Community Forums

BigRedLancer · 07-23-2005, 08:43 PM

On a hot day with a long climb in the mountains, which should I use the engine A/C or the coach A/C (gen. powered)? I just crossed the California central valley (on a car trip) with road temps up to 106 degrees during the day. I saw cars and RVs on the side of the road with their hoods up. I don't want this to happen to me.

Your thoughts.

BigRedLancer · 07-23-2005, 08:43 PM

On a hot day with a long climb in the mountains, which should I use the engine A/C or the coach A/C (gen. powered)? I just crossed the California central valley (on a car trip) with road temps up to 106 degrees during the day. I saw cars and RVs on the side of the road with their hoods up. I don't want this to happen to me.

Your thoughts.

RV Wizard · 07-24-2005, 01:25 AM

At times I use both the roof and dash a/c. When I were driving a gas coach up a long steep grade I would turn off the dash a/c on the pull up and let just the roof air run. This will allow the engine not to heat up as bad. If you are not running into the sun the roof air will give you better fuel milage on a gas coach. I haven't noticed much if any differance on the diesel fuel economy with dash air.

Gary RVRoamer · 07-24-2005, 05:00 AM

I recommend the roof a/c - your Sightseer will benefit from the much lower heat load on the engine cooling system and probably get better overall mpg as well.

When the sun is streaming in the windshield, it can get warm up front even when the house is cool overall. An extra fan in/near the cockpit area will help circulate the sun-heated air near the windshield to the rest of the "house" for cooling and make the pilot and co-pilot more comfortable. You can rig a 12V powered fan somewhere around the dash or simply plug in a home-type fan and sit it on the floor somewhere.

If your house a/c has a choice of fan settings, it is often better to choose a "continuous" fan setting rather than "automatic". That way the a/c fans continue to circulate air even when the compressor cycles off.

Novi · 07-24-2005, 06:52 AM

I certainly agree with the other posts. I find the engine A/C is not all that effective for the coach it just helps in the driver area. I have also read that it is more economical to run the gen. for A/C than use the engine A/C and I found this to be true also. I seldom use the engine A/C usually only if I want to cool things down as fast as possible and only for short periods, it does make the engine run hotter and in real hot weather and on steep hills and that is the last thing it needs.

Larry V. · 07-26-2005, 03:09 PM

On our just finished trip to Montana I used both roof and dash A/C. It was up to 118 F in Las Vegas and we needed both to make it bearable. In all of it, I never saw the engine temperature gage move at all.

Larry

2001 Rexair, 36', Ford V10

PDB · 07-27-2005, 05:10 AM

I'm curious. My Winny has a 350hp Cummins diesel. Will running the a/c really affect mileage on an engine like that? I understand the effect on cars, but on a DP?

RVRon · 07-27-2005, 08:30 AM

I felt that I lost "some" power in the old unit a W-22, with the dash air on and lost some efficiency. But if I'm too warm to drive comfortable, I really don't much care. My only concern running the dash air would be engine temps on a long, steep climb (never had the problem, but worried anyway). As far as the generator goes, go ahead and run it...it needs to be exercised regularly with at least a 50% load.
I run both mostly.

RandD · 07-27-2005, 10:14 AM

While I can understand the potential for lower fuel consumption by not running the engine A/C, we have not seen it in our Class C- (marketing calls it a b+). With the E450 chassis and the V-10, I can not tell any difference in mileage and the engine A/C keeps our coach very cool in 95+ weather, but then we are onky 26FT long.

When in teh Colorado mountians a few weeks ago, I did shut off the engine A/C while going up (used Gen/coach A/C) - However, I did always turn on the engine A/C going down hill for additional engine braking.

I think that the unit makes alot of difference and that there are no set 'rules' here. Try both ways and use the one that works the best for you!