deschlong

iTrader: (8)

Introduction

The inspiration for this post comes from a thread started by NOFX where she installed a Cabin Air Filter in her A/C-equipped USDM 6G 1999(?) Civic. The discussion that followed illustrated to me an interest in Cabin Air Filters in previous generations of Civics - specifically, some 5th Generation and 6th Generation which did not have the ability to add a Cabin Air Filter.

I set out to see if a retrofit was possible, and I report my results here. I have completed the retrofit of a CR-V evaporator unit into my 1994 Civic.
UPDATE, SUMMER 2011: I have successfully completed an entire functioning A/C retrofit, using the evap unit from a CR-V.

Note that these results will also apply to the del Sol, as this vehicle shares much of its heater and A/C ductwork with the 5th Generation Civic.

Disclaimer

Every effort has been made to make these instructions as complete and accurate as possible, but no warranty or fitness is implied. The information is provided on an “as is” basis. The author(s) and the website/publisher(s) shall have neither liability nor responsibility to any person or entity with respect to any loss or damages or inconvenience arising from the information contained herein. Read: Don't muck up your vehicle and try to blame me or anyone else without doing your own due diligence and research.

Cabin Air Filter retrofit in a NON-A/C-equipped 1992-95 5th & 1996-2000 6th Generation Civic

The optional pollen filter on non-A/C equipped 5th Generation Civics in Europe was part number 08000-SR3-00EH. Don't check your EDM parts database at home - for some reason it doesn't list many of the optional parts for 5th Gen's.

Try www.lings.com instead. It will list the item as "POL.FILTER CIVIC 92".

Photos taken from my non-A/C CDM 5G 1994 Civic are shown in Figure 1. The "Heater Duct", part number 79810-SR3-A01, is the piece in the centre. Note that there is no place to slide in a filter. The part number for the Heater Duct on CDM/USDM 5G 1992-95 Civic is the same as for EDM (LHD, obviously) 5G Civic vehicles. I don't know where the EDM optional 08000-SR3-00EH Cabin "Pollen Filter" for non-A/C 5th Generation Civics would have gone, unless it mounts inside the duct either on the left (most likely) or right hand side. But, it's really a moot point because Honda doesn't even make them anymore and they are impossible to get.


You would like a Cabin Air Filter. So, how to resolve this? Hopefully, you can follow the bouncing ball. I will try to be as clear as I can.

First let's have a look at the 6th Generation Civics. Examining the EDM parts diagrams, it looks like most or all trim levels of non-A/C EDM 6th Generation Civics came with a filter in its Heater Duct.

For example, the relevant part numbers in an EDM (KG:Germany) 1996-2000 Civic 3-dr 1.4i or VTi Hatchback are listed below the parts diagram in Figure 2:Figure 2. EDM (KG:Germany) "HEATER BLOWER" parts diagram for German 1996-2000 Honda Civic 1.4i or VTi 3-dr Hatchback. Note Cabin Filter assembly and larger Heater Duct.

8 = 79810-ST3-G01 (DUCT, HEATER)
10 = 79830-S04-003 (FILTER ASSY., HEATER), consisting of
--11 = 79831-S04-003 (ELEMENT, FILTER)
--12 = 79832-S04-003 (FRAME, FILTER)
--22 = 79833-S04-003 (SEAL, FILTER)

However, as mentioned, non-A/C CDM/USDM 6th Generation Civics also did not come with a filter in the Heater Duct, and thus received a different part.

For example, the Heater Duct part number in a USDM 6G 1996-2000 Civic DX 3-dr Hatchback is listed below the parts diagram in Figure 3:
Figure 3. USDM "HEATER BLOWER" parts diagram for 1996-2000 Honda Civic CX 3-dr Hatchback. Note no Cabin Filter assembly and different Heater Duct as in the EDM Civic in Figure 2.

7 = 79810-SR3-A01 (DUCT, HEATER)

And of course, as we know, non-A/C CDM/USDM 5th Generation Civics also did not come with a filter in the heater duct.

