Go Back   iRV2 Forums > iRV2.com COMMUNITY FORUMS > iRV2.com General Discussion
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on iRV2
 
Thread Tools Search this Thread Display Modes
 
Old 11-27-2011, 11:15 PM   #1
Senior Member
 
Davdeb1's Avatar


 
Monaco Owners Club
Freightliner Owners Club
iRV2 No Limits Club
Join Date: Jan 2011
Location: Avon Lake, Oh
Posts: 2,884
Dash A/C or overhead AC?

Everyday , it seems I learn more. This site plus my snooping around the coach leads to discoveries, then of course more questions.

While driving, what is more economical to use, the dash air, or the overhead AC units and of course the generator. The manual shows under 1/2 load the genny will use about 1/2 gallon an hour. I can not find anywhere, how much it drags from the engine to run the dash air.

I have 330 hp cat, and a 7500kw genny.

Looking underneath, the length of these a/c hoses on a 40 ft home, really seems inefficient. I'm willing to bet the cost of replacing the dash AC is almost s much as rebuilding a generator.

MH gets 10 mpg, gen uses 1/2 gal per hour. The faster your drive the more efficient using the genny becomes.

I can not be the first person to wonder about this.
__________________

__________________
2000 HOLIDAY RAMBLER ENDEAVOR
40 FT--330HP CAT
2 SLIDES-TOAD 2012 focus
Fulltime-Home is where we park it.
Davdeb1 is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free!

iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 11-28-2011, 03:57 AM   #2
Community Moderator
 
RV Wizard's Avatar


 
Country Coach Owners Club
Appalachian Campers
Gulf Streamers Club
Join Date: Mar 2000
Location: Chattanooga, Tn.
Posts: 12,062
You are not the first and you won't be the last. A gas coach is more effected by a difference than a diesel coach but the general rule is that the generator and roof air conditioner method of cooling is more economical. However, there may be a time when running west late in the day, that the dash air is necessary; due to the heat load on the windshield. Good luck, enjoy and keep us posted.
__________________

__________________
Mike, RVIA & RVSA Certified Master RV Technician
Amy, Dr. Assistant - Roxie & Mei Ling, four legs each
2000 Gulf Stream Scenic Cruiser 450 hp & 1330# torque
06 Saturn Vue, 06 Chevy Z71 4x4 & 2014 Corvette Z51 M7
RV Wizard is offline   Reply With Quote
Old 11-28-2011, 10:43 AM   #3
Moderator Emeritus
 
Gary RVRoamer's Avatar


 
Join Date: Jan 2000
Location: Silver Springs, FL. USA
Posts: 18,073
The dash air is a hidden load, often as much as 20-30 hp of constant power draw. You just don't notice it when you fill the tank. And the dash air won't cool the whole coach unless it is really small. In our 40 footer with a big glass "greenhouse", it barely keeps the front seat area cool.

Running one a/c on a 7500 watt genny is only about 20% load (1500 watts), so the amount of fuel used is tiny, around 0.2 gal/hour. Turn the big air on and enjoy it. We do so whenever the outside temp gets much above 80 and the sun is bright.
__________________
Gary Brinck
Former owner of 2004 American Tradition
Home is in the Ocala Nat'l Forest near Ocala, FL
Summers in Black Mountain, NC
Gary RVRoamer is offline   Reply With Quote
Old 11-28-2011, 11:15 AM   #4
Senior Member
 
DutchStar38's Avatar
 
Newmar Owners Club
iRV2 No Limits Club
Join Date: Mar 2010
Location: Sarasota,FL
Posts: 448
I use the dash a/c when driving facing a searing sun. Otherwise, both overhead units are running which keeps the entire unit cool. Also, it is very nice to have the entire unit cooled down already after getting all hot a sweaty setting up. I also use the dash a/c when my dog has to sit in my lap and sleep.
__________________
Lynda & Ronny Sarasota, Florida
2005 DutchStar DP 3809
Sammy (Brussels Griffon\Maltese)
TJ (Teacup Poodle 2.7 lbs)
DutchStar38 is offline   Reply With Quote
Old 11-28-2011, 11:37 AM   #5
Senior Member
 
sdennislee's Avatar


 
Monaco Owners Club
Winnebago Owners Club
Join Date: Sep 2011
Posts: 6,404
Quote:
Originally Posted by DutchStar38 View Post
I use the dash a/c when driving facing a searing sun. Otherwise, both overhead units are running which keeps the entire unit cool. Also, it is very nice to have the entire unit cooled down already after getting all hot a sweaty setting up. I also use the dash a/c when my dog has to sit in my lap and sleep.
Ditto for us. Dash unit will not cool more than the drivers area and on a bright sunny day it struggles to do that. I run the front coach unit at least.
__________________
US Navy Vet, Liberty Tree Member of Oath Keepers, NRA & VFW Life Member, Alaska EMT.
2009 Safari Cheetah 40 SKQ
2009 Winnebago Chalet 231CR
sdennislee is offline   Reply With Quote
Old 11-28-2011, 01:29 PM   #6
Member
 
