Aircon on a budget

[Phill S]

A couple of days ago I started looking at the feasibility of re-using the aircon/heating system in my 1987 110, that came from the engine donor Disco 1. While the donor was a V8 I'm guessing most of what follows is applicable to any of the Defender and earlier models, and there seem to be plenty of the diesel Disco's being broken so the parts I'm looking at here will be the same. Won't they? You just need a place to put all the bits under your bonnet. I've left as much space as possible behind the V8, so this is what I've got:

Ought to be able to get something useable in there didn't I?

First step, where's all the bits gone?

Astonishingly, I think I've found everything. A quick walk around to help anybody visiting a scrappy to find what they need (assuming this works out):

 

Then there's the big bad HVAC unit itself:

 

Pulling that apart I find a massive evaporator and a dinky little heater matrix:

Although it looks somehow bigger in that picture. Not sure I like the look of those push-in connectors to the heater matrix though.

Just now I'm looking at the basic layout of the main system components. Lots more to think about with getting the air into the thing and out into the inside of the vehicle

So what do we think the possibility of making something out of that little lot is?

Somebody will have tried this before...

[FridgeFreezer]

Interesting - there's naff all space inside for most of that but you do have a big gap behind the engine and where the original heater lives.

Worth looking at @TSD's custom heater box (on 2BEX) for packaging ideas if he's posted any pics of it... if not this is a nudge to do so

[Phill S]

6 hours ago, FridgeFreezer said:

you do have a big gap behind the engine

Aah yeah - I guess the diesel guys aren't going to have that so this might not be as much use to them as I'd thought. I've been keeping the area free and managed to squeeze a 300 Tdi air cleaner up front:

 

Still needs to have a lid put on it - other things more pressing at the moment, but I don't want to find I've got mice nesting in it...

 

7 hours ago, FridgeFreezer said:

for packaging ideas if he's posted any pics of it

Yes! obviously interested in what others have done.

Just to take things to their logical limit I've been chopping up the big old HVAC unit and get this:

 

Just rough cut at the moment, don't judge me, this is work in progress! The original heater matrix is not a natural fit anywhere, but I dig this out:

 

Don't have the part number but I think it's the earlier heater unit matrix? This one is Allmakes that I picked up somewhere along the line - I'd appreciate any recommendations on what a decent make might be. Because it's a natural fit and sits perfectly in there. But. It sits very close to the evaporator so there's no way all the flaps and ducts from the original unit can be used - I don't think being close is a problem? Except that I'll need a tap to turn the hot water on and off and redirect the flow for the thermostat bypass circuit. Just a reminder that mine is the 3.9 serpentine engine.

A bit of digging around and the only possible manual Land Rover unit I can find is JQD500080V:

Which might be workable...

With lots of assumptions on hose diameters etc it might do the job. The evaporator is obviously just an on/off job, but assuming the above does what I think it does we might just be in business. Then I would need to duct air out of each side of the rear of the chopped up Disco heater unit to get the air out again and into the truck.

Hmm. What do we think?

[FridgeFreezer]

I don't mean to keep dropping him in it but TSD did go through a lot of this (water valves etc.) with the heater on 2BEX, I certainly remember it being a struggle to find any that were regarded as reliable (they're universally plastic) - one option to look at is replacing the heater matrix with a PTC one from a modern car - it will burn a lot of electricity but it's instant heat and running a couple of chunky wires could be easier than the plumbing...

All I can directly contribute is that I did away with the factory heater on my 109 and replaced it with an Eberspacher mounted where the heater used to be, blowing in through the bulkhead.

[mad_pete]

Not wanting to side line but how did you mount the air filter ? I tried to find a spot to do the same but never found an angle that worked. 

[TSD]

Simple rule for heater valves - if there's loads for sale on ebay, it means that even the OEM part is a lemon. Avoid any of the common Ford parts.

The best heater valve I found is a VAG part used on the Phaeton thing, but also on large Audis and probably others.

It's used by VAG as a 3 port, but it's actually a full H valve (supplied with a blanking cap on one port), conveniently shaped, and the hose tails are close to Tdi heater hose sized.

