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 > Keeping cool

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ppine

Northern Nevada

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Posted: 07/14/19 09:36pm Link  |  Quote  |  Print  |  Notify Moderator

My solution is to head to the mountains.

Happytraveler

Capistrano Beach, Ca. USA

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Posted: 07/15/19 08:38am Link  |  Quote  |  Print  |  Notify Moderator

I would say we drive 90% of the time with the generator and air conditioner on. Sometimes we have two air conditioners running at the same time.


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PartyOf Five

Wheaton, IL

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Posted: 07/15/19 10:05am Link  |  Quote  |  Print  |  Notify Moderator

On max ac we have enough cold air circulating to keep the front ~15' icy with the interior door closed.
It's all lost by the time everyone gets out so we turn on the roof top unit when we're stationary.

If it's really hot we'll keep the roof vent in the rear closed, and try to limit use if that half until it cools down. Ditto with cool nights before firing up the furnace.


Da Moose - 2001 Dutchman 31' on E450

paddykernahan

Westland, MI

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Posted: 07/15/19 12:44pm Link  |  Quote  |  Print  |  Notify Moderator

pnichols wrote:

We keep all rooftop vents and windows closely tight during hot weather travel in our 24 foot E450 Class C. We then keep the dash air flow and dash air conditioning system set to Max A/C so interior air is merely reciculated over and over - hence the Ford air conditioning system does not have to continuously cool new hot air from the outside - it just has to keep the already cooled interior air cool ... which is a way more efficient way to use the dash air's cooling capacity.

What we wind up with is an entire coach interior that can be kept cool using only the Ford A/C system ... because it's so powerful and we're using it in the most efficient way. Our rooftop A/C system never is needed when traveling in even the very hottest outside temperatures.

As a bonus, the interior of the coach stays dust-free much longer because there is no constant flow of outside air coming into it from the cab air flow set to constantly get new outside air ... which then flows throughout the coach and out any open vents or windows in the coach ... depositing dust inside while this is going on as we travel down the road.

If we ever need to leave the roof vents open for some reason when traveling, they're protected from being ripped off via vent covers we've installed over them which still allow the vents to remain open. With vent covers, we can also leave the vents themselves open for fresh air ventilation when it's raining or snowing while camped.


I just did the same as you yesterday.
Small MB Sprinter class C.
Vents closed, air on max, air on recirculate.
Worked very well except MB decided to limit air recirculation to only 30 minutes and it resets to fresh air.

When plugging in or on generator, we just start the RV air conditioner.





Hank85713

Tucson, Az

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Posted: 07/15/19 06:28pm Link  |  Quote  |  Print  |  Notify Moderator

As to cooling when parked, I read someplace a recommendation to keep slides in initially when turning the ac on. Less area to cool down, thus will cool quicker (?). Havent really tried this but sounds reasonable.

Also camp world sells vent covers about same as MAxair but at lesser cost. Just have their logo on them.

Bordercollie

Garden Grove, CA, USA

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Posted: 07/16/19 09:46am Link  |  Quote  |  Print  |  Notify Moderator

"Dave", the generator expert at Smith Powerhouse, Inc, recommended using the RV generator and roof air conditioner while underway as the generator uses a lot less gasoline than the dash AC requires. I'm not sure that the comfort level in the cab will be as good as when using the dash AC. We'll try using one or the other or both. Best to travel in mornings and evenings when practical to be easiest on you and your rig. I worry about hot tires pounding on cupped concrete or superheated asphalt highways on hot days.

JaxDad

Greater Toronto Area

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Posted: 07/16/19 01:27pm Link  |  Quote  |  Print  |  Notify Moderator

Bordercollie wrote:

"Dave", the generator expert at Smith Powerhouse, Inc, recommended using the RV generator and roof air conditioner while underway as the generator uses a lot less gasoline than the dash AC requires.


I'm not sure how much faith I'd put in an "expert" that makes such silly statements as that one.

A basic 4kw genny at idle uses 0.3 gallons per hour, 0.5 at half load.

I saw a test a few years back where they concluded thata V10 in a large vehicle would consume an extra 1% in fuel. That makes sense since they figure an econo-box will use an extra 3% with A/C on, smaller engine, proportionately larger load.

If an RV then gets (for easy math) 10 MPG, running the A/C compressor will decrease that to 9.9 MPG if said RV is going 60 MPH then it will use 6.06 gallons per hour instead of 6 gallons.

If somebody thinks 0.3 to 0.5 gallons is "a lot less" than 0.06 they're no "expert" in my books.

A politician maybe, but NOT an expert.

pnichols

The Other California

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Posted: 07/16/19 02:14pm Link  |  Quote  |  Print  |  Notify Moderator

JaxDad wrote:

Bordercollie wrote:

"Dave", the generator expert at Smith Powerhouse, Inc, recommended using the RV generator and roof air conditioner while underway as the generator uses a lot less gasoline than the dash AC requires.


I'm not sure how much faith I'd put in an "expert" that makes such silly statements as that one.

A basic 4kw genny at idle uses 0.3 gallons per hour, 0.5 at half load.

I saw a test a few years back where they concluded thata V10 in a large vehicle would consume an extra 1% in fuel. That makes sense since they figure an econo-box will use an extra 3% with A/C on, smaller engine, proportionately larger load.

If an RV then gets (for easy math) 10 MPG, running the A/C compressor will decrease that to 9.9 MPG if said RV is going 60 MPH then it will use 6.06 gallons per hour instead of 6 gallons.

If somebody thinks 0.3 to 0.5 gallons is "a lot less" than 0.06 they're no "expert" in my books.

A politician maybe, but NOT an expert.

Well stated comments and analysis above!

Plus ... adding to your analysis and math ... in our case I pretty much trust that the Ford E450's air conditioning equipment powered by it's V10 computer controlled engine, when taken together as an air conditioning system, is probably "better and more modernly engineered" than our Onan generator and Coleman rooftop air conditioner. [emoticon]


Phil, 2005 E450 Itasca Spirit 24V

Bordercollie

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Posted: 07/16/19 03:58pm Link  |  Quote  |  Print  |  Notify Moderator

I guess we have a choice to believe the conclusion of "somebody's" test a few years back vs some "expert's" silly statement about use of RV generator and roof AC. It would probably be difficult to get reliable results comparing gas mileage with generator running vs use of dash AC, but we could try it on long runs over relatively flat land.

JaxDad

Greater Toronto Area

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Posted: 07/16/19 06:18pm Link  |  Quote  |  Print  |  Notify Moderator

Bordercollie wrote:

I guess we have a choice to believe the conclusion of "somebody's" test a few years back vs some "expert's" silly statement about use of RV generator and roof AC. It would probably be difficult to get reliable results comparing gas mileage with generator running vs use of dash AC, but we could try it on long runs over relatively flat land.


The “somebody” was Consumer Reports and their mileage on the small car was identical to that of the EPA’s testing.

But if you need a more reliable test, Jamie & Adam did a Mythbusters episode on A/C and couldn’t measure the loss in fuel mileage running A/C or not with the windows closed. With the windows open yes, the parasitic loses are significant.

I know that several on units I’ve come across including my 2 m/h’s and several of the V10 fleet units we have the OBD data stream doesn’t show any difference in mileage with A/C on or off.

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