Air8 Performance in T@B 400 & Resolution (Coming Soon!)

Denny16 · April 2020

Quote: ”My point regarding insulation was simply: regardless of insulation type there isn’t enough insulation for a small Air Cond unit to work effectively in the 400.”

Good point, I wish the TaB 400 had better insulation, but it has better insulation than many of the travel campers out there, and much improved over my previous caravan.
cheers

TabberJohn · April 2020

@Denny16 -- I mentioned the tropical roof idea on another thread.

The first Land Rover with that roof design was the long wheelbase Safari Station Wagon (1955). The inside was remarkably cooler especially in direct sun. In later years they added circulation vents that can direct air down onto passengers when vehicle is moving.
My Land Rover was a used 1973 Series III with PTO and Fairey Overdrive purchased in 1976. It was the only vehicle I've ever owned that appreciated in value; sold for $1100 more than I paid for it 7 years later.

Back on topic -- nuCamp doesn't need to alter their roof design to add this feature. They only need to elevate the solar panels. Imagine elevated solar panels mounted the full length of a T@B roof covering as much possible allowing for ceiling fan, vents, 400 rear window, and Outback rack.
The end result will be an interior cabin that will be MUCH COOLER in direct sun.

Plus solar panels are also more efficient with air circulation. Win-win. Damaged solar panel? Easier to replace too. Win-win-win.

Denny16 · April 2020

Thanks, didn’t see your previous post about the tropical roof. Your idea of using solar panels is grand!
cheers

jkjenn · April 2020

TabberJohn said:

@Denny16 -- I mentioned the tropical roof idea on another thread.
The first Land Rover with that roof design was the long wheelbase Safari Station Wagon (1955). The inside was remarkably cooler especially in direct sun. In later years they added circulation vents that can direct air down onto passengers when vehicle is moving.
My Land Rover was a used 1973 Series III with PTO and Fairey Overdrive purchased in 1976. It was the only vehicle I've ever owned that appreciated in value; sold for $1100 more than I paid for it 10 years later.
Back on topic -- nuCamp doesn't need to alter their roof design to add this feature. They only need to elevate the solar panels. Imagine elevated solar panels mounted the full length of a T@B roof covering as much possible allowing for ceiling fan, vents, 400 rear window, and Outback rack.
The end result will be an interior cabin that will be MUCH COOLER in direct sun.
Plus solar panels are also more efficient with air circulation. Win-win.
Damaged solar panel? Easier to replace too. Win-win-win.

Actually, the new solar panels they are using do not need the air flow that previous types of panels. They use a lower temperature coefficient and perform better during the hotter parts of the day.

https://www.sunflaresolar.com/our-technology

TabberJohn · April 2020

jkjenn said:

Actually, the new solar panels they are using do not need the air flow that previous types of panels. They use a lower temperature coefficient and perform better during the hotter parts of the day.

https://www.sunflaresolar.com/our-technology

Those will work even better since the top layer tropical roof can be a CNC cut aluminum panel with the Sunflare solar panels sized to fit.
The important thing is the gap to dramatically reduce inside cabin temp. My guess would be 10 degrees cooler in direct sun.
nuCamp could test this very easily with three T@B units. One unit with standard roof and no solar. One with standard roof and solar. And one mock-up unit with tropical roof and solar.
I'd be interested in seeing a table showing the inside/out temps for all three with days baking in full sun ranging from the low 80s to high 90s. Plus send the mock-up unit to Texas for the 100s testing.

Dutch061 · April 2020

splatmatt said:

My point regarding insulation was simply: regardless of insulation type there isn’t enough insulation for a small Air Cond unit to work effectively in the 400. You don’t need an engineer as any HVAC installer could tell you this. Ideally you want an air cond unit to be powerful to enough to effectively cool and dry air but you also do not want it so powerful that it only runs for a very short interval. A short interval run will not have enough time to effectively circulate and dry cabin air. I imagine around 11k BTU unit would work for the higher temps that overwhelm the models’ insulation efficacy while delivering long enough run intervals to remove moisture and cook the air. 13.5k unit may work too, but only a real world test will show if it’s run cycle will be too short. The supposed 8k and 6k units even with a properly placed sensor would run for long intervals but not have the ability to effectively cool and dry the cabin air in common higher summer temps as the insulation just isn’t enough. Kind of like the difference between a Yeti 3” walled cooler and a cheap grocery store cooler with barely a 1” wall; the ice in the cooler with the thicker insulation will last longer and yield cooler temps than the in the cooler with thinner (less) insulation. Both coolers having the same interior storage volume and amount of ice. So either the 400 needs a better insulation factor or more fresh ice added frequently. (BTUs).

