A/C and generator use--ettiquete, practicalities, technology

[samclem]

A newby question:
I'm not a fan of sleeping in the heat, and (more important!) neither is my wife. So, if we are gonna camp in a TT in the summer months, that means running the A/C at least part of the night and (consequently), a generator if we're not on shore power. The generator would be a quiet Honda or Yamaha unit.

1) Is it common for campgrounds to forbid the use of A/C at night (due to noise) when plugged in to shore power?

2) In what places is it generally allowed/accepted to run a generator and AC when it is hot (incl at night)?
a) Private campgrounds?
b) State/federal parks? (Different rules for "dispersed camping")
c) Walmart/Flying J, etc?

3) Are there any super-efficient camper/AC combinations that allow cooling on battery power? I'm guessing a camper with a FG/foam composite shell (r-8+) with small surface area and a very efficient AC unit (Peltier or other solid-state unit) might be practical, at least in theory. Or, a 10 lb block of ice in a cooler with a small fan. (I can crunch the number on that).

4) Are there small, affordable AC units that use propane for cooling (absorption cooling, like a propane 'fridge). It probably wouldn't be very efficient, but it would be quiet and (needing just a fan and no compressor) could probably run for a night or two on battery power with some help from solar panels.


Thanks!

[Bob Miller]

Hi and Welcome to the group Mark.


What you are asking is a very popular topic and there was a string of posts on the issue just last week. But I am afraid that you won't like most of the answers to your questions:


1. YES, most campgrounds set "Generator Hours. Some require shutting them down as early as 6PM, most by 8 PM and almost all by 10PM. Your tenting neighbors really don't want to listen to a generator, much less be downwind from the exhaust.


2. Pretty much the above applies at all kinds of campgrounds for generators, most places with hook-up seem to not mind a/c running at night. About the only safe place might be truck stops.


3. Battery powered cooling systems, for the most part, aren't defined. There really isn't a system that will work on 12 VDC short of carrying a huge battery bank and inverter system, but that would put most FGRV's over weight limits.


4. Nope... but if you invent something that is able to do that you could make a bunch of $$$$$$


BTW: It's assumed that everyone will be running something like an inverter generators with rated noise levels at least below 62dB. The old 3600 RPM generators are banned in a lot of parks.


About your only sure bet is to only hit sites with hook-ups

[Byron Kinnaman]

We've camped in all kinds of weather. We've found that two things make for more comfortable night in hot weather. If possible park in the shade, this keeps the trailer cooler. We also carry a "Constant Breeze" 12volt box fan, it may not cool the air the breeze blowing over you will help keep you cool.
One beauties of trailer traveling is that if you don't like the weather where you are you can move. I realize that this is more difficult for "week-enders" than long term campers. However, I would think there's places even in Ohio that have pretty cool night even in the hot summers.

[MyronL]

If you want to run your air conditioner all night your only practical option is to pay for a site that provides electric hook-ups. Of course, that likely means you will get no sleep. They ain't quiet. There is no air conditioner I know of that can run on battery power, even for a couple hours. Then, your batteries are dead. Any generator running all night, even if you dare do it at a truck stop, could result in your finding it not there in the morning.

[Carol H]

Since solar has become reasonable priced, the use of generators has become increasingly unpopular & more and more restrictions on usage as a result.

If allowed most campgrounds will restrict the hours of use of a generator - not just at night but mornings as well. Often only permitted for a couple of hours at a time. Its normal to be restricted at Public or Private campgrounds as well as some Forest service campgrounds - I have actually stayed at a Forest Service Campground as well as a Public campground that did not allow any generator use.

[Carl Pa]

I parked at a Walmart and there were two campers using a gen. I was surprised that one would do that. It was not for AC it was cold out. Carl

[Steve L.]

The price of solar may be coming down although I might quibble as to whether it’s reasonable. Reasonableness, I think, depends on one’s expectations. But any question on electrics does bring out the solar fanboys. For me and the places I prefer to camp (shady sites) it (solar) is largely useless. I’m a gadget freak and therefore solar appeals to me but I’ve been able to resist it because there is insufficient payback for me in terms of recharging.

But, even ignoring compressor startup, the electrical needs of current A/Cs are so large as to drain a battery (through an inverter), in less than an hour (assuming the 50% battery drain rule of thumb). Wanting badly to do something is not sufficient to overrule the physics. Running the A/C all night on a battery is one of those options that is denied us. We are forced to look for powered sites and forced to endure the temperature if without “shore” power. I haven’t run across a campground with a complete ban on generators yet but all have limited usage to 10pm or earlier. Stirring the air with a 12v fan seems the only option at the moment for those times stuck without a power post.

[Darral T.]

I'm with you....I HAVE to have an A/C to sleep comfortably in the deep south's humidity. Been there TRIED that without it in August one night. It was awful and killed camping for me for YEARS! (Was camping with my parents in an old camper he'd found).

