Blizzard NXT 15k Upgrade

[pteck]

Success! Finally after many months, had a long weekend to tackle this job.

I have an '07 27FB Ocean Breeze with original Penguin I 13.5k unit. Still worked, but as I'm in sunny Southern California, it wasn't up to task with a larger airstream. Enter the Blizzard NXT 15k. I've been eyeing this unit for a couple years as it's sold as the latest top of the line 15k high performance unit.

My aim was to keep a single roof top AC, transfer my Microair Easystart 366 so as to run on a single Honda 2200 generator, and have the best performance possible in a single energy efficient unit.

To be on the safe side as I was working alone, I rented a compact scissor lift. Best thing ever for this job. $200 rent and delivered. Also took the opportunity to refresh all the sealant on my roof.



Taking out the old Penguin with the original drip tray was probably the most time consuming part. Lots of sealant to break and scrape. A brick trowel, multi-tool, and plastic scraper were the best tools for the job.

The Blizzard uses more modern drip cups which were easily adapted. Needed a second seal stacked as is typical for this configuration.



The Easystart 366 installed nicely and fit in the electrical box. I used this schematic to install which is the same from the rest of the Dometic line.




And the lift:


Unit in place. It's about the same footprint, and a few inches taller. I'm okay with that for more cooling performance. The swoopy styling and split color tone help it look more compact than it is.



Haven't gotten to test it out much yet as I finished late in the day. It works! Feels very cold, and moves lots of air. Airflow in my non ducted AS is definitely louder than my Penguin I on high but that's okay if my goal is to move lots of air to cool it. Pretty mellow in low. Can't hear the compressor come on whatsoever, but that could be a function of the easystart too.

Will share more on the performance as I get more use out of it in the summer. But so far, so good.

[nryn]

Very cool (literally)!

On the non-ducted Airstreams, does the cooled air just descend from the spot below the AC unit or is there a means to distribute it around the interior?

[rmkrum]

There are vent louvers around the part of the unit that hangs down into the interior. They do distribute the Air well enough to keep the interior comfortable.

[pteck]

This is Dometics newer Air Distribution Box (ADB), which is common for their whole lineup of rooftop air conditioners.



As rmkrum mentions, there are louvers to every side of the box, to vent air in that direction. Plus two downward spouts. Each can be open/closed/adjusted.

The vent to the front of the ADB (nearest the intake grill) has the weakest flow. Which in my case is not ideal as that feeds the farther front bedroom space.

The NXT moves a LOT of air, which is probably more optimal for a newer gen ducted AS to more even distribution. In my use on high fan mode, I'll likely open every spout to maximize overall cooling rather than to manage flow.

Still, this represents a rather substantial upgrade form my Penguin 1. Especially coming in to a destination after the trailer has been heat soaked. It's overcast all week here, but I hope to test it under more demanding conditions soon.

[harryk]

Just finished up our install of a 15k Blizzard with heat pump in our Classic 31. Install was difficult because 2 of the top shroud screws were installed too tight and after trying everything I could think of, wound up drilling the stainless phillips heads off and that itself was a task because they are thru plastic and you have to spray coolant as you are drilling or the plastic melts Installed the drip cups and that part was easy. Subsequently changed all of the fasteners to stainless hex bolts. Also had to use several stainless hose clamps to help secure the top & bottom shrouds securely across the rear. Easy Start was simple to install & works well on our 32k inverter/generator.
Performance is OUTSTANDING ! Love it so far. Note: Purchased from PPL Motorhomes and their parts / customer service is the best !

[pteck]

Funny you mention the shroud screws. I had one that was cross threaded too. Fortunately, I had a hex drive impact with correct Philips bit and was able back it out without much problems.

I still can't comment on the performance as it's been may grey here in normally sunny socal.

The fan moves an incredible amount of air. 350CFM is what it's rated it, and is the highest in Dometics lineup. I can't find a document at the moment, but this unit also draws incrementally more, the most power for compressor and fan in Dometics linup, which should speak to its performance capacity, even if it's rated at 15k like others.

I have yet to fully "train" my easystart on as I'm waiting for warmer weather. My hope is that a single compact Honda EU2200i will still continue to support this unit. I believe it will.

