Raspberry Pi Weather Station - part 4

In the last post I covered the hardware for the sensors.  In this post I want to talk about the software that ties this all together.  There are several goals with the software.  Obviously it needs to read the sensor data.  I would like it to output that data to a local web page so I can access it with a web browser.  I also want it to export the sensor data to a Personal Weather Station (PWS) account registered with WeatherUnderground.  And lastly, I would ideally like it to record or save the data to a database in case I want to analyze the data later on.

Doing searches on the Internet I quickly found WeeWX, an open-source project that does all of this.  It reads sensor data, generates a web page, and can optionally log to WeatherUnderground.  I was ready to go with this option, but then I discovered it was written in Python which gave me pause for concern (more on that later).

I next found wview which, like WeeWx, is an open-source weather station project.  It's written in C which is good, but it sounds like the project has grown rather large over the years.  It's become a huge behemoth that's capable of doing almost everything when all I want/need is a simple targeted application.

In the end I decided to write my own weather station application.  After all, isn't that was software engineers do, write software?  I wrote a small simple program that reads all the sensors and outputs the data in 3 different ways.

1. It generates a local HTML file which can be viewed from another computer using a web browser.  My code is not a web server, it just outputs an HTML file.  So you still need a web server such as Lighttpd or nginx.
2. It sends all sensor data off to WeatherUnderground so the results can be viewed on their web site.
3. The sensor data is written locally to a SQLite file for later analysis.

I wanted to go back and talk about my opposition to the use of Python in WeeWX.  The main problem is I do not consider Python to be a "real" programming language.  It is a scripting language, and scripting languages have their place.  But not in final applications in my opinion.  I also do not like the extreme performance hit Python incurs.  And remember, this is running on a Raspberry Pi which is not a powerful machine to begin with, so any unnecessary overhead is exaggerated.  How much of a performance hit are we talking about?  Using the sample Python code from Adafruit, reading the temperature sensor takes approximately 5 seconds.  Most of that overhead is spent loading the Python libraries and creating the runtime environment.  Compare that to the C++ code I wrote to read the temperature sensor which is instantaneous.  To me writing this application in C++ was not only the only way to go, but it was a fun project!


I have uploaded my C++ code to GitHub for anyone to download, use, or modify.  Bear in mind this code was written specifically for my weather station.  So it assumes the sensor hardware I'm using connected to the Raspberry Pi on the GPIO pins I'm using.  But this could be a great reference for anyone doing a similar project.

And finally, the results.  Here's a link to my PWS on WeatherUnderground.

Raspberry Pi Weather Station - part 3

Next I wanted to talk about the hardware for the sensors my weather station will employ and how each sensor is wired to the Pi's GPIO pins.

BME280
As I previously said the BME280 can be access via either SPI or I2C.  I decided to use I2C.  In order to wire to the Pi you will need to connect 4 wires.  The first is the power wire which connects to the 3.3V pins on the Pi.  The second is ground which connects to one of the ground wires on the Pi.  And lastly are the two I2C data lines which get connected to the I2C pins on the Pi.  Wiring this sensor up is not hard, it just requires a little bit of soldering and time.

The rain, wind speed, and wind direction sensors were a single package and clearly not designed specifically for the Pi.  The output wires have RJ11 connectors (telephone connectors) on the end of them.  I believe they were originally designed to plug into a specific weather module that reads the sensors.  Since I am using the Raspberry Pi as my homemade weather module, I will need to modify each sensor.

Rain Gauge
The rain gauge is an interesting sensor.  It literally has two buckets side by side.  When one side fills with water it gets too heavy and tips over.  The other side then fills up and eventually tips back.  Each time this bucket tips over a magnet passes by a reed switch.  This causes a momentary close in the switch which can be detected by the Raspberry Pi.  This only requires 2 wires, power in and the signal detect line coming out.  For power in I used the same 3.3V pin as the BME280 sensor, and for the signal wire I picked any available GPIO pin.

