Stupid Aircon question

[been-and-bongo]

Agree with others my v6 (non lpg) gets toastie very quickly, in fact it's only the second car I've ever owned which I need to turn the temperature down. (The other was a mitsubishi galant)

[g8dhe]

Check that the servo mechanism and link down on the passenger are working, they control the heater vane in the box, ours certainly only takes 5 minutes to start pumping out the heat;


The much larger disk on the drivers side controls the direction flaps.

[been-and-bongo]

It took 6mins from a cold start to be comfortably heating the bongo.

[Spencer54]

Mine only seems to work well when I ramp it up to full 31 degrees, if its on anywhere sensible in the 20s it doesn't seem to make much difference.

Soon as I go full on it thunders - mines digital.

[wonkanoby]

same thing look for missing popped out control rods

digital a servo moves the rods bit like a radio controlled plane

[Northern Bongolow]

Am I right in thinking the heat comes from the engine coolant rather than a separate heater? So that you won't get warm air until the engine has warmed up?

tell me to shut up if im reading the question wrong

the heat for the aircon doesnt come from the engine coolant, or are you asking about the heater heat which is dependent on the coolant temp.
the aircon heat is created by the compressor on the aircon system, this acts on the gas in the system turning it into a liquid, in the proccess it creates heat. when the compressed liquid is depressurized it rapidly cools. this hot and cold can be used to either heat or cool the bongo cabin.
the reason it takes a little time to be felt in the cabin is that it takes a little time to get the system pressurized and its effects to be established.

from wikipedia.
In the refrigeration cycle, a heat pump transfers heat from a lower-temperature heat source into a higher-temperature heat sink. Heat would naturally flow in the opposite direction. This is the most common type of air conditioning. A refrigerator works in much the same way, as it pumps the heat out of the interior and into the room in which it stands.
This cycle takes advantage of the way phase changes work, where latent heat is released at a constant temperature during a liquid/gas phase change, and where varying the pressure of a pure substance also varies its condensation/boiling point.
The most common refrigeration cycle uses an electric motor to drive a compressor. In an automobile, the compressor is driven by a belt over a pulley, the belt being driven by the engine's crankshaft (similar to the driving of the pulleys for the alternator, power steering, etc.). Whether in a car or building, both use electric fan motors for air circulation. Since evaporation occurs when heat is absorbed, and condensation occurs when heat is released, air conditioners use a compressor to cause pressure changes between two compartments, and actively condense and pump a refrigerant around. A refrigerant is pumped into the evaporator coil, located in the compartment to be cooled, where the low pressure causes the refrigerant to evaporate into a vapor, taking heat with it. At the opposite side of the cycle is the condenser, which is located outside of the cooled compartment, where the refrigerant vapor is compressed and forced through another heat exchange coil, condensing the refrigerant into a liquid, thus releasing the heat previously absorbed from the cooled space.
By placing the condenser (where the heat is rejected) inside a compartment, and the evaporator (which absorbs heat) in the ambient environment (such as outside), or merely running a normal air conditioner's refrigerant in the opposite direction, the overall effect is the opposite, and the compartment is heated. This is usually called a heat pump, and is capable of heating a home to comfortable temperatures (25 °C; 70 °F), even when the outside air is below the freezing point of water (0 °C; 32 °F).
Cylinder unloaders are a method of load control used mainly in commercial air conditioning systems. On a semi-hermetic (or open) compressor, the heads can be fitted with unloaders which remove a portion of the load from the compressor so that it can run better when full cooling is not needed. Unloaders can be electrical or mechanical.

maybe the reason your not feeling its effects is because the evaporator is full of dead flys and road debris as is common.

[Diplomat]

tell me to shut up if im reading the question wrong

One would have to be a wealthy masochist to run air conditioning at this time of the year (and equally wealthy to run it in summer).


Frank

[mikeonb4c]

tell me to shut up if im reading the question wrong

One would have to be a wealthy masochist to run air conditioning at this time of the year (and equally wealthy to run it in summer).


Frank

I think the £ hit on a Bongo diesel fuel cost is relatively low as it's not an engine of great fuel efficiency with or without aircon on. And aircon is often most useful for demisting in cool weather!

[scanner]

tell me to shut up if im reading the question wrong

One would have to be a wealthy masochist to run air conditioning at this time of the year (and equally wealthy to run it in summer).


