New to the TT world

ChrispyjCSLT22 wrote:

block foam insulation, roof insulation, have they not improved? especially on these new rigs?

No.

Just because they use "block foam" doesn't mean they have been "improved".

Typical block foam is the same stuff used for you foam coffee cups to keep you from burning your hands while holding the cup know as expanded polystyrene. The R value of it is very low per inch, about R3.6-R4. It is used as a cheaper alternative to fiberglass or other higher R value foams.

It takes a lot of block foam thickness to get a decent R value and RVs only have 1 and 1/4" of wall thickness to work with..

The roof is not all that much better as it is not flat, it is higher in the center and lower on the edges to shed water.. Typically the center of the roof is only 2" and the ends taper to about 3/4". The exception to the 2" is RVs with ducted A/C as they need a bit more clearance to run ductwork.. But even so, the manufacturer dose not have to fill the entire cavity with insulation.

Basically in a nutshell, typical RVs will have about R3-4 in walls, and average of R4 in the roof even with "block insulation".

I have highly modified my TT when I gutted it, removed the fiberglass batting and used Polyisocyanurate foam board exclusively through out the rebuild. PolyIso has the highest R value per inch that you can get at R7 per inch but it is many times more expensive than your typical coffee cup insulation.

While my modification did help somewhat, it still is basically a hot box on wheels when you combine 80F and up temps plus high relative humidity. Basically to make a great big difference I would have had to stud in the walls and double or triple the thickness.. Then replace the single pane windows with double panes..

I do overnight without power when traveling and I have run into situations that just opening the windows at night was on the border line of insanity and that was even after running my A/C for a half hr to cool things down a bit..

valhalla360 wrote:

ChrispyjCSLT22 wrote:

valhalla360 wrote:

ChrispyjCSLT22 wrote:
This is alot of perspective to consider, and I'm appreciative of it, but I'm trying to avoid getting/using a generator and lugging around gas cans..

I get what you say about run time but would running the AC on low would help?

Let's say you want to stay comfortable for an 8hr overnight:
- Running on high at 1500w with a 50% duty cycle means it's pulling 1500w for 4hr for a total of 6000w-hr consumed.
- If it has a low output (most RV air/con units don't, they just have a lower fan setting to keep it quieter) of 750w but for the same cooling, it's going to have a 100% duty cycle. 750w for 8hr is still 6000w-hr.

If it's hot and you want it cooled, there is no free lunch.

In the end, your effort to avoid a simple reliable generator will cost more, be more hassle and reduce the quality of your experience. If you don't want a generator and you want to boondock, realistically, you aren't going to have air/con without a huge, expensive aftermarket system.

Even with a 3KW inverter, 400ah lith batts and a 11K slow start AC with the settings on low?

A 3KW inverter may or may not be able to start the air/con unit (some of them get picky about heavy startup loads) but start up is measured in milliseconds. Building a solar/battery/inverter system to kick the compressor over...easy. The issue is keeping it running for a meaningful period of time.

A 15000k BTU RV air/con unit typically will draw around 12amps @ 120v when running (startup might be 30-50amps but only for a second to get the compressor going). 12amps @ 120v is 1440watts. It will vary a bit depending on temp, altitude and a few other things but close enough for our purposes, we can call it 1500w to keep the math simple. 400amp-hr at 12v holds around 4800w-hr but you don't want to drag them down to 0% or it will quickly damage the expensive battery bank. Lithium can use around 80% of the rated amount, so let's say you have 4000w-hr of usable power. That gives you 2.7hr of run time at 1500w. If it's 50% duty cycle, you have 5.4hr of cooling but if you start with a hot RV, probably less because initially, it will run 100% until it gets the interior temp down.

As far as low setting:
- Traditional RV air/con, the fan makes up around 300-350w out of the 1500w. By dropping to the low fan speed, it will draw a little less wattage but the overall BTU output if the air/con unit will go down...that means it will take longer for the initial cool down and have a higher duty cycle...net effect, you don't really save on the total watt-hours consumed because it's running for a longer time period.
- If you were to retrofit an invert based mini-split, they can vary the compressor speed but you run into the same issue. If you run the 15k btu unit at 7.5k btu output, it cut consumption by roughly have but will run roughly twice as much of the time. Net effect no savings in total power consumed.

