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Topic: Roof AC Replacement Recommendations (Read 6560 times) previous topic - next topic

Roof AC Replacement Recommendations

My old Coleman roof AC's still work well but I think they are using too much electric. I thought about a mini split but don't feel comfortable installing one myself and none of the AC people around here want to install one in an RV.
I know at least some people on this forum have replaced their roof units. If so, what AC units did you use use and how do you like them? How do they compare to the Coleman Mach series? Are they more efficient?
Any input will be greatly appreciated.

Re: Roof AC Replacement Recommendations

Reply #2 –
Ernie, did you do 1500s front and rear?

Re: Roof AC Replacement Recommendations

Reply #3 –
Just bedroom. Middle air soon. Front air is the new loud penguin. All are 15k

Re: Roof AC Replacement Recommendations

Reply #4 –
Why do you want to lower electric usage? Are you metered? And do you think that the cost of other units installed will make up for a higher electric cost? All Air conditioners draw large amounts of electricity.

Re: Roof AC Replacement Recommendations

Reply #5 –
Quote from: Barry & Cindy –
Why do you want to lower electric usage? Are you metered? And do you think that the cost of other units installed will make up for a higher electric cost? All Air conditioners draw large amounts of electricity.
Thank you for asking. I am not metered where I am but I only have access to one 20 amp circuit and I've been tripping the breaker too often lately. I'm in Mohave Valley AZ where it has been over 120 the last week and there's no relief in sight. I don't know why I didn't think of this before but I switched my Norcold refrigerator from running on AC over to propane today and haven't tripped the breaker since so I may have solved the problem.
After doing some research and reading the replies on this topic, I don't think I have much to gain by replacing my existing Colemans.
I'm parked on a property that also has a house, garage and 3 stationary trailers besides my coach and I think the existing electric service coming in here is maxed out right now. I seem to be the only one who is tripping a breaker so maybe my breaker is going bad. All I know for sure is it's hot and the temperature in my coach goes up real fast when I lose power.

Re: Roof AC Replacement Recommendations

Reply #6 –
Quote from: Barry & Cindy –
Why do you want to lower electric usage? Are you metered? And do you think that the cost of other units installed will make up for a higher electric cost? All Air conditioners draw large amounts of electricity.

Boondocking?  Less generator demand?

Re: Roof AC Replacement Recommendations

Reply #7 –
Quote from: Dakota Slim –
Thank you for asking. I am not metered where I am but I only have access to one 20 amp circuit and I've been tripping the breaker too often lately. I'm in Mohave Valley AZ where it has been over 120 the last week and there's no relief in sight. I don't know why I didn't think of this before but I switched my Norcold refrigerator from running on AC over to propane today and haven't tripped the breaker since so I may have solved the problem.
After doing some research and reading the replies on this topic, I don't think I have much to gain by replacing my existing Colemans.
I'm parked on a property that also has a house, garage and 3 stationary trailers besides my coach and I think the existing electric service coming in here is maxed out right now. I seem to be the only one who is tripping a breaker so maybe my breaker is going bad. All I know for sure is it's hot and the temperature in my coach goes up real fast when I lose power.


You may have a weak breaker, after they trip a few times they tend to release easier...

Re: Roof AC Replacement Recommendations

Reply #8 –
If you are on a 20amp service a mini split is the way to go. There are Mexican companies just across the boarder that do mini split installs for cheap up here. You might be able to find one of them to install it for you. I know there is a company in Puerto Penasco that will service the Prescott area

Re: Roof AC Replacement Recommendations Off Grid or Not?

Reply #9 –
Plugged in a 20 Amp receptacle you are not off grid. How ever that thought opens up possibilities that you may be missing. 
Does your coach still have a working generator, Diesel or Propane?
So consider adding more solar, batteries, and a modern inverter that can do load sharing. Consider in inverter that manages the incoming power limiting consumption for both supported loads and battery charging. At night when the AC satisfies it can use the available power to charge the batteries. Adding solar will help some. The ultimate approach is to have high capacity charging off the generator. Start generator, run both AC to cool the unit down, put 300 A/H back into a 600 A/H battery bank in 2 hours. Turn off generator and let the load share get you through the rest of the day. Just some thoughts.

Re: Roof AC Replacement Recommendations

Reply #10 –
Slim's desire for lower electric air conditioner is understandable. Glad Slim found the best way to keep from tripping breakers: reduce all OTHER loads. Progressive Industries hard wired EMS with remote display in an easy to read location is every RVer's friend. Turn something off before turning something on when electric service is limited. Check meter for amps & volts at that moment. Keep all electric heating elements off, like fridge, hot water tank, hair dryers, toasters, and also microwave, when not needed. EMS also protects when voltage drops because all the other RVers start their A/C units. All running motors will have some level of damage when voltage drops too low, causing the amps to increase beyond design specs. Circuit breakers are rated to protect wire size from overloading, burning, melting, etc. If all cables after the breaker, including shore cable to motorhome is greater than AWG-12 wire size and wire size feeding breaker is also greater than AWG-12, maybe swapping a 20 amp breaker for a 25 amp breaker could be considered. Wire size AWG-10 can handle 30-amps if cable length is not too long. Any breaker amp change, although not-unheard-of may be unauthorized. BTW, absorption refrigerators may cool better on propane than electric due to a hotter and more consistent heat source.

Re: Roof AC Replacement Recommendations

Reply #11 –
I can run my mini split on a 12/100 ft cord no problem. 4-7 amps.
The Coleman is around 10-14 amps.
One mini won't cool a larger bus than my old GV .
Wait a bit.  It looks like there are manufacturers trying to use the inverter technology on the rooftop units.  Half the power and 10% of the noise. 

