Need more air power. RV AC question.

[GAmes]

I also added an A/C unit but I found the answer to the crappy divider. It increased the airflow to all my ceiling outlets and increased the efficiency of the unit. It took about 3 hours to install but I suspect different units would take less time. I'm not sure if I would have installed a 2nd AC if I had found these earlier. RV Airflow Systems

 

[Grumpy8811]

Working with a 2003 Arctic Fox 27-5L 5th wheel. 27' length hitch to bumper 25' living space with one small and one large slide. Assumed 13.5K BTU standard Coleman Mach AC. 30 Amp service with 3600W LP Onan.



What is needed/involved for the extra bracing to add a second AC to the bedroom on an older "wood framed" Arctic Fox?

realistically you are probably better off not adding a 2nd AC unit, just based on the low value the 20 year old RV has and the cost and complexity involved in adding a second unit, bracing and wiring.

I had an older 16 foot RV with a non ducted AC, that would freeze me out.. in FLA in the summer.
I had a 35 foot Fiver with one ducted AC, same climate and it had a hard time going below 80 degrees inside
I think these ducted AC units lose alot in the ductwork, as well as the fact they are heated by the sun on the roof..
so I suspect if you found a 15000 BTU non ducted and added it in place of the xisting unit would be the best bang for the buck you could get without going thru alot of changes..

 

[Tuesdak]

realistically you are probably better off not adding a 2nd AC unit, just based on the low value the 20 year old RV has and the cost and complexity involved in adding a second unit, bracing and wiring.

It cost $2500.00 for a new 15K RecPro Heat pump A/C unit (Unit cost alone $1,399), moving the old A/C over the bedroom in place of a vent fan, and the new 2nd shore power cord. No extra bracing was required. If I didn't have the height a low profile unit over the bedroom would have been used saving some labor cost of moving the old unit.

Value of the RV only matters when sold or to the insurance company. Value of being comfortable is worth it. A replacement RV better equipped with two OEM A/C units and 50A doesn't make economic sense. I visit places with 30A max and boondock on generator. I have had to adapt it to the extreme heat although when I bought it it's imagined purpose was to get out of the heat...New RV lack of any quality Vs. one built when they cared more is another debate.

Switching from a 13.5K BTU unit to a 15K BTU unit doesn't make sense. This is one reason I wanted to move the main system. 2nd reason is the bigger system is on the generator and found out little difference made.

There are other choices like making a quiet mini split system work, but, I have nowhere to mount the condenser easily.

 

[Grumpy8811]

It cost $2500.00 for a new 15K RecPro Heat pump A/C unit (Unit cost alone $1,399), moving the old A/C over the bedroom in place of a vent fan, and the new 2nd shore power cord. No extra bracing was required. If I didn't have the height a low profile unit over the bedroom would have been used saving some labor cost of moving the old unit.

Value of the RV only matters when sold or to the insurance company. Value of being comfortable is worth it. A replacement RV better equipped with two OEM A/C units and 50A doesn't make economic sense. .

your choice to make.. not mine. I didn't advise you to buy another RV,( I've owned five RV's, always with the understanding no matter what I spent on them they were worth zero when I got rid of them, and I have never been disappointed ) just saying a larger unducted unit to replace existing unit might have been the easiest cheapest option.. and throw a fan on the floor, I can't see one of those unducted being much more than a grand..

 

[slowmover]

Cooldown after heat soak is the problem more than A/C capacity. Used to know a Coleman engineer who’d state that the 15K unit is +/- equivalent to about a ton of A/C.

Can take my 35’ TT with a single 15K up to 24-hours to be genuinely comfortable (no lingering hot spots in cabinetry or odd corners). The first 3-4/hours on a North Texas peak heat summer day (100-105F) is brutal. Enough to get a hotel room for the night if arriving late, or to set-up, turn-on, and leave till past 2100.

As mines with an anodized aluminum skin the heat is magnified without some afternoon shade. Or, if parked on a graveled lot versus some grass, etc. I roll out the awnings all around as this decreases the direct AND indirect heating.

Also, cover any interior roof openings, same as in winter. On worst days I close off bathroom (mid-bath). If I have to close off rear bedroom, that’ll take awhile to cool down past sunset.

Use small table fans at each end of coach to speed return-air intake.

It’s not that 15K can’t do the job; it’s in “immediacy” and the conditions of where parked (compass orientation matters); and after cooldown it’s in window shading when parked a few days. I’m currently parked facing due east thus have a full REFLECTIX panel in west-facing bedroom rear window.

Second most valuable is window treatment. Mini-blinds and/or smoked glass ain’t it. The original owner installed both Day/Night shades plus corner curtain valances on the major windows (not bath or kitchen). Past “the look” this keeps the heating/cooling problems better contained. REFLECTIX panels for all interior windows is last. Interior storm windows are what’s wanted. An option nearly no one understands to buy (see window manufacturer for retrofit).

