Formula for relating time and heat gained for closed system

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Discussion Overview

The discussion revolves around finding a formula or method to relate outside temperature to the time it takes for the temperature inside two different closed systems to reach a certain temperature. The context involves experimental data collected from two containers with frozen goods, focusing on consumer-friendly presentation rather than precise scientific accuracy.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Homework-related

Main Points Raised

  • One participant seeks a formula to create a table showing the relationship between outside temperature and internal temperature change over time for two closed systems.
  • Another participant suggests using Newton's law of cooling and recommends plotting the data to find a trendline, while also cautioning that ignoring variables like wind may lead to inaccurate assumptions.
  • A participant expresses concern that including too many variables might introduce excessive variability, which could complicate the data presentation for consumers.
  • There is a challenge regarding the quality of data, with one participant emphasizing that poor data will yield poor insights.
  • Another participant argues that since the conditions for both systems were controlled, it may be reasonable to assume fair conditions despite the variability in data.
  • One participant suggests that simply graphing the data could effectively demonstrate the comparative warming rates of the products to consumers.

Areas of Agreement / Disagreement

Participants express differing views on the importance of including various environmental variables in the analysis. While some believe that simplifying the data for consumer understanding is essential, others argue that this could lead to misleading conclusions. The discussion remains unresolved regarding the best approach to present the data.

Contextual Notes

Limitations include the exclusion of variables such as wind, humidity, and pressure, which may affect heat transfer rates. The discussion also reflects uncertainty about the adequacy of the collected data and its implications for consumer presentation.

Who May Find This Useful

This discussion may be useful for professionals involved in product testing and marketing, particularly those focused on consumer-facing data presentation in the context of thermal properties and heat transfer. It may also benefit individuals interested in experimental design and data analysis in closed systems.

Allen Dowe
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This is for work. I need to make a table for a client.
What we did: had two different closed systems, only difference is material. We had frozen goods in both containers, the containers were both removed from the cooled surroundings they were in and placed outside. The temperatures were taken for both containers every minute.
What I need is a formula or something to help me create a table that will show a relationship between the outside temperature and the time it takes the temperature inside the system to get to a certain temperature (not yet chosen). I will be making 2 Tables one for each container.
Please help if you can!
NOTE: exclude variables like wind, humidity, pressure, being that this table is meant for consumers to see. they do not need exacts.
 
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The data you collected has the information you need. Have you plotted the data in excel or sim.? Add a trendline, the formula for that trendline should follow Newtons law of cooling:
http://formulas.tutorvista.com/physics/Newton-s-law-of-cooling-formula.html
http://en.wikipedia.org/wiki/Convective_heat_transferIgnoring wind may be a poor assumption, forced convection heat transfer can be orders of magnitude greater than natural convection heat transfer (that's why we blow on hot food and cars have radiator fans etc)
 
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Thank you sir, I appreciate it! And yes i agree, but it would leave me with too much variability to make a chart I think. What do you say?
 
Explain 'too much variability'.
If your data is poor then anything you glean from it will also be poor.
 
The goal is for consumers to see the comparison of our product to their current product. Since the conditions were exact for the two systems (held at same time/place) i feel it should be alright to assume fair conditions.

By too much variability I mean is there would be sooo much extra data that would almost be considered irrelevant from a consumer perspective. Your thoughts?
 
I don't understand what you're saying.
It's up to you to decide what data to give the consumer. Give them as much as you see fit.
I think simply graphing what you have will be fine. The consumer will see your new product warms up slower than the current.
Like this:
CoolingFull.png


(obviously, your products are increasing temp rather than cooling)
 

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