Do you have a safe ? That's where I put my compressor box. 
The inside unit is over the mid door with the lines running through the cabinets. Werx perfect so far at 6 yrs. Solar will run it at around 2000watts
Any less won't keep up imho .

Re: Roof AC Replacement Recommendations

Reply #12 –
Quote from: d23haynes57 –
Plugged in a 20 Amp receptacle you are not off grid. How ever that thought opens up possibilities that you may be missing. 
Does your coach still have a working generator, Diesel or Propane?
So consider adding more solar, batteries, and a modern inverter that can do load sharing. Consider in inverter that manages the incoming power limiting consumption for both supported loads and battery charging. At night when the AC satisfies it can use the available power to charge the batteries. Adding solar will help some. The ultimate approach is to have high capacity charging off the generator. Start generator, run both AC to cool the unit down, put 300 A/H back into a 600 A/H battery bank in 2 hours. Turn off generator and let the load share get you through the rest of the day. Just some thoughts.
Those are great ideas but I am not off the grid boondocking right now. I'm plugged into a 20 amp circuit in Mohave Valley, AZ where it's been 120+ degrees in the daytime with lows around 90. I am scheduled for cataract surgery later this month and again in August. My propane generator runs great but it isn't economical.

Re: Roof AC Replacement Recommendations

Reply #13 –
Quote from: Protech Racing –
I can run my mini split on a 12/100 ft cord no problem. 4-7 amps.
The Coleman is around 10-14 amps.
One mini won't cool a larger bus than my old GV .
Wait a bit.  It looks like there are manufacturers trying to use the inverter technology on the rooftop units.  Half the power and 10% of the noise. 

Do you have a safe ? That's where I put my compressor box. 
The inside unit is over the mid door with the lines running through the cabinets. Werx perfect so far at 6 yrs. Solar will run it at around 2000watts
Any less won't keep up imho .
Hi Mike. I've followed your solar and mini split posts. Good job. I do have a safe, probably right where yours is. I'm trying to research a lot of things with bad eyes right now and it's giving me a headache.

Re: Roof AC Replacement Recommendations

Reply #14 –
I had a similar experience when we first got our coach.  In my case, it "fried" my extension cord because the old CB did not trip.  I have since replaced all the CBs and then replaced the affected outlet with  10ga wire and 30A receptacle (once again upgraded to 50A when  I built the RV garage).  You can judge whether or not this is feasible.  Barry seemed to cover everything pretty well and I would add one thing:  If you are using an extension cord, get the shortest highest gauge one you can find.  Good luck, I don't envy you having to deal with that kind of heat.

Re: Roof AC Replacement Recommendations

Reply #15 –
Quote from: Sven and Kristi –
I had a similar experience when we first got our coach.  In my case, it "fried" my extension cord because the old CB did not trip.  I have since replaced all the CBs and then replaced the affected outlet with  10ga wire and 30A receptacle (once again upgraded to 50A when  I built the RV garage).  You can judge whether or not this is feasible.  Barry seemed to cover everything pretty well and I would add one thing:  If you are using an extension cord, get the shortest highest gauge one you can find.  Good luck, I don't envy you having to deal with that kind of heat.
Thank you. My 20 amp circuit has a 50 amp outlet that my shore power line plugs into. I picked up a new CB this morning and will probably (might) make the switch tomorrow. Meanwhile, I found out that I share 50 amp service with an Airstream trailer which is on another 20 amp CB, a heavy duty water pump, a chest freezer and a washer and dryer. The service box is in a small wooden shed where the water pump and tank are located. If I understand this situation correctly, there would be no power to the pump meaning there would be no water to put out a fire if this electrical nightmare starts a fire.

Re: Roof AC Replacement Recommendations

Reply #16 –

Hey Slim, any chance you could use one of these to get by on until recovered? 

Amazon.com: GE Profile ClearView Inverter Window Air Conditioner Unit,...

Very quiet and will run on a 15 amp 120 volt service.  These little inverter units crank it out. 

As an Amazon Associate Foretravel Owners' Forum earns from qualifying purchases.

Re: Roof AC Replacement Recommendations

Reply #17 –
Quote from: Chuck Pearson –
Hey Slim, any chance you could use one of these to get by on until recovered? 
Amazon.com: GE Profile ClearView Inverter Window Air Conditioner Unit,...
Very quiet and will run on a 15 amp 120 volt service.  These little inverter units crank it out.
Thanks for the link. I like the U shaped feature. I'd probably need one up front and one in the back in this heat. I alternate between the front and rear roof units now.
As of right now, I'm not tripping the breaker with the roof units since switching the refrigerator to run on propane so I'm inclined to stick with this arrangement.
*** Before I could finish typing that last line, the breaker tripped and I had a "no" flashing on the Norcold. I shut the Norcold off and restarted in and got the same error message so I switched it back to electric. No rest for the wicked.
I wish Moby would have followed up on his Norcold "no" issue.

* Update: I got the Norcold working on LP again. Not sure what the problem was but switching it to AC and then back to LP did the trick.
As an Amazon Associate Foretravel Owners' Forum earns from qualifying purchases.

Re: Roof AC Replacement Recommendations

Reply #19 –
Don't know if you have solar or note but I discovered a trick when we were in Indio with 30 amp service. Our GV has separate unit for convertor and invertor. Turned off convertor ( 120 volt to 12 volt  ) and used solar panels to charge coach batteries. Ran everything in the coach ( TV, lights etc ) off the invertor and just used the 30 amp service for nothing but the 2 AC units. Worked like a champ.