Why can’t the annual energy consumption of air conditioning boxes be estimated based on rated power only?

The annual energy consumption of the air-conditioning box cannot be estimated simply by multiplying the rated power by the number of hours throughout the year, because outdoor conditions, production shifts, air volume, and hot and cold humidity tasks will change with time. Reasonable estimates should be calculated separately according to representative working conditions and operating hours, and the statistical boundaries of fans, electric heat, humidification and external cold and heat sources should be explained.

Use case grouping instead of a year-round constant

Groupings can be established by season, production status and operating mode to provide air handling needs, equipment inputs and hours respectively. Fan speed adjustment, filter resistance growth, and heating and humidification activation time will affect the results. The cooling capacity consumed by the cold water coil cannot be directly regarded as the power consumption of the cooling station. The assumptions of the model should be able to be reviewed by the project party.

Meteorological conditions should include temperature and humidity changes and representative periods; usage conditions should include shifts, loads, air volumes, and shutdown and restart arrangements; energy models should include inputs to each equipment, external system efficiency, and measurement boundaries. The three types of inputs correspond to different influencing factors and cannot be given just one rated power number. What equipment should be included in the air conditioning box energy consumption assessment? Please refer toWhat equipment power consumption should be included in the energy consumption assessment of air-conditioning boxes?。

Rated power is not equal to actual operating power

The fan nameplate power is the motor rating and is not equal to the actual consumption during operation. Actual power input varies with operating point, rotational speed and filter resistance. If the fan operating point deviates from the high-efficiency area during equipment selection, the actual power may be higher than expected; during partial load operation, the power will not decrease linearly in proportion to the air volume.

How to check the fan efficiency range, please refer toWhy should we check the efficiency range when selecting air-conditioning box fans? . How to calculate fan energy consumption by operating period, please refer toHow to calculate the energy consumption of air conditioning box fans separately according to operating periods? . The regulation characteristics of DC fans under partial load are different from those of AC fans. Please refer toWhat driving conditions need to be matched when using a DC fan in an air-conditioning box?。

Changes in filter resistance can change power throughout the year

The filter resistance increases with the increase in dust accumulation, and the fan needs to increase the speed or increase the input power to maintain the air volume. If the annual energy consumption estimate is calculated only based on the initial resistance of the new filter material, it may underestimate the actual consumption. The variation range between the initial resistance and the final resistance should be included in the operating model.

How to configure filter classification, please refer toHow to configure the primary-efficiency and medium-efficiency filters of air-conditioning boxes in different stages? . What functional segments does internal resistance include? Please refer toWhat functional segments should be included in the internal resistance of the air conditioning box? . How to establish the fan pressure budget, please refer toHow is the total pressure of the air conditioning box fan determined by the internal resistance and external demand?。

Electric heating, humidification and external cold and heat sources should be counted separately

Electric heating and electric humidification belong to the direct use of electricity by the unit, with large power and input according to the working conditions. The evaluation should record the enablement period, control method and actual inputs rather than the rated power multiplied by the number of hours throughout the year. The cooling capacity of the cold water coil belongs to the water-side energy input. The actual power consumption of the cooling station also depends on the unit efficiency, pump consumption and operating conditions. The two need to be calculated separately or allocated according to an agreed method.

What problems do preheating, heating and reheating solve respectively? Please refer toWhat problems do air conditioning box preheating, heating and reheating solve respectively? . How to choose between hot water heating and electric heating, please refer toHow to choose between hot water heating and electric heating for air conditioning boxes? . How to determine the amount of humidification according to the wind inlet conditions in winter, please refer toHow to determine the humidification amount of air-conditioning box according to the air inlet conditions in winter?。

Running time and load distribution determine cumulative energy consumption

Annual energy consumption is the accumulation of power over time, and operating hours and load distribution are as important as equipment efficiency. Production shifts, duty patterns, shutdown pressure maintenance and seasonal changes will all change the operating time and load in each period. Giving only one number of hours for a full year fails to reflect these differences.

How the proportion of new return air affects the load can be referred toHow is the proportion of new return air to the air-conditioning box determined by project requirements? . How the circulating unit bears the indoor load can be referred toWhat indoor loads should the circulating air handling unit be selected based on? . For the cost impact of night duty air supply, please refer toWhat impact do chemical filters have on the cost of night duty air supply?。

What boundaries should be kept in estimating conclusions?

Make it clear whether the results are program estimates or measured statistics, and list key assumptions and sensitive factors. If there is a lack of load and weather data, conditional comparisons can be given instead of being packaged as accurate annual electricity bills. Only by correcting the model with actual records after it is put into operation can we determine whether the deviation comes from operating time, equipment performance or initial assumptions.

When energy-saving renovation involves both filtration and air conditioning, the boundaries must be clearly stated. Please refer toCan the chemical filter modification be done together with the energy-saving modification of the air conditioning box? . For cost comparisons on how to maintain the same service level, please refer toHow does a chemical filter energy saving program maintain gas control goals?。

Aili industrial supporting equipment

Aili Industrial can provide equipment-side parameters corresponding to the configuration for project evaluation. The annual model still needs to be established based on on-site shift, meteorological and cold and heat source system data. Aili's industrial manufacturing end covers the independent research and development and production of motors and fans, control systems, sheet metal, air filters and complete machine assembly. The power circuits of fans, electric heating, electric humidification and control accessories can be corresponded in the same set of supporting materials, which facilitates measurement by circuit and statistics by time period.

Product form can be viewedAir handling unit andFan box page; clean air supply package can be combinedFFU fan filter unit andEFU equipment end fan filter unit verification; multiple equipment linkage can understandMatching method of FFU computer group control system ; terminal particle filtering can be combinedHEPA/ULPA filter confirmation; when it comes to gaseous pollution control, you can communicate separatelyChemical filter solutions. Specific energy consumption data, measurement methods and delivery scope still need to be verified based on corresponding configuration data and on-site working conditions. The actual effect is subject to on-site measurement and performance test results.

Submit project parameters:https://ailigy.com/contactus.html

Related questions and answers

Rated power multiplied by the number of hours in a year, why is it not accurate?
The rated power is the rated value of the equipment. The actual operating power changes with the working conditions, rotation speed and resistance, as well as the operating time and load distribution, and cannot be simply multiplied.

Will the increase in filtration resistance affect energy consumption throughout the year?
meeting. When dust accumulates on the filter, the resistance rises, and the fan needs to increase its speed or input power to maintain the air volume. The annual energy consumption estimate should cover the change between the initial resistance and the final resistance.

Can Aili Industrial assist with energy consumption estimation?
Equipment-side parameters corresponding to the configuration can be provided, and the annual model needs to be established based on on-site shift, meteorological, and cold and heat source data.

Related articles

1. What equipment power consumption should be included in the energy consumption assessment of air-conditioning boxes?

2. How to calculate the energy consumption of air conditioning box fans separately according to operating periods?

3. Why should we check the efficiency range when selecting air-conditioning box fans?

4. What functional segments should be included in the internal resistance of the air conditioning box?

Key points for selection and acceptance inspection