Calculate Cooling Power

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Usethis calculator to estimate the cooling needs of a typical room or house, such as finding out the power of a window air conditioner needed for an apartment room or the central air conditioner for an entire house.

This is a general purpose calculator that helps estimate the BTUs required to heat or cool an area. The desired temperature change is the necessary increase/decrease from outdoor temperature to reach the desired indoor temperature. As an example, an unheated Boston home during winter could reach temperatures as low as -5F. To reach a temperature of 75F, it requires a desired temperature increase of 80F. This calculator can only gauge rough estimates.

The British Thermal Unit, or BTU, is an energy unit. It is approximately the energy needed to heat one pound of water by 1 degree Fahrenheit. 1 BTU = 1,055 joules, 252 calories, 0.293 watt-hours, or the energy released by burning one match. 1 watt is approximately 3.412 BTU per hour.

BTU is often used as a point of reference for comparing different fuels. Even though they're physical commodities and are quantified accordingly, such as by volume or barrels, they can be converted to BTUs depending on the energy or heat content inherent in each quantity. BTU as a unit of measurement is more useful than physical quantity because of fuel's intrinsic value as an energy source. This allows many different commodities with intrinsic energy properties, such as natural gas and oil, to be compared and contrasted.

BTU can also be used pragmatically as a point of reference for the amount of heat that an appliance generates; the higher the BTU rating of an appliance, the greater the heating capacity. As for air conditioning in homes, even though ACs are meant to cool homes, BTUs on the technical label refer to how much heat the air conditioner can remove from their respective surrounding air.

The following is a rough estimation of the cooling capacity a cooling system would need to effectively cool a room/house based only on the square footage of the room/house, as provided by EnergyStar.gov.

Generally, newer homes have better insulating ability than older homes due to technological advances as well as stricter building codes. Owners of older homes with dated insulation who decide to upgrade their insulation may not only benefit from lower utility bills, but may also see an appreciation in the value of their homes.

Thermal resistance, which is a measure of a material's resistance to heat flow, is indicated by a material's R-value. The higher the R-value of a certain material, the more resistant it is to heat transfer. In other words, when shopping for home insulation, higher R-value products are better at insulating, though they're usually more expensive.

When deciding on the proper input for the "insulation condition" field in the calculator, use generalized assumptions. A beach bungalow built in the 1800s with no renovations should probably be classified as poor. A 3-year-old home inside a newly developed community most likely deserves a good rating. Windows normally have poorer thermal resistance than walls. Therefore, a room with lots of windows normally means poor insulation. When possible, try to install double-glazed windows to improve insulation.

To find the desired change in temperature to input into the calculator, find the difference between the unaltered outdoor temperature and the desired temperature. As a general rule of thumb, a temperature between 70 and 80F is a comfortable temperature for most people.

For example, a home owner in Atlanta might want to determine their BTU usage during winter. Atlanta winters tend to hover around 45F and temperatures may fall as low as 30F occasionally. Given that the desired temperature of the residents is 75F, the desired temperature increase would be 75F - 30F = 45F.

Homes in more extreme climates are subject to larger fluctuations in temperature, which typically results in higher BTU usage. For instance, heating a home in Alaska during winter, or cooling a home during a Houston summer will require more BTUs than heating or cooling a home in Honolulu, where temperatures tend to stay around 80F year-round.

The cooling capacity is calculated by changing the energy transferred during the cooling process.

WHAT IS THE COOLING CAPACITY?

Cooling capacity is the amount of energy transferred during a cooling process. Cooling power is measured in joules or watts and can be calculated by calculating the change in energy transferred by the cooling process.

Cooling capacity is an important parameter in evaluating the efficiency of cooling systems and can be used to compare the performance of different systems. A higher cooling capacity value usually means that more energy is provided per time.

It is important to note that this formula only applies to isothermal processes where the temperature of the cooling medium remains constant. Other applications require more complex methods to calculate the cooling capacity. We recommend contacting an expert to calculate the cooling capacity for a specific application.

There are many occasions where it might be helpful to know how much time it will take to heat or cool your system to a certain temperature. Or, you may want to calculate how much power is required to heat or cool a given volume of fluid in a certain amount of time.

You can use the same basic equation when calculating heating or cooling time, although there is a little more work involved for calculating cooling time. When heating, the power applied is constant, but when cooling, the power (or the cooling capacity) is variable depending on the temperature.

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.

Ambient heat loss gain or loss is inevitable, even in a closed system. A cooled system can absorb heat from the ambient air or system components, decreasing its cooling capacity. In a heating system, you may lose heat to the ambient air or to components of the system, for example, as it runs through tubes or pipes.

