Coolers - Objective Measure of Efficiency?
- Thread starter jviss
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My old (and fine guy) Thermodynamics Professor would have let the boxes equalize in an inside location, added a specific amount of ice.. installed a couple of recording temp probes, then let it sit until the water temp is no longer rising (Ice fully melted and water up to ambient temp), then you can calculate the heat transfer (after figuring the area of the inside/outside of the box).. The slope of the temp increase curve would be a very quick way to see which box was going to perform better.. (I know you could do it by using cold water alone but adding some ice would make folks feel better)
My suspicion is that one could get a good guess by measuring the thickness of the foam insulation throughout the box; they are probably using an expanding foam that has very close, if not identical thermal characteristics.. If placed in the sun, then the solar heating characteristics of the case would have to be looked at as well..
My suspicion is that one could get a good guess by measuring the thickness of the foam insulation throughout the box; they are probably using an expanding foam that has very close, if not identical thermal characteristics.. If placed in the sun, then the solar heating characteristics of the case would have to be looked at as well..
There are some amazing new materials that don't require vacuum panels. See below:
"A number of new materials are now commercially available for cryogenic thermal insulation application. These new materials include aerogel blankets by Aspen Aerogels (Pyrogel® and Spaceloft®), aerogel beads by Cabot (Nanogel®), and polyimide foams by Sordal (SOLREX®) and Inspec Foams (SOLIMIDE®). Other materials and composites under development are nearing the commercialization phase."
If I were to be looking at larger area insulation, as you imply your whole boat, I'd be looking into the costs of the aerogel blankets or one of the foams. There are also some really promising materials coming out of the research as implied above that are phenomenal! Yet to see commercial products and cost, but I was looking at some research that was using a material that was something like the thickness of paint with thermal insulting properties of something like a foot thick closed cell foam.. That would make for an incredible refrigeration system on a boat!
dj
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Opening Pandora's box here.
As @thinwater eloquently mentions - there are a lot of variables to consider. In a former life, I guided multiday river trips for many years. 6 to 23 day trips - a few in summer averaging over 100 degrees every day.
Some real world large cooler thoughts. (Talking 150 to 200 quarts.)
How often do you access and how long is the lid up?
How much dead air space?
Extra insulation (ensolite pad on the inside), cooler condoms and sun protection?
What type of ice - cube, multiple commercial blocks or best yet - 1 block frozen in the cooler in a walk in freezer = optimal.
Do you drain or not?
In reality - cooler in question is small enough to stuff in a home freezer and freeze a block solid. I do it all the time with the 70 quart cheesy igloo that came with our H260 and - we have gotten up to about 13 days (with beer in a separate playmate), pre frozen food and anal management.
You won't be doing that with the little Ozark Trail.
River outfitters pretty much have all gone with Yeti style coolers but, as mentioned, they cost and have less interior space due to the insulation. We have a 70 qt yeti and it is awesome. Also a 178 qt Gott which works fine. And soft coolers. And 3 playmates and......
So..........it just doesn't matter.
Ice is cheap - pick your own.
As @thinwater eloquently mentions - there are a lot of variables to consider. In a former life, I guided multiday river trips for many years. 6 to 23 day trips - a few in summer averaging over 100 degrees every day.
Some real world large cooler thoughts. (Talking 150 to 200 quarts.)
How often do you access and how long is the lid up?
How much dead air space?
Extra insulation (ensolite pad on the inside), cooler condoms and sun protection?
What type of ice - cube, multiple commercial blocks or best yet - 1 block frozen in the cooler in a walk in freezer = optimal.
Do you drain or not?
In reality - cooler in question is small enough to stuff in a home freezer and freeze a block solid. I do it all the time with the 70 quart cheesy igloo that came with our H260 and - we have gotten up to about 13 days (with beer in a separate playmate), pre frozen food and anal management.
You won't be doing that with the little Ozark Trail.
River outfitters pretty much have all gone with Yeti style coolers but, as mentioned, they cost and have less interior space due to the insulation. We have a 70 qt yeti and it is awesome. Also a 178 qt Gott which works fine. And soft coolers. And 3 playmates and......
