AC upgrade conundrum

**CRM** · June 8

Been looking to replace our 14yo 9.2k Coleman with a new unit, not because it isn't working well, but because of it's age and we don't want to be left without AC or have to have it replaced while traveling. Was thinking about purchasing the Houghton 9.5k since it was also available with a heatpump but was a little apprehensive because of the always on fan issue and the need to mod the unit to shut the fan down when the compressor shuts off to keep humidity down. Thought maybe because of the low 9.5k rating it would run longer and might not have the same humidity issues as the Houghton larger units so I decided to do a test using my Coleman in both the auto mode that it has which shuts down the fan when the compressor is off, as well as the always on low fan setting which I figured should emulate the Houghton 9.5k performance fairly well.

Decided to test under the worst conditions to control humidity, conditions that are very common in the areas we camp- temps in the 70's at night with high humidity. The results were pretty shocking to me. As you can see in the pic, even with our smaller 9.2k Coleman the humidity shot up almost instantly when the fan was set to low/always on. Didn't expect this drastic of a rise so quickly and now I'm back to not knowing which direction to go... Not interested in modding a brand new Houghton, and also, not interested in a Truma since I don't want to have to have the custom fiberglass work done to accommodate it, nor do I even know how it performs under these same conditions. Has anyone here installed the Atmos 4.4 yet and used it similar conditions? Looks promising since it has a de-humidification / sleep mode, but it looks like it also operates with the fan always on too. Might just have to replace with a new Coleman Mach 8 Cub Plus since it has an auto fan mode and it can use our existing thermostat though I don't know how quiet that unit is. No heatpump either, though it does have a heat strip option.. The search continues...

**Ronbrink** · June 8

26 minutes ago, CRM said:

Has anyone here installed the Atmos 4.4 yet and used it similar conditions? Looks promising since it has a de-humidification / sleep mode, but it looks like it also operates with the fan always on too.

There is an owner on the Oliver FB that received an order from SDG, but no report yet on the install. The Atmos 4.4 is a 15K unit, and there are claims that it is much quieter and more energy efficient than the standard Penguin ll Oliver currently installs. I have talked to the company owner and following reports by a couple of SOB owners. Although preliminary reports are promising, there have been some discrepancies in the marketing of these units; specifically, (1) a claim that soft start was built into the unit, but found not to be the case and (2) it has an inverter compressor. The heat pump is a good feature, as well as the dehumidifier which may operate separate from cooling. I have read where the Atmos 4.4 is same as the Gree A/C with the only difference in type of refrigerant. I will pass on further information as made available.

**Ronbrink** · June 8

I went back and read where the aforementioned FB owner understood the dehumidifier to function only in Low cool mode per his conversation with SDG. I reached out to him for an update on his purchase and pending install.

Also read where SDG is testing soft start type devices on the Atmos 4.4, and independent others claim the new Micro-Air ‘Breeze’ is actually a better choice over the SoftStart brand. I will follow this closely, but my thought of reinstalling my Micro-Air 364 currently on my Penguin ll was nicked due to issues of memory and rebooting; however, not a problem reusing SoftStart devices on the Atmos. Later

**CRM** · June 8

4 minutes ago, Ronbrink said:

I went back and read where the aforementioned FB owner understood the dehumidifier to function only in Low cool mode per his conversation with SDG. I reached out to him for an update on his purchase and pending install.

I figured the dehumidifier mode was just a low cool mode. Totally fine with that as long as it can hold a temp in the low 70's with low humidity under the same conditions I tested in. I have my doubts now if the fan is always running but if the system has a way of throttling down the BTU's in that mode, then maybe?

**jd1923** · June 8

2 hours ago, CRM said:

... Not interested in modding a brand new Houghton, and also, not interested in a Truma since I don't want to have to have the custom fiberglass work done to accommodate it...

I agree in being against custom fiberglass work, and with Truma you must purchase and install through their dealers only, no DIY units or replacement parts available in the aftermarket.

