Installing Air Conditioning into an EH
If you would like to install air conditioning in an EH you may gain some information from my experience.
It had been a goal of mine to install air conditioning in the EH when I initially restored the vehicle but 7 years passed before I finally dedicated a week to the project.
One of the reasons for the long delay was due to my perception that the job would not be easy and to some extent this was true, however, having now completed the project I can say that it is not such a difficult task especially if the following is taken into consideration.
Over the preceding years I did gather some information and parts to do the job but some of what I collected was not used. Whilst restoring the EH I saw a number of other EH’s with air conditioning fitted but not always working. In most cases the units had run out of gas and the owners had decided not to spend any money fixing the problem ie re-gassing the units. I suspect some of the reasons why they were not “fixed” were due to the fact that they had previously been re-gassed but they did not function for very long because of gas leaks or inefficiencies with the then current technology. (The modern technology has gone ahead in leaps and bounds and really can’t be compared to the older designs. Even the refrigerant has changed considerably.) I also noted that in most cases the Compressor was driven by the same v belt which also drove the Alternator and Water Pump. This solution in most cases worked however the torque required to turn the Compressor was relatively higher than the Water Pump and Alternator therefore the v belt needed to have extra tension applied to enable the Compressor to work at maximum efficiency and if any belt slippage occurred (which often did due to the enormous loading on one belt) the Compressor would not function as required and the Alternator and Water Pump would also lose power.
Given all of the above I decided that whilst restoring the EH I would reposition the battery to the opposite side of the engine bay to enable enough room to fit the added components without having to contend with the battery being in the way. The extra space was paramount in achieving the final outcome.
Now, if you know the basics of how air conditioning works then you may like to skip reading the next section. Since my knowledge of air conditioning components was fairly basic I needed to have a better understanding of how the system functioned in order to be able to communicate with those who could give me guidance on what I should consider when making it all fit. It may help you to know the correct names of the specific components, how they function and where they reside.
There are 5 main components (not including hoses & wiring) 1/ Compressor 2/ Condenser 3/ Receiver/Drier 4/ TX Valve 5/ Evaporator (plus Hoses & Wiring)
The Compressor usually resides near the front of the motor and is driven by a belt. It compresses the gas and forwards it to the Condenser.
The Condenser usually resides in front of the radiator and it is used to expel the heat component generated in the system. During this stage the gas changes to liquid refrigerant.
The gas then passes through a Receiver/Drier which although small and shaped like a cylinder plays and important role in removing any moisture in the sealed system and storing the refrigerant until it is needed.
The refrigerant then moves on to the TX Valve which is part of the Evaporator and usually located in the cabin of the car. These two components cause the refrigerant to release energy and in doing so create a very cold process which gets transmitted into the cabin of the car via a fan. The refrigerant changes to gas, absorbs heat from the cabin and returns to the Compressor where the cycle continues again.]
The next sections describe how I fitted the 5 components and what to be aware of.
The most difficult part of the project was to fit a Compressor. For a number of years I tried to source a small compressor to fit a “Red” motor bracket that I found at a swap meet. This bracket included lugs for the Alternator and no doubt suited a specific make of Compressor but it seemed that the original style Compressors (longer and thinner in the body) were no longer available so I had to resort to locating a unit that was current and as small as possible to fit the space available. I chose a Sanden SD7 unit that was fairly compact, had good output cf/m specifications and I anticipated that it would be available for many years in case it should wear out or fail. I tried to fit the Sanden unit to the existing bracket but I eventually gave up on trying to use this bracket as it was just not suitable. I decided to visit the local wrecker and select a number of brackets that appeared could be modified to fit the 179 “Red” motor. Whilst browsing through the various cars at the wreckers I noticed that there were a number of different styles of brackets and I narrowed the selection to those on a Commodore VH model which had a “Blue” motor fitted. There also seemed to be a number of different makes of air conditioning brackets so I selected some that I thought could be adapted. (eg. Some had bracketry associated with enabling power steering pumps and some did not). None of the brackets that I looked at had the capability of having the alternator and compressor on a single bracket. I did find this surprising given that the “Red” motor and “Blue” motor are very similar in footprint and bolt locations. (Perhaps there is a single bracket out there that you may be lucky enough to find and save much time and effort as detailed in the next part).
