AC vs Fan: Energy Consumption
Subject
Building Services
,Climatology
,Academic Year
2'nd Year
,Complexity Level
Intermediate
,Content tags
Air Conditioning
,Climate Justice
,Energy Consumption
,Activity Type
Field Measurements
,Activity duration
1-2 hours
,Objective
To compare the energy consumption of a fan vs a room air conditioner.
Outcome
Students will realize that an air conditioner consumes much more energy than a ceiling fan.
Requirements
An air conditioned laboratory (in college building), power meter.
Prerequisites
- Conceptual knowledge of electrical energy consumption.
- Knowledge of how a power meter works.
- Suitable for final year architecture students.
Procedure
- Identify a laboratory (eg: a computer lab) in your college having an air conditioner in it.
- Insert air conditioner plug into the power meter.
- Insert the power meter into electrical socket
- Switch on the AC.
- Note the power consumption from the power meter.
- Keep noting the power consumption after every 10 minutes for 1 hour. Tabulate them as shown below.
- Estimate the mean power consumption by taking an average of all the intermittent values of power consumption.
- Estimate the energy consumption for 1 hour.
- Identify a fan in the classroom.
- Look for the nameplate on the fan which states it’s power consumption.
- Estimate the hourly energy consumption of the fan.
- Compare the hourly energy consumption of the fan vs AC.
- Estimate the no. of fans which collectively consume energy equivalent to one air conditioner.
Calculations
- Table for calculating energy consumption of an AC.
| Time Interval | Power Consumption (kW) |
| Initial Time (A) | |
| 10 minutes (B) | |
| 20 minutes (C) | |
| 30 minutes (D) | |
| 40 minutes (E) | |
| 50 minutes (F) | |
| 60 minutes (G) | |
| Average $$\frac{A+B+C+D+E+F+G}{7}$$ (PAC) |
Step 2: Energy Consumption of AC (kWh) = Average Power Consumption (kW) x no. of hours used (hrs) = PAC (kW) x 1 (hour)
Step 3: Energy Consumption of Fan (kWh) = Power Consumption x no. of hours used (hrs.) = PFAN (kW) x 1 (hour)
Step 4: No. of fans which collectively have the same energy consumption as that of an AC = $$\frac{\:\text{Energy consumption of an AC (kWh) }}{\:\text{Energy consumption of a fan (kWh)}}$$
Reference Images