I would HIGHLY suggest scouting out and calling places you plan on going before counting on a generator. You can make neighboring campers very upset with gens. The Hondas are alot quieter. I have a Champion 3500/4000 which is PLENTY of efficient to run my heat strip OR the A/C for 8 hours plus. But it's loud and I can rarely use it...but rarely need it since I stay on the grid most of the time.

[Carol H]

Originally Posted by Steve L.

[SIZE=3][FONT=Calibri]The price of solar may be coming down although I might quibble as to whether it’s reasonable. Reasonableness, I think, depends on one’s expectations. ]

OR ones history/experience with solar. First 15 watt solar panel and controller purchased for current trailer 7 years ago cost C$160. Daily Operating cost & maintenance cost for 7 years of use $0 & it still works and will be put to use by another family member on their trailer. to maintain battery. Recently replaced with 60 watt panel (4 times the watts of original panel), new controller (better quality than original & weather proof) & all wires and connections for C$110 recently..... again no daily operating or yearly maintenance cost. Not to mention the freedom the solar gives me to camp any where I want without having the neighbours glaring or yelling "shut it down". That to me is Priceless!

What does a generator cost these days? What's the cost of daily operating? Price of gas per gallon? Maintenance costs for generator in 7 years of daily use when camping/using 120+ days a year?

Totally agree though that where and how one camps & comfort level one expects does have an impact on whether or not one can live with or live without a generator. Have camped many days in temps in the high 90's low 100's with no AC - just a good 12V roof fan and still enjoyed the time spent camping

One just needs to be aware that these days depending on where you are camping there is a fairly high probability that the neighbours may not agree that a generator is really needed.

[Timber Wolf]

In thinking about this topic it amuses me that back during my Boy Scout days we would camp out all year in a tent and not think anything about it. Now I would DIE without A/C in the Summer Florida heat/humidity. And I am not sleeping on the ground anymore either. In answer to the question I would say just plan your trips according to the season. Summer, make it campgrounds with hook ups. Spring/Fall, go boondocking.

[stevebaz]

Originally Posted by Timber Wolf

In thinking about this topic it amuses me that back during my Boy Scout days we would camp out all year in a tent and not think anything about it. Now I would DIE without A/C in the Summer Florida heat/humidity. And I am not sleeping on the ground anymore either. In answer to the question I would say just plan your trips according to the season. Summer, make it campgrounds with hook ups. Spring/Fall, go boondocking.

That's because you played and had adventures all day. When you were tired you slept. But now the kids don't have the physical activity except their thumbs and they wan't more electrical power than you do.

Now adults hide out all day and wait for 5:00 for cool down libations. Not allot of activity to burn you out to sleep no mater the weather.

Its funny to go camping and see all the cellphone charger's plugged into the bathrooms electrical since the sites don't have power.

[Byron Kinnaman]

In days gone by people had screened porches complete with beds. When the night got so hot it was hard to sleep, off to the porch you went.
During my backpacking days when the tent was hot, or when I figured it going to be a warm night, the sleeping went on a ground cloth and the stars worked a ceiling.
Now everybody wants to burn up fossil fuel as much as possible.

[Darral T.]

I hear ya TW! Mom would have to MAKE me come in on the hottest days when I was a kid. All I can say now is, Thank God for FOSSIL FUELS!!

Originally Posted by Timber Wolf

In thinking about this topic it amuses me that back during my Boy Scout days we would camp out all year in a tent and not think anything about it. Now I would DIE without A/C in the Summer Florida heat/humidity. And I am not sleeping on the ground anymore either. In answer to the question I would say just plan your trips according to the season. Summer, make it campgrounds with hook ups. Spring/Fall, go boondocking.

[Byron Kinnaman]

Originally Posted by Darral T.

I hear ya TW! Mom would have to MAKE me come in on the hottest days when I was a kid. All I can say now is, Thank God for FOSSIL FUELS!!

Yup, the world needs a few wimps.

[Darral T.]

Speak for yourself. You were always good at it.

Originally Posted by Byron Kinnaman

Yup, the world needs a few wimps.

[Jon in AZ]

I think this may have something to do with where you live. In the western states, it's not hard to find temperate camping spots within a reasonable drive. Elevation helps, as does lower humidity. In large swaths of the eastern and central US, high humidity combined with warm temperatures make it harder. I grew up in Maryland, and we often traveled all the way up to Maine and the Maritimes to escape heat and humidity in the summer. We used a tent trailer. Though it lacked AC, it had huge windows for excellent ventilation compared to an egg.

[Darral T.]

Exactly Jon. So drop from Maryland on down to Alabama, Georgia, Louisiana..... You can just walk outside at night and cover yourself in sweat from the humidity. Instead of a "Snowbird", I think I need to be a Hotbird and fly north in the summer!