For example, the Heater Duct part number in a USDM 5G 1992-1995 Civic DX 3-dr Hatchback is listed below the parts diagram in Figure 4. Note that it is exactly the same part numbers as in the 6G 1996-2000 Civic above:


Figure 4. USDM "HEATER BLOWER" parts diagram for 1992-1995 Honda Civic CX 3-dr Hatchback. Note no Cabin Filter assembly (no markets came with one
as standard equipment) and Heater Duct.

8 = 79810-SR3-A01 (DUCT, HEATER)

Hopefully, you see where I'm going with this. At this point, note that:

1. All things being equal, the 6th Generation EDM Civic Heater Duct part number 79810-ST3-G01 (or its equivalent) should retrofit exactly into a 6th Generation USDM/CDM Civic as a substitute for 79810-SR3-A01, giving you the ability to add a cabin air filter. This should be good news for many of you.
2. Part number 79810-SR3-A01 for the 6th Generation USDM Civic is the exact same part number for the Heater Duct as in a 5th Generation non-A/C CDM/USDM/EDM Civic.
3. Logically, it follows that the 6th Generation EDM Civic part number 79810-ST3-G01 (or its equivalent) should also retrofit exactly into a 5th Generation CDM/USDM Civic as a substitute for 79810-SR3-A01, giving you the ability to add a cabin air filter! There should not be any obstructions to installing this larger piece; I base this on the fact that the duct area is designed large enough to fit the much-larger evaporator and casing on A/C-equipped vehicles.

The question remains, though, where to find 79810-ST3-G01? This Heater Duct is installed on the following vehicles (all LHD):

EDM

• 1995-2000 Civic 5-dr Fastback
• 1998-2000 Civic 5-dr Aerodeck

• 1996-2000 Civic 3-dr Hatchback
• 1996-2000 Civic 4-dr Sedan
• 1996-2000 Civic 2-dr Coupe

• 1997-2001 CR-V 5-dr

• 1998-2000 Integra 3-dr
• 1998-2000 Integra 4-dr
  • NB: This generation Integra was only available in Europe for 1998-2000, I believe.

USDM

• 1998-1999 Acura Integra RS 3-dr
  • NB: The RS model was discontinued after 2000(?).

So, this leaves rather limited choice if you're headed to the salvage yard: one model of Integra in the base RS trim level during two model years! You're choice is even more limited in Canada, where 4dr Integras weren't sold after 1998, if I recall correctly, leaving you only with a choice from 3dr models. If you don't feel like wasting your time hunting through yards, you could order a brand new heater duct - but at about $90, you're likely liable for severe sticker shock. Another option would be to monitor HondaMarketPlace.com for an RS part-out.

Of course, the Heater Duct that you pull from the Integra (or ordered) won't have a cabin filter either, but it *should* have the slot for one. The Heater Duct Cabin Filter, as mentioned in the earlier posting by NOFX, can be ordered brand new using the part numbers from a Honda Insight, as these are the exact same as for the non-A/C EDM 6th Generation Civic.

There is another possible option. Part number 79810-ST3-G21 is shown on the European parts diagram for the 1995-2000 5-dr Civic Fastback & Aerodeck as an alternative to 79810-ST3-G01 (ie., both parts are listed). This suggests that both parts are interchangeable. Part number 79810-ST3-G21 is also listed as the Heater Duct on the EDM & USDM Honda Insight. While there is only the remotest of possibilities of finding an Insight at a salvage yard, the ducts are available brand new through a Honda dealer at the more affordable cost of about $40.


Cabin Air Filter retrofit in an A/C-equipped 1994-95* 5th & 1996-97 6th Generation Civic

*NOTE: I restricted my investigations to vehicles with R134a-type A/C. I don't know if any of these steps will work on vehicles equipped for R12 (typically, 1992-93 Civics).

A retrofit of a cabin filter on a A/C-equipped 1994-95 5th & 1996-97 6th Generation Civic is possible. What follows is how I thought it could be theoretically done as of this original post in April 2009, and the reasoning behind it. This information was later substantiated when I and others performed cabin filter retrofit installs using this information.

To begin, we should examine the AC UNIT parts diagram of an EDM 1996 6G German Civic with A/C. In Europe, all 6G Civics came with a factory-equipped (stock) cabin filter, though the evaporator, casing, thermostat, etc. (herein: "Evaporator Assembly") changed for the model years 98-00 to match the one that is found in USDM 98-00 Civics. For a DIY How-To on installing a Cabin Air Filter on a 1998-2000 Civic, see the post by user NOFX here.

