VERY SHORT SURVEY: A/C Cooling Capability For OEII (TWO) Owners

[Geronimo John]

NOTE:  This thread is not about how loud your OEM A/C is.  Please go to the "Got Ear Plugs" or other threads for those discussions.

This thread does seek info from OEII  (TWO) owners who have used their trailers in hot conditions.

INTRODUCTION:  During the past four model years, the BTU (British Thermal Unit) capacity rating for our OEII's have been reduced.   It would be beneficial to know what owners think about the cooling capacity of various A/C units running in very hot conditions.    

From Oliver University, I gleamed the below BTU capacity of the OEM units.  These OEM A/C capacities have been verified by Jason.   

• 2018      Domenica 13,500 BTU unit used this model year
• 2019      Domenica 11,000 and 13,500 BTU units used for this model year
• 2020      Domenica 11,000 BTU unit used this model year
• 2021      Same as 2020

SURVEY QUESTIONS:

1.   What is your user name, OEII model year, and it's Hull Number?
2.   What A/C do you currently have and what is it's BTU rating?
3.   While using shore power, what was the max outside temperature you have stressed your current A/C?  How well did it perform?  
4.   Other comments you would like to add?  

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SAMPLE desired SURVEY RESPONSE FORMAT:   (Happens to be my response for my unit)

1.  Geronimo John, 2018, Hull 342
2.  Domenica  13,500 BTU
3.  I have run my unit at 100 degrees conditions under mostly direct sunlight.  It cooled very well.
4.  Generally I think my unit is oversized.  When I replace it, I will seek a smaller capacity model that uses less power; such as an inverter compressor with variable speed fans for evening use.

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Again please don't respond with comments about how loud your unit is.  We have beaten that horse enough.   However how quiet yours runs is fair game for owners that have replaced their unit.  Such experiences will help  other owners in selecting a future replacement A/C 's so both size and quiet experiences are encouraged.  I'm looking forward to reading your "Cool Experiences" .      

Thank you,

GJ

 

 

[Overland]

Good topic - I’m interested in the results. Something to keep in mind, which I just mentioned in another thread, is that I believe that Oliver increased the insulation a few years go. I was thinking 2020, but it may have coincided with the switch to the smaller AC. 
 

Regardless:

2017, #256

Dometic 13.5

85 degrees full sun - cooled very well but cycled a bit more than I thought it would, maybe a 75% on / 25% off ratio.

I too think mine is a bit oversized, and if/when I replace it with a quieter model, will likely size down a good bit, especially since we rarely use it at all and when we do it’s usually only on a warmish spring or fall night. 

[Mike and Carol]

Mike and Carol, 2016 #135

Dometic 13.5

106 degrees in full sun on low kept us cool

My next AC will not be as large.

[Mcb]

Mcb 2020 685

Dometic 11k

Mid 90s, full sun…. Kept us cool

We will replace  it with something quieter in the future. 

[Hokieman]

1.  Mike D, 2021, Hull 797
2.  Dometic 11k BTU
3.  I have run my unit many times in mid 90’s temps, high humidity, under mostly direct sunlight.  It cools very well.
4.  I think the cooling capacity is adequate at 11k.   The unit does cycle frequently, but we run the fan on Low, not Auto, so it is satisfactory.   If I replaced it, I would consider a smaller capacity unit. 

[stlipa]

Stlipa #137 Dometic 13.5

Mid 90’s with sun,  cooled fine

will downsize to smaller unit when the Dometic needs replacement 

[SeaDawg]

I think I'm the only Elite I so far. 

Seadawg, hull # 12 2008

The original 13500 btu Dometic (2008) was overkill. Would freeze us out in a short time.

Replacement 9500 btu Houghton has only been used and tested a handful of times in Florida spring, so high 80s to low 90s, and worked fine, cooled quickly, and maintained desired temp easily. I like the dehumidifier function, too. 

[CnC]

CnC, Hull #617, Dom 11K

Have yet to use this one.  Used the 13.5 K our MB Airstream (Sprinter) twice in 6 years.

Note that too frequent cycling usually means the humidity isn't being controlled because the temperature is being satisfied too quickly.  Additionally, the slower the fan speed the more humidity is removed. 

[NCeagle]

1.  NCeagle, 2020, Hull 688
2.  Houghton 13.5K BTU
3.  I have run my unit in 90-100 degrees conditions under mostly direct sunlight as well at night in 70-80 degrees.  It has cooled and controlled humidity very well.
4.  I think given the fact that we live in NC and camp year round (high heat / humidity in the summer) that a bigger 13.5K unit is going to be more efficient than a smaller  11K unit.  Given my experience thus far, I really don't think 13.5K is overkill for an Elite II and I'd likely stick with the same size if I had to replace.

[Geronimo John]

On 12/14/2021 at 7:03 AM, SeaDawg said:

I think I'm the only Elite I so far. 

LOL.   Yep, the survey was for the OEII owners.  But we enjoyed your input regardless.  In fact, I'll start another thread for the OE1's to respond to as it may be good info for OTT to have.  

GJ

 

GJ EDIT:  Second survey for OE1 (ONE) owners is posted.  🙂

[SeaDawg]

Since you've now changed the title to oe2 owners, I'll move my post, if you like.

do we need two surveys? There aren't that many of us with the smaller Elite.