Other items of note:
- After the first day, those 400a-hr batteries are down by 4000w-hr. 570w of solar can only be expected to add around 2000-2500w-hr back in (the charging systems aren't 100% efficient), so the next day, you don't have the full battery capacity to work with.
- This also ignores consumption by lights, pumps, etc...while boondocking which will further reduce your available power for air/con.
- No, RVs have horrible insulation. Really they are more akin to the old WWII movies when the Japs would put prisoners in the "hot box" for punishment. When it's 90+, it's not uncommon for the air/con to run full blast continuously and you may still see the temp creeping up mid afternoon.
- "4 season" and similar terms are mostly marketing. Slightly better if dual pane windows but don't expect anything close to 1950's vintage household insulation.

Ultimately, it's your money and your call but you have been warned.

Thank you for taking the time to respone, but IIRC, we are not talking about a 15K BTU, but rather a 11K soft start AC that comes with this system..

I am weighing all options which is why I am taking my time and not rushing into a purchase.. as well as I am still considering this system as prices are starting to drop some now that there is an influx of inventory..


https://imgbb.com/4dSv1fn

https://imgbb.com/dJtxzsM

Skibane wrote:

ChrispyjCSLT22 wrote:
its because everybody still thinks I'm trying to run it non-stop over night.. and Im not.. but just a couple hours during the day and during the night.

Everybody still thinks that running it just a couple hours during the day and during the night isn't worth bothering with.

15 minutes after you shut it down for the day, the interior of your RV will be pretty close to the same temperature as it is outdoors - Or maybe even hotter if you're parked in the sun.

^^^THIS^^^

Not to mention only running it for "15 minutes" does nothing to reduce the humidity level in your RV. Dropping the temp a degree or two while it sounds helpful in the end if you are dealing with high temps AND high humidity levels you only did HALF of the job to make it comfortable.

Unless you are living and camping in the desert you must remove not only some of the heat but humidity also. It is the HIGH HUMIDITY that really makes high temperatures feel uncomfortable.

It takes time for a A/C to remove a lot of humidity, more than 15 minutes and when you shut the A/C off and open the windows you are now inviting the outside air with high humidity back in.

There are times and places where you can sort of use A/C that way, like if it is dipping into the low 60Fs or lower at night and you are getting a nice breeze.. But not so well on July/August nights in places when you often have upper 80Fs and higher with boat loads of humidity and now breeze at all..

Or short story, running a camper AC, even in "mild" summer conditions is a very expensive and/or finicky adventure.
Trying to do the same in very high temperature and humidity conditions is like peeing into the box fan that you're standing in front of trying to extract the last bit of cool air before your batteries go dead. Wholly unproductive and adding the insult part (wet shoes and pant legs) to the injury part (dead batteries and no chance of re-charging them sufficiently based on the power of the sun).

ChrispyjCSLT22 wrote:

valhalla360 wrote:

ChrispyjCSLT22 wrote:
This is alot of perspective to consider, and I'm appreciative of it, but I'm trying to avoid getting/using a generator and lugging around gas cans..

I get what you say about run time but would running the AC on low would help?

Let's say you want to stay comfortable for an 8hr overnight:
- Running on high at 1500w with a 50% duty cycle means it's pulling 1500w for 4hr for a total of 6000w-hr consumed.
- If it has a low output (most RV air/con units don't, they just have a lower fan setting to keep it quieter) of 750w but for the same cooling, it's going to have a 100% duty cycle. 750w for 8hr is still 6000w-hr.

If it's hot and you want it cooled, there is no free lunch.

In the end, your effort to avoid a simple reliable generator will cost more, be more hassle and reduce the quality of your experience. If you don't want a generator and you want to boondock, realistically, you aren't going to have air/con without a huge, expensive aftermarket system.

Even with a 3KW inverter, 400ah lith batts and a 11K slow start AC with the settings on low?