I don't have number to hand but I will try to find it and some pics when I get time. I'll post some pics of my heater setup as well.

Edit : Something like 3D0820035, several listed for sale at silly prices, but you can see pics at least. I paid something like £25 for a used one that looked brand new to me, after the new genuine one I paid 40 quid never arrived.

Edited May 20 by TSD

[TSD]

I just added a few pics from my heater install on my (neglected) build thread of my (neglected) 2Bex...

 

[Phill S]

11 hours ago, FridgeFreezer said:

one option to look at is replacing the heater matrix with a PTC one

Hmm - sounds a bit new fangled to me 😉  An interesting thought but think I'll continue with the conventional thinking until I hit the stops. The RV8 is after all very good at producing hot water/coolant.

 

11 hours ago, FridgeFreezer said:

I did away with the factory heater on my 109 and replaced it with an Eberspacher

Yeah - might think about that if it all goes bad. Watch this space.

 

11 hours ago, mad_pete said:

how did you mount the air filter ?

Ok - this will look a little eccentric:

 

To the left is the original 2.5NA air cleaner bottom section. I'd been disposing of a massive old dead laser printer which had a nice chunky metal frame. It was a bit of a game and needs to be done radiator out, but I replicated the legs from the original and with some big fat pop rivets attached it to the end of Britparts finest. The laser printer legs are actually stronger than the original unit. Not pretty, but hidden in the mass of underbonnet stuff. A tight fit up against the power steering pump but the engine doesn't seem to move much. So far. There's just enough room to get your arm around and underneath to tighten up the screw thingy to attach the upper portion of the 300 Tdi unit. I have some stainless mesh to fashion a grille over the top to prevent birds nesting and visiting friends using it as an ashtray.

 

9 hours ago, TSD said:

The best heater valve I found is a VAG part used on the Phaeton thing

Yeah we had a bit of a chat about those a while ago, problem is they're all or nothing aren't they? On/off? 

 

8 hours ago, TSD said:

I just added a few pics from my heater install

That's great, thanks. I will study in detail in slow time and steal all your best ideas.

 

Now I know you'll all throw your hands up in horror, but I've had a close relation to this in my old Riley (SU HIF44 RV8) for about the last 5 years and it works fine:

 

Yes - we're talking cheapo Chinese and you'll find them listed on Ebay as something like "London Taxi TXII TX2, Kit Car - Metal Bypass Heater Control Valve - 16mm (5/8")"   typically £20 sort of mark. Now not all Chinese stuff is junk, it's a bit of a lottery granted. But it does have the facility to progressively increase/decrease water flow in the way that you'd want. Might even connect up to the original Disco 1 heater control knobbery I know I have in a box somewhere. I've been looking for an original second hand one of these without success. Anyway, if I can't find anything else I might have a £20 flutter - I'll check the hose diameters today. Structurally it should be fine, just a case of whether it's going to leak or not. Place your bets gentlemen...

Working on cleaning up my fuel tanks at the moment for the grand dual tank system so the aircon job isn't going to go very quickly until the rain returns and I'm forced back inside. Lots of getting ideas straight to do though...

[ThreePointFive]

Genuine question - is that air filter sucking and blowing the right way around?

[smallfry]

15 minutes ago, ThreePointFive said:

Genuine question - is that air filter sucking and blowing the right way around?

No it isn't clean air should be sucked through the inside of the filter. Normally find that the filter inlet is slightly smaller than the outlet too.

The idea with that filter is that the incoming air forms a centrifuge, to stop large things blocking the element.

[FridgeFreezer]

19 minutes ago, ThreePointFive said:

Genuine question - is that air filter sucking and blowing the right way around?

Not if the pipe to the plenum is going in the side, no. I run the same filter and the outlet is the top.

This was from test-fitting the Eberspacher...

 

[Bowie69]

Yeah, that is sub-optimal.

