A/C cooling capacity question...

[justinc]

Hoping some of you automotive A/C experts can help here.

I have been rethinking the A/C requirements for the 110, and have come across a dilemma regarding interior headroom, and now thinking a 'Red Dot R-6830' unit (http://www.rdac.com/Pages/product_pa...6830_unit.html), mounted between front seats may be a better alternative. It is rated at 17,000BTU/Hr, and 260CFM flow rate at max fan setting. Is this going to be sufficient to cool a 110 interior? Or do I need to fit 2 of them? (Back to back, between the front seats?)

Any help/ comparisons with factory air performance etc would help immensely.

JC

[Blknight.aus]

@5KW of cooling it should be about on the money the problem is going to be getting the air to circulate to where you want it.

[blitz]

bloody BTU's archaic terminology This is 1 BTU = 0.0002931 KW

Apart from Blknight, lada, myself and a few just plain smart buggers who are in the refrigeration industry and old enough to remember it no one in the industry uses it but sellers still do, we dropped it when metric came in back in umm 66? so long ago I cant remember.

Now that I have had my rant

as blknight said 5kw should be plenty, (I will conceed he is better at auto air than me hands down)

[rick130]

Never done a heat load on a car, where would you start other than 72w sensible per person

If it was a coolroom or domestic/commercial a/c system no worries

and yes, I need to drag the conversion book out if I come across BTU's or Tons of refrigerant.

[scarry]

The reason all that BTU crap keeps appearing is because the Chinese stuff is rated in it.Horse Power is also useless,but some people,including suppliers keep using it

Anyway,back to heat loads in vehicles,sorry,have no idea

In fact i think they have changed the regs so i am not supposed to work on auto air anymore,not that i would want to ......

[justinc]

...And BTU's are a USA thang, Red Dot are a US based company.

Doing my head in a bit, i did go through it wayyy back when, but can't remember any of it now

I was also interested if the flow rate would be enough, some slightly bigger units advertised by them have 400CFM+!

Anyway, keep the replies coming, it'll help immensely to find the right unit, without just reading through a catalogue

JC

[blitz]

I guess one way of making a comparison Justin is to get the size of the compressor that it comes out with, then you have a starting point; Obviously the evaporator needs to be sized the same so that it matches refrigerant flow rates.

Air flow? due to the amount of glass area and volume I would suggest the more the better as a rule of thumb, you can always turn the fan down but if you dont have enough when it's flat out then you have aproblem.

Sorry I cant be more accurate than that, all i can say is, in a vehicle over sized is better than undersized for the above reason (within reason )

Oi do you really need it in Tassy

[blitz]

Never done a heat load on a car, where would you start other than 72w sensible per person

If it was a coolroom or domestic/commercial a/c system no worries

and yes, I need to drag the conversion book out if I come across BTU's or Tons of refrigerant.

When I was doing cars, trucks and earth moving equipment - over 20 years ago in the Territory (and apart from my landy it's been that long since I played with them) we used to cram in the biggest unit we could that wouldn't stall the engine, never had a complaint

[slug_burner]

I think it is 1120 watts per square metre of surface area that the sun contributes to heat load. Then there is the issue of external air temp and humidity as in habital spaces you require a certain amount of fresh air. In vehicles I am not sure what percentage fresh air is brought into the vehicle when it is on recycling the interior air only. Five kW of cooling is a fair size aircon but I expect you would need that or better to maintain the ambient temp inside the vehicle due to the poor insulation.

I think that most vehicle aircon systems rely on the cold air ducts pointing at the body and therefore getting a greater degree of comfort to those that have control of the vents.

[scarry]

...And BTU's are a USA thang, Red Dot are a US based company.


JC

My mistake,yes they still do use it in the USA,But many of the Chinese split A/C's are rated in BTU's.

Could you find out what ,say,a D2 A/C system is rated at,therefore giving you a reference to start on.The D2 seems to have a very good A/C system,although it is smaller than a Defender.