The only place for a coil spring is up Zebedee's arse
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@LPGC. Having remembered the question and waiting for the delivery of the units for my 51st install since starting this lark, I called the tutor at the training place where I did my FGas. He had a look at his automotive test rig and the motor used to drive the compressor is a 2.2kW, 3 phase motor, so pretty substantial (which probably explains why the idle speed drops on some smaller engined cars when the AC clutch kicks in).

He was sceptical that a system from a car would be sufficient to work in a caravan. You have to remember that the important thing when sizing a unit is the volume of air it is expected to cool. So a system removed from even a large car like a Jag, is still only intended to cool a much smaller volume than a caravan. If you have a system removed from a campervan that would probably be OK (as the volume will be much the same).

I've heard of it but never seen it. I'm not sure why they are there as nothing is going to move, the Classic and all previous cars the used the same V8 had cast iron manifolds. I suppose they might be there to account for thermal expansion?

and the answer is, it needs at least 3 gallons in the tank before the pickup is submerged. Reminded me of something I read once. I think it was on an MGB where someone advocated dropping gravel into the tank when you ran out of fuel as that then filled up the vacant space at the bottom of the tank and caused the fuel level to rise. I bet the noise of a load of gravel inside a metal fuel tank when going over bumps would get really annoying.......

Drained over 5 gallons of foul smelling stale petrol then dropped the fuel tank on the Classic. Did battle with hose clips and hoses that haven't moved in 32 years and finally gained access to the pump. 4 out of the 5 screws holding the old pump came out but, as usual, one put up a fight. Pump out, new one in and put it all back together. Went to the local garage, took out a mortgage and bought 2 gallons of petrol. Put that in the tank, tried starting it and nothing. Confirmed the pump was running, disconnected the fuel line at the filter and put my bit of hose with the priming bulb on it. Seems that 2 gallons isn't enough to cover the fuel pickup on the pump. This is going to get expensive......

StrangeRover wrote:

Are you going to keep hold of it after some titivation or is it a fix it and sell for profit?

I'm going to drop the tank, fit the replacement fuel pump (which came with it) and advertise it for sale. My ex-LR workshop manager neighbour suggested not even washing it so people can see exactly what is there. He also looked under the bonnet and said he'd never seen one more than 5 years old that still had inner wings! If it doesn't sell, I'll put an MoT on it (so will probably need to get the sills done) and try again.

Amazingly I didn't miss the entrance. My satnav informed me I had arrived at my destination in the flat featureless Lincolnshire countryside with no sign of 'Cobweb Farm' but I drove slowly another fifty yards & saw the sign on my left.

You obviously drove slower than I do, I always see the sign just as I drive past it.

Why do you think I drove 3,300 miles to collect it? It was an offer I couldn't refuse. Compared with what you usually find over here which is either rotten through and through or fully restored and going for ridiculous sums of money, it's amazing. It was taken to Spain in 1998 so was only 8 years old and has been there ever since. Chassis and underside is solid with just surface rust from standing but the sill are rusty and there is a small hole in one inner wing (compared to a small piece of remaining inner wing that you usually see) but even the rear lower tailgate only has a bit of surface rust. All the usual places you expect to see rust on a Classic are fine. I expected the interior to have been destroyed by the heat but that is in amazing condition, it needs a headlining (don't they all) and the carpets could do with a good vacuum but the seats look barely used. Only got 154,000 on the clock and now it has been run a bit it fires up and runs perfectly too.

Getting it onto the trailer required a bit of what the Aussies call 'bush engineering' as it was at the top of a mountain with about 3kms of very steep track to get down to somewhere flat enough to load it. The fuel pump died on it 8 years ago so it has sat there in the sun doing nothing (not even going rusty) since then. It's a 1990 model so doesn't have the fuel pump access hatch so dropping the tank was one option but the wasps nest under the rear bumper made that a hazardous exercise (I could cope with the 34 degree heat and the humidity but not being attacked by the wasps I was disturbing), so it was on to plan B.

Plan B involved the fuel pump from an XJ12 dangled next to the chassis where the fuel filter sits and held in place with a couple of tie wraps. Other problem was the 1/4 tank of 8 year old stale fuel so it needed fresh. Then discovered that the Jag pump would normally be fitted below the fuel level as it isn't self priming. A quick trip to a Jet Ski place supplied a priming bulb and with that fitted to prime the pump, she's a runner. Fresh fuel was fed from the temporary fuel tank.......

