Second AC Installation Question - Page 2

Frank G · 07-07-2018, 02:59 PM

When the factory installs the second AC in the bed room of the 325RL it is the 13,500 BTU model, There is a separate thermostat on the bathroom wall and it is ducted in the raceway duct system. It will be interesting to see if you have access to these ducts. We use the low setting on the BR AC to do dehumidification duty with lower outside temperatures and high humidity conditions. You know' those 75 deg days with 95% humidity in Florida.

RoscoeV · 07-07-2018, 03:31 PM

Frank, I'll know when I pull the air vent but I'm pretty sure the duct is blocked at the vent. The duct work does go to the bathroom from the bedroom with the current bedroom duct work. I popped the vents down and put foam insulation in the ducts that went past the vents that pushed air to the ceiling. I'm not too concerned about adding a thermostat, I'm adding a non-ducted ADB.

ht40 · 07-07-2018, 04:23 PM

I too was going to add a second A/C to the bedroom. I was wondering if there was any advantage to tying into the ducted system. Does anyone have any experience with the bedroom A/C unit only cooling the bedroom and not spilling cool air into the rest of the trailer.

Dan

14george · 07-07-2018, 05:29 PM

I had a second ac unit installed in bedroom non ducked helped cool rest of trailer mines not a fifth wheel.

Frank G · 07-07-2018, 06:11 PM

Lets specifically talk about the Laredo fifth wheel units. To this day they continue to use the "Race Track" AC duct system. Forgive me if you are aware of this system and how it works.

I do not know how many other models use this system, I know the FR Cedar Creak line uses it.

Below is a link
https://www.keystonerv.com/media/2281/laredo-2016.pdf

The system is described on page 11. After 2016 it appears Keystone quit providing construction details in there literature, go figure.

The reasoning behind this post is, in the long run you will be much happier if you have a ducted system, and let the "Race Track" system work as designed. It is a good system. I have no idea as what the factory does when they do not install the second AC. The dealer we purchased from sells about (5) 325RL a year and all have the 2 AC from the factory.

johnlewis · 07-12-2018, 08:17 AM

I have a friend who installed one of the low headroom units, and he said the noise inside is a lot loader with the low headroom unit.

I have bought a couple of things from PPL that were on sale (better prices than I found anywhere else), and I have been completely satisfied with their communication after the order, and the speed of delivery. Either watch for a sale on PPL, or call them and tell them the price you have found elsewhere, and see if they will match it.

goldtrigger · 07-12-2018, 12:01 PM

In Texas we have to have 2 airs. I ran in to an issue with my bedroom air. Initially we had a 13K Coleman un-ducted on the bedroom of our 2011 Montana Mountanaire. In 100+ degree heat-high humidity, the two AC's would not cool the rig below 90 degrees.

Additionally, the front air would develop condensation on the down plenum when run on low speed/high cool at night and drip beaucoup water on the bed. This did not make me or the DW happy at all about 0200 when this happened.

When I had the second roof replaced after my second collision with a tree, the repair shop somehow broke the front air, which their insurance agreed to replace at no charge. I decided to fork over the difference for a low profile 15K Coleman unit.

Through experimentation, we have learned we can run the front air on max with a small fan from the bedroom door blowing air into the main body of the rig and cool the rig down to low 80's no matter what the outside temp. At night, we run the front air on low cool, half speed and it keeps the bedroom and rig cool and the plenum dry, no drip and DW and me happy!

PopBeavers · 07-17-2018, 12:32 PM

I am replacing my tall a/c unit with an ultra low (8.5 inch). This will drop my height from 14 feet to 13 feet 7 inches.

14 feet is legal west of the Mississippi, except for Oklahoma. We are planning a 1.5 year trip to points east of the Mississippi next spring. The maximum height allowed east of the Mississippi is 13 feet 6 inches. I have no way to lower it another inch.

louielouieohoh · 07-17-2018, 04:27 PM

Quote:

Originally Posted by PopBeavers

I am replacing my tall a/c unit with an ultra low (8.5 inch). This will drop my height from 14 feet to 13 feet 7 inches.

14 feet is legal west of the Mississippi, except for Oklahoma. We are planning a 1.5 year trip to points east of the Mississippi next spring. The maximum height allowed east of the Mississippi is 13 feet 6 inches. I have no way to lower it another inch.

@PopBeavers; I'm pretty sure you only need to meet the requirements for ANY vehicle in the state where it is licensed.

I know that some states require brakes on trailers based on different weight classifications etc. A law enforcement officer cannot hold you accountable for a state where you do not live.

Can others chime in on this?

travelin texans · 07-17-2018, 05:32 PM

If I'm not mistaken 13'6" is not the max you can be, but rather the minimum an overpass/bridge can be before "low clearance" must be posted by the state.
Most rv manufacturers build them at slightly over 13' then you may add vent covers or satellite dishes that may put you at about 13'6", unless you've added suspension lifts or other modifications I've never heard of a rv at 14'.

**sourdough** · 07-17-2018, 05:51 PM

Quote:

Originally Posted by louielouieohoh

@PopBeavers; I'm pretty sure you only need to meet the requirements for ANY vehicle in the state where it is licensed.