Re Houghton, it appears the relay install is quite simple, instructions on this forum. It could be easily reversed if you had to return the AC unit for warranty replacement. I would work this wiring on the workbench and then install. Being careful, perhaps an hour of work. We have little in humidity concerns out west, but I would install the relay just so most of the night when the temps drop considerably in the mountains the fan stays OFF!

My main goal is hush... being very quiet... I have not heard another product recommendation in this regard. Still wondering if their 9.8K BTU is feasible on an Elite II. They say it covers 400 SF which is double the E2 footprint. It is much cheaper, especially without the heat pump and we'll just run the furnace when heat is needed. The smaller unit would also pull less amps on the batteries and would be easier on a 2KW inverter.

**CRM** · June 8

19 minutes ago, jd1923 said:

Still wondering if their 9.8K BTU is feasible on an Elite II. They say it covers 400 SF which is double the E2 footprint.

In my expedience, 9.2k has been more than enough. Haven't been at a high altitude or in temps much over 100 degrees with our LE2 yet but I don't see how it wouldn't be enough. If not, either the BTU's are overrated or the LE2 isn't as insulated as we think it is. A 13.5k or 15k unit might cool the inside down faster but they're certainly overkill under the typical conditions we camp under.

**Ronbrink** · June 8

2 hours ago, CRM said:

Haven't been at a high altitude or in temps much over 100 degrees with our LE2 yet

Understood, but everything is bigger in Texas, including the heat and humidity! Waiting to hear from current installers about unit size in a few Sprinter Class B motorhomes, which appear to have comparable interior space as an Oliver, as well as other performance measures.

Edited June 8 by Ronbrink

**CRM** · June 8

8 minutes ago, Ronbrink said:

Understood, but everything is bigger in Texas, including the heat and humidity! Waiting to hear from current installers about unit size in a few Sprinter Class B motorhomes, which appear to have comparable interior space as an Oliver, as well as other performance measures.

So far, the hottest we've camped in is 101 with 90% humidity in full sun. There's got to be a breaking point, and I hope to never be camping somewhere to find it!

**jd1923** · June 9

7 hours ago, CRM said:

In my experience, 9.2k has been more than enough. Haven't been at a high altitude or in temps much over 100 degrees with our LE2 yet but I don't see how it wouldn't be enough...

Yesterday high was 97 in Prescott, today milder and although this is more like August temps, we sat on our deck and do so every evening. When 90+ is the daytime high, we will be in the 70's by dinner time, sitting on our deck that gets the evening shade.

We lived in the Austin burbs for 9 years. If midday in the summer, it Could be 107 and dry, or 93 and humid if the winds were coming from the gulf. Had a tennis coach once say, who was brought up in the country between H-town and Corpus, for 5 months it's Swamp-A$$! His words. We always remembered this coach for this and many reasons. That would be your hood @Ronbrink and not much different from your location @CRM, both coastal gulf swamp-a$$ locations.

Yes, everything is bigger in Texas! Loved our time there. We also spent 4 years in S FLA in the WPB area, and if it was possible, we would have preferred being closer to Ft Myers, or miles +/- from there on the gulf coast. Our country has so many great spots to visit, just travel at the right time of year.

No swamp-a$$ out here. AC units run more efficiently in dry air. Why are we home for 4 months of the summer, every year, while y'all are pulling you Olivers out of storage and traveling, some of it climate painful!?

If say today, tomorrow, or over the next 3 months, we venture off the mountain to go ANYWHERE, in ANY direction, we drop 3000 FT elevation and climb +20F in the first hour. Our ONLY future summer trip would be to leave in May to get to ID, WY, MN, ND, Canada or en route to Alaska, before it gets too hot.

We're home this summer, doing M&R on our newly purchased Oliver and will do a local trip in September, followed by our travel to the 2024 Oliver Texas Rally. Hope to meet you Ron and CRM if you venture the longer trip. We'll see some of you, hopefully more of you, and next thing you know it will be time! 😂

**Jason Foster** · June 9

I have the Truma Aventa Eco in my LE2. I believe it is a 13.5 btu unit. It seems to drop the temperature down from mid 90s within about 10 minutes or less and that is in full sun. A smaller unit should be able to handle it, but it will run longer. On the flip side, an AC unit that runs for a longer amount of time will remove more humidity, so if you live in northern climates with cooler temps and higher humidity, a smaller unit is the right way to go in my opinion.

