Can Venta Airwasher Effectively Reduce PM2.5 or PM10?

There is not official tests state that whether Venta airwasher is able to reduce PM2.5 or PM10 effectly, hence, I made some tests with the help of Dylos air particle counter during the good weather, PM2.5 index less than 100 means good or moderate, PM2.5 larger than 100 which means unhealthy or even hazardous. My bedroom's door or window is closed all the time and it's a confined space.

The answer is partially efficient. In centain conditions, it works, other times, no.

When the PM2.5 outside is less than 100, Venta can effectly keep the indoor PM2.5 around 30 or even less.

However, when outside is unhealthy, which means the index is above 100 and beyond, it really can't effectly reduce the particles inside, and the metrics I got from Dylos indoor have positive correlation with outside index, sometimes, Dylos even get 100 or even more which is totally unacceptable for people in the bedroom.

Now, the answer is quite clear, if the weather outside is good, just keep the Venta open and it can handle. When outside is unhealty, you really need to turn on your air filter, and don't rely on it, you need HEPA filter.

What about PM10? Venta seems work all the time, no matter good or bad outside, it can keep the index under 100 or lower, most of time, my bedroom PM10 is around 50, sometimes, after long time filter without opening the door, you can see single digit.

Setup a AQI(Air Quality Index) Monitoring System with Dylos and Raspberry Pi 2

I have been using air purifier for years in Beijing, China. So far so good except the only problem troubles me, is that effective? is my PM2.5 or PM10 reduced? the answer is probably obvious, but how effectively is it? Nobody knows.

At the morment, Dylos is the only manufacturer that provides consumer level product with accurate air quality index, so, not many choice. I got a Dylos air quality counter from Amazon, there are many products, if you want to export the index data from the black box into your desktop for later process , you'll need at least a DC 1100 pro with PC interface or higher version. Strongly not recommend buying from Taobao or the similar online stores, as far as I saw, None of them can provide the correct version, most of them exaggerate for a higher sale.

Now, half done. You need to Raspberry Pi, at the time of writing, Raspberry Pi 2 is coming to the market. I got a complete starter kit with a Pi 2 Model B, Clear Case, power supply, WiFi Dongle and a 8GB Micro SD.

In order to make the Raspberry Pi up, it's better to find a screen monitoring, or it will take huge pain to you.

After turning Dylos and Raspberry Pi on, the left process is quite simple. You need to connect the Dylos and Raspberry Pi with a serial to USB interface, the serial to USB cable is uncommon these days, if you are a network engineer, you should be quite familir with the cable, else, you can get one from online or somewhere else.

Now, write a tiny program to read the data from Dylos. You can make use of Python's pyserial module to read the data with a few lines. Here is mine. Besides that, you can use other language to implement, such as PHP. The interval depends on your Dylos collecting data interval, the minimum is 60s, ususally 3600s is enough.

Once got the data, you can feed them into different metric systems like Munin, or you can feed them into highcharts to get a more pretty look.

kindle Fire & kindle PaperWhite

12 年托我司 CTO 从 US 带了台 Kindle Fire 回来。用了两年了,实话说,体验不是很好,首先太重,其次太厚,最后归结起来就是拿在手里不舒服,尽管是一个深度定制过的 Android,我用到的功能寥寥无几,主要就是看书,其他什么照片电影包括各种 app 的安装我基本没碰过。在 Fire 上看过的书应该不超过 10 本,之前也妄想在上面看看专业方面的文档,后来发现完全行不通,连基本的高亮做笔记的功能都没有。
年初公司发了台 PaperWhite,虽然价格只有 Fire 的一半不到,但是使用起来却比 Fire 好的多。当年向 @HDWei 借个 Kindle 3 体验了个把月,除了翻页比较慢,需要配备一个外置的阅读灯之外,整体感觉还觉还是蛮爽的。现在 PaperWhite 修正了以上的缺点,内置的阅读灯晚上熄灯看书非常方便,机身比 3 也轻不少。没理由不喜欢它,推荐。