A 3KW inverter may or may not be able to start the air/con unit (some of them get picky about heavy startup loads) but start up is measured in milliseconds. Building a solar/battery/inverter system to kick the compressor over...easy. The issue is keeping it running for a meaningful period of time.

A 15000k BTU RV air/con unit typically will draw around 12amps @ 120v when running (startup might be 30-50amps but only for a second to get the compressor going). 12amps @ 120v is 1440watts. It will vary a bit depending on temp, altitude and a few other things but close enough for our purposes, we can call it 1500w to keep the math simple. 400amp-hr at 12v holds around 4800w-hr but you don't want to drag them down to 0% or it will quickly damage the expensive battery bank. Lithium can use around 80% of the rated amount, so let's say you have 4000w-hr of usable power. That gives you 2.7hr of run time at 1500w. If it's 50% duty cycle, you have 5.4hr of cooling but if you start with a hot RV, probably less because initially, it will run 100% until it gets the interior temp down.

As far as low setting:
- Traditional RV air/con, the fan makes up around 300-350w out of the 1500w. By dropping to the low fan speed, it will draw a little less wattage but the overall BTU output if the air/con unit will go down...that means it will take longer for the initial cool down and have a higher duty cycle...net effect, you don't really save on the total watt-hours consumed because it's running for a longer time period.
- If you were to retrofit an invert based mini-split, they can vary the compressor speed but you run into the same issue. If you run the 15k btu unit at 7.5k btu output, it cut consumption by roughly have but will run roughly twice as much of the time. Net effect no savings in total power consumed.

Other items of note:
- After the first day, those 400a-hr batteries are down by 4000w-hr. 570w of solar can only be expected to add around 2000-2500w-hr back in (the charging systems aren't 100% efficient), so the next day, you don't have the full battery capacity to work with.
- This also ignores consumption by lights, pumps, etc...while boondocking which will further reduce your available power for air/con.
- No, RVs have horrible insulation. Really they are more akin to the old WWII movies when the Japs would put prisoners in the "hot box" for punishment. When it's 90+, it's not uncommon for the air/con to run full blast continuously and you may still see the temp creeping up mid afternoon.
- "4 season" and similar terms are mostly marketing. Slightly better if dual pane windows but don't expect anything close to 1950's vintage household insulation.

Ultimately, it's your money and your call but you have been warned.

Skibane wrote:

ChrispyjCSLT22 wrote:
block foam insulation, roof insulation, have they not improved? especially on these new rigs?

Typically, the best insulation comes as part of an "Arctic" or "4 Season" package - usually an optional upgrade.

There's nothing exotic about it. It's just thicker-than-typical insulation, and double-pane windows* - the same sort of stuff that's been available on higher-end RVs for decades.

*The storage and tank compartments usually also have ducts from the furnace routed to them, although that doesn't do anything to help with summertime cooling.

4 seasons such as this?

High Capacity Furnace
Heated and Enclosed Underbelly with Suspended Tanks
Designated Heat Duct to Subfloor
High Density Roof Insulation with Attic Vent
Moisture Barrier Floor Enclosure
Residential Heating System Throughout(Ductless)
Double Insulated Roof and Front Cap(R-40)
Heated and Enclosed Dump Valves

https://www.granddesignrv.com/showroom/2022/travel-trailer/imagine-xls/floorplans/17mke

or Keystone's Extended Season Camping Package-Heated and Enclosed Underbelly

jayco's Glacier package,

it seems like those marketing ploys are done by manufactures who use wooden trusses and pink panther insulation in the roofs...

opnspaces wrote:

ChrispyjCSLT22 wrote:

Skibane wrote:

ChrispyjCSLT22 wrote:
its because everybody still thinks I'm trying to run it non-stop over night.. and Im not.. but just a couple hours during the day and during the night.

Everybody still thinks that running it just a couple hours during the day and during the night isn't worth bothering with.

15 minutes after you shut it down for the day, the interior of your RV will be pretty close to the same temperature as it is outdoors - Or maybe even hotter if you're parked in the sun.

block foam insulation, roof insulation, have they not improved? especially on these new rigs?

