|
|
04-15-2014, 05:21 PM
|
#29
|
Senior Member
Vintage RV Owners Club
Join Date: Jul 2009
Location: Beaverton, OR
Posts: 312
|
Quote:
Originally Posted by kschoon1
I don't have anything to add as far as which method provides better mileage but I do know that my coach stays cooler running the house AC. Biggest issue I have is when everyone (passengers) are sleeping and I get too cold while driving and have no way to turn the temp up. Anyone know of anyway to control the house AC's remotely?
|
Heck yea! Power down the gen from cockpit will kill the house AC's quickly!
__________________
fkloster = Fritz, Erin, Sadie, Bo (& Lucy the Weim)
1991 Beaver Marquis 40' (1,225 ft. lbs. torque)
2011 JGC Overland Summit Toad / U.S Gear Brake
|
|
|
|
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!
|
04-15-2014, 05:46 PM
|
#30
|
Senior Member
Join Date: Feb 2012
Location: Aiken,SC
Posts: 1,025
|
Quote:
Originally Posted by spritz
If AC is needed I will run the Gennie and house AC while under way. I hate sweating. The mileage or Gas consumption really don't matter to me I got to go where we want to go and I am going comfortably. I prefer to having the horsepower while underway and to be com-fie. I think that is why they were built they way they were and that was to make it com-fie weren't they?
JMO,tb
|
Same Here!
__________________
Good Sam Life Members
Served in U.S.A.F.
|
|
|
04-16-2014, 07:32 AM
|
#31
|
Senior Member
Join Date: Feb 2011
Location: Snowbird - Waterford Mi and Citrus Springs Fl.
Posts: 3,609
|
Quote:
Originally Posted by fkloster
Heck yea! Power down the gen from cockpit will kill the house AC's quickly!
|
Functionally yes, but your not doing any favors to some expensive electrical components, or the generator engine itself.
From a "best practices" and longevity standpoint, the A/C's should be shut off first, then allow the engine to cool itself down without a load on it for a few minutes, then shut it down.
__________________
1997 37' HR Endeavor, 275hp Cat, Freightliner
03 CR-V Blue Ox, Ready Brake
|
|
|
04-16-2014, 02:39 PM
|
#32
|
Senior Member
Damon Owners Club Workhorse Chassis Owner
Join Date: Mar 2009
Posts: 24,024
|
I have heard that many times. and it is true in part.. YES, using the dash A/C will "Rob" power from the engine and it WILL reduce your Miles per gallon... As computed by the dash computer.
Running the GENERATOR will also consume fuel (Just this fuel does not run through the dash computer) so if you figure MPG by the "Miles since last fillup / gallons to re-fill, method,,, My guess is you will find your savings are negative (That is it burns more gas than the Dash.
HOWEVER.. there is more...
NO way can the Dash A/C keep the RV cool when it's 90 in the shade and you are in full sun. That takes all 3 of 'em. Dash plus both Roof top units.
__________________
Home is where I park it!
|
|
|
04-16-2014, 05:25 PM
|
#33
|
Senior Member
Workhorse Chassis Owner
Join Date: Feb 2004
Location: Raynham, MA
Posts: 140
|
Interesting conversation. My dash air went out and I attempted to use the roof unit to cool my 37 foot Class A Motorhome with no luck. I ended up putting the window down and using the fans.
Does anyone have a scientific study as to the actual fuel consumption of a 7000 watt Onan?
r0n…..
__________________
Full Time Wana Bs
2004 MACA3781
|
|
|
04-16-2014, 05:54 PM
|
#34
|
Senior Member
Join Date: Aug 2001
Location: North America somewhere
Posts: 30,971
|
Quote:
Originally Posted by ron & deb
Interesting conversation. My dash air went out and I attempted to use the roof unit to cool my 37 foot Class A Motorhome with no luck. I ended up putting the window down and using the fans.
Does anyone have a scientific study as to the actual fuel consumption of a 7000 watt Onan?
r0n…..
|
http://www.irv2.com/forums/f84/gener...on-179407.html
__________________
2000 Winnebago Ultimate Freedom USQ40JD , ISC 8.3 Cummins 350, Spartan MM Chassis. USA IN 1SG 11B5MX,Infantry retired;Good Sam Life member,FMCA. " My fellow Americans, ask not what your country can do for you, ask what you can do for your country. John F. Kennedy
|
|
|
04-16-2014, 06:34 PM
|
#35
|
Senior Member
National RV Owners Club
Join Date: Jun 2010
Posts: 4,581
|
I run an 120 volt floor fan a few feet aft of and pointed towards the front seats when running the generator and house air conditioning. Really helps circulate the air though the RV.
__________________
Bob & Sandi, dogs Tasha a Frenchie and Tiki a Skipperkey
SW OREGON 2005 34 foot DolphinLX
If towing: a bright red 2016 Mini Cooper on a tow dolly.
|
|
|
04-18-2014, 11:41 AM
|
#36
|
Senior Member
Workhorse Chassis Owner
Join Date: Feb 2004
Location: Raynham, MA
Posts: 140
|
Quote:
Originally Posted by Ray,IN
|
Thanks Ray….I am thinking about 1 gallon per hour. I was calculating the cost of running the AC instead of paying for a campground. 8 hrs = 8 gal * $3.50 =about $28.00 a night. Think I will get my Passport America book out.
r0n…..