**jd1923** · June 10

I did a side-by-side comparison of the specs. First the 9.5K (w heat pump option) vs. the 13.5K, In the last columns I compared the 15K with the "condensate pump." This unit may connect to the OTT condensate plumbing and I wonder if this would alleviate the humidity issue.

At first glance the 9.5K unit is 2/3rds the weight and much smaller. The 13.5K is 5" longer and 11" wider but with the fan on LOW is the quietest at 47 dB and on high pushes 318 CFM some 35% more air flow than the 9.5K model!

**CRM** · June 10

8 hours ago, jd1923 said:

At first glance the 9.5K unit is 2/3rds the weight and much smaller. The 13.5K is 5" longer and 11" wider but with the fan on LOW is the quietest at 47 dB and on high pushes 318 CFM some 35% more air flow than the 9.5K model!

All things being equal, when it comes to controlling humidity, higher CFM is not your friend- especially in the small area of an LE2. The air does not stay in contact with the evaporator core as long and less moisture is removed from the air than it is at a lower CFM. To make matters worse, the higher CFM of the 13.5k coupled with the higher BTU's will knock the temp down faster resulting in shorter run times reducing the amount of humidity removed even more.

**Ronbrink** · June 10

Just watched a video on installation of a SoftStart on an Atmos 4.4, necessary to resolve an inherent issue regarding LRA.

Also, a screenshot of the dual squirrel cage fan blower in the Atmos for higher airflow, and sound reduction both from outside and inside the RV; 4 fan speeds, including Sleep mode.

A few other notes on the Atmos 4.4: (1) condensate drains on the rooftop, (2) the R32 refrigerant requires a lower pressure, thus more energy efficient, and (3) 12,000 BTU heat pump.

**jd1923** · June 17

On 6/10/2024 at 5:59 AM, Ronbrink said:

Just watched a video on installation of a SoftStart on an Atmos 4.4, necessary to resolve an inherent issue regarding LRA.

Can't find much on Atmos or who sells them. Read they are designed in Germany but manufactured in China.

I wrote RecPRO on the Houghton dB ratings. They replied today with this:

"Hello, the compressor in the larger one is a little further back in the unit from the hole to the RV which makes it quieter. I have listed the Houghton Information we have: Phone +61 8 8448 2929 Email contact@houghtonleisure.com"

**Ronbrink** · June 17

24 minutes ago, jd1923 said:

Can't find much on Atmos or who sells them.

sdgelkhart.com, $1350 delivered was my quote. See pic for a forum to visit to obtain in depth information on the Atmos 4.4, including installation and performance testing videos.

**jd1923** · June 17

15 minutes ago, Ronbrink said:

sdgelkhart.com, $1350 delivered was my quote. See pic for a forum to visit to obtain in depth information on the Atmos 4.4, including installation and performance testing videos.

Thanks Ron, great info here. Have you made your decision? Your timing?

This will take some study, questions I have... Can the Atmos connect to the Oliver condensate drain. Does the fan turn off with the compressor? Does it truly dehumidify? (not a big concern for us living in AZ, but on some travels) Any of these would certainly be an improvement over the Houghton.

It's almost as quiet (53 dB at which fan speed?) and not like we need 15K BTU. It's 25 LBS lighter, 2" shorter, 5" less width, though 3" taller. Also, 4 fan speeds vs. 2 and only 1160W cooling! Our electric tea kettle is 1100. The Houghton is 1550 to 1700W MAX (meaning 34% to 47% more current required for the Houghton). This will easily run off a 2KW inverter all afternoon with decent AH rating in LiFePO4 batteries. I will read more. Please, let us know of your progress.

**Ronbrink** · June 17

10 minutes ago, jd1923 said:

Have you made your decision? Your timing?

Upon contact a couple weeks ago, I was placed on a waiting list for a white unit, said to take 8 weeks for their shipment to arrive. They do have in stock however, black units.