My third most-valuable comfort device is a de-humidifier. Gets used year-round. At this time of year it’s from past dusk to an hour or more past dawn. Winter condensation or summer humidity, it pays for itself pretty quickly in comfort terms. One is later in lowering thermostat, and earlier in raising it thus helping shorten peak A/C demand. 35-50 pint, in my case. Bigger than RV sq footage, just as with heating or cooling compared to a house.

Best strategy (year-round) has always been to travel with a pre-dawn departure. Lowest traffic volume = lower risk, higher average MPH & MPG. If parked by/before 1400 the A/C has a chance to throw up a defense against the late afternoon heat soak from the ground (including underneath where parked). Similar advantage for furnace in cold weather. Late departure is nothing but penalties all-around.

I use a small thermometer/hygrometer to monitor throughout the day. Ballpark is 40%. I find 30-40% is the summer ideal. 45-50% and higher is uncomfortable . It’s as vital as monitoring campground AC Voltage. Get the most from the least. (Winter use is a separate topic, but pre-dawn till several hours past full sunrise is similar).

I’m at 77F @ 33% at 1900 on a day where it’s been 99F with a Heat Index of 105F. Feels just right. About a half-hour past sunset I’ll reduce the A/C “power”. It’ll get a roughly 12-hour break with an overnight low of about 80F.

Roll up awnings after dark.
Stay aware of weather alerts.

“Have a plan”, describes the day of travel.
It also describes use of devices and the tactics for temperature control given conditions expected.

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[slowmover]

I've owned five RV's, always with the understanding no matter what I spent on them they were worth zero when I got rid of them, and I have never been disappointed

Bummer. Mine — bought used — is now worth more than I paid for it in both real & adjusted terms. There’s more than one way to do it.

“Value” is the pleasure of travel.
“Expense” is total nights aboard over length of ownership.

Incentive is to maximize nights aboard.

Most “campers” get used well the first few years. Then after the national park tour and visiting relatives one barely knows, it tends to sit up more. Till several years have gone by and it gets sold.

A second A/C is cheap in these calculations if it increases use. “Value”.

@Tuesdak 5’er in age isn’t terribly old, though for most of the type it’s past normal lifespan. If a moisture meter shows no serious breaches , then all is good. Mine was already 14-years old when his was built.

I’d imagine it was paid off long ago. The adjustment isn’t to some non-applicable Blue Book, it’s to how he and his family prefer to travel.

No RV is comfortable in hot days or cold nights. One chases shirtsleeve weather. Even the big Mohos don’t like the extremes. Pay to play.

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[Grumpy8811]

lets face it, I was just offering a viable cheaper opinion.
heat load is a large part of the problem.. for any of these.


I was living in a 35 footer fifth wheel for a year on the edge of the Everglades, it only had 1 ac
and in the summer, it was about 78 to 80 inside with the AC running constantly..

versus the non ducted AC in a 16 foot trailer, which kicked butt.

yeah,old RVs usually get purchased at low prices, so there isn't the depreciation hit..they already depreciated. This one was a few years old, I paid about half of what it cost new.. but its still money down the drain as far as residual value goes. its not going to go up in value..

 

[Tuesdak]

Cooldown after heat soak is the problem more than A/C capacity.

I actually don't have this problem. One of the big disadvantages to all tin cans and nearly all but one fiberglass RV is the lack of a factory generator option. I use the onboard Onan during travel to stop the heatsoak. I leave with a cool RV, have lunch in a cool RV, and arrive with a cool RV. (Around 80F inside in extreme heat.) On arrival The second A/C will pull the bedroom area down to 71F pretty fast. Can't run both on the generator as it's too small... maybe an upgrade in the future.

When traveling to cooler areas, AKA altitude here, this doesn't matter. Except when stopping for lunch and using the RV to make lunch.

I am getting more use out of the RV be being able to use it in the extreme heat now.

I did see a super rare Silver Streak 5th wheel "Command Center" that was equipped with a Wisconsin flat head 4 cylinder gasoline generator. It was in an RV salvage yard and IDK if it was re-sold or scrapped. I will always regret not asking about it or touring it inside.

It’s not that 15K can’t do the job; it’s in “immediacy” and the conditions of where parked (compass orientation matters)

Yes, one learns quick to park pointed east or west when choosing a camping spot.

End of the day a 13.5K BTU being replaced with a 15K BTU A/C unit is not going to make the RV comfortable in the heat. One is simply needing to add an additional A/C unit.

The vent repairs were already covered and done including this system having both vents and the ability to open registers at the A/C unit itself.

Fans just blow hot air around when the A/C is overloaded.

I did notice that using better aftermarket air filters, Merv 6, for the single A/C unit increased the inside temperature by 1-2F due to the extra airflow restriction. I find a stand alone HEPA air filter keeps the OEM A/C filters cleaner longer. (Cleaning the A/C filters every single day at one point.)