[TSD]

There's not much wrong with the TX2 valve (until it starts leaking). The only reason I didn't start with one is that trying to get it into my heater design felt like octopus wrestling - once you include a mount and a control cable, there's always one leg sticking out in the wrong direction.

PTC heater was an interesting experiment - mine worked great for instant demist in the depths of winter, which is what I was aiming for. As a general heater it wouldn't be much cop. 1Kw is a lot of electricity, but not much heat in the grand scheme. A constant load of 80-100A means effectively no battery charging until everything is well warmed through. I did intended putting one in the 2Bex heater box though. I designed in a Freeland 2 unit, but the example I have seems to require some smart control, not just supply 12V, and I didn't get around to reverse engineering it, so it went to the back burner.

The original PTC thread was here, but my pics are long gone. I can try to find them if anyone is interested.

I have thought a few times of putting aircon in the Ibex, but I never got much past the thought stage. One idea was to use the rear aircon unit from a middle east spec D1, to avoid having to fit stuff in and around the crowded dashboard/bulkhead area. Those units are a lot more common now, most early high spec D3 have a similar unit in the boot. Following this thread with interest...

(And yes, if plumbed as it appears in the first photo, that filter is in backwards!)

[rusty_wingnut]

Following with interest, I'd been contemplating going for a puma style heater/aircon evaporator or potentially just fitting the entire puma bulkhead but cost is always an issue! I did also consider removing the cubby box and building up some sort of evaportator in there - that way the original heater setup/bulkhead is retained.

[Phill S]

2 hours ago, ThreePointFive said:

Genuine question - is that air filter sucking and blowing the right way around?

Whoops - so I've got it the wrong way round? I went to a lot of trouble to get it in the wrong way round then 😕

[tommobot]

Possibly stupid suggestion, but Car-Builder solutions sell units that could sit in the cabin(under the rear seats / centre cubby box)..  

As long as you had the pump, radiator, bottley thing (evaporator?) then its 'simply' just a case of hosing it together and figuring the electrics?

Obviously its way more complex than that in reality, but if you have the space and the bits then its not out of the realms of DIY feasbility..

This is on the assumpition that the AC unit would be entirely separate to the heater, I don't think the unit in the car would require a water/coolant supply?

[Bowie69]

You on about the Vintage Air units?

[tommobot]

https://www.carbuilder.com/uk/universal-air-conditioning-unit

That sort of thing... 

 

[Phill S]

Ok - I'm dealing with the embarrassment of getting the air cleaner the wrong way round. However, I have a running vehicle, the filter will be filtering and it will become one of those things that needs fixing. Having had it pointed out I have no idea how I managed to screw that one up. Any suggestions for reconfiguring welcome...

With poor weather on the way I've been working on the side tank while the sun is shining getting it cleaned up so very little progress on the aircon front.

 

7 hours ago, TSD said:

The original PTC thread was here

Ok - more study material

2 hours ago, tommobot said:

https://www.carbuilder.com/uk/universal-air-conditioning-unit

That sort of thing... 

Yeah but if you're prepared to wait for the slow boat from China you can get (what I think is the same unit and) a complete system for £150.

https://www.aliexpress.com/item/1005002114765964.html?spm=a2g0o.detail.pcDetailTopMoreOtherSeller.2.6774n0WMn0WMoR&gps-id=pcDetailTopMoreOtherSeller&scm=1007.40050.354490.0&scm_id=1007.40050.354490.0&scm-url=1007.40050.354490.0&pvid=231ab12a-0604-48bb-a7a6-ae0ac15274eb&_t=gps-id:pcDetailTopMoreOtherSeller,scm-url:1007.40050.354490.0,pvid:231ab12a-0604-48bb-a7a6-ae0ac15274eb,tpp_buckets:668%232846%238116%232002&pdp_npi=4%40dis!GBP!148.47!148.47!!!183.16!183.16!%40211b801817163067181072921e2efd!12000018786517980!rec!UK!4304489456!&utparam-url=scene%3ApcDetailTopMoreOtherSeller|query_from%3A

If you look at the pics closely they look a bit too nasty even for me, but what do I know. But apart from all that I'm determined to get that breeze block of a Disco 1 evaporator squeezed in if I possibly can.