So..........it just doesn't matter.
Ice is cheap - pick your own.
I'll give you another one to chew on. Block ice and frozen bottles last the SAME amount of time per unit of cooling. A cooler with 10 pounds of block ice will be warmer and last longer than one with 10 pound of cube ice.
What works for me:
What works for me:
- Place the cooler on something insulated, if only a carpet. A blanket or Ensolite is better. It will gain heat through deck contact faster than air.
- Out of the sun and down low. Obviously.
- Throw a blanket over and around it if practical. It really helps.
- Freeze any food that can be frozen. That goes on the bottom.
- Stuff that needs to be near freezing, such as meat. Better yet, avoid taking things that are likely to spoil. Refrigeration didn't exist 100 years ago, so you don't need them.
- Freeze water bottles. On top of the frozen food. No mess and you can drink them later.
- Cheese and vegies etc. on top. They don't need freezing temperatures. This will also help hold the ice (insulation).
One of the challenges of testing coolers side-by-side, with a realistic amount of ice (not full of ice) is making sure the temperature inside both is the same. You will also be surprised by the temperature gradient, top to bottom. It can easily be 20 degrees.
Measuring heat gain is easy. Just measure the melt water. But don't go by days and contain the ice, because melt water laying in the bottom creates more variables.
Measuring heat gain is easy. Just measure the melt water. But don't go by days and contain the ice, because melt water laying in the bottom creates more variables.
I'm not trying to live out of the thing, I just want to take some cold beer to the beach. Oh, and maybe some wine. But probably just beer.
Was thinking I could strap this thing into the RIB, charge it up with beer and ice on Friday night, and enjoy it Saturday and Sunday.
It will be in the sun, unfortunately, but it's white, and if it proves to not work that way, I guess I can devise a cove that won't be too much of a pain in the dink.
Was thinking I could strap this thing into the RIB, charge it up with beer and ice on Friday night, and enjoy it Saturday and Sunday.
It will be in the sun, unfortunately, but it's white, and if it proves to not work that way, I guess I can devise a cove that won't be too much of a pain in the dink.
IMO you are going to need to do some experimenting. Personally I would start with chilled beer, freeze 3" of water in the bottom of the cooler, fill with beer and cube ice, drain accordingly and cover with a wet white towel.
Next step would be to freeze your beer assuming its canned. Old river trick with the caveat that some brands cans are so flimsy that this will not work.
Last step is to freeze beers, freeze a layer of ice in the cooler, add the frozen beers and freeze around them. Sounds like a pain in the ass but it only takes a few minutes each day if you start 5 days out.
Again, I assume you have a freezer big enough to put that small cooler in.
or...just buy a bag of cubes every second day, don't drain and add beers as needed.
Too muck work. I'll get to the yard with a cold 12 pack, buy a block of ice, throw it in the cooler with the beer on top, see what happens.
You'll be happy, I bought a 35 qt Yeti knock off at BJ's last season. I keep it under the cockpit table and use it for beer, wine and drinks. Everything stays cold ( colder than my frig) for 3 - 4 days. Like Thinwater said freeze some water bottles. I use the Simply Orange bottlles when finished as they are heavy plastic with a screw on lid.
One thing about the price, when they are clearing these out at WalMart they practically give some of them away. I ended up with two of the 26 quart Ozark Trails coolers, and one 73 quart one for $48 each and $100, respectively.
When you compare them to Yeti there's not a lot different. Both are roto-molded with 2 to 3" of polyurethane insulation, steel hinge pins, rubber T-latches, lid gasket, and so on. The equivalent Yetis would be $300 and $450.
Found a good site on coolers, albeit biased towards Yeti:
The Cooler Box
When you compare them to Yeti there's not a lot different. Both are roto-molded with 2 to 3" of polyurethane insulation, steel hinge pins, rubber T-latches, lid gasket, and so on. The equivalent Yetis would be $300 and $450.
Found a good site on coolers, albeit biased towards Yeti:
The Cooler Box
Sports drink bottles last. I use Gatorade (which I don't really like--a 12-pack lasts several years) because they withstand freezing many dozens of times and fit bike holders.