AC temperature

[JamieGeek]

Originally Posted by bthode@gmail.com View Post
A big factor for my Vegas is sun exposure... the big windshield really heats up the front of the motorhome. I just installed sun screens that are supposed to reduce sun-induced heating by 94%... we'll see.
Luckily the Challengers come with a motorized black out shade for the front window. We also have both solar and black out shades on most of the windows. This significantly reduces sun exposure to the inside.

The Vegas/Axis models also have a motorized black out shade.

The Sunguard windscreen really works well at reducing the heat from the fishbowl front window.

[DNS]

I am new to this forum as we just purchased our first Thor. We are having a problem with A/C as well. We just brought home our Challenger 37GT a couple of weeks ago and we were trying to check everything we could think of before our first trip. Several minor things as well as the hot water heater does not work. It has been running for over 2 hours now and the inside temperature will not come down below 84. It is currently 87 outside with 59% humidity. If anyone has any ideas, I would love to hear them. We love to travel to Florida and the southwest where temperatures commonly exceed 100. There are two 13,500 BTU air conditioners on this unit. Prior to this we had a 33 ft. Coachman Mirada and summertime in south Florida, the air conditioners cooled everything down within an hour. I just do not understand this. I am getting pretty upset about it because there was nothing wrong with our 2007 Mirada, we just wanted to upgrade and update. We had only a couple of minor things wrong with it in the 8 years we had it. I am feeling sick that we made a terrible mistake. These larger motor homes cost as much as many houses do. The quality should be so much better.

[EA37TS]

Originally Posted by DNS

I am new to this forum as we just purchased our first Thor. We are having a problem with A/C as well. We just brought home our Challenger 37GT a couple of weeks ago and we were trying to check everything we could think of before our first trip. Several minor things as well as the hot water heater does not work. It has been running for over 2 hours now and the inside temperature will not come down below 84. It is currently 87 outside with 59% humidity. If anyone has any ideas, I would love to hear them. We love to travel to Florida and the southwest where temperatures commonly exceed 100. There are two 13,500 BTU air conditioners on this unit. Prior to this we had a 33 ft. Coachman Mirada and summertime in south Florida, the air conditioners cooled everything down within an hour. I just do not understand this. I am getting pretty upset about it because there was nothing wrong with our 2007 Mirada, we just wanted to upgrade and update. We had only a couple of minor things wrong with it in the 8 years we had it. I am feeling sick that we made a terrible mistake. These larger motor homes cost as much as many houses do. The quality should be so much better.

Hello fellow challenger owner.

First, hot water: Have you verified the hot water bypass valves are not closed and that the hot water tank is full of water? The challengers have two water heater by pass valves. One is on the Anderson termination center in the storage compartment (where you select city water etc...) and on mine the other is accessed through the bottom right closet drawers in the bedroom. I believe the second is accessed through a bedroom drawer closet the location of water heater on the GT as well.

AC, did you notice what the inside temp was when you turned on the AC units? The first time I turned my AC on when the outside temp was over 80 (the inside temp at that time was over 90) it took some time to cool down. Since I have 50 Amp shore power on the side of my house I now leave the AC units on and set at 80 to dehumidify and make it easier to drop the temp before a trip.

[DNS]

The water heater does not try to ignite at all, so no flame. Checked the terminals and everything seems to be connected.

A/C - The inside temperature was 89 when we first turned on the air conditioners and after 2 1/2 hours it only got down to 84 in the front, but 74 in the back. Cannot tell if the compressor is running on the front air conditioner.

Trying to get it in for service.

[EA37TS]

Originally Posted by DNS

The water heater does not try to ignite at all, so no flame. Checked the terminals and everything seems to be connected.

A/C - The inside temperature was 89 when we first turned on the air conditioners and after 2 1/2 hours it only got down to 84 in the front, but 74 in the back. Cannot tell if the compressor is running on the front air conditioner.

Trying to get it in for service.

If you read this thread from the beginning we discuss the temperature split and how it can be used to determine whether or not the system is functioning. You may want to give that a try before hauling the unit back to the dealership.

I believe one of the other Challenger folks had an issue with their water heater as well and his issue was the inline fuse at the water heater. He found it by removing the inline fuse from the wire (it is a sort of jumper) and then turning the water heater on and it fired up.