What I know is that I snaffled the last valve unit on Ali Express, like the taxi one shown above, for £7.50. There's taxes applied but it's still less than a tenner - should be here next week. Hopefully it'll get me going while I look for something better. Or maybe I'll just buy a 6 pack and swap them out as they start leaking.

More stuff coming tomorrow, trial fitting of the engine bay side. Maybe...

Edited May 21 by Phill S

[ThreePointFive]

Where's the embarrassment?

It's one detail in an entire build, you can't catch it all, in my view this is exactly what the forum is for.

I'm just amazed for once I noticed the mistake rather than made it.

[Phill S]

4 hours ago, ThreePointFive said:

in my view this is exactly what the forum is for

I couldn't agree more, all the help I get on here is very much appreciated

[smallfry]

The other thing about the filter, is that the element has a tube of mesh up the middle, this is to stop the filter material collapsing and being ingested, as it could be if it gets wet of damp for example. Also with the air coming in the correct way from the outside, it presents a greater area of material to that incoming air, and will not block as quickly.

TBH if you are going on an overseas touring trip, I would forgo the aircon, and fit the big OE V8 90/110 type instead. That will fill the space nicely !

[Phill S]

Ok - I have the air cleaner eebie jeebies. Once I've worked out how I'm going to do the aircon I'll be returning to that. Off the road at the moment while I sort out the mechanics of how I'm going to implement the twin tank system but you have focused my attention!

18 hours ago, smallfry said:

I would forgo the aircon

I would never dream of travelling through south eastern Turkey with madam in the absence of air conditioning...

So today I did a mock up of how things might fit together and get a handle on what I can and can't re-use. There are a lot of pictures because I think others might want to look at all the bits and how it might fit together. Holler if you have opinions. Holler louder if you have any expertise in aircon systems. Also where you see I've done anything else "non-optimal" in my engine bay.

And before I forget...

On 5/21/2024 at 5:13 PM, Phill S said:

a bit too nasty even for me

Sorry if I sounded a bit sniffy but I have had occasion to buy some utter rubbish Chinese stuff in the past. On the more positive side if anybody has used he kind of systems that Car Builder Solutions sell I'd be interested in how that went.

On 5/21/2024 at 1:11 PM, Bowie69 said:

You on about the Vintage Air units?

Seen several vids on these on You Tube, they certainly look like good kit.

So starting from my chopped up Disco 1 HVAC unit, I'm going to step through all the bits so that it's easier to see what's what:

 

Low pressure evaporator to pump in pipe - notice the grey LP port. It's had a repair in the past but I would replace the rubber section in any case. So I can use that and alter the length of rubber section if I need to.

 

 

 

So now we've got hot high pressure vapour. The pipe I've left sticking out in the air connects to the condenser like so:

 

Just to be clear, it's the same pipe we saw in the last pic now attached to the condenser. With lots of ifs and buts I can certainly use the pump end and if the geometry were to permit also the condenser end. And of course the rubber section will be replaced so there are things that can be done with the length.

A general view of the condenser:

 

So hot high pressure vapour is coming in stage left, and comes out stage right as cool liquid under high pressure. Dryer in the middle which would be replaced as a matter of course and then the liquified refrigerant leaves stage left through the narrow pipe. Am I going to be able to use as is? Unlikely. I'll need one of those sticky out front grilles probably. Picture also serves to show the you need to clean your condenser once in a while. That's going to restrict the radiator behind it as well.

 

Just to show the high pressure, cooled, liquid refrigerant pipe as it attaches to the condenser in its original config. Same things apply about how the condenser can be configured.

Before we leave the front end, here's the condenser mounting frame offered up:

I know I've seen inverted L shaped support struts somewhere along the line, but I'd probably just make something ou of box section. Wouldn't I? The frame also carries a pair of fans that are always on when the aircon is on. I'd like to do that differently. The frame will need some adaption but it looks like a good start.

Now what...

