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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: RJ on March 05, 2015, 10:48:55 AM

Title: MC-8, MC-9 OEM Driver's AC Capacity
Post by: RJ on March 05, 2015, 10:48:55 AM
Does anybody have a clue as to the capacity of the OEM Driver's A/C on an MCI 8 series?

I know that the whole system was about "8 tons", but that seems to be the total of both the main cabin plus driver's.  MC-9s were a little larger, at about "10 tons," again I think this was total capacity.

Reason I ask is that a PO of my coach removed the big compressor for the OEM HVAC, but left all the other components.  I could pick up another compressor and hook everything back up, but as most folk know, coach A/C is a high maintenance item, one I'd really not like to play with.  (Altho in a 5C you can hang meat when it's working.)

Since all the plumbing is still in place, I've been toying with the idea of using a Red Dot unit plumbed into just the OEM driver's A/C for running down the road.  In chatting with the local Red Dot guys, the capacity of the dash air unit came up in the conversation, and having that number is something they need to size the system properly.

So, does anybody have any capacity numbers for me?

TIA,

RJ
Title: Re: MC-8, MC-9 OEM Driver's AC Capacity
Post by: luvrbus on March 05, 2015, 10:59:39 AM
Most drivers AC are 22,500 to 38,000 btu that is 2 to 3 tons of AC for the drivers area  check the Pro Air line cheaper and just as good as Red Dot. I found it for the  MCI 8 it's 2 tons or 26,000 btu for the drivers AC that should cool you it would be same as 2-13,000 roof tops
Title: Re: MC-8, MC-9 OEM Driver's AC Capacity
Post by: bevans6 on March 05, 2015, 01:47:06 PM
If you still have the OEM condenser, you might be looking at changing it to a smaller unit.  I think they need to match the capacity of the evaporator.  The OEM condenser fan motor is a real power hog, and I think you could do better.  That OEM condenser bay is pretty handy space...

Brian
Title: Re: MC-8, MC-9 OEM Driver's AC Capacity
Post by: RJ on March 07, 2015, 06:14:53 PM
Thanks, guys, appreciate the info.

Got to thinking again today (dangerous!!) about this idea after looking in the condenser compartment behind the LF wheel on the 5C. 

I've got this big 24V, 2hp electric motor in there driving two squirrel-cage blowers to pull air thru the OEM condenser.  If I removed one blower and replaced it with a properly-sized double-grove pulley, I could theoretically drive a Sanden automotive A/C compressor with that electric motor just for operating the OEM Driver's A/C system while motoring down the super slab.  According to Sanden's website, their Flx-7 compressor #4862 draws about 50W maximum, or roughly a little over 1/2 hp, which is probably less than one of the existing blowers draws.

Naturally, the huge OEM condenser would come out, and I'd probably be able to get away with a unit off a GM/Chevy Suburban or similar, mounted to the access door, with a nice matching panel from a parted-out MC8/9 baggage bin door to cover what's not being used.

Remember, this is strictly for running down the hiway.  Coach has two roof airs which work fine, but the forward one is too far back to help the driver, thus the idea to use the existing factory driver's A/C.

Thoughts?

TIA. . .
Title: Re: MC-8, MC-9 OEM Driver's AC Capacity
Post by: solodon on March 08, 2015, 11:58:06 PM
I've retained the 24v motors associated with the OTR HVAC and hope to do something similar but didn't know how much power was needed.  The 1/2 hp number is good to know.  I too considered using an automotive based condenser and system connected to the driver A/C.  Your statement helps with that decision.
Don
Title: Re: MC-8, MC-9 OEM Driver's AC Capacity
Post by: Tony LEE on March 11, 2015, 12:00:49 AM
Whole system is working on my MC8 and I can state without the slightest hesitation that the drivers AC unit operating on its own would be a total waste of the effort to switch it on. Even with the main unit blasting away a few feet behind, the drivers AC adds very little to the drivers comfort.

Trouble is you have big unshaded windows 2 feet from your nose and a fair bit of hot air infiltrating through the front of the bus and that takes a lot of heat pumping to counteract.