The relevant part numbers in an EDM Germany 6G 1996-97 Civic 1.4i or VTi 3-dr Hatchback are listed below Figure 5:
Figure 5. EDM (KG:Germany) "AC UNIT" parts diagram for 1996-97 Honda Civic 1.4i or VTi 3-dr Hatchback. Note Cabin Air Filter assembly.

7 = 80201-ST3-G00 (CASE, EVAPORATOR UPPER (SAK))
8 = 80202-ST3-G00 (CASE, EVAPORATOR LOWER (SAK))
10 = 80215-ST3-G01 (EVAPORATOR COMP. (SAK))
20 = 80290-ST3-E01 (FILTER ASSY., A/C)
24 = 80430-SR3-003 (THERMOSTAT, A/C)

However, as mentioned, A/C-equipped CDM/USDM 6th Generation Civics did not come with a filter in its "Evaporator Assembly", and thus received different parts.
For example, the relevant "Evaporator Assembly" parts in a USDM 6G 1996-97 Civic DX 3-dr Hatchback are listed below Figure 6:

Figure 6. USDM "AC UNIT" parts diagram for USDM 6G 1996-97 Civic DX 3-dr Hatchback. Note no Cabin Filter.

5 = 80201-SR3-A10 (CASE, EVAPORATOR (UPPER))
6 = 80202-SR3-A00 (CASE, EVAPORATOR (LOWER))
10 = 80210-ST7-A21 80210-SR1-A12 (EVAPORATOR SUB-ASSY.)
22 = 80430-SR1-A12 (THERMOSTAT, A/C)

And of course, as we know, A/C-equipped CDM/USDM 5th Generation Civics did not come with a filter in its "Evaporator Assembly", and thus received different parts.
For example, the relevant "Evaporator Assembly" parts in a USDM 5G 1994-95 Civic DX 3-dr Hatchback are listed below Figure 7. Note that they are exactly the same part numbers as in the 6G 1996-97 Civic.

Figure 7. USDM "AC UNIT" parts diagram for USDM 5G 1994-95 Civic DX 3-dr Hatchback. Note no Cabin Filter.

5 = 80201-SR3-A10 (CASE, EVAPORATOR (UPPER))
6 = 80202-SR3-A00 (CASE, EVAPORATOR (LOWER))
10 = 80210-ST7-A21 80210-SR1-A12 (EVAPORATOR SUB-ASSY.)
22 = 80430-SR1-A12 (THERMOSTAT, A/C)

Hopefully, you see where I'm going with this, here too. At this point, note that:

1. All things being equal, the EDM LHD 6th Generation 1996-97 Civic "Evaporator Assembly" should retrofit exactly into a USDM/CDM 6th Generation 1996-97 Civic as a giving you the ability to add a cabin air filter.
2. The "Evaporator Assembly" for the USDM 6th Generation 1996-97 Civic is the exact same as in a 5th Generation 1994-95 A/C-equipped CDM/USDM/EDM Civic.
3. Logically, it follows then that the 6th Generation EDM LHD Civic "Evaporator Assembly" should also retrofit exactly into a 5th Generation 1994-95 CDM/USDM Civic as a substitute, giving you the ability to add a cabin air filter!

The question remains, though, where to find an identical "Evaporator Assembly"? Table 1 details the part numbers for "Evaporator Assemblies" in a number of different vehicles from different markets. The goal is to match the "Assembly" from a EDM LHD 6G 1996-97 Civic, such as the EDM 6G (KG:Germany) 1996 Civic 3-dr 1.6VTi in column seven, highlighted in yellow.

You have multiple options, with a 1998-2001 vintage Integra LS, GS, or GS-R being the closest match; you would just have to add the filter assembly from a CR-V or Insight. (Note: Only the Integra RS came with optional A/C). It will also give you access to all the mounting brackets, etc. Definitely your top choice. An "Evaporator Assembly" pulled from a CR-V or Insight is another option, but you'll need to swap the 2-wire thermostat with a 3-wire one like part number 80430-SR1-A12 or 80430-SR3-003 and rig it up to connect to your wiring harness. All USDM CR-Vs have A/C; it was optional on some Insights.