Oh yes. Same pipe as before, the one leaving with high pressure cooled refridgerant shown just poked in under the RHS wing to get a first impression:

 

You can see it wandering about behind the power steering reservoir and coolant expansion tank. Might be able to do something with that. But:

 

It neatly has a coupling into the next section so an easier job to make up a bespoke pipe section to replace it. Which I'm guessing is highly likely. And in the next section you can see the high pressure port. Underneath that is the max/min pressure switch obscured in this pic by the old fixing clip. So we can see that all he clever bits are in the next and final section of pipe:

There's a lot going on and space under the bonnet is tight to show it, here's the bit we've just seen from the other side. A bit of a tangle going on and I've got the bonnet release coming through wrongly, but it's not bad.

And finally:

 

The same pipe going back to he big black box. Having run out of attention span I'll stop there for today, but thoughts, conclusions and plans coming soon.

Spoiler alert: I think I can make something of most of it...

[Phill S]

Been occupied with sorting out my twin fuel tank system, but some dribs and drabs of progress on the aircon...

Been delving into the circuit diagrams of the Disco 1 - I've used this wiring loom to convert from 24v to 12v and bring a whole bunch of other goodies with it. Fitting that was not a trivial task. More on wiring shortly. My first step has been in devising a 2-stage fan system that will serve the needs of the engine cooling system and also the aircon condenser. Following the lead from:

On 6/1/2023 at 10:12 AM, FridgeFreezer said:

As it happens because I'm intending to fit the Freelander setup properly to the ambulance soon I've revised and corrected my write-up: https://fuddymuckers.co.uk/wiki/doku.php?id=alfie:electric_fans

So I went and bought one of those for £30 - ebay special - from a 2000 Freelander L314 (whatever that is) with a claimed 51k miles on the clock. I'm using a 2.5TD NTC6168 radiator in my truck, and here's my fan purchase offered up to an old one of the same type I'm using that I picked up along the way hoping to get recored until I found out how much that was going to cost. Free to anybody that wants it when the fan part of the project is completed.

 

That seems to give plenty of whoosh on a quick lash-up full blast parallel, and half(ish) speed series connections. Think that ought to do the job of looking after both the engine and aircon?

I'm running the standard 88deg thermostat, and the standard Disco 1 let's have some cooling help from the aircon fans switch is 100deg. so I found a decent quality switch from T7 Design - read their blurb:

https://www.t7design.co.uk/m22-x-1-5-radiator-fan-switch-dual-stage-97-92-101-96c-cd8-c93-66c.html

And here's what I got:

 

Spanish made.

Think that should be about right although 97deg is rather hotter than I'd like, but I'll include a manual over-ride in any case.

So those items look like the beginning of something - I just need to figure out how to mount the fans in my truck...

So how to implement. I'm looking for cheap and reliable. The Disco 1 has its condenser fans operating all the time the aircon is active which seems unnecessary. Ploughed through a number of implementations and I like the P38 arrangement:

The document refs are all in the pic, along with the specs on the pressure switches. Now the Disco 1 pump control pressure switch is different to the X312 trinary unit shown in the diagram, the P38 uses pins 1 & 2 for that purpose. Pins 3 & 4 control the fans, so between the original Disco 1 pressure switch and a P38 trinary I have what I want. I think.

I should say that the incoming at point C in the above is the Left Condenser Motor looking for an earth, it's a simple enough thing and I didn't want to clutter up this blurb unnecessarily. Also don't forget that the fans shown are purely the aircon condenser fans, the P38 has the big old propeller type fan attached to the water pump. However, I'm reckoning that the Freeloader fans will have sufficient oomph to serve both purposes, engine and condenser cooling. If not it's down to the compressor circuit to look after the aircon system.

The P38 pressure switches are attached to the dryer so naturally I went and bought a scrap one of those. The dryer obviously would need replacing, but that gives me a unit I can wave about and see how it might fit together with with Disco bits. More on that when it gets here.

Am I on the right track?

 

[rusty_wingnut]

This is the sort of arrangement I had thought of, one single set of fans to cover engine and air con at once - interested to see how this pans out.