You raise several valid points, along with the importance of not having a unit that is sized to large and not running long enough. Once again, I forget the exact ratio of BTU per Square Foot but "The Google" shows us that in high temperature climates (IE Las Vegas) that you need 1 ton (12,000 BTU's) per 400 Square foot with variables related to insulation, number of windows, etc. According to NuCamp's website, the dimensions of a TAB 400 are 219" x 90" (18.25' x 7.5') which calculates to 136.875 square feet. I am assuming this is outside dimensions and not inside but close enough for this purpose. With this being said, "in theory" the Air8 should be more than adequate if it is truly 8K BTU's. If we use this math, 8K BTU's should be double what it takes but of course the R value of the walls, floor, and ceiling are much less on ANY RV than a building of any type.

This much I do know; time will tell, because I have one (2020 400 BDL) and will gladly be vocal if there are issues because the heat and humidity in NC during the summer is a pretty good load.

The point where you are mistaken is your cooler temperature comparison, ice in a cooler is the same temperature regardless of the insulation whether it is a Yeti (I own 2 and there isn't a better made cooler bar none) or a Coleman Extreme. How long it lasts is the only difference.

TNOutback · April 2020

working full work days in my T@B this week, I have noticed the power of direct sunlight to heat up the camper. This week in TN we have started two days at 42 degrees. When the sun gets on the camper, it has been 45 degrees outside, and I had the heat set on 60 overnight. In very short order, once the sun hits the camper, the inside temp climbed to 75 degrees - while it was still 45 outside!

Denny16 · April 2020

Yes, isn’t that great — solar gain! It is in high 40s at nightp and the 50s in the day, with a cold wind the last two days. The TaB 400 warms up to 75;very nicely. I have a heater set at 60, which makes the TaB 58 in the morning. Closing the screens and partial shades can
reduce the solar gain, and opening the roof vent. Happy work camping!
cheers

splatmatt · April 2020

Dutch061 said:

The point where you are mistaken is your cooler temperature comparison, ice in a cooler is the same temperature regardless of the insulation whether it is a Yeti (I own 2 and there isn't a better made cooler bar none) or a Coleman Extreme. How long it lasts is the only difference.

I am not mistaken; I just didn't articulate my expression thoroughly. My point was the ice in better insulated cooler(ice chest) would maintain lower temperatures *longer* than the equivalent ice in a cooler(ice chest) with less insulation.

rh5555 · April 2020

Once the ice in your cooler starts to melt, the temperature of both the ice and the melt water is 32F. The temperature of ice and water will remain at 32F until all the ice melts. This is high school physics. The temperature of your food is more difficult to define and is certainly affected by the quality of cooler insulation. The better the isulation, the more even the temperature in the cooler will be and the closer that average temperature will be to 32F and the longer the ice will last. I think you're both right!

TNOutback · April 2020

Being in the camper every day as my office, even just sitting in the driveway, has been a great place to work. Now though, the temperatures are increasing, and it’s becoming more difficult to stay here. Today in TN is bright sunshine, starting out at 50 degrees. I had the heat set overnight for 60 degrees. As the sun came up and began hitting the camper, I transitioned to open windows and the ceiling fan. Outside temp was 60, and inside temp was 75. Once it hit 77 degrees inside, I closed up and turned on the Air8, setting the thermostat at 64 degrees (to try to overcome the sensor’s location). After 2 hours of running, the inside temp is now 81 degrees, and the outside temp is . . . 80 degrees!

I’m really looking forward to a replacement air conditioner!

dutsmiller · April 2020

@TNOutback Was the air coming from the vents cold? The only time I ever tried using the Air8, my experience was similar to yours. I never really felt that the output air was anything resembling cold, more like "cooler".