For cooling systems, cooling capacity can be impacted by maintenance issues too. In water-cooled condensers, corrosion, scale buildup, or biological growth can inhibit heat transfer, lowering the cooling capacity. In air-cooled condensers, dust and debris buildup on fan blades and fins can decrease air flow, having a similar effect of lowering the cooling capacity.

Move a slider to your specified cooling requirement (Qc) and click the SEARCH button. As you move the slider to the right, multiple product categories may offer suitable standard solutions. You will see multiple sliders moving simultaneously at this time.

The optimum thermal management solutions will display below the sliders. If there are multiple product category solutions available, they will appear in their respective Thermoelectric Module (TEM), Thermoelectric Assembly (TEA) or Liquid Cooling Solution tables. If you know your application's ΔT, enter that value in the box to the left of the SEARCH Button for more optimized results and click SEARCH. If you don't find the exact solution for your requirement, Laird Thermal Systems will engineer a custom TEM, TEA or LCS solution that meets your specific requirement.

If you know your ΔT, enter that value in the box to the left of the SEARCH Button for more optimized results and click SEARCH.

Viewing Product Solution Tables

SORT - when viewing product tables, you may sort each data column by increasing or decreasing values by clicking the arrow next to each column header Qc Op - displays the cooling performance of the thermoelectric module at the temperature difference requested. The cooling performance shown is at a typical operating point (Iop) set at 75% of the maximum current (Imax). By clicking on the part number, cooling performance (Qc) can be viewed graphically over the entire operating range from minimum to maximum voltage or current (Imin to Imax or Vmin to Vmax). V Op - displays the voltage corresponding to the operating current set at 75% Imax. Qc Max - displays the maximum cooling performance capability of the thermoelectric module. This value is measured at zero temperature difference with the current set to the maximum effective value. Actual thermoelectric performance is always less than QcMax because of input and output thermal resistances operating through a temperature difference, and the likelihood of operating at more efficient (lower) currents (see Qc Op). ΔT Max - displays the maximum difference in temperature seen across the thermoelectric couple. This value is measured at zero heat flow (Qc) with the current set to the maximum effective value. Typically the thermoelectric module is operated at ΔT's much less than ΔT Max in order to move heat from the cold to warm side of the thermoelectric module.

PART NUMBER - displays an active data sheet. You can fine-tune your application requirements by adjusting values for voltage, current, control temp, ambient temp, ΔT, Hot Side thermal resistance or Cold Side thermal resistance and then click the UPDATE button. To view a different product, click the Back Button on your browser or click the BACK Button

BUY NOW - displays the available inventory and pricing for this part number at authorized distributors via the Octopart Inventory Search Engine

REQUEST QUOTE - opens a form prompting you for contact and additional application information. Your part number of interest and Qc specification will pre-populate in your form. A Laird thermal expert will respond to you

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If you know the inlet and outlet temperatures, enter the values in the boxes to the left of the SEARCH Buttonfor more optimized results and click SEARCH.

Viewing Product Solution Tables

Sorting - when viewing product tables, you may sort each data column by increasing or decreasing values byclicking the arrow next to each column headerQc Op - displays the cooling performance of the thermoelectric module at the temperature difference requested.The cooling performance shown is at the operating point determined by the supply voltage.By clicking on the part number, cooling performance (Qc) can be viewed graphically over theentire operating range from minimum to maximum voltage or current (Imin to Imax or Vmin to Vmax)Power Supply - the power consumed by the thermoelectric modules, as well as any fans in air-cooled modelsSupply Voltage - displays the nominal supply voltage designed to achieve the rated cooling capacity of the assembly.The fan and thermoelectric modules in the assembly can be operated at higher or lower voltages depending on the coolingload required and efficiencies requiredQc Max - the maximum cooling performance capability of the thermoelectric assembly.This value is measured at zero temperature difference with the supply voltage set to the nominal value.Actual thermoelectric assembly performance is usually less than QcMax because of the requirement to operatethrough some temperature differenceΔT Max - displays the maximum difference in temperature seen across the thermoelectric assembly.This value is measured at zero heat flow (Qc) with the supply voltage set to the nominal value.The thermoelectric assembly is typically operated at ΔTs less than ΔT Max in order to move heatfrom the cold to warm side of the thermoelectric assembly.

Description - displays an active data sheet. You can fine-tune your application requirements by adjusting values for voltage,current, control temp, ambient temp, ΔT, Hot Side thermal resistance or Cold Side thermal resistance and then click the UPDATE button. To view a different product, click the Back Button on your browser or click the BACK Button

Check Stock - displays the available inventory for this part number at authorized distributors with links to the distributors for pricing.

Contact a Laird Thermal Expert Now

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