# What does "horsepower" of an air conditioner mean? Can a car air conditioner calculate fuel consumption and power consumption by horsepower?

This is an interesting question, "horsepower" seems to be a commonly used unit when discussing power consumption of residential air conditioners, what does power mean, and can it be used to calculate fuel consumption and power consumption of car air conditioners?

Of course you can.

Pi is a transliteration, but it can also be understood as a literal translation; horse means metric horsepower and unit is PS. When discussing engine power, horsepower is also mentioned. Now common unit is metric horsepower instead of imperial horsepower, metric horsepower and horsepower can be converted, and relationship between power, speed and torque is obvious for car air conditioners.

Two formulas:

1. Speed ​​× torque ÷ 9549 ≈ power
2. Power × 1.36 ≈ metric horsepower

1 PS equals a force of 75 kg. The idea is to pull an object with a mass of 75 kg so that it moves one meter per second.

1PS=1÷1.36, answer is 0.7352941179647...kW (kilowatt/unit of power), take three decimal places, one horsepower is equal to 0.735kW, then general algorithm of air conditioner for one horsepower is consumed power per hour 0.735 deg, plus fans and losses will be about 0.8 deg per hour. Of course, this is cooling power input according to rated power. The inverter air conditioner will reduce cooling power after reaching set temperature, power will decrease accordingly, and power consumption will decrease accordingly.

Let's talk about electric vehicles first. After all, they all use electricity. The power of car air conditioners is very large, usually about 5HP, corresponding power is about 3.676KW, which means that air conditioner cools according to rated power At that time, it consumes 3.676 degrees of electricity per hour.

Power consumption is still very high, but don't worry, most EVs use variable displacement compressors that are equivalent to frequency conversion.

After setting temperature, for example 25°C, power will be automatically reduced when temperature in car reaches temperature; average power consumption after constant temperature can be controlled at about 1KWh, it is still very hot outside and sun is strong When temperature is low, average power consumption can be controlled within one degree. The impact on range will be negligible. For example, power battery pack capacity is 80kW, power consumption per 100km is 15kW, and battery life limit is 533km. It also has a battery life of 500 km.

Do you believe it?

Vehicles running on liquid fuel should be counted as "fuel consumption" and air conditioners are no exception

Because air conditioning compressor on a fuel-powered vehicle is not driven by engine, but by crankshaft of internal combustion engine, and crankshaft is its output shaft, driving compressor and overcoming resistance of compressor will result in loss of power Electric vehicles Relying on battery power to supply power to compressor motor, so it will not affect power.

Power is not discussed, but focus is on fuel consumption.

The power of compressor and power of fuel-powered vehicles is similar to that of electric vehicles. Let's also calculate according to 5 liters. engine power; 5 hp The loss of power is equivalent to a decrease of 375 kg of force, and when accelerating, power will definitely deteriorate, and speed of car corresponding to same speed will also decrease. Since compressor power is lost by 5 HP, power is weakened, and vehicle speed is of course reduced, if slower acceleration and lower speed can be accepted, fuel consumption will not increase. Conversely, acceleration memory and speed memory are formed for a long time. If you want to race, you need to increase your speed to make up for lost power.

Speed ​​should be increased by a few hundred revolutions, let's calculate based on standard 1.5T 135kW/300Nm (1500~4000rpm).

2000rpm × 300Nm÷9549≈62kW, 84HP, 66kW must be reached after turning on air conditioner.

66×9549÷300Nm≈2100rpm, speed is increased by about 100 rpm, which equals another 50 jobs per minute.

This is calculation result based on high power. If a 1.5 liter NA (naturally aspirated) engine is used as a reference, standard power is around 85 kW/145 Nm and maximum torque is typically around 4000 rpm. only reach peak value, and it only rises slowly between 1000-4000rpm, corresponding torque at 2000rpm is about 125Nm, and corresponding power and output is 26kw/35hp, speed should exceed 2200 rpm, higher speed of a naturally aspirated engine in low to medium rev range, greater fuel consumption per job, so an increase of two hundred rpm will lead to a significant increase in fuel consumption, which can be increased. About two liters or so.

Therefore, stronger power of fuel-powered vehicles, smaller increase in fuel consumption after turning on air conditioner. Electric vehicles and plug-in hybrid vehicles have no effect because air conditioning compressor does not affect power.

Finally, let's briefly talk about heating system. The fuel vehicle heating system has nothing to do with "PS" because it does not depend on operation of compressor, its heat comes from non-freezing coolant heated when internal combustion engine is running , so theoretically warming up does not affect fuel consumption.

However, low temperatures will affect fuel consumption. If temperature is too low, it will increase cooling of water tank and body due to strong low temperature air flow during driving. It is difficult to heat body and antifreeze. increase fuel consumption.

The standard can be equivalent to using a cold air conditioner, which is about 2 l / 100 km.

Then, suppose car's fuel tank is 50 liters (standard scooter standard), crude oil consumption is 8 l/100 km, and normal limit is 625 km. Adding two liters will reduce range limit to 500 km. km, which decreased by as much as 125 km.

The heating system of electric vehicles must be calculated according to "PS" because there are two sets of heating systems; very little influence; second PTC electrical heating system. This system consumes more power because it relies on high current heating resistors and then heats up antifreeze coolant. Peak power consumption can reach more than 5 kilowatts. If temperature is too low, it will maintain this range for a long time, and after a constant temperature, it may drop to about 2 kilowatts.

Using a PTC system will indeed affect battery life to a certain extent, which is little more than lowering vehicle fuel temperatures in winter; but, fortunately, price per unit of electricity is very low, at least it is not. unpleasant to use. here we are.

(Home air conditioning is a dual operation of a heat pump and electric auxiliary heating. Electric auxiliary heating is electric heating, but it does not heat water, but directly heats air)

Editor: Tianhe Auto-Car Science Island

Copyrighted by Tianhe MCN

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