TNOutback · April 2020

@dutsmiller, I have measured the outlet temperature at the under-bed outlet at 65 degrees. It’s not quite that cold at the upper bed outlet or the outlet under the front dinette. That seems to be a reasonable outlet temperature; just not enough of it? I don’t really know. I’ve never had occasion to measure the outlet temperature of RV air conditioners, so I don’t really have anything RV-related to compare to.

Another observation just confirms they need to relocate the temperature sensor. As I mentioned, I had set the thermostat to 64 degrees. We had a rain shower come in, and the Air8 started making some progress inside the camper. It finally cut itself off when the cabin temperature reached 75 degrees (it was reading 64 at the sensor location). While the sun is not out yet, the rain has stopped, and the cabin temperature is back up to 80 degrees - but the Air8 has not kicked back on yet. :(

SweetlyHome · April 2020

We haven't a lot of experience with the Air8 in our new 400. However in our one experience I had no problem getting the T@B cool on an 80º+, sunny day in Florida. But humbly suggest some experimentation might help.

Based on our experience with a 2012 T@B (sorta 320), with a floor level mounted AC, I knew in advance there would be issues. As with the Air8 this window style unit had the temp sensor on the inlet of the unit.

When when we picked up the unit we insisted the AC be operating. The tech had all the windows and the doors open, and the thermostat all the way down for demo. I'm not sure if he did deliberately or not to cover the issue? Anyway all the cold air settled right out the door resulting in the Air8 generating lots of cold air and never ingesting it back into itself resulting in it shutting itself off. Perhaps this is arrangement is a good test of an Air8 unit functioning correctly?

Next, based on the 2012 experience, I insisted the Tech assure both the round AC vents mounted below bench height rotated so the slats would force air upwards and away from the Air8. From the factory they both aimed at the floor (frustration)!! Cold air settles not rises. Although it took him sometime and some lubricant they now and will always be aimed up and slightly away from the Air8. Maybe this is the plus?

Finally in the 2012 experience I would hang a small fan on the cabinet below sink right in front of the AC exhaust aimed up and back over the bed. This effort usually resulted in a cool camper and the AC short cycling after a short period. If I have to resort to this in the 400 I'm on the warrenty list with Nücamp!

Dutch061 · April 2020

TNOutback said:

@dutsmiller, I have measured the outlet temperature at the under-bed outlet at 65 degrees. It’s not quite that cold at the upper bed outlet or the outlet under the front dinette. That seems to be a reasonable outlet temperature; just not enough of it? I don’t really know. I’ve never had occasion to measure the outlet temperature of RV air conditioners, so I don’t really have anything RV-related to compare to.

Another observation just confirms they need to relocate the temperature sensor. As I mentioned, I had set the thermostat to 64 degrees. We had a rain shower come in, and the Air8 started making some progress inside the camper. It finally cut itself off when the cabin temperature reached 75 degrees (it was reading 64 at the sensor location). While the sun is not out yet, the rain has stopped, and the cabin temperature is back up to 80 degrees - but the Air8 has not kicked back on yet. :(

Okay, at risk of being kicked for this, I am going to reply. If the AC outlet temperature is 16 to 22 degrees colder than the inlet temperature the system is working and producing chilled air equal to ANY RV unit. The theory being that as the unit continues to run, the overall temperatures will continue to come down; no different than a residential unit.

Definitely handicapped from the location of the temperature sensor, which I discovered when I used mine a week ago and quickly realized IF you let the air conditioning shut off that the only way to get it back on without baking is to change the setting of the control panel to "fan only". This draws the air though the unit so it can get an accurate reading. If the you can't get the system to take an accurate air temperature reading, it will never turn on. So, this winter when I take my 2020 BDL back to the dealer for a couple of issues that need to be taken care of I will get this taken care of. Unless I do it myself sooner, it is nothing more than a thermistor and I am pretty sure I am smart enough to be able to buy one with matching properties.

Do you have the diverter added to the outlet of the air conditioning unit to force the air towards the street side of the camper? Silver scoop bolted to the floor?

I am very interested in working through this, we don't camp that often in the heat because we can go to higher elevations, but it still needs to work correctly.