Wind Speed
For wind speed there are 3 cups that are free to spin as the wind hits them.  Each time it spins another magnet passes by a read switch.  As with the rain, the Pi can detect these events and use that to calculate the wind speed.  Again, only 2 wires are necessary, one for power (the same 3.3V pin) and a signal detect line which is any available GPIO pin.

Wind Direction
The wind direction sensor works using magnetic reed switches, but unlike the previous sensors it contains 8 reed switches.  Each reed switch corresponds to a direction; N, NE, E, SE, S, SW, W, and NW.  As the magnet moves around according to wind direction it closes different switches which allows you to determine direction.  To complicate matters, it is possible for the magnet to close two neighboring switches at the same time.  This gives you a total of 16 possible bearings.

Reading the wind direction was by far the hardest.  The problem is the wind direction sensor is designed to be read using analog and only has 2 wires, power in and signal out.  So if you apply 5V in then the output voltage will be one of 16 different values between 0 and 5V.  The Raspberry Pi however cannot read analog values, it only reads digital signals.  One possible solution is to use an analog to digital converter which requires additional hardware.  But there is a cheaper way, hard wire the 8 reed switches directly to the Pi.  To do this I had to open the wind direction sensor and remove the circuit board.  On this circuit board are 8 small surface mount resistors which had to be desolder.  In their place I soldered 8 wires, one for each switch.  Lately I soldered a power wire to the outside ring which ties all reed switches together.  This allows me to provide power in (again, 3.3V) and read each sensor one at a time using the 8 signal wires I attached to available GPIO pins.  This required a lot soldering on a small circuit board, but the end result is a digital wind direction sensor that was originally designed to be analog.

Raspberry Pi Weather Station - part 2

Continuing this project, in this post I will talk about preparing the Raspberry Pi to become a weather station.  I won't go into the details about installing Raspbian onto the SD card or using raspi-config to set the time zone and locale info for your system.  You can read my previous Pi posts for those details.

For this project the Raspbian group has released something new - a "lite" version of Raspbian.  This is perfect, I can get a clean bare bones Pi right out of the box.  Getting wifi setup on the Pi zero is a little more complicated because there is no ethernet port.  So it's a multi-step process.  First you must use a keyboard and monitor and manually edit the /etc/wpa_supplicant/wpa_supplicant.conf file to add info for your wifi network.  Then power down the Pi, remove the keyboard and monitor, attach the wifi adapter, then power up the Pi and connect via SSH.  This is where I ran into my first problem.  The RNX-N180UBE I've used in the past and ordered for this project did not work.  I quickly discovered Rosewill is now making "version 2" of the adapter which uses a different chipset and Linux does not have drivers for this adapter.  After much searching I found this forum post with details on where to download drivers specific to the type or Raspberry Pi and version of Raspbian you are running.

For the BME280 sensor I bought, it can be accessed via SPI or I2C.  The Pi supports both, but is one better than the other?  From what I can tell, SPI is a faster connection, but I2C is a better designed interface with more control.  Since reading this sensor won't involve large amounts of data, I decided to go with I2C.  But in order for this to work you need to enable the I2C bus inside of raspi-config.

Another step was to solder in the header to the Pi Zero.  This isn't hard, and in fact it's kind of fun.  But if your soldering skills are lacking then save yourself the trouble and use a Pi 1, 2, or 3.

Raspberry Pi Weather Station - part 1

My latest Raspberry Pi project is a home weather station.  My original goal was a have a useful set of sensors connected to the Pi, and to make the results accessible over the Internet.  That said, this process took several twists and turns along the way, probably because there are fewer people out there doing this type of project than say my previous projects of a homemade DVR or home theater.  This project, unlike my previous Pi projects, is less a step-by-step guide.  This is for several reasons.  First, this project morphed and changed several times so it was harder for me to document as I went.  And secondly, I had less free time to work on it, so I gave up on documenting while I worked.

