Here are the factors you need to consider: 1. Similarly, if you’re using the calculation to determine how much power you need to achieve a given heating or cooling time, you should assume some additional power will be required. As such, if you’re using this equation to determine heating or cooling time, you should assume that the process will take a little longer than expected. Factors to Consider When Calculating Heating or Cooling TimeĪs mentioned, there are several reasons your calculations may not deliver a realistic result. However, if the specs don’t provide the cooling capacity at a temperature that is close to the minimum temperature of the unit, you can ask the manufacturer or us to provide the information you need. If you’re trying to cool to a lower temperature, it may be too low, meaning the unit won’t be able to provide the cooling capacity you need. What if your minimum temperature is below the lowest temperature cooling capacity specification provided? This generally should not be a concern as cooling capacity values are typically provided for a temperature at or below the minimum temperature of the unit. Opt for an alternative quick method that uses an average of cooling capacity values at various points in the temperature range (the points would need to include the upper and lower ends of the temperature range for this to be viable).Use a quick and dirty (and likely less accurate) method by only considering the cooling capacity at the midpoint temperature.Potentially underestimate but with more accuracy by taking the average power between various temperatures.For instance, taking the specifications above, you could assume that the cooling capacity is 250 W for all temperatures between -20☌ and 0☌ and 800 W for all temperatures between 0☌ and 20☌. Use a conservative estimate by assuming the lower power up to the next listed temperature.You have a few options here depending on how to accurately you want your calculation to be: Heat transfer is reduced so cooling capacity is lowered.įor example, here are the cooling capacity specifications for the PolyScience 45 L Refrigerated & Heated Circulating Baths. Cooling capacity decreases at lower setpoint temperatures because there’s a smaller temperature differential between the chiller liquid and refrigerant. The cooling capacity (or cooling power) is different depending on the temperature. The question is what value should you use for power. To calculate cooling time, you can use the same equation as above. It has two options enabling you to calculate either power required or time required. If you need to deduce heating time for other fluids, this calculator is more suitable as it lets you enter the specific heat capacity of the substance you’re using. This calculator is nice and simple and lets you calculate time, power, or energy consumed, but it’s only good for calculations involving water. Instead, you could use an online calculator to help. While these equations are fairly straightforward to follow, there can be some confusion when it comes to which units to use. Similarly, to calculate the power needed to heat or cool a bath to a certain temperature in a given time, you can use this equation: P is the power at which energy is supplied in watts or joules per second.
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