Regards,

Brad

Marceline · April 2020

TNOutback said:

Being in the camper every day as my office, even just sitting in the driveway, has been a great place to work. Now though, the temperatures are increasing, and it’s becoming more difficult to stay here. Today in TN is bright sunshine, starting out at 50 degrees. I had the heat set overnight for 60 degrees. As the sun came up and began hitting the camper, I transitioned to open windows and the ceiling fan. Outside temp was 60, and inside temp was 75. Once it hit 77 degrees inside, I closed up and turned on the Air8, setting the thermostat at 64 degrees (to try to overcome the sensor’s location). After 2 hours of running, the inside temp is now 81 degrees, and the outside temp is . . . 80 degrees!

I’m really looking forward to a replacement air conditioner!

Do you have coverings over the window? It makes a huge difference on my clamshell.

jkjenn · April 2020

Marceline said:

TNOutback said:

Being in the camper every day as my office, even just sitting in the driveway, has been a great place to work. Now though, the temperatures are increasing, and it’s becoming more difficult to stay here. Today in TN is bright sunshine, starting out at 50 degrees. I had the heat set overnight for 60 degrees. As the sun came up and began hitting the camper, I transitioned to open windows and the ceiling fan. Outside temp was 60, and inside temp was 75. Once it hit 77 degrees inside, I closed up and turned on the Air8, setting the thermostat at 64 degrees (to try to overcome the sensor’s location). After 2 hours of running, the inside temp is now 81 degrees, and the outside temp is . . . 80 degrees!

I’m really looking forward to a replacement air conditioner!

Do you have coverings over the window? It makes a huge difference on my clamshell.

Agree. As does a sunshade of some kind.

TNOutback · April 2020

@Dutch061, I’m at a loss to explain it, and I understand what you are saying. I’ve owned RVs for years; I’ve never had one that could not cool the unit in the sun, and I didn’t have to manually run the blower, or use a separate fan, or close the window shades; it just worked. When I turned the a/c on today, the cabin temperature continued to RISE, not go down, even after 2 hours of constant running on high, and finally held at 81 degrees, with an outside temperature of 80 - in full sun. Only when it became cloudy and we got a brief shower did it start knocking the temperature down in the cabin.

Yes, I have the prototype “scoop” installed that NuCamp sent me last summer. I cannot tell it did anything to improve the Air8 performance, but without a doubt it worked well to get the hot air out from under the camper, and significantly lowered noise levels outside the camper on the door side.

I was told by an Elwell engineer back in early January, that they had a retrofit kit being made to send to dealers “within weeks” to relocate the temperature sensor out into the cabin, and a replacement a/c unit would be ready to ship to dealers by the end of April. Of course, that was before this awful pandemic set in.

Dutch061 · April 2020

TNOutback, is the outlet temperature 16 to 22 degrees lower than the inside temp? IE 80 inside should yield 58 to 64 degree temps at the outlets. If not, it could be a sign that the compressor is not running or there are other refrigeration issues. Really dumb question which I hate to even ask, I assume you see the "snowflake" on the Elwell display panel? The manual looks like a 5 year old translated it from Chinese or similar, so it is nearly useless and it would be very easy to overlook this.

The reason I am so curious, is that we also have a 2020 BDL and it was 87 outside (and inside) the weekend before last while we were in the mountains boondocking. I fired up my 3500 watt genny, didn't use the 30 Amp outlet initially but used one of the 15 amp outlets. AC ran for about an hour and all of a sudden quit just when it was getting a good bite on the heat. I realized pretty quickly that the power draw exceeded 15 amps (batteries were also far from being charged but that itself is another story). So I got the factory 30 Amp cord out and my adapter to plug it into the 30 Amp outlet of the genny. It was then, that I also realized that the temp sensor was showing 68 degrees +/- while the Alde display and my temp gun were crowding 90 pretty fast. We were in full sun, so it was heating up inside pretty fast.

After this, I set the thermostat to 62 (lowest is 61) and in about 60 seconds (reasonable pause before cycling a compressor to equalize pressures). the compressor kicked back on and in 2 hours it was close to 70 degrees inside. At that time the Elwell display and the Alde display were within 2 degrees of each other. That is why in my original post I stated that the location of the ambient sensor can certainly be an issue for proper control. If my experience of performance is an indicator, I feel confident that I can address my concerns by relocating the sensor.