When I decided to make a homemade weather station, I wanted to do as much "homemade" as possible.  So all my sensors are connected to the Raspberry Pi's GPIO pins.  The more common solution for people is to buy an off-the-shelf weather station and connect that to the Raspberry Pi's USB port.  I purchased all the hardware necessary for this project (more on that later) before I even knew how it would fit together.  I just had faith it was possible to do what I wanted to do.  The major missing link was the software.  I did not know how to read the sensors and display it meaningfully.  And it was researching the software solutions available is where this project deviated from my initial thoughts.  But I'll get into all that in a future post.  First let's look at the hardware I used.

Raspberry Pi Zero:

For this project I went with the new Raspberry Pi Zero.  Any Pi would do, but I chose the Pi Zero for several reasons.

1. The smaller size, so the weatherproof enclosure doesn't need to be as large.
2. The extremely low-power consumption.  As a weather station this won't need the processing power of the Pi 2/3, so save on electricity use.
3. It's new and cool.  I've worked with the original Pi and the Pi 2, so this was something new to try.

However, working with the Pi Zero did have several drawbacks.  First and foremost was obtaining the Pi itself.  Pi Zero's are in VERY short supply and hard to get.  It took 2 weeks of waiting for Adafruit to get a shipment in before I could order one.  And even then, they only sold the Pi Zero in a "kit" with other things I didn't need like power supply, memory card, USB adapters, etc.  Another issue with the Pi Zero is you have to manually solder the header connector onto the Pi.  I like soldering so this was no problem for me, but others might find the regular Pi models more appealing since the GPIO pin headers are soldered on at the factory.

Temperature / Humidity / Pressure
For basic atmospheric measurements I went with the Adafruit BME280.  This sensor measures temperature, humidity, and pressure.

Wind / Rain
For the final set of sensors I went with the SparkFun weather sensors.  These sensors measure wind speed, wind direction, and rainfall.  But at $77 they are by far the most expensive item in this build.

Miscellaneous
To complete the project I needed a bunch of smaller items.  I bought a Samsung Pro micro SD card because it's one the fastest cards available and I've had good luck with them in the past.  For wireless I went with the Rosewill RNX-N180UBE.  For power I selected an Anker wall charger (I selected a dual-port model because this single charger will power a couple of my Raspberry Pi's) as well as a 10' long Anker power cord.  Lastly I purchased a waterproof electrical case at Home Depot originally designed for running conduit outside, but houses the Pi nicely and has openings on the bottom where I can run wires into the housing.

Programming Languages

As a computer programmer the language I prefer to program in is obviously an important subject.  In my opinion C/C++ is the best all-around programming language.  When I was learning to program in the mid '90s, C/C++ was the undeniable king of programming languages.  However, in the time since then I feel like the industry has moved away from C/C++ to the point where some developers consider me to be a "dinosaur" for using such an old language.  But I don't think I'm a dinosaur, so I wanted to talk about languages in general and defend my preferences.

There are literally hundreds if not thousands of programming languages.  If you're learning programming for the first time or if you're starting a new project, how do you know which language to select?  Programming languages breakdown into 4 categories; 1 low-level category and 3 high-level categories.

Assembly:
Assembly is the only low-level language where the developer writes code targeted at a specific hardware platform.  Whereas hand-written assembly can be used for general purpose programming, it's very difficult to manage and nowadays assembly is mostly reserved for very specific cases, typically firmware and embedded programming systems.

Native Machine Languages:
Native machine languages are high-level languages that are compiled to target a specific platform.  That is to say, if your code will run on different platforms you must compile your code once for each platform it will run on.  This category includes languages like C/C++, Pascal, Fortran, Cobol, and Ada.

Virtual Machine Languages:
Virtual machine languages are similar to native in that they are compiled.  But the output is not hardware or platform specific.  Instead the output is "virtual" machine code that must be converted at runtime to the native machine code for the platform where your code is running.  The benefit is the developer compiles once and releases a single binary, but it can run on multiple platforms.  This category includes Java and C#.