Join Date: Aug 2011
Posts: 81
We do it by comfort. If the dash air does the trick fine, if not we turn in the generator and roof air(s).
__________________
Blaster 22 is offline   Reply With Quote
Old 12-02-2011, 10:05 PM   #7
Member
 
Mr John's Avatar
 
Winnebago Owners Club
Ford Super Duty Owner
Join Date: Dec 2010
Location: Boynton Beach, Fl
Posts: 96
Smile

In our Aspect 26A we run the dash air and it keeps the whole MH cool. I haven't checked running the roof air and checking the fuel mileage to see if there is a difference. I may do that the next time we take a trip. I know the genny is supposed to be super effecient when used to run the A/C.
John
__________________
Mr John is offline   Reply With Quote
Old 12-04-2011, 09:30 AM   #8
Senior Member
 
footdoc's Avatar
 
Join Date: Jul 2006
Location: Mobile, Alabama
Posts: 1,002
I did a calculation last summer for my 400HP DP and I think it was about 2-3% cheaper to run the roof air vs dash...not a biggie but with my 66" tall windshield the dash air definitely is worth it...!!!!
__________________
2006 Mountain Aire 43 and 05 Honda Pilot
Air Force One..Real Whirlpool Fridge !
3 sugar gliders, long hair daschund and short hair wife for security
footdoc is offline   Reply With Quote
Old 12-04-2011, 11:50 AM   #9
Senior Member
 
Join Date: Jul 2009
Posts: 466
In the overall scheme of things, the operating cost of one over the other is miniscule.

Jim E
__________________
Pairajays is offline   Reply With Quote
Old 12-04-2011, 12:00 PM   #10
Senior Member
 
1ciderdog's Avatar


 
Join Date: Jun 2010
Posts: 4,325
I agree with Pairajays about operating cost. For me it is creature comfort - If it's hot I use the generator & AC unit (just like in the cold winter I'll run the furnace to keep warm). On my RV it seems to take forever for the basement airconditioning to cool the RV if it is hot inside when we arrive at our destination.
Safe Travels
Bob
__________________
Bob, Sandi & Marmaduke the Big Pug
SW OREGON 2004 Journey 39K, 330 Cat
If towing: a 2006 Mini Cooper or 1995 Wrangler
1ciderdog is offline   Reply With Quote
Old 12-04-2011, 12:47 PM   #11
Senior Member
 
336muffin's Avatar
 
Join Date: Apr 2011
Posts: 2,569
We always run the roof airs, we set the bedroom a little cooler than the front air. We also when facing the sun, run the dash FAN only to circulate the cooler air up front. This helps a lot and does not put the load on the diesel.
__________________
336muffin is offline   Reply With Quote
Old 12-04-2011, 01:39 PM   #12
Senior Member
 
wa8yxm's Avatar
 
Damon Owners Club
Workhorse Chassis Owner
Join Date: Mar 2009
Posts: 22,792
I have seen this question many many many many times.. Many argue it is less expensive to run the genny.

What I find, and yes, this will very from rig to rig, is the HOUSE air does a tripple P job of cooling the cockpit area (I won't tell you what the first P iss but the other two are POT POOR). Silibant S on purpose)

Likewise the dash air don't do much for the house.

I use dash when driving less it's really hot, then I double up. (or if it is my 30 minutes under half load day)
__________________

__________________
Home is where I park it!
wa8yxm is offline   Reply With Quote
Reply



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Allegro Dash A/C on Ford F-53 ? GARYMC74 Tiffin Motorhomes Owners Forum 3 01-20-2011 10:02 AM
Dash a/c hapyhrs Newmar Owner's Forum 7 11-10-2010 08:27 PM
No Dash A/C on 2009 Knight...Fan Only...No Cold Air Alga Forrest Monaco Owner's Forum 12 10-14-2010 08:39 AM
Dash A/C 2000 Adventurer Ford tlumpkin Winnebago Industries Owner's Forum 3 08-28-2009 01:12 PM
Dash A/C Fan Problem AlpineAZ Alpine Coach Owner's Forum 17 10-22-2008 03:10 PM

» Virginia Campgrounds

Reviews provided by


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 11:23 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.