That said, Dometic recently acquired the Atwood Air Command unit. This is documented at 16k-18k BTU performance, so if one absolutely must have unequalled performance in a single unit, it will be that one. It has a interior fan CFM rating of 360CFM in case anyone is wondering. With split fan and cooling motors. It is physically larger and "commercial" looking if that's a consideration. It's thermostat setup is a bit different too.

[pteck]

Found the table of specification which I chopped down to compare the NXT, Penguin II, and Brisk II units. Even though they are all rated as 15k units, you can see that the specifications for power draw and refrigerant are indeed different enough to suggest more cooling capacity from the NXT model.

[jeffmc306]

Originally Posted by pteck

Found the table of specification which I chopped down to compare the NXT, Penguin II, and Brisk II units. Even though they are all rated as 15k units, you can see that the specifications for power draw and refrigerant are indeed different enough to suggest more cooling capacity from the NXT model.

Attachment 340247

pteck, thanks for sharing the great photos and description of your upgrade! Takes a lot of ambition to tackle a big job like that.

Looking at the table you posted, it's interesting how much more refrigerant there is in the NXT compared to the other two - and they're all "rated" at 15K BTU. I'll bet yours is going to have much better performance.

Congrats on the great job and upgrade!

[pteck]

It's always been a question whether a single high output A/C unit can keep a larger Airstream cool.

Just got back from a long summer road trip in the sunny southwest region. Happy to report, the Blizzard NXT delivers on the promise of a personal frosty flurry reprieve through the summer heat!

It's cold and effective enough that even heat soaked during long drive, that turning it on for a luncheon in a hot and exposed rest area, that it can provide immediate cooling comfort. Much like a car A/C, there's enough cooling and airflow that it gives an immediate reprieve by directing the strong cold air to the dinette. And it makes reasonable headway to cool the rest of the trailer even without a morning headstart.

[elbundi]

Originally Posted by pteck

It's always been a question whether a single high output A/C unit can keep a larger Airstream cool.

Just got back from a long summer road trip in the sunny southwest region. Happy to report, the Blizzard NXT delivers on the promise of a personal frosty flurry reprieve through the summer heat!

It's cold and effective enough that even heat soaked during long drive, that turning it on for a luncheon in a hot and exposed rest area, that it can provide immediate cooling comfort. Much like a car A/C, there's enough cooling and airflow that it gives an immediate reprieve by directing the strong cold air to the dinette. And it makes reasonable headway to cool the rest of the trailer even without a morning headstart.

Great write up pteck, much appreciated. Am looking to replace the original Duo-Therm (600312) in my 05 CCD which is only an 11k unit!

Wasn't interested in another Dometic due to a lot of warranty issues my local long time dealer mentions, but will look at the NXT.

How are the noise levels on the lowest settings? This is important as my Airstream is also my current work office (due to Covid19). I can live with my current unit as it still cools some, but it is getting old and vibrating the whole camper. Yes, I have cleaned the fan blades, tightened the fan screws, and sound dampened as best I can, it's just an old and about worn out unit.

[pteck]

The noise on low is about what the fantastic fan is at medium speed.

On high, yes, it can get noisy as it's moving a ton of air.

[rowiebowie]

Originally Posted by pteck

The noise on low is about what the fantastic fan is at medium speed.

On high, yes, it can get noisy as it's moving a ton of air.

That was the main problem with my old Coleman. It's two fan speeds were "high" & "higher". The new unit has an actual medium speed which accounts for a great improvement in sound. But the new one on "high" isn't much different than the old one.

[pteck]

What new unit are you referring to?

[rowiebowie]

Originally Posted by pteck

What new unit are you referring to?

Two years ago, I replaced my failing unit with a Coleman Mach 8 Plus. In my application I needed the lowest profile I could get. And, the Mach 8 was the only Coleman to that criteria. Staying with the same brand made the install an easy plug & play.

The manufacturers had not yet begun producing some of the "quiet" models offered today, but as I said, it is quieter (and more efficient) than the unit it replaced. I would love it if they had offered a NDQ version in low profile at the time I replaced mine. Quiet (or at least quieter) ac's are long overdue.

Now, if only the new inverter Onan generator is quiet and dependable, what will we have to complain about?