Interpreted Languages:
Interpreted languages (often times called scripted languages) are not compiled.  Instead at runtime a program called the interpreter converts the code from human-readable to machine code.  Interpreted languages have the benefit of not needing the slow compilation process and can be quickly changed or tweaked.  This category includes Python, Perl, PHP, Javascript, Ruby, and many more.


So how do you pick a language?  What is the best programming language?  Well, the answer is the right tool for the right job.  All languages have pros and cons, so picking the best language requires an understanding of those.

Skipping assembly, because it's not really general purpose in today's world, let's talk about interpreted languages first.  I might take a lot of flak for this, but I don't consider interpreted languages to have much use outside of academia.  Interpreted languages are perfect for learning the basics of programming.  Because these languages don't require the developer to think about things like variable types, memory management, strings, etc. they allow the person to focus on learning the basics of programming.  After all, pilots don't fly a 747 as their first plane, they start on small propeller planes.  To me the only use for interpreted languages is when used as a scripting language to speed up tasks and eliminate human errors.  For example, say an IT person needs to create a new user account, add a machine to the domain, and assign that user to the machine.  This is a perfect task for a scripting language.

But languages like Javascript, Python, PHP, and Ruby are some of the most popular programming languages, so what's wrong with these languages?  The problem is speed and efficiency, or lack thereof.  Because these languages are interpreted at runtime there are significantly slower than other languages.  A recent comparison found these languages can be as much as 400x slower than a natively compiled program.  Probably a good rule of thumb is expect between 10x and 100x slower performance compared to natively programs.  That is a huge price to pay.  I'm dumbfounded that so many server applications are running in languages like Javascript.  That's like entering a car race with a bus.


Ok, so that leaves us natively and virtually compiled programs.  Here too native programs have the performance advantage, although it's much less pronounced.  A recent study found that on average C/C++ outperforms Java/C# by 20%.  On the flip side, Java/C# can be faster and easier to develop in compared to C/C++.  For many software companies, their highest cost is developers' salaries.  So picking Java or C# may result in quicker development times which results in lower development costs.  This all assumes your application is not performance critical (which most client/desktop applications aren't).

However, there is another side to the equation which developers rarely consider.  If your application runs on the server side, that extra 20% performance increase by going with C/C++ translates directly into 20% less electricity used by the servers.  It also means less electricity for cooling the server room which saves even more money.  When you start talking about applications that run on servers, suddenly the hardware for those servers, electricity used to run those servers, and the cooling costs for the servers outweighs development costs.  So in cases like this a native language is probably your best choice.

There is another benefit to native languages - extended battery life.  In that same study above, they found that C/C++ programs ran for approx. 20% longer on a given battery charge compared Java/C#.  So anyone developing applications that will run on a laptop, tablet, or phone should seriously consider a native language.

It is true that C/C++ is not the king it once was.  However, when you group C/C++ together it's still the number 1 programming language ahead of Java.  Also, any programming field where you need performance (e.g. video games) then C/C++ is the language of choice.  Yet another example is operating systems.  Every major operating system in existence is written in C - which includes Windows, Linux, Mac, Unix.  Even "mobile" operating systems like Android are built on top of Linux which is written in C.

So without a doubt C/C++ has a place in the modern world.  I think it's unfortunate that so many developers have gotten caught up in the virtual and interpreted language hype and forgotten about the power of a native programming language.  That said, recently there has been a resurgence in native programming languages driven largely by mobile devices with their relatively low resources and battery power, they are the perfect platform for a native programming language.

Free Windows License Keys

In this post I wanted to give away dozens of Windows license keys for free!  No, this isn't illegal.  These are perfectly legitimate keys and they are free to use.  The catch is, these keys cannot be used to activate Windows. These keys can be used to install Windows, and once installed you'll get between 3 and 30 days of free use depending on the version of Windows (more if you "rearm" Windows).