 

[slowmover]

I use a BLUE AIR floor-unit air purifier.

Table fans work. Used them for years to increase the return rate. It’s about size (small), location (experiment), and blade speed (low). Have to do something at the eddy or stagnation point.

This is what I use up front:

https://www.vornado.com/shop/circulators-fans/personal-compact/pivot-personal-air-circulator

Once I’m parked and have had several hours of cooldown, the need for a second A/C unit on this 35’ TT almost disappears if temps stay below 100F. The game is then played with controls for exterior shade & interior windows; as above.

Mini-blinds and no awnings, yeah, the interior would heat pretty fast. Have fifty-plus years experience with this sort of heat in an aluminum TT. I get asked pretty often at campgrounds whether awnings help, or how-on-earth-can-you-stay-comfortable-with-one-A/C-unit?

If I had children along, then a 9k unit at rear bedroom would pick up the slack for entrance door in constant/use.

As they aren’t popular any more (cost-cutting) jalousie windows capture breezes which sliders don’t. Meaning one can open windows earlier and close them later. Having three (powered) roof vents is the other. One learns to work with prevailing breeze to expedite hot air expulsion.

It isn’t the expense or difficulty of another A/C so much as it’s dependence on electricity to be comfortable. Pushing that temp barrier higher is a worthwhile goal.

This is one aspect of self-contained. I think it was Wally Byam coined that term. It was him who convinced a manufacturer to design & build the first propane furnace to allow its use (Airstream, circa 1957).

I’ve found it a handy way to plan potential upgrades if we divide all needs by power source. An example is the propane furnace. A retrofit with (bad name) CHEAP HEAT unit to utilize the blower and ducting can be done to lower propane use (or bypass), same as with having 3-way refrigerator/freezers. Or, having an induction burner with which to cook versus sole use of propane. Etc.

Propane gensets were an available option on these trailers in the 1970s. I’ve seen recent custom examples. Solar is the replacement as keeping house batteries charged is the thing.

On electric mains? Run the whole rig that way.
Propane only? Come close. (Propane lamp should be added).

The all-around best question is, Given X-persons aboard, what is the maximum number of nights aboard without any re-supply? Water & Propane are the limiting factors. Big capacity is a winner. Two forty-lb propane tanks and 70-gals water go quite a ways.

I believe 30-nights given one can access water to clean/filter is a goal to sketch out. (Bladder & separate water pump to retrieve water remotely using truck bed).

Having a way to leverage that CTD as Genset would be the ideal. PTO to hydraulic power unit (as on fire or utility truck). I’ve seen the 7500 Onan diesel built onto a chassis cab, but weight and service access was hell past expense.

A/C is an expensive luxury off of the mains. Which campground then becomes the task.

Would I want to run the CTD 36-hours at high idle? No, but I’d consider the investment a worthwhile undertaking for emergency purposes. Children, the elderly, and the sick & injured are surely worth what’s required prior to evacuation.
As that’s the last part of being self-contained: it’s not a toy, it’s a family asset.

Those dumb enough to ride out a hurricane soon find that the aftermath is the problem. A gasoline Genset will be worn out and have consumed a big shelf full of engine oil & filters before power restored. A 60-gal pickup truck tank looks a whole lot better if trapped from leaving. Get gone when the roads are cleared.

Obtain the right design/construction of TT and it’s one that your toddler grandchildren could inherit as adults. My fathers’ trailer is still in use at 49-years. “Expense” doesn’t mean as much when one looks at two decades or more versus five years. And not be limited by tow vehicle choice, either.

I’ve seen a pic of that mobile command center. That’d make quite a HAM shack, huh? I’m not a fan of 5’ers, but acquisition of the somewhat rare AVION unit could be incentive. 38’, true aero, low COG and about 14K empty :

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[Units]

I also added an A/C unit but I found the answer to the crappy divider. It increased the airflow to all my ceiling outlets and increased the efficiency of the unit. It took about 3 hours to install but I suspect different units would take less time. I'm not sure if I would have installed a 2nd AC if I had found these earlier. RV Airflow Systems

I bought one of those, well worth the money. AC noise cut pretty much in half. Much more flow through the vents. I did have to trim a little off of the lip to be able to fit the ac mounting plate back on. We use a small fan to help circulate the air.

 

[Grumpy8811]

I use a BLUE AIR floor-unit air purifier.





Those dumb enough to ride out a hurricane soon find that the aftermath is the problem. A gasoline Genset will be worn out and have consumed a big shelf full of engine oil & filters before power restored. A 60-gal pickup truck tank looks a whole lot better if trapped from leaving. Get gone when the roads are cleared.



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you dont ride out a hurricane in a RV... you use the wheels on the RV to get out of harms way
and return after the hurricane with your house on wheels,, using a gen set for AC while shore power is in short supply..

I haven't worn my generator out yet.. and it has done hurricane duty several times..