I needed to use two brackets to mount the Compressor and Alternator. The bracket which held the Alternator in position was the main part of the solution and it fitted using the two alternator bolt holes located near the sump (although I needed to redrill the bracket so that the alternator pulley lined up with that on the “Red” motor). This bracket placed the Alternator towards the top of the motor and enabled the Compressor to be placed in the position where the Alternator normally resided. The bracket would have attached to the “Blue” motor via a bolt hole in the side of the “Block” however the “Red” motor does not have this hole so I welded a short lug to reach one of the Water Pump bolts as well as welding another bracket to reach another bolt hole near the front passenger side Head bolt. It sounds a bit complicated but it was not too difficult. I added a spacer to the bracket so that it touched the Block where the bolt was not able to be used. This added extra strength ensuring the bracket would not twist when tension was applied to the belts.
The next part was to fit the bracket that would hold the Compressor. This bracket had lugs that were a standard distance apart and matched a common size for many different air conditioner Compressors including the Sanden Compressor. It needed to be welded to the newly installed bracket. To do this I needed to mount the Compressor to it and then offer the bracket with Compressor attached to the vehicle and weld it in a position that enabled the drive belt to line up with the newly added pulley on the Harmonic Balancer. This process was difficult as I needed to tack weld the bracket whilst on the car as well as make sure that the Compressor and Alternator could be tensioned without fouling one another and that the Compressor would not hit the inner mudguard panel. There was not much room for error. In order to apply tension to each v belt I was able to utilise two of the same design Alternator tension brackets from VH commodores. The Alternator tension bracket was attached to one of the Water Pump bolts and was not modified much but the curved bracket for the Compressor had to have some extra “Arc” to enable it to work correctly. This bracket bolted to a new hole drilled on the Alternator bracket. I used a nyloc nut on the pivot bolt as the bracket needed to be installed prior to installing the Compressor and prior to tensioning the Alternator and I could not gain access to this pivot bolt after the Alternator and Compressor were installed.
It is also important to note that you can source several different styles of pulleys to add to the Harmonic Balancer. The best solution is to get one that butts up against the existing pulley and does not have a gap. This will ensure that you can still use the metal fan blades for extra cooling capacity if desired. You still will need to space the fan blades forward but only by a small amount. The pulley that I sourced was slightly smaller than the Harmonic Balancer pulley so as not to come in contact with the front stabiliser bar. It suited an 11mm v belt and the Sanden Compressor had pulleys to suit 13mm v belts however the v belt tapers were such that the different sizes did not cause a problem. Of concern to me before the air conditioner modifications were done was the fact that the motor temperature increased significantly whilst at idle and I did not want to make this issue worse.
Once the air conditioner was installed I did not experience any motor overheating problems but it may be worth noting the vehicle had a three-core radiator. The metal fan blades were also positioned closer to the Radiator. The transmission was a Tri-matic and during the installation of the air conditioner I had the cooling tank in the radiator removed to enable maximum water flow. (Cooling for the transmission was already being done by using a pair of air-cooled heat exchangers).
The Condenser was the next most difficult item to fit although relatively easier than fitting the Compressor. I chose to use a Modien Parallel flow (or Multi-Flow) style rather than a Uniserp (or Serpentine) as the efficiency is ten fold and only about 30% more expensive. (about $100 more). The largest Condenser that would fit the allocated space was a 14” high by 27’’ wide unit. Some slight modifications needed to be done to the underside of the boxed section of the Radiator Upper Support Panel. This entailed using a Ball Pein Hammer and dishing a 20mm section on the drivers side. I also spaced the Condenser away from the Radiator so as not to introduce radiant heat into either cooling unit as well as enabling the Condenser to be easily mounted. The method I chose was to use 1” square tubing strips either side and attach the Condenser to the tube and then secure the tube by self tapping screws through the panel either side of the Radiator. This also enables the Radiator to be removed from the vehicle at any time without interfering with Condenser mounting. I also fitted two 12” Craig Davies fans to the front side of the Condenser. Again I looked for an easy method to mount the fans and I was able to fit them to two 27” long angle iron supports that attached to the Condenser side support tubing. I also wanted to force all the air these fans pushed through the Condenser through the Radiator so I made sure any side and top gaps were blocked using .55 gauge metal angle flashings. (There are quite large gaps on the either side of the bottom radiator tank as well as across the top and down the passenger side and I figured some of the air would take the path of least resistance if I did not block the escape passages.)