All of these keys came from Microsoft directly.  They give these keys away.  The problem is, there is no master list you can easily download and reference.  So I've taken the time to gather all these keys into one place for you to use.

There are two types of keys in this list; Generic Volume License Keys (GVLK) and Retail Installation Keys (RIK).  The difference is GVLK keys must be used for "volume license" versions of Windows and RIK are used for regular versions of Windows.  If you don't know which one to use, then you need retail (RIK).  Chances are anyone using volume license versions of Windows knows it because you have to pay a lot more and have a special contract to have and use that version of Windows.

In order to use one of these keys you must exactly match the key below with the version of Windows you're trying to install.  So from the list below, Windows 7 Professional N (Volume) will only work on the N edition of Windows 7 Professional volume license version.  Architecture (x86 or x64) and language do not matter, these keys work on all architectures and languages.


Windows Vista
Windows Vista Starter (Retail)
X9PYV-YBQRV-9BXWV-TQDMK-QDWK4

Windows Vista Starter N (Retail)
X9PYV-YBQRV-9BXWV-TQDMK-QDWK4

Windows Vista Home Basic (Retail)
RCG7P-TX42D-HM8FM-TCFCW-3V4VD

Windows Vista Home Basic K (Retail)
RCG7P-TX42D-HM8FM-TCFCW-3V4VD

Windows Vista Home Basic N (Retail)
HY2VV-XC6FF-MD6WV-FPYBQ-GFJBT

Windows Vista Home Basic KN (Retail)
HY2VV-XC6FF-MD6WV-FPYBQ-GFJBT

Windows Vista Home Premium (Retail)
X9HTF-MKJQQ-XK376-TJ7T4-76PKF

Windows Vista Home Premium K (Retail)
X9HTF-MKJQQ-XK376-TJ7T4-76PKF

Windows Vista Home Premium N (Retail)
KJ6TP-PF9W2-23T3Q-XTV7M-PXDT2

Windows Vista Home Premium KN (Retail)
KJ6TP-PF9W2-23T3Q-XTV7M-PXDT2

Windows Vista Business (Retail)
4D2XH-PRBMM-8Q22B-K8BM3-MRW4W

Windows Vista Business (Volume)
YFKBB-PQJJV-G996G-VWGXY-2V3X8

Windows Vista Business K (Retail)
4D2XH-PRBMM-8Q22B-K8BM3-MRW4W

Windows Vista Business K (Volume)
YFKBB-PQJJV-G996G-VWGXY-2V3X8

Windows Vista Business N (Retail)
76884-QXFY2-6Q2WX-2QTQ8-QXX44

Windows Vista Business N (Volume)
HMBQG-8H2RH-C77VX-27R82-VMQBT

Windows Vista Business KN (Retail)
76884-QXFY2-6Q2WX-2QTQ8-QXX44

Windows Vista Business KN (Volume)
HMBQG-8H2RH-C77VX-27R82-VMQBT

Windows Vista Enterprise (Volume)
VKK3X-68KWM-X2YGT-QR4M6-4BWMV

Windows Vista Enterprise N (Volume)
VTC42-BM838-43QHV-84HX6-XJXKV

Windows Vista Ultimate (Retail)
VMCB9-FDRV6-6CDQM-RV23K-RP8F7

Windows Vista Ultimate K (Retail)