Originally Posted by Jon in AZ

I think this may have something to do with where you live. In the western states, it's not hard to find temperate camping spots within a reasonable drive. Elevation helps, as does lower humidity. In large swaths of the eastern and central US, high humidity combined with warm temperatures make it harder. I grew up in Maryland, and we often traveled all the way up to Maine and the Maritimes to escape heat and humidity in the summer. We used a tent trailer. Though it lacked AC, it had huge windows for excellent ventilation compared to an egg.

[Jon in AZ]

Or move West!

We toured the Southeast many times during spring vacation. Summer? No thanks!

[samclem]

Thanks for the input so far, additional ideas/feedback is welcome.

So, it sounds like there are virtually no restrictions anywhere an actually running the A/C unit (i.e. campgrounds and other campers don't object to the noise of an A/C running).

But, with current technology, I'll either need shore power or a generator to have the energy for the A/C unit. And running even a quiet generator at night is frequently taboo.

Like everyone, I've slept where it is hot. I could do it again. But I don't think it will be part of our leisure travel plans if I can help it.

I've got a few ideas I'll bounce off you guys after I do some calculations. Thanks again for the help.

Mark

[samclem]

Long post follows . . .
Okay, I did some back-of-the-envelope calculations that I think are interesting. The objective was to find a way to keep 2 people comfortable and cool as they sleep without need for a generator.

- A sleeping person gives off about 250 BTU/hr in heat. So, two people = 500 BTU per hour in cooling is needed just to keep them from heating up the sleeping area.
- Heat gain from the outside: If we assume it is 90 deg F outside and we want it to be 70 deg F inside, an R-10 wall (2" of rigid foam insulation) will pass 2 BTU per sq ft per hour. If we imagine a sleeping "capsule" with a queen-size bed and 4' walls all around, that would be 148 sq ft, or 300 BTU required. But even in Dixie we can expect it to cool off a bit overnight, so let's assume that it will be 80 degrees outside in the morning (8 hours later), and at that point the heat gain will be just 150 BTU/hour through walls, ceiling, and floor.
So, we'll figure an average of 225 BTU/hour gain through the walls for the whole night, plus 500 BTU for the people. We'll round up to 750 BTU/hr on average, total. 8 hours of sleep = 6000 BTU of cooling required for the whole night. Note that there's not much point in going for "superinsulated" walls--the 2" of foam gets us to the point where the majority of the heat we're removing is coming from the two people, it's not heat gain from outside.

Now, that's not a huge amount of energy, and might make generator-free cool sleeping feasible, even for those on a budget. Examples:

Using ice: It takes 144 BTUs to melt a pound of ice, and approx 40 more BTUs to warm up the resulting water from 32 deg F to 70 deg F. So, each pound of ice gets us 15 minutes of sufficient cooling. A gallon (8 lbs) of frozen water buys us 2 hours of comfort, and it takes 4 gallons to get us through the 8-hour night. Bring a mid-sized cooler with 4 one gallon jugs of frozen water/iced tea, etc and we'd be good to go (they make simple rigs like this for cooling small airplanes--it's not much more than a cooler with holes int he lid for 4" ducting in and out, plus a small fan. We'd want a thermostat on the incoming air for our sleeping chamber. As a bonus, you can use the water for drinking, washing dishes, flushing toilets, etc. the next day. Obviously, the big downside is needing to get 36 lbs of ice for each night of comfort, but it might be ok for single overnight away from AC power.

Using a small A/C unit: A 5000 BTU/hr AC unit draws about 500 watts when it is running, which is a lot. But we need only 750 BTU/hr of cooling, so the unit will only need to run 9 minutes per hour, and in that time it will draw only 75 watt/hours. For the whole 8 hour night, that amounts to 600 watt/hours. For a 12V battery, that's 50 amp-hours, or about what a fully-charged Group 27 deep cycle battery can yield if drawn down to 50% of capacity. Now, there will be other losses (12VDC to 120VAC conversion, etc), but some of these could be addressed by using a DC air conditioner. This approach has a lot of advantages--much less hassle than using ice, the 5000+ BTU A/C unit can be used to cool the whole egg during the day using a generator or shore power, the nighttime batteries can be recharged from the generator during "generator hours" each day, etc. And a major "+" for this approach is that it will constantly be removing moisture from the air, which can make even higher temps much more comfortable.

Solar: The small power demands of the "cool chamber" approach might even make it possible to keep cool with PV-produced electricity. Even dropping the nighttime temp by 10 degrees, together with the removal of humidity and accompanied by some air movement with fans, might be a big victory for the devotees of silent solar power.

Other options--a regular home fridge can produce about 1200 BTU/hour of cooling, so if somebody wanted a science project, the "guts" of one could probably be adapted to provide adequate cooling to a well-insulated sleeping area. I don't know if it would be more energy efficient (due to the longer duty cycle) than just using a regular 5000 BTU air conditioner at a shorter duty cycle. Also, maybe Peltier (solid state) cooling might work, but last time I checked on these units they were pricey and not especially efficient.

Sorry for the lengthy post, thanks for indulging my number-crunching.

Mark