[elbundi]

Originally Posted by rowiebowie

Two years ago, I replaced my failing unit with a Coleman Mach 8 Plus. In my application I needed the lowest profile I could get. And, the Mach 8 was the only Coleman to that criteria. Staying with the same brand made the install an easy plug & play.

The manufacturers had not yet begun producing some of the "quiet" models offered today, but as I said, it is quieter (and more efficient) than the unit it replaced. I would love it if they had offered a NDQ version in low profile at the time I replaced mine. Quiet (or at least quieter) ac's are long overdue.

Now, if only the new inverter Onan generator is quiet and dependable, what will we have to complain about?

You can get a hush-kit for Coleman Mach 8

https://www.youtube.com/watch?v=jpZmD48qXpI

the product link is in the description. The new mach 8's may have the speed already slowed down on the condenser fan. The NDQ's apparently don't have a condensate pump, or place to add one, so I hear. Am I being told right?

[elbundi]

Originally Posted by pteck

The noise on low is about what the fantastic fan is at medium speed.

On high, yes, it can get noisy as it's moving a ton of air.

Usually have the AC on low anyway, so that sounds like an option. Would be nice to have a thermostat too. Was that an easy install?

[SeeMore]

I purchased the newest version of the Mach 8 15K Heat Pump with condensate pump (Airxcel #47024B876) this past summer as a replacement for a 2003 vintage Domestic 13.5K Duo-Therm. The Mach 8 units manufactured since mid-2019 use the new exterior fan blade and housing design which eliminates the need to buy the Hush Kit.

The Mach 8 runs more quietly than the old unit, cools the trailer better on really hot summer days, and can be installed with a wall thermostat that operates both the overhead HVAC unit and propane heater from a single location with digital settings. The set and forget approach to managing interior temperature is a giant improvement to the intermittent futzing with the ceiling mounted fan speed and temp dial method of old.

The combination of this thermostat (8530-3481 Wall Thermostat with Single Stage For Heat Pump/ Gas Furnace Control & Digital Readout) and this control board (707415 Coleman Mach Air Conditioner Control Box Assembly) plus the addition of a new 6 wire cable (18/6 Shielded Plenum Rated Wire) between the thermostat and overhead housing was all it took to transition to current technology.

There is a new interior ceiling distribution housing (part# 9430D7153 Deluxe Coleman Ceiling Assembly w Down Vents) that has two ports that manually open to allow cold air to dump out the bottom directly with little back pressure which accelerates the temperature drop.

https://www.pplmotorhomes.com/parts/...le-new_72.0727

[rowiebowie]

Originally Posted by elbundi

You can get a hush-kit for Coleman Mach 8

The newer Mach 8 is the "Plus" version (mine). Coleman implemented an improved condenser fan on the Plus version. Not exactly the "hush kit" in the video, but they did quiet it externally a significant amount.

I wouldn't recommend the Mach 8 Plus to anyone who can use their new NDQ instead since it is significantly more quiet and 2-3 amps more efficient. Again, I had to have an extremely low profile model on my Airstream Avenue class b because the unit hidden under a rear shroud on the roof (looks like an boat hull under there).

[elbundi]

Originally Posted by rowiebowie

The newer Mach 8 is the "Plus" version (mine). Coleman implemented an improved condenser fan on the Plus version. Not exactly the "hush kit" in the video, but they did quiet it externally a significant amount.

I wouldn't recommend the Mach 8 Plus to anyone who can use their new NDQ instead since it is significantly more quiet and 2-3 amps more efficient. .

From what I've been told so far, the NDQ units do not come with a condensate pump and cannot have one added either. Otherwise it would be the perfect unit, if you could find one.

[SeeMore]

Originally Posted by elbundi

From what I've been told so far, the NDQ units do not come with a condensate pump and cannot have one added either. Otherwise it would be the perfect unit, if you could find one.

Whomever informed you a condensate pump option can not be added did so in error. I was told the same by a retailer but a call to the tech support line disputed that fable promptly. The part number is 47233A3091 Coleman Mach Air Conditioner Condensate Pump (~$45-55) and the installation could not be simpler.

sample: https://www.ebay.com/i/324204321309

You have to plug two drain holes (1/8" diameter) in the mounting location which can be accomplished with either a compound or a very short screw. There are two wires to connect and then a section of flexible vinyl pipe routed to the old in-wall drain pipe.