VMCB9-FDRV6-6CDQM-RV23K-RP8F7

Windows Vista Ultimate N (Retail)
CVX38-P27B4-2X8BT-RXD4J-V7CKX

Windows Vista Ultimate KN (Retail)
CVX38-P27B4-2X8BT-RXD4J-V7CKX

Windows 7
Windows 7 Starter (Retail)
7Q28W-FT9PC-CMMYT-WHMY2-89M6G

Windows 7 Starter K (Retail)
7Q28W-FT9PC-CMMYT-WHMY2-89M6G

Windows 7 Starter N (Retail)
D4C3G-38HGY-HGQCV-QCWR8-97FFR

Windows 7 Starter KN (Retail)
D4C3G-38HGY-HGQCV-QCWR8-97FFR

Windows 7 Home Basic (Retail)
YGFVB-QTFXQ-3H233-PTWTJ-YRYRV

Windows 7 Home Basic K (Retail)
YGFVB-QTFXQ-3H233-PTWTJ-YRYRV

Windows 7 Home Basic N (Retail)
MD83G-H98CG-DXPYQ-Q8GCR-HM8X2

Windows 7 Home Basic KN (Retail)
MD83G-H98CG-DXPYQ-Q8GCR-HM8X2

Windows 7 Home Premium (Retail)
RHPQ2-RMFJH-74XYM-BH4JX-XM76F

Windows 7 Home Premium K (Retail)
RHPQ2-RMFJH-74XYM-BH4JX-XM76F

Windows 7 Home Premium N (Retail)
D3PVQ-V7M4J-9Q9K3-GG4K3-F99JM

Windows 7 Home Premium KN (Retail)
D3PVQ-V7M4J-9Q9K3-GG4K3-F99JM

Windows 7 Professional (Retail)
HYF8J-CVRMY-CM74G-RPHKF-PW487

Windows 7 Professional (Volume)
FJ82H-XT6CR-J8D7P-XQJJ2-GPDD4

Windows 7 Professional K (Retail)
HYF8J-CVRMY-CM74G-RPHKF-PW487

Windows 7 Professional K (Volume)
FJ82H-XT6CR-J8D7P-XQJJ2-GPDD4

Windows 7 Professional N (Retail)
BKFRB-RTCT3-9HW44-FX3X8-M48M6

Windows 7 Professional N (Volume)
MRPKT-YTG23-K7D7T-X2JMM-QY7MG

Windows 7 Professional KN (Retail)
BKFRB-RTCT3-9HW44-FX3X8-M48M6

Windows 7 Professional KN (Volume)
MRPKT-YTG23-K7D7T-X2JMM-QY7MG

Windows 7 Enterprise (Retail)
H7X92-3VPBB-Q799D-Y6JJ3-86WC6

Windows 7 Enterprise (Volume)
33PXH-7Y6KF-2VJC9-XBBR8-HVTHH

Windows 7 Enterprise N (Retail)
BQ4TH-BWRRY-424Y9-7PQX2-B4WBD

Windows 7 Enterprise N (Volume)
YDRBP-3D83W-TY26F-D46B2-XCKRJ

Windows 7 Enterprise KN (Retail)
BQ4TH-BWRRY-424Y9-7PQX2-B4WBD

Windows 7 Enterprise KN (Volume)
YDRBP-3D83W-TY26F-D46B2-XCKRJ

Windows 7 Ultimate (Retail)
D4F6K-QK3RD-TMVMJ-BBMRX-3MBMV

Windows 7 Ultimate K (Retail)
D4F6K-QK3RD-TMVMJ-BBMRX-3MBMV

Windows 7 Ultimate N (Retail)
HTJK6-DXX8T-TVCR6-KDG67-97J8Q

Windows 7 Ultimate KN (Retail)
HTJK6-DXX8T-TVCR6-KDG67-97J8Q

Windows 8
Windows 8 (Retail)
FB4WR-32NVD-4RW79-XQFWH-CYQG3

Windows 8 N (Retail)
VDKYM-JNKJ7-DC4X9-BT3QR-JHRDC

Windows 8 Professional (Retail)
XKY4K-2NRWR-8F6P2-448RF-CRYQH

Windows 8 Professional (Volume)
NG4HW-VH26C-733KW-K6F98-J8CK4

Windows 8 Professional N (Retail)
BHHD4-FKNK8-89X83-HTGM4-3C73G

Windows 8 Professional N (Volume)
XCVCF-2NXM9-723PB-MHCB7-2RYQQ

Windows 8 Enterprise (Volume)
32JNW-9KQ84-P47T8-D8GGY-CWCK7
8M9BN-YB7W9-YV3­VJ-7WMGG-MKH3V