__________________
Full Time Wana Bs
2004 MACA3781
|
|
|
04-18-2014, 11:43 AM
|
#37
|
Senior Member
Workhorse Chassis Owner
Join Date: Feb 2004
Location: Raynham, MA
Posts: 140
|
Quote:
Originally Posted by 1ciderdog
I run an 120 volt floor fan a few feet aft of and pointed towards the front seats when running the generator and house air conditioning. Really helps circulate the air though the RV.
|
I will give that a try…dog…….
Thanks, r0n…..
__________________
Full Time Wana Bs
2004 MACA3781
|
|
|
04-18-2014, 12:46 PM
|
#38
|
Senior Member
Join Date: Jan 2014
Posts: 143
|
Lots of great info on these 3 pages of postings…….
but generator fuel consumption is very hard to predict as it will vary with the load on your generator……one or two AC units, hot water, refer.
I liked the comment that using the generator to power an AC unit while driving is a good opportunity to give it some good exercise while under a load.
|
|
|
04-18-2014, 02:22 PM
|
#39
|
Senior Member
Join Date: Jul 2011
Posts: 2,303
|
Quote:
Originally Posted by wa8yxm
My guess is you will find your savings are negative (That is it burns more gas than the Dash.
|
Of course. It's easy to confuse efficiency with capacity. The dash air is good for maybe 15k BTU or so and running two rooftop A/C units are about twice that so obviously the latter will use more fuel. Even running a single rooftop A/C, you are comparing a compressor driven directly off of the engine vs. one driven by running a second engine that first has to generate electricity (creating losses) and the the air conditioner has to turn that electricity back into mechanical energy to drive the compressor (more losses.) It seems very unlikely that a separate generator and A/C unit would be as efficient as a direct engine-driven unit when BTU capacity is similar.
But that's all efficiency... and if the dash air doesn't have sufficient capacity then you don't have much option than to run the house generator and A/C units to create additional cooling. But it's highly unlikely that running another engine and (probably multiple) electric A/C units could possibly use the same amount or less energy (and thus fuel) as using the dash air, it just about has to use more.
|
|
|
04-19-2014, 08:30 AM
|
#40
|
Senior Member
Join Date: Oct 2012
Location: Pawleys Island SC
Posts: 339
|
In connection with the efficiency discussion in this thread, I am the one who compiled the published fuel figures from all the RV generators I could find. The latest PDF with this data is attached. This version has some other facts beside fuel.
My Brisk Air units draw 1.91 KW under full load for a total of 3.82 KW while running. Adding a Dometic refrigerator to that load adds 0.38 KW. That’s a total of 4.2 KW, and of course none of these will run100% of the time, and some service factor should be applied to arrive at a reasonable amount of power required. I suspect that service factor will be in the range of 50%.
Below is a little table showing four generators operating at half load which appears to be enough to support most any service factor that actually occurs.
PowerTech CD-7 Constant Speed Diesel__0.32 gph at 3.5 KW
Onan 8.0 HDKAK Variable Speed Diesel____0.49 gph at 4.0 KW
Onan 7 HGJAB Constant Speed Gasoline____0.70 gph at 3.5 KW
Onan 6.5 HGJABConstant Speed Propane___0.80 gph at 3.25 KW
As indicated, there is a pretty large difference in fuel efficiency between different fuels and also the price in fuel for the variable speed diesel as compared to constant speed..
These figures indicate to me that running the generator for coach air conditioning while under way is very efficient for diesel operation, but less so for gasoline and propane.
Good Luck!
Wil
__________________
Wil Andrews
2007 Newmar Kountry Star DP
Cummins ISL, Cummins E-Brake
|
|
|
04-19-2014, 11:02 AM
|
#41
|
Senior Member
Join Date: Jul 2011
Posts: 2,303
|
Quote:
Originally Posted by wil01
These figures indicate to me that running the generator for coach air conditioning while under way is very efficient for diesel operation, but less so for gasoline and propane.
|
No, it will be the same, assuming that a diesel powered coach is carrying a diesel-powered generator and a gasoline-powered coach is carrying a gasoline-powered generator, as is almost always the case. For a given BTU cooling capacity the energy is coming from either the RV engine or the generator engine, and since these use the same fuels then the amount of additional fuel used for A/C will be about the same (or perhaps slightly more for the separate generator as explained above.)
|
|
|
04-19-2014, 11:07 AM
|
#42
|
Senior Member
Winnebago Owners Club Ford Super Duty Owner
Join Date: Aug 2013
Location: Lake Elsinore, CA
Posts: 230
|
Rv Doctor's advice
|
|
|
|
|
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
|
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
|
» Recent Discussions |
|
|
|
|
|
|
|
|
|
|
|
|
|