[Geronimo John]

On 12/14/2021 at 7:54 AM, CnC said:

Note that too frequent cycling usually means the humidity isn't being controlled because the temperature is being satisfied too quickly.  Additionally, the slower the fan speed the more humidity is removed. 

CNC you are spot on.  One additional thought that compliments yours.  By running the fan continuously, the dehumidification features is greatly reduced.  WHY?  Because when the compressor cycles off, it stops cooling the coil.  With the fan still running, the gallon or more of water trapped in the coil evaporates off back into the trailer.  Resulting in a much higher average humidity in the trailer. 

The above will likely result in the occupant setting the unit to a cooler temperature.  Result: use of more energy and marginal comfort improvement.   Bad.  But MUCH worse is that by evaporating off all that water, the entrained minerals plate out on to your evap coil.  This becomes a rock hard deposit that only strong acid will remove.  Not something that 99.5% of us want to be doing.

Best solution for humidity control for an oversized A/C is to run the fan on auto and low speed.  This also keeps in "solution" the minerals and the majority of it runs out the evap drain tube to the ground.

GJ

[SeaDawg]

Interesting.  I've not ever heard of an Oliver owner complaining about "rock hard" deposits on the coil. 

Sometimes, honestly,  I  think some of us here,  as a group, get a bit carried away here, and imagine the very worst outcomes.  But then, I could also be accused of 14 year old rose- colored glasses, as well. 😅

Our  friend in the luxury yacht industry (naval architect) has explained to me that the new dehumidifier function on marine ac is basically running the ac on a very small temp differential, and fan on low. No problems.  Seems to be what our Houghton does. Quite possibly what Truma does. I don't know for sure. 

For those of you who want to run your ac fan on low, constant, instead of auto, I think there are a bunch of others that do that here. We don't do that with our home ac, because we live in very humid Florida.  I personally can't see it being an alarming problem, especially in the arid west, in an rv, used part time, and ac probably even less. That water that runs out of my rv ac is pretty minimal, even in Florida. One of my friends in NC sometimes collects ac and dehumidifier waste water to wash his car, as it's his feeling that it's pretty much rain water, as an ac/dehumidifier byproduct. In a big cabin, he doesn't get a gallon a day.

But, of course, I could be wrong. I'll wait to see what others have experienced,  as we truly don't use the ac much, at all.

 

[Geronimo John]

On 12/16/2021 at 12:45 PM, Geronimo John said:

This becomes a rock hard deposit that only strong acid will remove.  Not something that 99.5% of us want to be doing.

SeaDog:  

I can assure you that if you don't use your A/C much, you'll likely never suffer from mineralization of your evap coil regardless of your fan setting.

In practice, for even part time A/C use, the fan setting would not cause mineralization for just about any location.  The unit will generally die first of old age, electrical shorts or compressor failure....not mineralization.

However, for those that rely on their A/C and use if consistently, especially down south where hot and humid humid conditions prevail, the problem of mineralization accumulation primarily caused by coil drying with each cycle (Due to the fan running continuously,  climbs significantly. 

For that group, the removal of calcified deposits requires a strong acid, and THAT is something that most of us would not want to mess with.

Sorry I was not more clear.  

GJ

[SeaDawg]

@Geronimo John,  its all good.

I get your engineer background,  and your look ahead  mindset for potential problems.  My husband is also a retired engineer. Looking ahead to avert problems is never a bad thing. Just don't get carried away, imo. That's sometimes my job, as wife of engineer.  😉

I'm just saying I've yet to hear of anyone with an  Oliver having that issue of huge, hard, mineral deposits. Actually, no one else, either. Could it be a potential problem for someone who's a full-timer in Florida?  Maybe. But I've never heard of it with even my full timer Florida friends. 

Something to watch for? Ok. I'll bite.

I live on the saltwater, so we clean the outside units at home every year (or so.) That's often just a good long  spray with a hose, and sometimes adding  a mild solution. What could actually turn to crap is windblown salt, and dirt, mostly. We all know salt air is corrosive, so regular cleaning of pretty much everything is important, in my neck of the woods, and everywhere else, as well. 

My point was, I've yet to ever, ever hear of someone's ac (including my 14 year old one) locking up with hard deposits. That includes other forums I read.

The usual advice in humid Florida is don't run your fan on high, continuous, as it circulates humid air. With units that tend to short cycle (most rv units have only  1 or 2 degree differential in the thermostat), that whole scenario is unlikely to ever occur,  imo, especially  running fan on low.

Just pointing out that some posts, taken without a grain of salt, not understanding personal experience,  can alarm folks, unnecessarily. 

I think you and I can agree to disagree in an amicable fashion, especially for the most of us, who are part timers. I only camped 152 days this year, and probably only ran 10 to 15 days with ac, in the side driveway, non-camping, while setting up, and cleaning up, at beginning and end if season.

I see lots of posts about birds' nests and mud daubers, though. It is indeed important to inspect and clean, especially if, like us, your camper is outside 24/7/365.

My screen name is seadawg, btw, but you can call me Sherry,  too. Putting my virtual hand out there, for the 🤝 handshake. 

 

 

[Geronimo John]

22 minutes ago, SeaDawg said:

My screen name is seadog, btw, but you can call me Sherry,  too. Putting my virtual hand out there, for the 🤝 handshake. 

Nice to meet you Sherry.  

GJ