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MKH
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Location: Dallas

AC Condenser Protection - A How To

Tue Apr 02, 2019 10:38 am

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.
After 2 r.jpg
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First ordered this grill mesh - in powder coated black (they also have it in polished silver).
https://www.ebay.com/itm/CCG-UNIVERSAL- ... 2749.l2649

then created a paper pattern of the grill.
Grill Mesh.jpg
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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.
Section 2 r.jpg
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... more
Last edited by MKH on Thu Apr 11, 2019 3:57 am, edited 3 times in total.
Mark H.
2015 i3 Rex, Capparis White, Tera World, Technology & Driving Assistant, Parking Assistant, Harman Kardon Audio System, 19 inch 427 wheels, EVoInnovate EVSE

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MKH
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Location: Dallas

Re: AC Condenser Protection - A How To

Tue Apr 02, 2019 10:43 am

... continue

Doing the right side first, I added wire loops for 'handles' for easy maneuvering,
Handles r.jpg
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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'.
Hook Wire r.jpg
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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.
After 1.jpg
After 1.jpg (108.82 KiB) Viewed 3364 times
Easy, Peasy :D
Mark H.
2015 i3 Rex, Capparis White, Tera World, Technology & Driving Assistant, Parking Assistant, Harman Kardon Audio System, 19 inch 427 wheels, EVoInnovate EVSE

IvanRex
Posts: 19
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Re: AC Condenser Protection - A How To

Tue Apr 02, 2019 3:17 pm

Thank you for sharing :)

alohart
Posts: 2121
Joined: Sat Nov 01, 2014 7:36 pm
Location: Honolulu, HI

Re: AC Condenser Protection - A How To

Tue Apr 02, 2019 7:30 pm

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.
Aloha,
Art

2014 BMW i3 Arravani Grey, Giga World, Tech + Driving Assist, Parking Assist, DC Fast Charging, JuiceBox EVSE

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MKH
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Re: AC Condenser Protection - A How To

Wed Apr 03, 2019 4:30 am

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.
Mark H.
2015 i3 Rex, Capparis White, Tera World, Technology & Driving Assistant, Parking Assistant, Harman Kardon Audio System, 19 inch 427 wheels, EVoInnovate EVSE

Seasidenj
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Joined: Mon Oct 29, 2018 6:02 pm

Re: AC Condenser Protection - A How To

Sat Apr 13, 2019 6:06 am

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
Posts: 124
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Location: Toronto Ontario Canada

Re: AC Condenser Protection - A How To

Sun Jun 30, 2019 7:05 pm

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
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Joined: Sat Nov 01, 2014 7:36 pm
Location: Honolulu, HI

Re: AC Condenser Protection - A How To

Thu Oct 17, 2019 9:40 pm

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.
Last edited by alohart on Fri Feb 21, 2020 3:20 pm, edited 1 time in total.
Aloha,
Art

2014 BMW i3 Arravani Grey, Giga World, Tech + Driving Assist, Parking Assist, DC Fast Charging, JuiceBox EVSE

alohart
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Location: Honolulu, HI

Re: AC Condenser Protection - A How To

Thu Dec 05, 2019 1:05 am

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.
Aloha,
Art

2014 BMW i3 Arravani Grey, Giga World, Tech + Driving Assist, Parking Assist, DC Fast Charging, JuiceBox EVSE

panamamike
Posts: 121
Joined: Sat Jan 25, 2020 10:21 am

Re: AC Condenser Protection - A How To

Sat Feb 15, 2020 5:35 pm

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

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