I bent the wire ends around the outer wire rows to prevent these rows from unweaving. This was rather tedious and time-consuming with a result that isn't especially attractive.

I began by cutting cardboard templates of the right, center, and left grill sections. I didn't bother shaping the outer ends of the left and right templates to match the shape of the grill because the woven wire mesh would be installed behind the grill where there is room for rectangular ends. I then cut the woven wire mesh to the sizes of the templates and created the borders. Using a right-angle dental pick to help position the woven wire mesh sections, I positioned the mesh sections behind the grill inside V-shaped openings in the grill supports which held the mesh sections in place until I could tie the mesh sections to the vertical grill supports.

To secure the mesh sections, I had planned to use galvanized steel wire that I already had. However, galvanized steel begins to rust fairly quickly in our humid, salty environment, so I decided to use small black plastic zip ties that I already had as can be seen in the left and right halves of the protected grill. Also visible is the closed top third of the grill on our BEV which is open on the REx model.

 

[alohart]

Someone is selling a precut screen for the i3. I would prefer openings larger than ⅛" because such a small opening would reduce airflow significantly. I would also prefer stainless steel or aluminum because some galvanized steel has such a thin galvanized coating that rust can occur sooner than I would like.

Also, installing a full-width screen by feeding it through the grill can be very difficult, and removing the bumper and other body pieces to access the backside of the existing grill is way too much work. Cutting the screen into 3 pieces would make installation much easier. However, if you're going to do that, you might as well order a piece of aluminum or stainless steel mesh to cut your own screen for considerably less money.

 

[panamamike]

Too bad they don't make an aftermarket replacement grill. How do you keep the added mesh from moving around?

 

[symonray]

There is one available on eBay.

https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com%2Fulk%2Fitm%2F274121868636

 

[alohart]

There is one available on eBay.

This might be a good solution for someone not wanting to cut a protective grill although doing so is easy. I would want to know the percentage of open space in this grill to get an idea how much the cooling airflow would be reduced. I wouldn't want galvanized steel in our salty, humid environment unless I knew that the zinc coating is thick which I don't know in this case.

I used stainless steel. An aluminum grill material is easier to cut. Neither would oxidize destructively.

 

[sheinr4143]

For what it's worth, beginning with the 2018 model year a baffle has been included in the space between the front grill crossbars and the a/c condenser so that the vulnerable part is not visible from the front of the car (see linked photo), cannot be struck by road debris, and yet still receives the same flow of (redirected) air.

Those seeking to modify earlier model years may wish to inspect this reengineered front grill part.

https://imgur.com/a/s4qefcX

 

[joni3s]

So its just a “wall” or screen?

 

[joni3s]

Is it the “air duct”

 

[alohart]

For what it's worth, beginning with the 2018 model year a baffle has been included in the space between the front grill crossbars and the a/c condenser so that the vulnerable part is not visible from the front of the car (see linked photo), cannot be struck by road debris, and yet still receives the same flow of (redirected) air.

As best I can determine, only 2 air ducts have been available for all i3's: part #51747306421 for i3's with the seat heating driver/passenger option (S494A) and part #51747296811 for i3's without this option. There is no air duct shown that became available with the 2018 model year.

I have found the grill which is described as "insert, air intake, center". However, I haven't been able find a baffle between the grill and air duct, so I assume that it's part of the air duct.

Our 2014 BEV without option S494A doesn't have this baffle whereas a local 2019 BEV with option S494A has the baffle. These i3's have different air ducts which is evidence that the baffle is part of the air duct for i3's with option S494A.

The owner of the 2019 BEV has noticed that this baffle opens and closes in our warm Hawaii weather thus exposing the A/C condenser to rock damage while open. However, he's doesn't know under what conditions the baffle is open or closed.

Because the baffle seems to exist only on i3's with option S494A, we're guessing that its operation is related to cold weather. Because the heat pump transfers heat from ambient air to the cabin when cabin heating is on, maybe the baffle closes to block really cold ambient air from passing through the A/C heat exchanger. However, no REx has a heat pump, so the A/C heat exchanger would not be used for cabin heating in a REx, yet a REx with option S494A has this baffle.

So I'm baffled by this baffle

 

[abeln2672]

I'm buying a 2014 Rex out of state this weekend and making a LONG drive home with it (almost 600 miles!). I'm sure everything would be fine, but with that many hwy miles I'm a bit paranoid about the condenser. I've purchased the aluminum mesh, but I obviously can't make a template to cut them before I leave. Would it be a problem to just zip tie big sheets on the front for the drive and remove them once I get home in order to cut to fit? Or does someone else have a better idea? Or am I being WAAAAY too paranoid about this road trip, lol?!

 

[panamamike]

Did you guys cut the wire mesh to be slightly larger than the hole? How did you manage to slip in the the mesh between the grills? Seems like you might hit the ac condenser, Can the mesh be slightly bent to avoid hitting the condenser. Wondering if the stainless would bend and leave a crease.

What's the best thing to attached the mesh? Wondering if the zip ties will stand the test of time given that they are plastic.

 

[alohart]

Would it be a problem to just zip tie big sheets on the front for the drive and remove them once I get home in order to cut to fit? Or does someone else have a better idea? Or am I being WAAAAY too paranoid about this road trip, lol?!

It's unlikely that your A/C condenser would be damaged. If this were a common problem, we'd read about it more often.

However, since you have the grill mesh material, just cut it to fit and zip-tie it to the outside of the grill.

 

[alohart]

Did you guys cut the wire mesh to be slightly larger than the hole? How did you manage to slip in the the mesh between the grills?

All of this is discussed in the first few posts of this thread with even the mesh dimensions specified.

Can the mesh be slightly bent to avoid hitting the condenser. Wondering if the stainless would bend and leave a crease.

If you've read the instructions in this thread, you'd know that this isn't a problem.

What's the best thing to attached the mesh? Wondering if the zip ties will stand the test of time given that they are plastic.

So what if the plastic zip ties fail over time? The mesh protector is inside the grill and won't fall off the car if the zip ties fail. The zip ties would be easy to replace from the front of the grill.