Not sure about the link but there is a video on the web about troubleshooting Attwood water heaters.

[DNS]

Originally Posted by dstankov

If you read this thread from the beginning we discuss the temperature split and how it can be used to determine whether or not the system is functioning. You may want to give that a try before hauling the unit back to the dealership.

I believe one of the other Challenger folks had an issue with their water heater as well and his issue was the inline fuse at the water heater. He found it by removing the inline fuse from the wire (it is a sort of jumper) and then turning the water heater on and it fired up.

Not sure about the link but there is a video on the web about troubleshooting Attwood water heaters.

Thanks so much - I will check it out.

[Gigi]

I purchased a 2015 Vegas last July. I was under the impression from what I was told that I could get better milage if Ac was not only in the cab but in the house portion of the RV. Not sure if this is true or not but secondly not sure how to effectively cool bedroom area while on the road. Any ideas on this?

[bthode@gmail.com]

Gigi-
In order to run the roof AC you would need to run the generator...that's going to reduce your milage a bit. I did it once when it was really hot and it worked great. I didn't run it long enough to check the milage with generator ON.
Another reason to run the generator and AC would be to keep a pet cool (our black lab, Moose, rides on the bed.)
Brad

[EA37TS]

Originally Posted by bthode@gmail.com

Gigi-
In order to run the roof AC you would need to run the generator...that's going to reduce your milage a bit. I did it once when it was really hot and it worked great. I didn't run it long enough to check the milage with generator ON.
Another reason to run the generator and AC would be to keep a pet cool (our black lab, Moose, rides on the bed.)
Brad

The Onan 5500 on my Challenger uses 1.2 gallons per hour at full load. At half load it uses just under a gallon an hour.

Your Onan manual will tell you what the generator's fuel consumption will be at various loads. In the grand scheme of things I believe it works out to be maybe one or two tenths of a mile per gallon.

[bthode@gmail.com]

Assuming the generator uses one gallon per hour, after five hours of driving that's 5 gallons. That is very close to 10% of my fuel tank that would be gone. (55 gal tank). I think it would be worth a few gallons of gas to be comfortable running the gen/AC, however.

[EA37TS]

Originally Posted by bthode@gmail.com

Assuming the generator uses one gallon per hour, after five hours of driving that's 5 gallons. That is very close to 10% of my fuel tank that would be gone. (55 gal tank). I think it would be worth a few gallons of gas to be comfortable running the gen/AC, however.

Also while running the generator the refrigerator is not burning propane at approx 4.25 per gallon. Since I got the new rig I lost track of what the appliance LPG consumption was.

[Chance]

Originally Posted by bthode@gmail.com

Assuming the generator uses one gallon per hour, after five hours of driving that's 5 gallons. That is very close to 10% of my fuel tank that would be gone. (55 gal tank). I think it would be worth a few gallons of gas to be comfortable running the gen/AC, however.

It would be interesting to estimate whether it is more fuel efficient to have the V10 engine power the vehicle's alternator (assuming adequate capacity) that would then power a large inverter and then the AC.

A Sportsmobile owner ran a test and found his inverter pulls 150 Amps running his 13,500 BTU/hr AC. That's roughly 1800 watts which sounds about right taking inverter efficiency into account.

A standard Ford alternator probably can't supply that much power on a steady basis, but the optional higher-capacity ones may be able to run a 9200 BTU/hr AC indefinitely while driving. Aftermarket alternators can do much higher current -- but they are expensive.

Anyway, there is Ford data that can be used to estimate incremental fuel consumption for the engine to serve as the generator. It could also reduce noise, vibration, and wear on generator if it worked.

[JamieGeek]

Originally Posted by Chance

It could also reduce noise, vibration, and wear on generator if it worked.

Except that not running the generator can be almost as detrimental. When we had our unit at the Cummins shop getting the genny's fuel pump replaced (Cummins shipped a bunch of gennys with bad fuel pumps) the tech doing the job said: "If your engine is running your generator should be running." His point was that the genny uses a carb and it can get all gummed up if not run periodically and they had plenty of RVers come in complaining that their genny wouldn't run because they never ran it and then the one day they needed it, it wouldn't.

