Dual vs Single AC units.

msmith1199 wrote:

enblethen wrote:
Common?
You need to check to see what ducted outlets come off which AC unit. Yes, the bedroom one should only feed the bedroom, however it is possible that the duct from the bedroom unit may feed into hall or bath area.
Some thermostats or system allows the AC unit to switch automatically from AC units. This would allow the whole rig to stay cool, yet save energy by running only one at a time.

I can't speak for all ducted units, but all the ones that I've looked closely at (including mine) are all connected together. I can turn on my bedroom A/C and close the bedroom vents and it will push air to the front of the motorhome. I have done that before on hot days to get both units cooling the front. Also on hot nights I have turned off the rear unit and closed most of the front vents and let the front unit cool the bedroom. Makes for a quieter night without the A/C unit over your head running.

Ours is all tied together. You would need to close the vents in the area not desired. Though not perfect, it would direct the greater air flow to the area desired.

msmith1199 wrote:
You can't just assume running two units will cost more than running one. The opposite may in fact be true. Your goal is to cool the motorhome to a certain level. Two units will get you there far quicker and then turn off. One run may have to run twice as long to get you there. I have had units with both. My first Class A was a 32 foot with one unit and I took it to Vegas once in the summer. It was over 100 out and that one AC unit ran solid the entire time and still was unable to make the motorhome comfortable during the day. It was barely able to get us to a comfortable level at night.

Yup. You need to do some testing. sometimes how you set the fan setting makes a difference. I set the front fan (from auto) to "on" so it keeps air circulating.

All these people who say you can't run 2 ACs on 30 amps don't know what they are talking about. I had a '96 Pace Arrow 30 amp coach and an Intellitec power management system and I ran both ACs regularly. We would lose 1 AC compressor if we turned the microwave on. Refrigerator was always on.

at most parks electric is included in the price.

if it isn't, run one A/C.

We would not be without 2 A/Cs.

Bumpyroad wrote:
on my RVs with 2 ACS I could run either one of them separately. could run both using EMS. that was one thing great about two units, could usually run the one in the area that we were not in, front one at night, etc.
bumpy

That's the way we run ours, if watching TV in the front, we run the back. And at night the front. And ours is 50A, can run both if we want. And do if we leave the dog, for a day trip. just in case one quits.

The OP needs to verify how is rig is ducted. Yes, they can be done in different ways. Some have a smaller AC unit that feeds the bedroom area and bath.
It could overwhelm a single AC unit trying to cool the whole rig or even a restricted area.

enblethen wrote:
Common?
You need to check to see what ducted outlets come off which AC unit. Yes, the bedroom one should only feed the bedroom, however it is possible that the duct from the bedroom unit may feed into hall or bath area.
Some thermostats or system allows the AC unit to switch automatically from AC units. This would allow the whole rig to stay cool, yet save energy by running only one at a time.

I can't speak for all ducted units, but all the ones that I've looked closely at (including mine) are all connected together. I can turn on my bedroom A/C and close the bedroom vents and it will push air to the front of the motorhome. I have done that before on hot days to get both units cooling the front. Also on hot nights I have turned off the rear unit and closed most of the front vents and let the front unit cool the bedroom. Makes for a quieter night without the A/C unit over your head running.

You can't just assume running two units will cost more than running one. The opposite may in fact be true. Your goal is to cool the motorhome to a certain level. Two units will get you there far quicker and then turn off. One run may have to run twice as long to get you there. I have had units with both. My first Class A was a 32 foot with one unit and I took it to Vegas once in the summer. It was over 100 out and that one AC unit ran solid the entire time and still was unable to make the motorhome comfortable during the day. It was barely able to get us to a comfortable level at night.

We have a 2002 32 foot Itasca Sunrise with two units and the power management system, we can run both on shore power and on generator, however since we only have a 30A system, if we use the microwave or a hair dryer, we have to shut one of the AC units off.

on my RVs with 2 ACS I could run either one of them separately. could run both using EMS. that was one thing great about two units, could usually run the one in the area that we were not in, front one at night, etc.
bumpy

All depends on amps. If it is 50a, it will run both. 30a, and one.