The next item to fit was the Receiver/Dryer and I mounted this near the Compressor on the inner mudguard panel. I chose this location rather than in the front grill area near the Condenser as it would be difficult to access if under the Radiator Upper Support Panel and it makes it easier to maintain the gas system as well as being able to see the sight glass on the Receiver/Drier. It also enabled easier hose connection.
Initially I wanted to conceal the Evaporator behind the Dash-board and I spent a number of hours and money over the 7 years investigating the feasibility of an “in dash” solution. There really is not enough room to tailor a solution to be concealed so I conceded to using an “Under Dash” unit.
(If you really do not want the unit to be seen then you need to place the Evaporator in the Boot compartment under the rear parcel shelf. This is not the solution that I wanted as I would lose valuable Boot space as well as having to cut into the rear parcel shelf to install vents which would also be difficult to adjust from the front seat area).
The “Under Dash” system I used was mounted to the passenger side and I fitted it so that the glovebox could still be used and the glovebox lid would open all the way to enable easy access to the compartment as well as being able to use the “Tray” function for drinks etc. A small issue I needed to address was due to my vehicle being a Premier with the standard heater unit and tubular vent tubes for the front window demister. The Under Dash unit partially obstructed the area near the passenger side heater vent leading to the window demist connection. I had to discard the existing hard coil flexible tube and source a flexible PVC hose with wire support rings to re-establish the air duct connection.
As the Evaporator was fitted the next job was to make and fit the gas connection hoses and having a mate in the automotive industry was a big help. There are 3 different size hose diameters to be used 6, 8 and 10mm. I used a combination of straight, 90 and 45 degree crimp fittings dependent on what angle best suited connection to the specific component. Each hose needed to be measured and made to fit the exact location and in some cases they needed to pass through rubber grommets which were installed in suitable locations.
Other jobs that needed to be done were to install the cables necessary to make the system function. I noticed the fan in the Evaporator ran slower when installed in the car than when I had tested it on the bench with a short lead to a battery. This was due to the voltage drop over a few metres of cable to the battery which can be quite high if the minimum size cable is used. It is necessary to increase the cable size feeding the Evaporator fan switch as power for the Compressor clutch is also sourced via this cable.
In summary there are a number of ways to achieve the end result and it is up to the individual to determine how they wish to install the various components.
The performance of the system was excellent due to the Sanden SD7 Compressor being capable of cooling larger size systems, the Condenser being very efficient as well as being the largest that could be fitted in the space available, the large capacity of the cooling fans and lastly the Evaporator being an “Under Dash” unit which was very efficient.
The amount of R134a gas that was installed in the system after it was evacuated was 500 grams ie half a Kilogram. I measured 0 degrees at the cooling fins and found the 179 “Red” motor not to require an idle increase solenoid. The cost to complete the project (early 2006) was approximately $1,000.00 bearing in mind that most components were sourced at trade rates and very little labour costs were incurred. Most of the components were sourced from Ingram Corporation (who have offices all around Australia ). The guys there were very helpful.
Should more detail be required I would be happy to assist address your questions and can be reached as per details below.
The Compressor is Sanden SD7 SDH715-CXS8031 which is a general purpose unit. It has twin pulleys to suit 13mm v belts but only one belt and pulley was used. The Modine Parallel or Multi-Flow Condenser CNX413. Two Cooling fans type Craig Davies DCSL 12. To assist further the following may be of benefit. The part numbers of the Bosch V Belts that I used were 11A0990 for the Compressor and 11A1105 for the Alternator/Water Pump. (both belts are 11mm section). The various crimp air conditioner fittings were:- Evaporator blx1113 (10mm45flared) and blx1121 (6mm90flared). Compressor blx1323 (10mm90) blx1322 (8mm45). Condenser blx1302 (8mmStr) blx1321 (6mm90). Receiver /Drier blx1301 (6mmStr) blx1311 (6mm45). The Under Dash Evaporator Part # ZCD850SE is a three vent Sanden unit that seemed fairly new when I bought it second hand. You can still source new Under Dash units eg. Sanden747-EV11472. (There are also units on the market that have heater and cooling elements in a single housing but cooling BTU’s may be less).
The Receiver/Drier is rdx025/6159. The bracket is rdx911. The valve to add gas attached to the R/D is afx4000. The inline valve to add gas is blx6103-3 (10mm T). Heater air vent hose PVC 2” diameter 12” long is SPX022
Author – Peter Lenthall (Member of EH Holden Club of SA)