High Ambient Temp Operation

[jack14r]

My cruise airs draw 11-12 amps which means 24 amps per leg with all 4 running,I usually see 35-40 amps per leg with battery chargers,water heater,water pump,etc. running on each leg total.

[phorner]

That sounds logical to me, Jon.

And, I wouldn't trade my genuine Prevost OTR air conditioning for a roof load of air conditioners.....

I kinda like the way my sun glasses immediately fog up the moment I step outside the bus on a nice hot day

[phorner]

My cruise airs draw 11-12 amps which means 24 amps per leg with all 4 running,I usually see 35-40 amps per leg with battery chargers,water heater,water pump,etc. running on each leg total.

I'm running all 4 right now and drawing 36.7 amps on one leg and 34.4 on the other. It only becomes an issue if both the hot water heater and pump kick on at the same time.

[GDeen]

Paul, if you search "tapecoat" you will find a thread about their product. It is an elastomeric and I applied it to my roof about 16 months ago. I think it definitely improves the heat rejection characteristics of the roof. Product still looks great and does not show any adverse weathering or soiling.

On the other hand, the white color is very visible on the roof if you are standing back from the coach. Doesn't bother me, but it may bother some.

My original color was metallic gray or silver, so if you go over your black with the tapecoat product, I suspect you will really notice a difference in temps.

[phorner]

Gordon,

Thanks for the info. I'll definitely check into this product.

My paint scheme is essentially a black outline, probably a foot or so wide, around the perimeter of the roof with a dark gold color center. I wouldn't mind a white roof color at all.

[dreamchasers]

So I finally found a place to load test the roof AC units. We have been traveling down I-10 from Houston to I-8 and on to San Diego.

Out of Houston on Sunday evening, we ran the dash air and two ACs on inverter and it was plenty cool.

Started with that Monday morning and ended up with the generator on around Fort Stockton with the OAT around 97.

Started this morning in Las Cruces with the generator and 4 ACs and hit Tucson at about 104 and still cool.

Now we are between Gila Bend and Yuma with the OAT at 112. Dash AC is on high as are the 4 roof air units. The roof airs are running a 14 to 12 degree delta between inlet and outlet and holding the front of the coach around 77. The galley / rear is 73. The sun is shining in the front quite a bit.

The roof on this coach is not coated which I think makes a big difference.

I never had our OTR air coach out in this kind of heat but so far we have made it thru the heat of the day pretty comfortable.

Jerry,

Your post mimics how my systems work in extreme heat. However, I have found that if I lower all my salon window shades, I notice a significant decrease in the heat load from the outside. During a run through Forth Worth with 105 temps, I lowered my shades and the roof airs started cycling.

Such a simple thing as lowering the shades reduces the heat load inside the salon area significantly.

Also, I have installed an insulation product on my roof. I can not remember the name of the product. I am currently on the road, when I get home I will look up the name from one of the leftover cans.

I can't tell if the coating or the lowering of the salon shades enabled the roof airs to cycle during the high heat.

Hector

[treedoc]

I would think that not only would your shades keep the heat from in, but the cold from going out as fast. Rick

[Reagan Sirmons]

JDUB,
Wally Melia at Freightliner in Houston is using a"Cool Coat" application on our roof after he removes the old clearcoat. On mine, the removal is a 30 hour job because he is removing the sealant around all roof attachments, a/c's etc. The application he is using is the same product recommended for school bus roofs. I do not know if this is a good recommendation or not but trust his judgement and experience with the product. If you want the specific name, I will obtain it for you. It is white and I believe more of a soft finish which I assume is of a rubber type base... good or bad?? Thoughts?
Pres