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Gear lever (3.9 V8 with an auto box) wouldn't move and found a sliding thingy below the lever had dried out and seized but a dribble of ATF on that freed it off. Then it didn't want to move so slackened off the adjuster on the parking brake and it tried to move a bit. Stuck it in Low, reverse gear, gave it some welly and the brakes freed off too and it moved under its own power for the first time in 8 years. Ran it back and forth stomping on the brake pedal every so often and it was ready for the journey down the mountain. Had a bit of an air lock in the fuel hose so it didn't syphon down to the pump so every couple of hundred yards had to stop and give the bulb a few squeezes to get the fuel flowing again. Managed it though.......

Just got to drain the tank, find a way of disposing of the stale fuel and fitting a new pump.

Not just today, but last Thursday (28th July), I took this......

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Then by late last night, 8 days later, I took this.....

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Last Friday I set off for southern Spain towing a car transporter trailer. Having got there, I spent a couple of days working on the reason for my visit, then set off on Wednesday, getting home in the early hours of this morning, towing this

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1,587 miles at 50-55mph takes an awfully long time.

nigelbb wrote:

Yesterday I drove my 2001 Vogue up to Lincolnshire so that V8 Developments can totally recondition the engine

I bet you overshot the entrance. I have every time I've been there......

I bought a pair of seat bases once from a regular eBay seller which I still have somewhere. I wanted to replace my well worn drivers base but I have grey cloth seats and everyone seems to only sell leather ones. However, the grey cloth changed in 1997 from a soft velour, similar to what everyone refers to as the teddy bear seats fitted in the Classic, to a darker colour, harder wearing cloth. His listing picture showed the later, darker coloured one but when they arrived, they were the lighter coloured, earlier one. Despite sending him pictures on my seats, the picture from his listing and what he had actually sent me, he refused to give me a refund. However, the point of this is that the drivers seat had a motor on the underside to raise and lower it. My manual drivers seat has a telescopic lever on the side to raise and lower the height, but manual front/back and twiddly knob to recline the backrest. It appears you may have the same half electric seat that I still have the base for stashed away in the pile of assorted bits that may come in useful one day. You are welcome to it if you want it, don't think it has a switch on it though.

I suspect it's much like the non-timed car rallies. You normal insurance is still valid as long as it isn't a competition or timed.

davew wrote:

That 'only £200 cold water box/fan' nonsense is of course 'well dodgy' - probably as far as the ASA is concerned of course; You may as well just fill a hot water bottle with ice water.... ?

It's basically a fan that blows the air over cold water or ice to cool it, better than nothing but not by much and certainly not worth the money.

By proper A/C above I probably should have said "proper" ( ie. with inverted commas ) - simply as it has cold out one end and hot out the other.... and that is is at least externally vented

As for the 'heat pump / conditioner' I mentioned without external box it was something very similar to this (and only 1K fitted ...): https://www.appliancesdirect.co.uk/p/a1%2fiqool-smart12hp/electriq-a1iqoolsmart12hp-air-conditioner

Those things are noisy as they have the compressor, condenser and evaporator all in the one box inside the house. They work well enough (although not the ones with ElectriQ on the front), better than the portable units, and are an option if you can put up with the noise and have a reason why you can't site an outdoor unit.. The ElectriQ units are sold almost exclusively by Appliances Direct (and their other identity, Aircon Direct) and are horrible Chinese made units that look good (ish) but aren't particularly good or well made. They are cheap for a reason.

Of course I agree that an external box will be (functionally) best, again it is just that aesthetics certainly affect folks' buying decisions.... not just my neighbours. Ask a woman !? Fan noise is key too. Some expect if to be almost silent "like the one in my office building..." (!!)

They are almost silent as they are the same units as fitted in office buildings. Often, the units installed in offices are more industrial so noise level is considered less important anyway so are noisier than ones intended for a domestic install. Indoor unit noise level of the units I fit is 20 dB(A), while the outdoor units are about the same.

