The following phrase is taken from an NHK News article:


I translated this as:

When the window is open, you'd better not turn off the air conditioner if you don't want a higher electrical bill.

Which... doesn't really make sense to me.

What does negative verb+ほうが mean in this sentence?

I'm just interested in the use of negative verb+ほうが. I've only seen it used with ほうがいい.

  • 1
    I took a look at the article and it does make sense in context (with the meaning you translated it as). Perhaps you haven't fully comprehended the preceding/following sentences?
    – sbkgs4686
    Commented May 16, 2020 at 13:30
  • 1
    "Most air conditioners can't let the outside air in, so sometimes it's necessary to open a window to let the outside air in. Air conditioners use a lot of electricity when turned on. When you open the window, electricity cost won't be higher unless you turn off the air conditioner". I mean, electricity cost won't be higher unless you turn on air conditioner. I don't understand. It's the opposite. Commented May 16, 2020 at 13:43
  • This article is hurting my physics brain too. Why would an air conditioner need to let outside air in? When I studied thermodynamics the important thing was dumping the hot air to the outside. And what has any of this got to do with Corona virus? Commented May 16, 2020 at 13:50
  • @user3856370 I think because if you change air inside the room there's less probability that you'll catch the virus (given that someone in the house has the virus). Since the density of the infected particles per m^2 will be smaller. Commented May 16, 2020 at 13:55
  • 2
    The two premises are "you have your AC on" and "you want to get rid of the stale / corona-y air in your room". Not speaking to its veracity, the article is saying that switching your AC on uses more electricity than if you just let it run, so when you open the window to let fresh air in, don't turn it off, because when you've re-closed the window and turn it back on, you've just used a bunch of electricity. The article then goes on to say that b/c the outside air is warm, you should at least increase the temperature it's set at while the window's open to save electricity.
    – sbkgs4686
    Commented May 16, 2020 at 14:14

2 Answers 2


I think the grammar not as complicated as you think if you know that 〜である方がいい means "It's better that [something affirmative goes here]". Similarly, 〜ない方がいい is "It's better that [something negative goes here]".

For example, consider an example where you are suggesting that your friends watch a TV program or not watch it. The literal translation of あの番組は見た方がいい would be "it's better to watch the TV program" and あの番組は見ない方がいい would be "it's better not to watch the TV program".

I think the context and logic is bit difficult to understand. So, I searched a little bit and they say "leaving air-conditioner on" consumes less electricity and costs less the electricity price in case just for 30 minutes between 9:00 and 18:00.

According to the article by Daikin Industries, Ltd., one of the largest air-conditioner manufacturers, they collected the opinion from consumers and 70% of them believe the case of "leaving the air conditioner on" costs less electricity price than the case of "frequently turning on and off".

They did experiment to verify that

実験(1): 「つけっぱなし」の方が消費電力が小さくなる 9:00~23:00まで「つけっぱなし」にしたエアコンと、30分間隔で運転ON/OFFを繰り返したエアコンの消費電力量を比較し、「つけっぱなし」の方が安くなる時間帯を検証。

結果 日中9:00~18:00の時間帯は、30分間であればエアコンを切るより「つけっぱなし」にする方が消費電力量は少なくなりました。

That is to say, if you are going outside for just 30 minutes, "leaving the air conditioner on" costs less the price than "turning it off when you leave and turning it on again after coming back".

The graph below shows the relationship between electricity price (vertical axis) and time (horizontal axis). つけっぱなし: "leaving the air conditioner on" and こまめに入り切り: "Frequently turning it on and off".

Electricity price over time graphs; leaving AC on vs. turning it on and off

All in all, regarding electricity price, in the midst of hottest summer, keeping the room cool is better than turning off air-conditioner and let the warm air pass through the room just because you want to let the virus/dusts/micro-particles/etc. out from the room.

There are some other intersting graphs regarding electricity consumption and room temperature and humidity in the same article: 日中30分の外出ならエアコンは切るより「つけっぱなし」がお得でした!

  • From a thermodynamic perspective, this also makes sense, because turning off the aircon will cause the temperature to rise, and turning it on again will require more energy. physics.stackexchange.com/questions/345824/…
    – rebuuilt
    Commented May 17, 2020 at 8:34
  • @rebuuilt Thanks for the mention. The company did the experiment that setting temperature of AC is 26 degrees and outside temperature is about 37 degrees. So , AC has to work harder to cool down for its goal if you turn it off before go out and turn it on when you come back. I think the link of NHK news(not an overview one but an original one) also has similar things explained by the company like DAIKIN, an AC maker and YKK AP, a Fenestration company. Commented May 17, 2020 at 11:03

The phrase ほうがいい can actually be understood in terms of its component parts. ほう means "side". So Xほうがいい literally means the "X side is good" - i.e. given a choice, choosing X is the best result, or X is better.

This construction extends naturally. For example if you were comparing two buildings, you could say このビルのほうが高い = "the side (where I choose) this building is tall" = "this building is taller".

Regarding the quote from your question:


This sentence works the same way. "The side where you choose to not turn off the air-con does not result in the electric bill becoming high" = "Not turning of the air-con doesn't make the electric bill get higher."

The reasons for this counter-intuitive statement are explained in kimi Tanaka's answer.

  • This way of interpreting Xほうが is enlightening. Commented May 16, 2020 at 21:07

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