Windows 8 Enterprise N (Volume)
JMNMF-RHW7P-DMY6X-RF3DR-X2BQT
NCVKH-RB9D4-R86X8-GB8WG-4M2K6

Windows 8.1
Windows 8.1 (Retail)
334NH-RXG76-64THK-C7CKG-D3VPT

Windows 8.1 N (Retail)
6NPQ8-PK64X-W4WMM-MF84V-RGB89

Windows 8.1 Professional (Retail)
XHQ8N-C3MCJ-RQXB6-WCHYG-C9WKB

Windows 8.1 Professional (Volume)
GCRJD-8NW9H-F2CDX-CCM8D-9D6T9

Windows 8.1 Professional N (Retail)
JRBBN-4Q997-H4RM2-H3B7W-Q68KC

Windows 8.1 Professional N (Volume)
HMCNV-VVBFX-7HMBH-CTY9B-B4FXY

Windows 8.1 Enterprise (Volume)
MHF9N-XY6XB-WVXMC-BTDCT-MKKG7
FHQNR-XYXYC-8PMHT-TV4PH-DRQ3H

Windows 8.1 Enterprise N (Volume)
TT4HM-HN7YT-62K67-RGRQJ-JFFXW
NDRDJ-3YBP2-8WTKD-CK7VB-HT8KW

Windows 10
Windows 10 Home (Retail)
YTMG3-N6DKC-DKB77-7M9GH-8HVX7

Windows 10 Home N (Retail)
4CPRK-NM3K3-X6XXQ-RXX86-WXCHW

Windows 10 Home KN (Retail)
4CPRK-NM3K3-X6XXQ-RXX86-WXCHW

Windows 10 Professional (Retail)
VK7JG-NPHTM-C97JM-9MPGT-3V66T

Windows 10 Professional (Volume)
W269N-WFGWX-YVC9B-4J6C9-T83GX

Windows 10 Professional N (Retail)
2B87N-8KFHP-DKV6R-Y2C8J-PKCKT

Windows 10 Professional N (Volume)
MH37W-N47XK-V7XM9-C7227-GCQG9

Windows 10 Professional KN (Retail)
2B87N-8KFHP-DKV6R-Y2C8J-PKCKT

Windows 10 Professional KN (Volume)
MH37W-N47XK-V7XM9-C7227-GCQG9

Windows 10 Enterprise (Volume)
NPPR9-FWDCX-D2C8J-H872K-2YT43
XGVPP-NMH47-7TTHJ-W3FW7-8HV2C

Windows 10 Enterprise N (Volume)
DPH2V-TTNVB-4X9Q3-TJR4H-KHJW4
WGGHN-J84D6-QYCPR-T7PJ7-X766F

Windows 10 Enterprise KN (Volume)
DPH2V-TTNVB-4X9Q3-TJR4H-KHJW4
WGGHN-J84D6-QYCPR-T7PJ7-X766F

Windows 10 Enterprise 2015 LTSB (Volume)
WNMTR-4C88C-JK8YV-HQ7T2-76DF9
FWN7H-PF93Q-4GGP8-M8RF3-MDWWW