As BrianH said New Builds/New Regulations may mean house design needs to change.... along with expectations.

Rather than putting an indoor unit into every room making the install complex (and expensive), the way to do it on a new build would be to incorporate ducts (or use the void space between joists) so a ducted system could be installed. This uses a single indoor unit (or one per floor anyway) that lives in the attic or in a service cupboard and outputs via vents installed in each room.

The main point is that there is definitely a real need for Customer/Consumer education on all this though: I have lost count of the number of folks asking me questions like 'why their whole garden needs to be dug up' for a Heat Pump Installation...? usually because they have (only) heard about Ground Source kit: Perhaps the BBC could oblige instead of all their celebrity baking/dancing/etc twaddle; I won't be holding my breath.....

A ground source heat pump will work much better than an air source one as the ground temperature remains reasonably constant a few feet down. So while the air temperature can vary anywhere between -10 and +35C, 10 feet down, the temperature will probably be between 5 and 10C and won't change much at all. So when you are using this as a source for the evaporator (in the case of a heat pump installed for heating), it is far more reliable as the temperature differential is constant. Downside of course, is that you need to dig up a large quantity of the garden (if you have a garden in the first place, not the postage stamps that most new builds come with these days).

davew wrote:

Lgpc: As a fixed A/C installation does not have the advantage of forward motion (ie. cooling air over the condenser so you need a big fan instead, as you mentioned) then an electric motor of 1 or 2 kW would probably be needed (or say about 2HP in old money) ?

Big fan not needed, think about it, there's very little airflow though the condenser when sitting in traffic, and it doesn't really matter how hot it gets (within reason). The place where I did my FGas course also did the automotive course and had a test rig for training that contained everything you would find in a car except for an electric motor to drive the compressor instead of the engine. I'll give then a bell and see what motor it needs when I'm back in the UK.

davew wrote:

In the meantime some of my over-heated neighbours are happy it seems to buy a big plastic box with a fan in it.... merely cooled by 10L of cold water. That's TV ads. for you though, and 'only' £200 (!).

My daughter had one of those, a total waste of money, even if you fill them with ice.

A few have the free-standing (proper) A/C units with a tube out of the window (but then they panic about night-time security).

Not proper by any stretch of the imagination. They also seem to use the Italian horsepower/Chinese stereo makers output rating type of information in their specifications. I measured up a bedroom for a customer and it came out at needing a 7,000 Btu unit which surprised the customer as he had used a 9,000 Btu portable and it hadn't been capable of keeping the room cool in hot weather. Not only did the unit I installed cool the room but if the door was left open it cooled half the house.....

Some even have A/C with an 'ugly' external box.

So how else do you house the condenser? Even if the customer wants it, I will not fit the outdoor unit on the front of a house. Hide it round the back or down the side where it can't be seen.

Accordingly the type of heat-pump with large vents through the wall (ie. nothing external) seems ideal but even then they think an enclosure 1X0.5X0.5m is 'too intrusive'...

That isn't a heat pump but a heat recovery system where the heat is extracted from the room and used to provide hot water. The external box for a heat pump is considerably larger, usually with two fans, than the one for a smaller AC system

Further to Dave’s comment in this thread https://rangerovers.pub/topic/3016-ac-leak-test-at-home?page=2#pid38452, I’ve had a bit of time on my hands today. The car is ready and loaded up so I’ve spent the time waiting for Dina to finish work so we can set off before driving to Spain to write this.

I would like to think that at least some of you understand how the AC system in your car works, but in case you don’t, a little explanation. Everything has 3 states, solid, liquid and gas, the only thing that differs is the temperature that they change from one to another. Water, as we all should know, has a boiling point of 100C, the temperature where it changes state from liquid to gas (and 0C when it changes state again from liquid to solid, aka ice). However, if it is under pressure, the boiling point increases. That is why your cooling system has a pressure cap and the increase in pressure means it doesn’t boil (change from liquid to gas) until around 120C. That is why, as long as you don’t have a leak anywhere, your cooling system can run at 105-110C without boiling. In the same way, if you run on LPG you fill your tank with a liquid (Propane in this case) at around 10bar (145psi) so it remains a liquid but, as Propane has a boiling point of -44C, as soon as it is no longer under pressure, it becomes a gas.