Since I live in Canada, and Integras seem to be a little more difficult to find in this country, and Insights are nearly impossible to find, my choice was essentially restricted to 1997-2000 CR-Vs.

UPDATE 2011: Since originally posting this thread I have determined that the evap from a 98-00 Civic is ALSO a direct swap and is an EXCELLENT option (probably the best, and definitely easy to find).

For reference, a factory-installed A/C "Evaporator Assembly" behind the glove compartment from a CDM 5G 1994 Civic 3-dr DX (with dual SRS) is shown in Figure 7. Figure 8 shows the "Evaporator Assembly" on a CDM 1G 2000 CR-V 5-dr (trim level unknown).

Figure 7. Reference image: Factory installed A/C "Evaporator Assembly" behind the glove compartment from a CDM 5G 1994 Civic 3-dr Hatchback.
Note 3-wire thermostat connector at top centre. (Multiple images stitched together.)


Figure 8. Reference image: Factory installed A/C "Evaporator Assembly" behind the glove compartment from a CDM 1G 2000 CR-V 5-dr (trim level unknown). Some mounting screws are already removed (sorry!).
The panel door with the handle at centre is where the Cabin Air Filter is installed. Note 2-wire thermostat connector at centre left.

As suspected, the CR-V "Evaporator Assembly" mounted perfectly in a 5G Civic, as shown in Figure 9 and 10. The vehicle was a CDM 5G 1993 Civic 3-dr CX (non-SRS).

Figure 9. A 1G 1997-2000 CR-V "Evaporator Assembly" complete with Cabin Air Filter mounts directly into a CDM 5G 1992-95 Civic.
The door for the Cabin Air Filter was removed and the filter assembly can be seen in white at centre. (Multiple images stitched together.)

Figure 10. For the "doubting Thomases" of the world who might question the authenticity of the above shot, here is a wide-angle
shot showing the 5G Civic dashboard and passenger area, with CR-V "Evaporator Assembly" installed complete with Cabin Air Filter.

For reference, Figures 11 A through E visually compare the "Evaporator Assemblies" from the CDM 5G 1994 Civic 3-dr DX (with dual SRS) on the LEFT and the CDM 1G 2000 CR-V 5-dr (trim level unknown) on the RIGHT. Note that the "Assembly" from a 1992-93 Civic MAY BE DIFFERENT.

The thermostat and drain tube from the 5G Civic should be removed and installed on the "Assembly" for the 1G CR-V. The OEM mounting location for the thermostat is located on the little lip visible at the bottom right of the 1G CR-V "Assembly" in Figure 11A and seen again at the bottom left of the same "Assembly" in Figure 11B.

Figure 11B. Visual comparison of 5G Civic A/C (LEFT) and 1G CR-V (RIGHT) "Evaporator Assemblies".


Figure 11E. Visual comparison of 5G Civic A/C (LEFT) and 1G CR-V (RIGHT) "Evaporator Assemblies".


Conclusion

A retrofit is definitely possible for A/C and non-A/C equipped Civics to add a Cabin Air Filter. I have added the CR-V evaporator unit shown here to my vehicle. I have yet to complete the full install of an A/C system to test it out, but will be completing that project this summer.

UPDATE, SUMMER 2011: I have successfully completed an entire functioning A/C retrofit, using the evap unit I pulled from the CR-V in this DIY.

deschlong

iTrader: (8)

I have now completed the retrofit and updated my above post.

First I replaced the old filter with a new OEM one (and got fleeced at the dealer, ah well). See Figure 1.
Figure 1. Used filter on the left, new OEM one on the right.

Figure 2 is the CR-V evaporator unit installed in my 1994 CDM Honda Civic.