Frank

I think the £ hit on a Bongo diesel fuel cost is relatively low as it's not an engine of great fuel efficiency with or without aircon on. And aircon is often most useful for demisting in cool weather!

If you think it is "too expensive" to use a Bongo's aircon you should buy a different car. I notice no discernable difference whatsoever in MPG aircon on or aircon off.

[Diplomat]

If you think it is "too expensive" to use a Bongo's aircon you should buy a different car. I notice no discernable difference whatsoever in MPG aircon on or aircon off.

There's a far simpler solution than buying a different car. I don't use the aircon!

(except once in a blue moon, going downhill, to see if it still works - I wouldn't want to reduce the resale value and if i ever have to scrap it I can sell the pump as hardly used but seals ok)

Surely the engine knows that there is additional load? Doesn't it compensate to keep the tick over up?


Frank

[scanner]

If you think it is "too expensive" to use a Bongo's aircon you should buy a different car. I notice no discernable difference whatsoever in MPG aircon on or aircon off.

There's a far simpler solution than buying a different car. I don't use the aircon!

(except once in a blue moon, going downhill, to see if it still works - I wouldn't want to reduce the resale value and if i ever have to scrap it I can sell the pump as hardly used but seals ok)

Surely the engine knows that there is additional load? Doesn't it compensate to keep the tick over up?


Frank

Yes it probably does BUT the difference it makes to the running cost of a Bongo especially on the "Econ" setting is unmeasureable and probably far less than using 10W-40 oil instead of 5W-30 or running the tyres at 32 PSI instead of 36PSI.

Or even driving with the wing mirrors extended instead of folded flat.

My aircon needs regassing so isn't on and hasn't been on since the belt broke last year - have I noticed that it now does 40MPG - NO!

The MPG now, fill-up to fill-up, is still within the same range as it has always been.

On a 1.0litre gutless little petrol shopping car yes aircon can make a HUGE difference.
I drove a Daihatsu Charade belonging to my sister in Florida a few years ago and it made a huge difference - so huge you could feel it cut in when you were driving along. That car even had a "kick down" switch on the throttle that cut out the aircon when you booted it to get past something slower (the occasional Armadillo or sunbathing Alligator) because it you tried it with aircon working even I-95 wasn't long enough to get past anything.

Bongos do not have that problem.

[rita]

If you think it is "too expensive" to use a Bongo's aircon you should buy a different car. I notice no discernable difference whatsoever in MPG aircon on or aircon off.

There's a far simpler solution than buying a different car. I don't use the aircon!

(except once in a blue moon, going downhill, to see if it still works - I wouldn't want to reduce the resale value and if i ever have to scrap it I can sell the pump as hardly used but seals ok)

Surely the engine knows that there is additional load? Doesn't it compensate to keep the tick over up?


Frank

When the Air Con is engaged you should notice an instant DRAG on the engine/vehicle on tick over and whilst driving. There is not many accessories /light etc that you can use without increasing the fuel consumption. You don't get anything for nothing.

[scanner]

If you think it is "too expensive" to use a Bongo's aircon you should buy a different car. I notice no discernable difference whatsoever in MPG aircon on or aircon off.

There's a far simpler solution than buying a different car. I don't use the aircon!

(except once in a blue moon, going downhill, to see if it still works - I wouldn't want to reduce the resale value and if i ever have to scrap it I can sell the pump as hardly used but seals ok)

Surely the engine knows that there is additional load? Doesn't it compensate to keep the tick over up?


Frank

When the Air Con is engaged you should notice an instant DRAG on the engine/vehicle on tick over and whilst driving. There is not many accessories /light etc that you can use without increasing the fuel consumption. You don't get anything for nothing.

Nope, never have on the Bongo, never noticed any change in MPG either, too many other variables that have a far worse effect.

[g8dhe]

The air con. on my V6 drops the MPG by 5%, tried it on two runs of 300 miles or so, there was a discussion here with all the figures but looks like its been removed.

[scanner]

Unless every single factor on both runs were exactly identical there is no way of telling if the 5% reduction was due to using aircon or not.

It can indicate a likelihood that it has an effect but not exactly how much.

Perhaps the superior torque of diesels means they are less affected.

As I say, when I was driving without an aircon belt last year I noticed no appreciable difference. The Bongo didn't perform 5% better or get 5% more MPG.

I can however see that using aircon might have more impact on a petrol, especially a 2 litre.