So, what does this have to do with AC? Because it uses this to move heat from one place to another. It is filled with R134a gas, Tetrafluoroethane (CF3CH2F) with a boiling point at atmospheric pressure of -26.1C. Your system also has what are termed a low side and a high side signified by the pressure in the system. Starting at the low side, the system is full of a gas at a pressure of around 2.6 bar when operating. That gas passes through a compressor which raises the pressure to around 10.3 bar (at the High side) at which point it is fed to the condenser (the one in front of the radiator, the one that leaks with monotonous regularity) where, it condenses and becomes a liquid. That generates heat which is dissipated by the airflow though the condenser. This liquid then passes through a small orifice where it vaporises as the pressure drops on the other side of the orifice and goes through the evaporator (see how the names of the various components start to make more sense now?). At this point it gets very cold (although strictly speaking, in thermodynamics there is no such thing as cold, only a lack of heat, so the correct terminology is that it ‘draws heat’, something it took me ages to get my head around when I did the FGas course) in the evaporator, air is blown through it and that is the nice cool breeze you should get out of your vents. At that point the cycle starts again as the gas gets to the compressor to be compressed and turned back into a liquid. This is just the same as a Calor gas bottle getting condensation or even ice forming on the outside if you have your barbecue/patio heater/ blowtorch running flat out for a while. The liquid in the bottle is vaporising so is getting cold (sorry, drawing heat).

OK, so that is an automotive AC system and a domestic AC system works in exactly the same way. You have the compressor and condenser in a box outside your house (along with a load of control electronics). That is linked by two copper pipes (liquid and gas) to the indoor unit. These come in a variety of forms but the most common ones are the wall unit, the rectangular box on the wall up near ceiling height, or the ceiling cassette, the square units set into the ceiling that (usually) have 4 outlets blowing the cold air out in different directions. There’s multiple different designs but they all work in the same way. The big difference between a domestic system and that in your car is that they are reversible. The flow of the refrigerant can be reversed so the condenser becomes the evaporator and vice versa. That way, when the flow is reversed, the indoor unit gets hot and the outdoor unit gets cold. That way they can provide heating as well as cooling. Different units differ in how they achieve this, with some of the cheap Chinese made systems you have to manually set them for heating or cooling. The better systems, like the Fujitsu units I prefer and install, have an Auto setting. You put it on Auto, set the temperature and it reverses the flow as and when it is required. That way you can set 21C and no matter if the ambient is -5C or 30C (or higher as it has been recently in some areas), it will automatically maintain an indoor temperature of 21C.

On a decent quality system working correctly, with an ambient temperature of 25C when set for maximum cooling, the air coming out of the indoor unit will be down to 2-3C. When set for maximum heating, it will achieve 55-60C. If the ambient is cooler, this will be a bit lower but the Fujitsu systems will still provide 50C down to an outdoor temperature of -15C. This is spread around the room by a fan so is much the same as using an electric fan heater. The big difference is that it can achieve the equivalent of 3kW of heating (or cooling) while only drawing sufficient electrical energy to power the compressor, which will normally be around 600W, making it a cheap way of heating a room. Multiply that by the number of rooms in your house and it adds up to a considerable saving. The outdoor units can supply a single indoor unit or up to 8 but the install does get pretty complex…….

That brings us on to air source heat pumps (or ground source heat pumps for that matter, they work exactly the same). They are configured just the same as an AC system when using it for indoor heat as they aren’t reversible. The difference being that instead of giving a source of heat which then has air blown over it to distribute the heat throughout the room, a heat exchanger is used so that heat is used to heat water which is then sent around the existing pipework to your radiators.