Our previous 2017 TAB 320 S with the 5K BTU couldn't even come close to this level of performance I have seen compared to this so far. I am sure that I will get many more chances to validate the AC Unit before I take it in for the work scheduled in December. If it doesn't perform, it will be resolved to my satisfaction.

Regards,

Brad

TNOutback · April 2020

@Dutch061 thanks for your insights. Yes, the “snowflake” is illuminated. As you point out, it’s hard to say just what is the temperature in the cabin? It can be 90+ degrees at head height, and 64 down at the Air8 intake! I have had lots of communications back and forth troubleshooting with an Elwell engineer last summer, and he never blinked at my measured outlet temperature of 65 degrees, never said he suspected a problem with unit. I took that to mean that was an expected outlet temperature.

That being said, I am not seeing the performance you are apparently getting in direct sun. The unit simply cannot keep up with direct sunlight and cool the camper, even setting the thermostat at it’s lowest setting and forcing it to run continuously. Cloudy or in the shade, it has no problem cooling off the camper, but sunlight is a different story. Monday was a good example of that, with 2 hours of constant run on high, the best it could do was 81 in the cabin with an outside temperature of 80.

Denny16 · April 2020

Try setting a small usb fan in the front, blowing the warm air back and getting some circulation between the top and bottom areas.
cheers

TNOutback · April 2020

Denny16 said:

Try setting a small usb fan in the front, blowing the warm air back and getting some circulation between the top and bottom areas.
cheers

I have already tried that with little effect, other than to take up valuable floor or counter space and make even more noise. (We do use a USB fan to circulate some air when we are not using the a/c.) This is a function that the a/c system should be handling, and you shouldn’t have to resort to other devices to do what it is supposed to do. I think there is a missed opportunity with the placement of the blower outlets. They need to be up high in the cabin, not down low next to the floor. The one under the bed could be routed through the back of the closet/larger refrigerator to a vent near the ceiling at or beside the closet; the front outlet could be routed up behind the “cubby hole” storage area to an outlet near the ceiling - with very little loss of storage space. Most “standard” roof-mounted RV air conditioning units drop the air from the ceiling, and that would certainly help this situation.

Marceline · April 2020

TNOutback said:

That being said, I am not seeing the performance you are apparently getting in direct sun. The unit simply cannot keep up with direct sunlight and cool the camper, even setting the thermostat at it’s lowest setting and forcing it to run continuously. Cloudy or in the shade, it has no problem cooling off the camper, but sunlight is a different story. Monday was a good example of that, with 2 hours of constant run on high, the best it could do was 81 in the cabin with an outside temperature of 80.

As you keep mentioning the problem being related to direct sun, I'd like to ask again: Do you have any kind of awnings or shades over the windows? Or do you have the inside window shades closed (a bit gloomy)? If you look at the ratio of window area to the trailer interior volume, that's a heck of lot of heat pouring into a small space. I think that it would be hard for almost any AC to keep up if the windows are uncovered.

TNOutback · April 2020

@Marceline the window manufacturer has warnings that state that you should not close the shades in direct sun due to the heat build up can permanent damage the acrylic windows. We typically leave about 2-3 inches of screen at the top to ensure they stay vented, yet try to block the solar radiation as much as possible.

However, this is not something we have ever had to do in 30+ years of RV ownership. Our Jayco popup with an a/c was better able to handle warm weather, as was our Coachman and our Outback. Spent many summers in the blistering hot Florida sun with a cool camper. We never before canceled trips due to the weather being too warm. We’ve never worried about our pet being left in the camper while we went hiking, until now. We’ve never used other fans to try to circulate the conditioned air in the camper before now. I am trying to remain hopeful that Nucamp will fix this, because we never would have bought a $30K camper you couldn’t use in warm sunny weather. We ordered this camper when the Cool Cat was being used, and I rarely, if ever, heard anyone say anything about about problems with the Cool Cat. We are 8 months into ownership now, still without a way to keep the camper cool in sunny weather, and no word on when that might be fixed.

** as I’m writing this, it has clouded up in the past 30 minutes, 79 degrees outside. The inside temp has gone from 81 to 75!**

Marceline · April 2020

TNOutback said:

@Marceline the window manufacturer has warnings that state that you should not close the shades in direct sun due to the heat build up can permanent damage the acrylic windows. We typically leave about 2-3 inches of screen at the top to ensure they stay vented, yet try to block the solar radiation as much as possible.