**Ronbrink** · June 17

14 minutes ago, jd1923 said:

This will take some study

Indeed, but impressed thus far! More energy efficient, competitively priced and much quieter than the Dometic, mine is the 11,000 BTU model. I have read some discussion on Houghton vs Atmos. In watching videos on performance you can make your own judgement on the db levels and energy consumption being reported. Most interest and testing is done running off an inverter.

**Geronimo John** · June 17

Buying anything that increases the trailer height would not be a positive move for many of us. Weight, width, length all to a point, would be less so.

GJ

**jd1923** · June 17

1 hour ago, Ronbrink said:

Upon contact a couple weeks ago, I was placed on a waiting list for a white unit, said to take 8 weeks for their shipment to arrive. They do have in stock however, black units.

Given an 8-week wait, I should decide soon!

**CRM** · June 17

2 hours ago, jd1923 said:

Thanks Ron, great info here. Have you made your decision? Your timing?

This will take some study, questions I have... Can the Atmos connect to the Oliver condensate drain. Does the fan turn off with the compressor? Does it truly dehumidify? (not a big concern for us living in AZ, but on some travels) Any of these would certainly be an improvement over the Houghton.

It's almost as quiet (53 dB at which fan speed?) and not like we need 15K BTU. It's 25 LBS lighter, 2" shorter, 5" less width, though 3" taller. Also, 4 fan speeds vs. 2 and only 1160W cooling! Our electric tea kettle is 1100. The Houghton is 1550 to 1700W MAX (meaning 34% to 47% more current required for the Houghton). This will easily run off a 2KW inverter all afternoon with decent AH rating in LiFePO4 batteries. I will read more. Please, let us know of your progress.

Based on your location, you may want to research the watts required while cooling under "desert" conditions on any of the units you are considering. The Coleman 9.2k I'm considering uses almost 25% more watts under desert conditions than it does in "standard" conditions- 1150 watts vs 1410. Not sure if this large difference in watts is typical or something specific to this unit itself...

**rideadeuce** · June 18

Looking forward to someone installing the Atmos 4.4 (Gree, Tosot, Eco cool) unit. Looks great from what I read on the Sprinter van thread.

Compared to the Dometic PII it has almost the same footprint and weight. 2 1/2 inches longer in the back.

No condensate pump or line connection (drains onto the roof)

Remote control and WiFi thermostat available. Should make for easy install. Also, app controlled.

Quite a bit more efficient on shore power and batteries.

Very quiet!

$1350 shipped. Not including soft start if needed. (Single or small battery bank). Or cheaper depending on which brand you get off of Amazon, etc.

Definitely interested.

@Ronbrink and others let us know how the install goes.

Best,

M

Links for unit introduction and installation:

Edited June 18 by rideadeuce

**Ronbrink** · June 18

7 hours ago, rideadeuce said:

Looking forward to someone installing the Atmos 4.4 (Gree, Tosot, Eco cool) unit.

What sets the Atmos 4.4 apart from the other similar brands you listed is the type of refrigerant, R32. As I recall reading, requires a lower operating pressure and thus, more energy efficient.

Shawna and Scott · June 18

Are there any modifications needed to attach to the Oliver? When I questioned about upgrading to the Truma I was told that it needed a platform to sit on, available thru Oliver. Other fiberglass work was involved.

**rideadeuce** · June 18

39 minutes ago, Ronbrink said:

What sets the Atmos 4.4 apart from the other similar brands you listed is the type of refrigerant, R32. As I recall reading, requires a lower operating pressure and thus, more energy efficient.

@Ronbrink From what I understand, they all use R-32 due to Gree being the manufacturer for them all and then they are distributed under different labels depending on market. Which is great since R-410A is going to be retired and R-32 is much more efficient. Thanks for making us aware of an exciting new option.

@Shawna and Scott From what I have seen it will work perfectly due to having almost the exact same footprint. Curious to see pics of first install on an Oliver.

TST-RV-GC15K-User_manual_230707.pdf

PPI-SG-GREE-002.pdf

Best,

Mike

AC upgrade conundrum

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