2nd A/C install question

Readi2Roll · 04-15-2023, 03:31 PM

I am getting ready to add a second A/C unit in the prewired location (bedroom) of my 2019 Keystone Cougar (26RBS).
I have determined that the existing unit pushes air out of all of the ceiling vents. When I add the second unit to this duct system wouldn't the two units now be combating each other for air flow (when they are both running)?

**sourdough** · 04-15-2023, 04:43 PM

They don't "combat" each other, they push more air through the ducts from each end. The flow pressure equalizes against each other and the increased flow comes out of the registers - noticeable difference.

SargeW · 04-16-2023, 07:04 AM

My second AC does not dump into the existing duct work. I wanted it set up that way, but the dealer indicated that it was not possible. When I opened it up and looked for myself it appears that Keystone did not make any pathway through the roof joists to allow the 2nd AC to be ducted. It appears that I would have to cut a hole in the joist to get through to the existing ducting. I don't think I want to roll those dice....

**sourdough** · 04-16-2023, 07:18 AM

My 14 Cougar High Country had the main a/c vented through the trailer but the 2nd a/c in the bedroom was not vented either. We liked it that way because we liked the bedroom cold, it had the dump feature and we could just put a fan on top of the chest of drawers and direct cool air into the living area. OPs description and the year of the trailer made me assume the 2nd a/c was ducted - the link below confirms that (4:48).

https://www.youtube.com/watch?v=e7iI5Q9UP1k

If your's isn't ducted I would leave well enough alone and just adapt in some manner like we did. We managed 100+ temps but that was ALL it could handle (or us).

Readi2Roll · 04-16-2023, 10:46 AM

I'll be satisfied even if the second unit does not connect to the ducts. I begin the install on Tuesday, will keep the group posted!

**chuckster57** · 04-17-2023, 04:31 AM

I would remove the bedroom vent garnish ring and look. Some manufacturers will use aluminum tape to cover the ducting.

Readi2Roll · 04-17-2023, 09:11 AM

10-4! will do.

Dallasrules · 04-27-2023, 10:13 AM

Quote:

Originally Posted by Readi2Roll

I'll be satisfied even if the second unit does not connect to the ducts. I begin the install on Tuesday, will keep the group posted!

Make sure the bottom unit is for non-ducted. you can get it for ducted or non-ducted. If you just want it to blow out at the ac unit, you need the bottom with the controls and vents.

rlh1957 · 04-27-2023, 04:18 PM

The Cougar uses ducting and both a/c’s pump into the same plenum crossover.

If the system has the a/c controls as part of the InCommand system then a separate module will need to be added to the new A/C.

Readi2Roll · 06-01-2023, 09:56 AM

MANY THANKS TO ALL WHO HAVE POSTED "HOW-TO'S"; THIS REALLY MADE ME COMFORTABLE WITH TACKLING THE PROJECT!
A few thoughts: I elected to NOT tie the second unit into the In Command system. I really did not see any value in doing so: 1) If I wanted to adjust the temp in the bedroom in the middle of the night, I would either have to wake up my phone and get into the software to adjust the temp OR 2) go to the back of the trailer wake up the system and adjust - forget it. With the thermostat, I can reach up and adjust the thermostat with two button touches. It is also "separate" from In-Command, in case that system has a "bad hair day (again)" I still have one A/C unit in operation.
All wires were in the ceiling as described by others. Ductwork was there, just needed to tidy up the seals with alum tape. Items were purchased from PantherRV - very helpful folks. Total cost about $1,200.00. There are many more lessons learned, if anyone is contemplating this and needs addl info, feel free to contact me.

**chuckster57** · 06-01-2023, 11:50 AM

Nice!! Only hope that thermostat (capacitive touch) doesn’t go wacky on you. It’s a not real common, but a common issue.

Readi2Roll · 06-01-2023, 12:04 PM

Thanks, I am keeping an eye on it as it does not turn the unit off until it is way too cold (IE: set for 72, finally shuts off at 66). The trailer is parked in the shade when being tested. I have it in auto mode. I have a temperature tester and have made sure the wall (outside) is not keeping the state "hot." If it persists, I will see if Dometic will replace it.

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