However, this is not something we have ever had to do in 30+ years of RV ownership. Our Jayco popup with an a/c was better able to handle warm weather, as was our Coachman and our Outback. Spent many summers in the blistering hot Florida sun with a cool camper. We never before canceled trips due to the weather being too warm. We’ve never worried about our pet being left in the camper while we went hiking, until now. We’ve never used other fans to try to circulate the conditioned air in the camper before now. I am trying to remain hopeful that Nucamp will fix this, because we never would have bought a $30K camper you couldn’t use in warm sunny weather. We ordered this camper when the Cool Cat was being used, and I rarely, if ever, heard anyone say anything about about problems with the Cool Cat. We are 8 months into ownership now, still without a way to keep the camper cool in sunny weather, and no word on when that might be fixed.

** as I’m writing this, it has clouded up in the past 30 minutes, 79 degrees outside. The inside temp has gone from 81 to 75!**

The trailers that you mention all have a much lower window to interior volume ratio than the T@Bs. Personally I think that this is a pretty big factor. I think that you need to find some way to cut the amount of sunlight beaming into your trailer. In hot weather I think that most of us use window awnings/covers attached to the exterior of the windows and/or one of the keder rail visor/awning options. The 400 in particular has that big stargazer window. I'd guess that it's pretty important to prevent sunlight from beating straight down into that window. If not, you'd have quite a greenhouse effect there. As an experiment, I'd try throwing a packing blanket over that window. It might look pretty redneck but it might convince you of the utility of covering the windows.

I bought my window awnings from Lisa Roddy but plenty of people have made their own. https://shinersview.com/collections/frontpage/products/tab-400-trailer-window-awnings

Honestly, If I were in a hot climate and I was using a trailer in my driveway as an office, I would try to get some kind of canopy to cover the whole trailer.

For sure the position of the temperature sensor seems very unfortunate and it's something that should be fixed. I think @Dutch061 is probably on the right track with setting the unit at the lowest possible setting. And since the cool air is coming out at the floor, it seems logical to me that some method for moving the cool air up (a fan?) would help. I wonder if you cracked the roof vent slightly and turned on the fan to the lowest exhaust setting that it would be enough to draw the cooler air up and push the hotter air out. Heck, maybe even just cracking the roof vent would be enough to get the air moving.

b407driver · October 2020

I wonder how hard it would be to turn the output over the bed into the/an input, so it is inhaling the hottest air in the trailer? Maybe someone's done it, haven't been following closely.

Blueespy · February 2021

N7SHG_Ham said:

Or sweaty and then stinky

NuCamp made good on the bad batch of floors which basically requires major surgery (seperating the walls from the floor, removing old floor and replacing. I would guess that also entailed removing all the other bits too that are fastened to the floor and walls), so putting a cool cat back in these units wouldn't be out of the question, they already know how to do it.

Could you tell me which year models had floor issues? We have an early (March) 2019 t@b 400 BDL.

Denny16 · February 2021

The floor recall that N7SHG_Ham was referring to was in Oct to Dec 2017 and Jan 2018 TaBs that were made with a substitute composite sub floor when Azdel was in short supply.

The repair did not require removing the trailer walls and complete interior. The galley lower cabinet under the sink was removed, as well as front dinette area sear fronts and Alde heater cover, and front face of the rear bunk. The problematic sub floor is cutout between and replaced with in Azdel in the center area of the camper only, going back under the cabinet faces, not all the way back to the side walls. We had ours repairs under this recall, the trailer was not dismantled.

However, nüCamp does completely remove the camper body on older Tabs built on plywood floors that need their floor replaced, at the customer’s cost (not free), and the entire camper body is limited off the floor, plywood floor removed, and a new sliming floor,frame with composite flooring installed in place of the plywood. This is on old Dutchman TaBs and a few of the TaBs built before 2016 or so, not sure on the exact date, Azdel composite floors were used instead of the plywood subfloors.

Your March 2019 TaB 400 should have the Azdel floor system used on all the original TaB400s in 2018/2019 (except for the ones made at the end of 2017).
cheers

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