Nope they have not improved. I believe Azdel walls are 2 inches thick, that's about R5 or maybe R7. That really is not a lot of insulation.

In reading through this thread you come across as already having made up your mind and just looking for the experienced members on the board to say yes it will work...But they're not going to do that. They are telling you like it is based on their many many years of experience.
Yes the trailer has 400 watts of solar and some 400 ah of batteries. But that will just get you enough solar to keep the batteries comfortably charged after a day and night of light electrical usage. Turning on the AC is a whole different ballgame.

The factory AC and factory insulation is just plain mediocre at best.
I live in Southern California. That means I have heat, but no real humidity. If my trailer is hot, say on a 90 degree day and I turn on the AC at 1 PM I might start to feel cool a few hours later. If I turn it off I'm hot again within 30 minutes.

You said you live in lower Alabama.That means heat and humidity. People on this board who live in an area like that have repeatedly said the only way to keep the trailer cool is they turn the AC on in the early morning and let it run all day. Or they leave it running all night. If they don't the AC will never be able to keep up and cool the trailer.

You said you have friends with trailers. Ask them how long it takes to cool their trailer down. Then ask how long the trailer will stay cool sitting in the blazing hot sun (which is required for your solar panels to do anything) after they shut the AC off.

I will ask them once they return from their camping trip, however I wasn't on here looking for experience campers to say yes it will work but rather a experienced camper who actually has this system I'm looking to get say it will or will not..

Lots on here has provided valuable feedback, but the way it seems if I were to get a system like I want, I would have to boondock late oct - March, maybe april and early may when the weather isn't blistering hot.. then RV park with full hook ups during the hot parts of summer

ChrispyjCSLT22 wrote:


The brand of the equipment is Mastervolt.. I priced each component and it seems expensive to me.. do you think Mastervolt brand is junk?

No, I just mean that I'm not familiar.

ChrispyjCSLT22 wrote:
block foam insulation, roof insulation, have they not improved? especially on these new rigs?

Typically, the best insulation comes as part of an "Arctic" or "4 Season" package - usually an optional upgrade.

There's nothing exotic about it. It's just thicker-than-typical insulation, and double-pane windows* - the same sort of stuff that's been available on higher-end RVs for decades.

*The storage and tank compartments usually also have ducts from the furnace routed to them, although that doesn't do anything to help with summertime cooling.

ChrispyjCSLT22 wrote:

Skibane wrote:

ChrispyjCSLT22 wrote:
its because everybody still thinks I'm trying to run it non-stop over night.. and Im not.. but just a couple hours during the day and during the night.

Everybody still thinks that running it just a couple hours during the day and during the night isn't worth bothering with.

15 minutes after you shut it down for the day, the interior of your RV will be pretty close to the same temperature as it is outdoors - Or maybe even hotter if you're parked in the sun.

block foam insulation, roof insulation, have they not improved? especially on these new rigs?

Nope they have not improved. I believe Azdel walls are 2 inches thick, that's about R5 or maybe R7. That really is not a lot of insulation.

In reading through this thread you come across as already having made up your mind and just looking for the experienced members on the board to say yes it will work...But they're not going to do that. They are telling you like it is based on their many many years of experience.
Yes the trailer has 400 watts of solar and some 400 ah of batteries. But that will just get you enough solar to keep the batteries comfortably charged after a day and night of light electrical usage. Turning on the AC is a whole different ballgame.

The factory AC and factory insulation is just plain mediocre at best.
I live in Southern California. That means I have heat, but no real humidity. If my trailer is hot, say on a 90 degree day and I turn on the AC at 1 PM I might start to feel cool a few hours later. If I turn it off I'm hot again within 30 minutes.

You said you live in lower Alabama.That means heat and humidity. People on this board who live in an area like that have repeatedly said the only way to keep the trailer cool is they turn the AC on in the early morning and let it run all day. Or they leave it running all night. If they don't the AC will never be able to keep up and cool the trailer.

You said you have friends with trailers. Ask them how long it takes to cool their trailer down. Then ask how long the trailer will stay cool sitting in the blazing hot sun (which is required for your solar panels to do anything) after they shut the AC off.