• Vacuum out the area around the heater core - it will be full of leaves, pine needles and crud. See Figure 3. This is why you got a cabin filter, after all - partly to prevent this mess.
• Don't forget that you need the drain hose, thermostat, and firewall grommets from a Civic A/C evaporator unit.
• Also, you need the 2 extra 10mm self-tapping screws, the 10mm bolt (at base) and the 10mm nut (for a non-SRS vehicle) at the top. These can be obtained from the CR-V or the Civic vehicle.
• To install the filter, you need to unhook both brown wire retainers visible to the left of the above photo. The wiring loom will then move far enough out of the way to remove the Cabin Filter unit.
• The thermostat mounts in its stock location at the base to the left of the unit. See Figure 4. Will the connector reach? Still a mystery.
• Refrigerant oil will leak out of the holes in the evaporator unit. Not a big deal since you will be flushing it anyway, but don't get it on the paint of your vehicle. Important: PLUG THE HOLES UP TO PREVENT MOISTURE AND DIRT FROM ENTERING THE UNIT. I stuck some corks in the holes, which should hold until I install the rest of the A/C system.

Good luck with your install. Post back here if you have any questions, or to give mAd Pr0pz, yo.


deschlong
April, 2009

Davus

This is pretty cool. How come there are no replies? Saw this thread a few days ago even.

DB1_559

great mod nice fresh cool air great stuff

wrestler72

So once you have all the parts how long would you say it would take to complete install?

mage182

A model writeup. Thanks for taking the time to included detailed pictures and directions. I was going to buy the pass through to use on my EG project car which I don't need AC in but now that I've read your post I'm going to get the one with the cabin air filter.

deschlong

iTrader: (8)

Once you have all the pieces? I'd say about an hour ... or less. It's really not that tricky.

Some people have said they had trouble removing the original duct, but I did not. I imagine they got hung up on the little lip hook on the bottom left of the duct which holds it in place. Push back on the firewall padding with one hand and slide it off (to the right) with the other.

Unseen Racer

very nice

rickkane

So which year crv's in the US will have what is needed for the swap over?

NastyHabitzCRX

nice, i wonder if maybe that evap will be more efficient??? damn getting kinda warm, don't know if i want to mess with it this year!

deschlong

iTrader: (8)

Good Q ... I see I wasn't really clear about this. 1st Generation CR-Vs will have what you need ... model years 1997-2001.

rickkane

One more quickie. Is is necessary to use the CRV evap unit or can I use the stock civic one with the cabin filter from the CRV?

deschlong

iTrader: (8)

You definitely need the whole unit. Replace your entire Civic evaporator. There are no reusable parts on it -- except for the thermostat! You need that.

Inliner

cool write up I found the Insight non ac version on a honda parts catalog for 45 or so

NastyHabitzCRX

you charged the system yet?

deschlong

iTrader: (8)

Not yet - hunting for the last part: a pipe from the condenser to the dryer. Got everything else. Not yet sweltering here, so I've got a bit of time still. Guess I need new O-rings, too.

NastyHabitzCRX

damn, just order it new!!

The_Honda_Guy

Well, I looked on my 97 DX and it does not have the setup for the cabin filter.

Does this mean I would need the evaporator and evap box or do I just need the evap box? And only the CR-V and Integra box would work?

deschlong

iTrader: (8)

You have A/C already?

Integra or 98-00 Civic is your best choice, followed by a CRV. You need the whole thing - Box with evaporator. The thermostat with the Integra one should fit exactly. The CRV one cannot be reused - replace it with your current one. It mounts on the bottom left - see the photo above.

The_Honda_Guy

Yea, I have A/C already. I would like to do this, but it seems like quite the swap to perform. Can it be done by just pulling out the glove box or does the whole dash need to comeout? I'd rather not pull the dash. lol Cabin filter would be extremely nice though. The problem is trying to find a good Teggy evap and box though. I doubt the junkyards around here would have them. A new evaporator would own me too.

deschlong

iTrader: (8)

Haha - OK, I've got it now! One step closer.

You only need to remove the glove box, as shown in the pictures. You're right about the Integra, though - could be tricky to find. Look for a CRV, too. Used units aren't too pricey - mine cost about $50, so there's your incentive.

RedFerioEG8

bump for a cool idea. def gonna consider doin this to my ferio

MonkeyBoy668

I'm pretty sure this is a stupid question, but am I assuming correctly that, when installing into a car with a working A/C system, the A/C system would have to be discharged in order to remove the existing evap unit?

NastyHabitzCRX

yes!!

jbs

iTrader: (1)

DeSchlong, good post.