家用中央空调怎么选？
How to choose a home central air conditioner?
接下来进一步将从性能上、指标上、选购上教大家如何选购家用中央空调。
Next, we will teach you how to buy household central air conditioning from the aspects of performance, indicators and purchase.
在讲之前，大家先要注意几个小点：安装家用中央空调层高在2.70米以上是最好的，需注意室内机适不适合家里的吊顶高度。
Before speaking, we should first pay attention to a few points: it is
best to install a household central air conditioner with a floor height
of more than 2.70 meters. We should pay attention to whether the indoor
unit is suitable for the ceiling height at home.
好啦，接下来我们开始进入选购知识吧！
Well, let's start to buy knowledge!
1、在性能上：
1. In terms of performance:
（1）压缩机
(1) Compressor
压缩机是家用中央空调的最核心部分，主要作用于空调的制冷性能，在家用中央空调中主要有双转子、涡旋式压缩机。涡旋式效率最高，但价格相对也贵些，目前双转子压缩机用的多，它结构简单，低频性能好，可靠性强，用的比较广泛。
Compressor is the core part of household central air conditioning, which
mainly acts on the refrigeration performance of air conditioning. There
are mainly double rotor and scroll compressors in household central air
conditioning. Scroll compressor has the highest efficiency, but the
price is relatively expensive. At present, double rotor compressor is
used more. It has simple structure, good low-frequency performance,
strong reliability and is widely used.
一般品牌用的都是日系高技术压缩机，像三菱、大金、日立、东芝都是很不错的，海尔中央空调用的就是三菱双转子压缩机。
General brands use Japanese high-tech compressors, such as Mitsubishi,
Daikin, Hitachi and Toshiba. Haier central air conditioner uses
Mitsubishi double rotor compressor.
家用中央空调高配都为直流变频压缩机，豪华版用的是全直流变频压缩机，一级能效，更省电。
The high configuration of household central air conditioner is DC
variable frequency compressor, and the luxury version uses full DC
variable frequency compressor, which has first-class energy efficiency
and saves power.
（2）冷媒
(2) Refrigerant
冷媒就是制冷剂，用的比较多的是氟利昂，可以通过管道加入达到制冷制热的效果，冷媒有R22、R32、R134a、R290、R410A几种。
Refrigerant is refrigerant. Freon is mostly used. It can be added
through pipeline to achieve the effect of refrigeration and heating.
There are several kinds of refrigerants: R22, R32, R134a, R290 and
R410A.
R22：无色无味，性能好，但对臭氧层有一定的破坏性。
R22: colorless and tasteless, with good performance, but it is destructive to the ozone layer.
R32：无味无毒，易燃易爆，安全性不高，是高危制冷剂。
R32: odorless, non-toxic, inflammable and explosive, with low safety, it is a high-risk refrigerant.
R134a：对臭氧层不起破坏，比较环保，但沸点比较低，性能会受下降。
R134a: it does not damage the ozone layer and is relatively
environmentally friendly, but its boiling point is relatively low and
its performance will be degraded.
R290：新式环保冷媒，无色，不含臭氧，但易爆，安全性能上够高。
R290: new environment-friendly refrigerant, colorless and ozone free, but explosive, with high safety performance.
R410a：是一种新型环保冷媒，没有颜色无味，不会破坏臭氧层，比较稳定，性能好。
R410A: it is a new type of environment-friendly refrigerant. It has no
color, tasteless and will not destroy the ozone layer. It is relatively
stable and has good performance.
现在主流家用中央空调品牌基本用的都是R410a，性能好，又比较环保，安全。
Now the mainstream household central air conditioning brands basically
use R410A, which has good performance, environmental protection and
safety.
2、在指标上：
2. In terms of indicators:
（1） 制冷（热量）配比
(1) Refrigeration (heat) ratio
制冷量是指空调在运作时，单位时间在制冷情况下从空间或房间区域内排出的热量。
Refrigeration capacity refers to the heat discharged from the space or
room area per unit time under refrigeration when the air conditioner is
in operation.
制热量是指空调在运行时，单位时间在制热情况下从空间或房间区域内排出的热量。
Heating capacity refers to the heat discharged from the space or room
area per unit time during the operation of the air conditioner.