I know that some states require brakes on trailers based on different weight classifications etc. A law enforcement officer cannot hold you accountable for a state where you do not live.

Can others chime in on this?

Various states can't dispute your driving license from your home state, but, any/all regulations relating to size, length, height etc. are enforceable in the state you are in....that's why you need to KNOW where you are going and what the laws are if you are in any way questionable.....just like gun laws.

As far as 13'6" regulations, here is the link to what the TX DPS says:

What's the maximum height for my vehicle?
The Texas Transportation Code specifies that the maximum height of a vehicle and its load may not be higher than 14 feet (View code) Transportation code, chapter 621, section 621.207).

PopBeavers · 07-19-2018, 07:57 AM

Quote:

Originally Posted by travelin texans

If I'm not mistaken 13'6" is not the max you can be, but rather the minimum an overpass/bridge can be before "low clearance" must be posted by the state.
Most rv manufacturers build them at slightly over 13' then you may add vent covers or satellite dishes that may put you at about 13'6", unless you've added suspension lifts or other modifications I've never heard of a rv at 14'.

Tall a/c unit with a 4 inch lift.

boxcar · 07-24-2018, 10:37 AM

OK, the posters in this thread has convinced me to get a matching black Dometic Penguin II low profile for my Sprinter 2nd A/C - thanks!

For a couple hundred extra I can get a heat pump option, which I expect will require a new thermostat. While I believe it would be good to have the extra heater that comes with it up front I've never owned a heat pump.

Any comments for or against?

My current stock A/C would only lower the temperature inside to 89 degrees when it was 93 outside - still under warranty so I'm taking it in as soon as I can get the appointment. The outlet was 64 degrees so I'm sure it's ductwork. We're going to be camping in Palisade CO in August with expect 100+ temperatures so I need to get this right!

Thanks,

xrated · 07-24-2018, 11:08 AM

Quote:

Originally Posted by boxcar

OK, the posters in this thread has convinced me to get a matching black Dometic Penguin II low profile for my Sprinter 2nd A/C - thanks!

For a couple hundred extra I can get a heat pump option, which I expect will require a new thermostat. While I believe it would be good to have the extra heater that comes with it up front I've never owned a heat pump.

Any comments for or against?

My current stock A/C would only lower the temperature inside to 89 degrees when it was 93 outside - still under warranty so I'm taking it in as soon as I can get the appointment. The outlet was 64 degrees so I'm sure it's ductwork. We're going to be camping in Palisade CO in August with expect 100+ temperatures so I need to get this right!

Thanks,

Something is wrong with your numbers there! An A/C unit, if it's working well, is normally showing an 18-20 degree difference between the inlet air and the outlet air. You are showing 25 degrees difference. What I suspect is that some of the outlet air is getting sucked right back into the inlet or return because of faulty ductwork or an air leak inside the unit. In other words, not all of the outlet air is being pushed out the ductwork through the registers/outlets......it is just recycling through the A/C unit....going in a circle. Getting that issue resolved would be my first priority, then see how well the unit cools the trailer on hot days

boxcar · 07-24-2018, 11:14 AM

I agree with your analysis completely xrated, but after reading everything here I'm adding a second unit in addition to getting the problem fixed - just need to decide which model. We'll be using this camper in some 110 degree weather eventually.

I have an appointment with a Keystone shop to get the ducting fixed before this goes off warranty.

travelin texans · 07-24-2018, 12:36 PM

The heat pump would be a great option, especially if you're somewhere that doesn't get extremely cold, they only work with the outside at about 38 degrees or more, lower than that it will blow cool/cold air.
One of our acs has the heat pump & works great.

boxcar · 07-24-2018, 01:37 PM

Thanks, Danny. The cold weather camping I do is normally well below 40 and closer to 0, so I'll save the money!

xrated · 07-24-2018, 03:30 PM

If Dometic is like the Coleman Mach ??? that I had on a previous trailer, don't bother with the heat strip either. Mine produced a little heat, but in my opinion you would be better off with an aux. freestanding heater that you could place where ever you wanted to put it. My T.H. has a 35,000 BTU furnace in it and it does a great job heating the trailer, but if we camped in cold weather, I would also buy/have an additional free standing heater for it.

boxcar · 07-25-2018, 05:04 AM

That's another good tip, xrated, and will save some money. As long as I have ground power a standalone heater makes sense. We had a problem with the thermostat in the old camper one night when it was below freezing and a freestanding saved us - have to move that to the Sprinter before it gets cold.

I'm sure air flow is going to make a big difference and everyone should read this thread if they haven't:

http://www.keystoneforums.com/forums...ad.php?t=25849

xrated · 07-29-2018, 09:05 AM

UPDATE......Well, the new Dometic Brisk II 13.5K BTU is done. The hard part was getting all the sealant for the existing vent off without damaging the TPO roof. I used a rope hoist to lift the unit up in the air and backed the trailer under it and let it down. I completed the install this morning and fired it up to test the unit. I got a 20-21 degree difference between inlet air and outlet air which is about as good as it gets. There should be absolutely no problem cooking the entire trailer now.

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