JUGS: DOES SIZE MATTER?

Introduction

When constructing a hydration system for Long Distance Motorcycle Riding, the rider / engineer, strives to design a system that is lightweight, compact, easy to refill, and can provide water at a comfortable drinking temperature for a reasonable period of time. Based on the author's personal observation, hydration systems of 64 - 128 oz (0.5 - 1.0 US Gallons) strike a balance between having enough water to drink, and adding unneeded weight to the motorcycle. 

Our previous experiments compared the heat transfer of the Yeti Rambler 1 Gallon Cooler to the Coleman 1 Gallon Cooler. Our first experiment started with ice water of 33F over a 48 hour period, and our second experiment started with 155F water over a 12 hour period. In both experiments, the Yeti outperformed the Coleman . 

For this experiment, we will be comparing the heat transfer abilities of the Yeti and Coleman Coolers in their 1 Gallon and 1/2 Gallon Sizes. 

Materials

Taylor Digital Probe Thermometer, Item #9848BEFDA, Operating Range (-40F - 450F).

Yeti Rambler 1 Gallon Jug, Item # YRAMOGJ.

Coleman 1 Gallon Cooler, Item # 3000000731.

Yeti Rambler 1/2 Gallon Jug, Item #  YRAMHGJ

Coleman 1/2 Gallon Cooler, Item # 3000001016

Methods

On September 1, 2017, the author intends to fill the coolers with ice and water, record the temperature of the contents, seal the coolers, and place the coolers in a sunlit area. Ambient temeratures are expected to be 55F - 75F during the day.The coolers will be opened, temperatures recorded, and the coolers resealed. The coolers will be moved indoors after sunset, and returned outdoors after sunrise. After suffcient heat transfer data is obtained, the experiment will be stopped, and results recorded.

Technique

On the afternoon of September 1, 2017, each cooler was carefully inspected by the author. Each cooler was noted to be in good, usable condition with a properly fitting lid. Based on the previous experiments, the 1 Gallon sized coolers were filled with 3 pounds of ice and 64 ounces of water. The 1/2 Gallon coolers were filled with 1.5 pounds of ice and 32 ounces of water.

The starting temperature in all four of the coolers was rounded to 33F. The coolers were placed outdoors on a heat absorbing surface during daylight hours, and moved indoors to a climate controlled room at 70F.

Results

Under the controlled conditions of this experiment, the Coleman 1 Gallon and 1/2 Gallon Coolers showed different rates of heat transfer, with the larger cooler outperforming the smaller.

The Yeti 1 Gallon and 1/2 Gallon Coolers also showed different rates of heat transfer. Again, the larger cooler outperforms the smaller one. 

A comparison between all four of the coolers:

After reviewing the data, size does matter when it comes to Jugs.

Future Research

• The author plans to compare a more varied assortment of coolers in the half gallon size. 
• The author plan to compare the performance of the coolers when placed in a constant 100F environment to more closely simulate riding conditions in hot weather. 

THE IDIOT AND THE $130 COOLER. I LIKE MY COFFEE HOT, BUT NOT TOO HOT!

Introduction

In my original experiment, THE IDIOT AND THE $130 COOLER. AN EXPERIMENT IN HEAT TRANSFER. we saw the difference in heat transfer between the Yeti Rambler 1 Gallon Cooler and the Coleman 1 Gallon Cooler using a controlled amount of ice and water.

While the  Long Distance Rider (LDR) can exist for extended periods of time solely on water, beef jerky, and the carefully chosen non-melting protein bar, there are times when a hot cup of coffee, tea, or even soup, would be a welcome addition to the LDR's diet. 

I decided to perform a second experiment, to test the relative performance of the Yeti and Coleman Coolers on hot beverages. But, it was not immediately clear, what the best temperature to start would be. So, I made myself a cup of coffee, and did a little research. 

175F was way too hot.

147F was stll a little too warm for my tastes.

134F was just about right!

It turns out, that someone else had already done some real research, with a study of 300 coffee drinkers: Calculating the optimum temperature for serving hot beverages.

I was actually pretty close. The study found that a range of 140F (+/- 15F) was ideal, with a mean of 136F. Temperatures of 160F or above can cause scald burns. So, I decided to start my experiment at 155F. 

Materials

Taylor Digital Probe Thermometer, Item #9848BEFDA, Operating Range (-40F - 450F).

Yeti Rambler 1 Gallon Jug, Item # YRAMOGJ.

Coleman 1 Gallon Cooler, Item # 3000000731.

Hot Water

Methods

On August 31, 2017, the author plans to fill the Yeti and Coleman Coolers each wth 128oz (1 US gallon) of hot water to attain a temperature of 155F. The coolers will be placed on a kitchen counter away from any external heat source. The room temperature is controlled by digital thermostat to an ambient temperature of 70F. The coolers will remain sealed between temperature readings and opened only for the minimum amount of time needed to take a temperature reading. The author plans to run the experiment for 12 hours.

Technique

On the evening of August 31, 2017, each cooler was carefully inspected and noted to be in good, usable condition, with a properly fitting lid.

Coleman Cooler Start Temperature, 155.2F

Yeti Cooler Start Temperature, 154.9F.

The temperature in both coolers was noted at 155F (rounded).

At the first temperature reading, the lid on the Coleman Cooler was significantly warmer than the lid on the Yeti Cooler. You may recall from our firt experiment, that the lids had significant design differences:

Yeti vs. Coleman Lids

A temperature reading was taken of the lids surfaces, using the Taylor thermometer:

Coleman Cooler Lid, 98.4F.

Yeti Cooler Lid, 77.1F

Multple temperature readings were then taken for a 12 hour perod, and rounded to the nearest whole degree. 

Results

On September 1, 2017 the Yeti and Coleman Coolers were opened 12 hours after the start of the experiment. At the end of the 12 hour period, the temperature in the Yeti Cooler remained at 130F, while the temperature in the Coleman Cooler had dropped to 94F.

Using the data from the 2008 Burns study referenced earlier in this post (140F +/- 15F) for the optimum serving temperature of coffee the lower heat transfer properties of the Yeti Cooler become more significant than durng our previous ice water experiment. The Yeti Cooler is capable of keeping a hot beverage at optimum temperatures for 12 or more hours, while the Coleman Cooler is only capable of maintaining these optimum temperatures for 4 hours. 

Future Reasearch

• Half Gallon Coolers from Yeti, Coleman, or other manufacturers. 
• Smaller cup or tumbler style coolers with various lids, since not everyone wants to carry around a gallon of coffee or soup. 
• Changing the external temperature of the environment the cooler is placed in to simulate cold riding conditions, such as running the experiment with the coolers in a refrigerator. 
• A combination study using two or more coolers to start off with ice and hot coffee, and eventually a combined result of iced coffee.