Granted the tech may have anterior motives given that if you run the genny more you'll need more service as well.

[Larry]

IMO, running the genny whenever the engine is running seems extreme. Quite a few folks on various forums have stated they run their genny an hour or two each month under a ~ 50% load. That's what I've been doing for about a year now and adding Stabil to the gas tank during winter months. So far, no problems with the genny. Knocking on wood.

[EA37TS]

Originally Posted by JamieGeek

Granted the tech may have anterior motives given that if you run the genny more you'll need more service as well.

Jamie

The tech was right on the money with one exception, he apparently didn't mention replacement of dry rotted seals, gummed fuel pumps and fuel filters because the fuel was not circulating through the pump as well as the carb. One additional item not common but possible are fires caused by dirt dauber nests in the generator exhaust when a generator is started once every two or three months.

With over 20 years in the Army and numerous deployments using gas and diesel generators ranging in size from 1.5 to 250 KW I will tell you that the biggest threat to a generator is the lack of use under load.

Economic factors (cost considerations):

High Output Alternator = 350.00 - 100.00 core charge = 250.00
Additional 6 v batteries = 150.00 each * 2 = 300.00
Total not counting installation or additional cabling required for batteries = 550.00

Generator fuel consumption = 1.5 gph (this is high and is generally around .9 - 1.2 depending on the load)
Travel day = 8 hours (generator running the entire time)
Fuel consumption per day = 12.75 gpd
Fuel cost 2.50
Fuel cost per day = 31.88

Mod 550.00 / fuel per day 31.88 = 17.25 8 hour travel days (not camping days) to break even on alternator and battery cost alone and that is without any generator use at all. If the generator is run to warm lunch or make coffee on the travel days extend the time required for break even.

If you factor in 50.00 for the cost (high end) of a generator 100 hour service the break even point drops to approx. 15.6 days. The generator service on my last coach cost me 27.95 at the dealer.

This does not factor in the cost of an Inverter capable of running the AC unit or the savings realize from running the frig on electric rather than LPG.

One must ask themselves if this type of upgrade makes sense of is it simply a "cool or nice thing to do" and since everyone id different only they can answer that question. Myself, I also ponder the question, why am I considering doing this and what are the non economic factors.

[Chance]

Originally Posted by dstankov

....cut...

One must ask themselves if this type of upgrade makes sense of is it simply a "cool or nice thing to do" and since everyone id different only they can answer that question. Myself, I also ponder the question, why am I considering doing this and what are the non economic factors.

Very few people should consider this "upgrade" at all at this point, not to mention actually implementing it.

On the other hand it's always good to ponder other options to see what potential they may have. Or not.

I have a technical background so my view of things is sometimes biased compared to others. I personally see the traditional RV generator on its way out for some campers. Advances in technology like somewhat-affordable high-capacity inverters offer options that didn't exist just a few years ago. And when lithium batteries come down in price, it will make elimination of the generator much more practical than it is today. For the few occasions when they are needed a backup Honda (or similar) can work.

Already some manufacturers of high-end Class Bs are offering such RVs. Some have a dedicated high-capacity 5kw alternator for the house and house batteries. Along with high capacity house battery bank they can run the AC, microwave, refrigerator and coffee maker simultaneously if needed.

Yeah, it's expensive right now, and nobody is suggesting to run out and modify their RV, but if starting out from scratch the cost and weight of a diesel generator on a Sprinter-based motorhome can be offset in large part. On a gasoline RV less so. Mostly there are factors other than cost.

I used my generator so little other than for microwave and coffee during the day, that I could easily trade it for newer technology of equal value. I couldn't even run the generator at the last National Park I stayed except a couple of hours a day. An inverter and larger batteries would have served us much better that entire trip.

[DocMike]

In 1989 my wife and I had our first RV when the boys were little. It was a Coachman B+ built on a GMC 3500. While camping if it got hot outside we would turn on the 120 AC to maximum; then crank up the Van, put the Van's AC on recycle air and set it at full blast...it would really drive the temperature down (actually got cold)! Granted, it was a smaller RV back then and I do not even know if our Vegas has a recycle option on the chassis AC.

DocMike
NCNG Ret

[aa9zz]

It does have a recycle.

[Ron&Joy]

do you have a 30 or 50 amp service