This is where the problems start. First of all you have in inherent loss in the heat exchanger dropping the water temperature down to around 50C, many of the more modern houses have 10mm microbore pipework, perfectly adequate when the water is being pumped around from a gas boiler at around 70 degrees but too restrictive for water at a lower volume and 20 degrees cooler. Then a radiator will have been specified for the size of the room. Radiators tend to be specified in Btu’s (British Thermal Units), as are many AC units. You take the volume of the room in cubic feet, multiply by 5 and that gives the size of the unit or radiator you need in Btu. So an average living room or bedroom of 5m x 4m with conventional ceiling height is 16.4 ft x 13ft x 8ft, giving a volume of 1,705 cubic feet. Multiply by 5 gives 8,528 so I would install a 9,000 Btu AC unit. Radiators are also rated in Btu but that figure assumes they are fed with water at 70C and at the sort of flow rate achieved by a central heating pump. As the water from a heat pump is cooler and the flow is lower, in virtually all cases larger radiators (and often pipework) need to be installed. This is why people are having to spend in excess of £20k for an installation only to complain that the house isn’t as warm as it was with a conventional gas boiler. Radiators aren’t that efficient anyway, as all you have is a hot spot in one place in the room and the heat is spread mostly by convection with a little by radiation. That’s why it is recommended that the insulation properties are improved, to keep what feeble amount of heat you have from escaping.

Is it cheaper to run though? No not really. Let’s take the average 2 storey, 3 bedroom house. You’d be looking at a footprint of roughly 30ft square, so that is 900 square feet per floor so 1,800 square feet floor area. With 8ft ceiling height, that means you need around 72,000 Btu in total heating capacity or 28kW equivalent. OK, so AC units and air source heat pumps are pretty efficient so won’t be drawing that amount of power, but they will still draw in the region of 6kW as there’s one serious compressor in there (anything over a conventional house system will need a 3 phase supply). At today’s average electricity costs of around 30p per kWh, that’s £1.80 for every hour it is on. Not that cheap compared to a gas boiler, even at today’s prices, without taking into account the purchase price and the modifications needed to what you already have.

The only time a heat pump system will work adequately is if you have underfloor heating (and walking on a floor at 50C is a little more comfortable than one at 70C!). Although even then I have installed an AC unit into a house with underfloor heating fed by a heat pump as it would kick in as soon as the temperature dropped but if, after a couple of days the sun came out, it would switch off again. The owner of the house wanted AC to fill in the gap between the weather getting cold and the underfloor heating starting to work properly and also to give him the benefit of cooling in summer.

The irony of the whole thing is that you can get a Government grant of up to £5k to install a heat pump and they have a lower VAT rating too reducing the cost to buy and install. Although as they are so damn expensive in the first place there’s still a considerable outlay, particularly when you consider you can replace an existing gas boiler with a more efficient, modern one, for a couple of grand. But, even though it works in the same way and is probably better in many cases, you can’t get a grant for AC (and the systems are still rated at 20% VAT) as it gives you cooling as well as heating, so you are getting a bonus which the Government won’t pay for.

Personally I think Hydrogen fuelled boilers are the way to go but technology moves a lot faster than Governments so when they first made their recommendations that we should all be going for heat pumps, Hydrogen fuelled boilers weren’t around. Much like how they advocate we should a be driving battery electric cars when hydrogen fuel cell powered ones , or even a near conventional internal combustion engine running on Hydrogen, seem a much more viable, and ecologically friendly, option.

Seems it's after VIN YA445076 that they changed, so if your VIN is before that it is part number STC3679 (which is the same as for the petrol models) but afterwards it is JRB000030. However, Island 4x4 say you can fit the earlier one if you change a hose and modify a bracket, see https://www.island-4x4.co.uk/condenser-9402-nissens-stc3679g-p-6871.html. Mind you, with the price of the pipe (https://www.island-4x4.co.uk/pipe-condenser-compressor-9400-awr5075-p-26888.html), it might be cheaper to get the more expensive correct one.

Depends on what you buy. I assume heat pumps are much the same but with AC systems some, usually cheapo Chinese ones, can't provide heat if the external temperature drops below -5C, so a bit pointless. Better quality ones, like the Fujitsu units I use, will still provide the normal amount of heat down to -15C. I installed a Panasonic branded system that the customer had sourced himself and the manual said that the difference between ambient and output should be greater than 8 degrees C, pretty poor by anyone's standards.

That's where they always leak. A combination of the rubber foam holding moisture so it can rot through the thin aluminium and vibration chafing though.

But it also says Out f Stock. But the one thing with JLR is that if you click the Notify me button, they will get stock in as you are showing there is demand.

I may well do that when I get the time. I'm in Spain next week and nothing bores me more than sitting in the sun doing nothing so it would be a good opportunity.