RV Coolbox ? Keeping the hot Texas summer cooler

[Louise Hose]

My commute to and from work involves staying under the Class B airspace at 1800 and 2800 feet for about 20 minutes, a swelter experience on a summer afternoon in south Texas. Not to mention the taxiing on each end of the flight! I love my RV, but these conditions discourage even the most avid of pilots!

So, I obtained an RV Coolbox (http://rvcoolbox.com/) last week and I?ve been trying it out. The first success was that the regional temperatures that have been hitting triple digits everyday for weeks dropped into the low- to mid-90s. Who knew that this simple device could change the weather! Maybe this is the answer to global climate change? OK, maybe just a coincidence?

The Coolbox fits easily into the back of the RV-6. It does require a charge of ice for each flight. Fortunately, the College Station FBO has a convenient ice machine. I just walk through the FBO, fill a couple of large Zip-loks with ice, and head out to the plane, where I dump the ice into the Coolbox. (If you have perishables, you can also throw a little into the Coolbox, ensuring that they don?t lie next to the cooling element.) The lid is closed and the black, corrugated vent tube directed at my neck. As soon as the plane fires up, I hit the switch and the cool air flows. The usual sweaty taxi becomes a lot more comfortable.

Filling the RV Coolbox with ice, drinks, and snacks for the weekend


The simple blower tube positioned to cool the front part of the cabin.

In flight, we find the temperature difference subtle unless the blower is on your neck. But, if you turn the Coolbox off, the difference becomes evident. With the cool air blowing on your neck, the flight is downright pleasant. Even in the pattern at the end of my afternoon flight home, where I occasionally worry that I?ll pass out from heat stroke before rolling out and opening the canopy, the cabin remained tolerable if not pleasant. I haven?t even been opening the canopy on roll-out and taxing lately.

At the end of the flight, most of the water has to be pumped out in preparation for the next trip. This process takes several minutes.

Mikey relieving himself at the end of the flight

So, the testing has been limited (only one week), but the observations are:
Plusses:

• Definitely cools the cabin and makes low level operations like pattern work, practicing IFR approaches, and flying under the Class B wedding cake reasonable activities on a hot summer?s afternoon. It is particularly comforting for the person with the blower directed on the back of their neck.
• Cost (around $200) fits the RVer?s budget
• Compact and lightweight ? fits in the back of the -6 with room for our weekend bags
• Provides an ice chest for a few drinks after the flight
• Could easily make the difference between a potential passenger who refuses to take the plane because "it's too hot" and a passenger anxious to avoid the long drive for a summer weekend get-away.

Drawbacks:

• You must obtain a substantial amount of ice for each flight
• You must pump (or drain) out most of the water at the end of each flight
• The cooler is a little awkward to put in and take out, requiring that both of the -6?s seat backs be pulled forward
• It isn?t a substitute for a ?real? (expensive and heavy) air conditioner. It cools the cabin but it doesn?t create movie theater cold.

[frankh]

A couple of thoughts..

1) You could make your own does that sound cheap?...Busted I guess..

2) Could you fit a 3/8ths bulkhead fitting to the bottom and run a flex hose/valve arrangement out through the bottom of the fuse for quick draining ops?..Thinking about it you wouldn't even need a valve just the let the water widdle out as the ice melts. Slightly less efficient as the water at 0C does provide some useful cooling, but most of the cooling effect is the latent heat of the ice turning into water. Seems this small mod would fix the major hassle factor.

3) other option is to syphon it out over the side of the airplane using say 5' of tygon tube.

4) Dual uuse..turn it into a smoke oil tank...Ok just kidding..

Otherwise I like the concept!

Frank

[Ironflight]

Originally Posted by frankh

2) Could you fit a 3/8ths bulkhead fitting to the bottom and run a flex hose/valve arrangement out through the bottom of the fuse for quick draining ops?..Thinking about it you wouldn't even need a valve just the let the water widdle out as the ice melts. Slightly less efficient as the water at 0C does provide some useful cooling, but most of the cooling effect is the latent heat of the ice turning into water. Seems this small mod would fix the major hassle factor.

Actually Frank, the water is very important, if I am figuring this thing correctly. The pump circulates the cool water through a heat exchanger through which the fan draws it's air - so if you let the water drain out during operation, you lose most of the cooling. This isn't just passing air over ice - it is using the chilled water as a media. The effect of a bag of ice does only last about 45 minutes to an hour down here in the Houston climate. Then it just becomes a high-volume fan.

Paul

[frankh]

I see, in that case you presumably want say a min level of water, say a inch or so on the bottom? So could you put the drain say at an inch or so above the bottom so that it acts like an overflow?

[Mike S]

Originally Posted by frankh

I see, in that case you presumably want say a min level of water, say a inch or so on the bottom? So could you put the drain say at an inch or so above the bottom so that it acts like an overflow?

Quantity of water is a factor in how long the thing will cool.

A gallon of water has more BTU absorption than a quart.

Your drain idea is fine, just use a manual valve to drain it as needed, not continuously.

[rvator51]

Another Moosehead fan, I see! This sounds like a cool idea to ameliorate the summer heat.

[andrew phillips]

I have the sliding sunshade that Vans sells. It is awesome with respect to how much less heat there is in the cabin while using it. I bet if you added that with the A/C you would see a much bigger difference whenever the sun is shining. Obviously won't make much of a difference on a hot cloudy day.

[Danny7]

if you want to really boost the performance of that cooler for a long trip or a real hot session try enough ice/ water to make the exchanger work and fill the rest up with dry ice

[rv7boy]

Thanks for taking the time to post the photos and the evaluation, Louise. The web site doesn't mention the size or empty weight. Could you post that also?

One other thought, it would help a little if the canned drink(s) were frozen before placing in the cooler. With this little machine, every BTU/calorie counts!

[Mike S]

Originally Posted by Danny7

if you want to really boost the performance of that cooler for a long trip or a real hot session try enough ice/ water to make the exchanger work and fill the rest up with dry ice

Hope no one takes this seriously, dry ice and water create a lot of carbon dioxide in a hurry.

Not recommended to breathe a lot of carbon dioxide