Add more A/C

[bighamstoy]

I have a Dometic 15,000 air conditioner and it isn't enough for my 35' toy hauler. Is it relatively easy to add a second smaller roof unit or is there a better solution. My service is 30 amp.

[BFlinn181]

Unless you add a very small extra A/C, you will be over 30 amps. One of the smallest I've seen, 9200 BTU, still uses 9 amps. Small RV Air Conditioner on Sale - PPL Motor Homes

Have you cleaned filters and roof top fins? Checked the duct seals and made sure air isn't recirculating in the unit? Measure the temperature between input and output, it should be about a 20º drop.

[WPRam]

What size system you have 50 amp or 30 amp

[bighamstoy]

The A/C unit is on a 2012 Extreme Warrior, not been used much thus far. it is 120 degrees outside here so that makes a big difference. Every other RV here has 2 A/C units. Can't be too tough to make this a 50 amp service. I would think the tough part would be installing a new roof unit & wiring it all up. I have a 4K Onan, BTW.

[WPRam]

In your garage your overhead vent does it have a small fan like in the bath or does it have a large full bladed fan the size of the vent?

[BFlinn181]

It would be a much bigger deal to convert from 30 amp to 50 amp than installing a second A/C. 30 a only has one circuit of current, 50 a splits all the power needs of the MH in two separate circuits. You'd need a new auto transfer switch, new power panel, new circuit breakers, and much more. Parts alone could easily run $500 or more, then add labor on top of that. If you are in a very arid area you might think of adding a swamp cooler which uses minimum power but can provide a lot of cooling if humidity is low. There are swamp coolers that are sized to fit in 14" roof vents.

http://www.turbokool.com/

[REWahoo]

I have a 30 amp 5th wheel that had only one AC and needed to add a second to survive the Texas summer heat. Rather than go to the trouble and expense of upgrading to a 50 amps, I added a separate 20 amp service to power a bedroom AC, including a separate breaker box and power cord to the campground power pedestal. I also added a bedroom wall socket on the circuit so we can power a hair dryer or, in the winter, an electric heater without worrying about overloading the 30 amp circuit.

This has worked great for us.

[TXiceman]

You will need to add a 2nd A/C. In the south, 1 A/C is barely adequate for a 28 to 30' RV. As a work around, you can add a separate 20 amp circuit with a brrreaker and power it separately.

Ken

[Ray,IN]

I would do as REWahoo did. Develop a habit of using a 50A to 30A adapter and plug into 50A. The result will be a stronger connection, you still only have 30A available inside the 5er though.
Our old 30A 5er had a 3-way switch to control main A/C, microwave, and added 2nd A/C in bedroom. Kinda like a manual power management control. I could run main A/C and microwave - or bedroom A/C unit. Both A/C units were 13,500 btu.

[bighamstoy]

Originally Posted by REWahoo

I have a 30 amp 5th wheel that had only one AC and needed to add a second to survive the Texas summer heat. Rather than go to the trouble and expense of upgrading to a 50 amps, I added a separate 20 amp service to power a bedroom AC, including a separate breaker box and power cord to the campground power pedestal. I also added a bedroom wall socket on the circuit so we can power a hair dryer or, in the winter, an electric heater without worrying about overloading the 30 amp circuit.

This has worked great for us.

So how did you accomplish the separate 20amp service? Is the separate power chord just a regular 110 chord? The only roof vent I have with power to it is in the bathroom. How did you get power from the new service to your new roof air? If it were at my home I would knock a few holes as needed in the drywall & patch when done. Not sure how to do that on my toy hauler. BTW, thanks for all the info!

[sc3283]

bigham ,my 28' toyhauler had 1 15k AC....we had to use a box fan to keep it cool when parked in sun with 90+ degree temps

you may have a roof vent prewired for another AC...many times manufacturers will do that.

Do you have a roof vent that has a covered AC outlet box nearby?

[bighamstoy]

In the front bedroom there is a vent in the center and there is a plug-in in the ceiling over by the wall for a TV. Sounds like my 30amp service won't handle another A/C unit though.

[bighamstoy]

What about this option. Mach 3 P.S. 13,500 BTU Roof Unit: 49096 Ceiling Unit: 38236. It says it has an 11.2 amp draw. If I have power pre-wired to a roof vent, that should run the A/C unit if the breaker is 15amp, yes? So if I went to the expense, I could buy 2 of these & replace my existing 15K Dometic with one of these I would have 2 units, 13.5K each & both running would, in theory, draw 22.4 amps. As long as I don't use the microwave while they were both running I would be OK, right (I'm no electrician)?

[REWahoo]

Originally Posted by bighamstoy

So how did you accomplish the separate 20amp service? Is the separate power chord just a regular 110 chord? The only roof vent I have with power to it is in the bathroom. How did you get power from the new service to your new roof air?

I ran 12 gauge wire from the vent opening in the bedroom through the ceiling over to an internal bedroom/bathroom wall, then down through the wall (installed a standard wall outlet while I was at it) to the storage area under the bedroom. I mounted a small breaker box with a 20 amp breaker to the wall of the storage bin, then ran more wire down into the enclosed area under the camper, running it all the way over to my existing 30 amp power inlet. I installed a second 30 amp inlet next to the existing one, and bought a second 30 amp power cord.

With a 50 to 30 adapter and a 30 to standard plug adapter I can hook up both cords wherever I have two plugs on the pedestal. Whenever possible, I use the 50/30 adapter to plug the "house" power into the 50 amp, and plug the second AC cord into the 30 amp.