Windows 10 Enterprise 2015 LTSB N (Volume)
2F77B-TNFGY-69QQF-B8YKP-D69TJ

Windows 10 Enterprise 2015 LTSB KN (Volume)
2F77B-TNFGY-69QQF-B8YKP-D69TJ

Windows 10 Education (Retail)
YNMGQ-8RYV3-4PGQ3-C8XTP-7CFBY

Windows 10 Education (Volume)
NW6C2-QMPVW-D7KKK-3GKT6-VCFB2

Windows 10 Education N (Retail)
84NGF-MHBT6-FXBX8-QWJK7-DRR8H

Windows 10 Education N (Volume)
2WH4N-8QGBV-H22JP-CT43Q-MDWWJ

Windows 10 Education KN (Retail)
84NGF-MHBT6-FXBX8-QWJK7-DRR8H

Windows 10 Education KN (Volume)
2WH4N-8QGBV-H22JP-CT43Q-MDWWJ

Server 2008
Windows Server 2008 Standard (Volume)
TM24T-X9RMF-VWXK6-X8JC9-BFGM2

Windows Server 2008 Standard Core (Volume)
TM24T-X9RMF-VWXK6-X8JC9-BFGM2

Windows Server 2008 Standard without Hyper-V (Volume)
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Server 2012
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Server 2012 R2
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Microsoft Hyper-V Server 2012 R2 (Retail)
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Your hot water heater is set too high!

Based on my experience visiting other people's homes and businesses, most people have their hot water heaters set too high.  What's surprising, if you suggest that they consider turning down the temperature often times they get defensive.  I think people consider hot clean water to be a luxury item and so to turn it down is like losing a part of their status or livelihood.  So I hope to approach this logically and convince you it's worth turning it down.

Let's start off by looking at all the uses of hot water in your home.  Hot water is piped to two appliances, the dishwasher and the clothes washer.  It also goes to showers, baths, and sinks.  That's it.  All other places in the home with water (refrigerators, toilets, and all external hose bibs) are cold only.  So let's look at each of these places hot water is used an evaluate if we truly need scalding hot water.

Dishwasher
The dishwasher is the easiest one to analyze, because it doesn't need hot water to work.  All modern dishwasher have a built-in heater (the same one that heats up to dry off the dishes).  This heater is turned on during the wash cycle to heat the water even more.  So even if your dishwasher were connected to cold water it would wash just as effectively because it heats the water up internally.

Laundry
Many of us have been told for years to wash whites in hot water, certain clothes in warm, and dark colors in cold water.  But these are old outdated methods.  Modern efficient machines with modern laundry soaps wash almost all clothes great in cold water.  There are very few clothes that need to be washed in warm or hot water.  In fact, hot/warm water may actually cause more harm than good.  Modern soaps use enzymes that are active between 60°F (16°C) and 75°F (24°C).  Beyond that and the enzymes are less effective, and you're more likely to "set" in stains and damage fabrics.  So hot or warm should only be used on special garments with special soaps.

Showers/tubs
When you take a shower or a bath, I doubt you'll do so using 100% hot water.  Most likely you'd scald yourself.  So you mix hot and cold to get the desired temperature.  This means you could lower your hot water heater without having to take a colder shower.  I would argue the ideal hot water heater temperature is when your shower/bath is nearly 100% hot water to still get the temperature you'd like.  Anything more means you're just overheating the water.

Sinks
The primary reason people want hot water at the sink is to washing things; e.g. their hands, dishes, the floors, etc.  Hot water helps kill germs and bacteria, right?  Technically yes, but in practice no.  The water temperature and time at that temperature required to kill germs and bacteria would instantly scald and burn you!  If you've ever gone backpacking you know the rule is to boil the water for 5 minutes to kill anything in the water.  The hot water coming out of your sink is well below the temperature required to kill anything, all you're going to do is burn yourself and not kill anything.  That's what soap is for.


So hopefully I've convinced you that your hot water heater can be turned down.  But how far, what temperature do you set it to?  Few hot water heaters have an actual thermostat, most just have a high-low adjustment.  Instead the way to adjust your hot water is to go to the sink farthest from the hot water heater and turn on hot water.  Let the water flow over a thermometer.  You want the water coming out of the tap to be 120°F (49°C).  This is the industry recommended temperature to be hot enough for things like showers, but not so hot as to burn you.  If you adjust your hot water heater down then obviously you need to wait hours/days before retesting.

When I made these changes to my hot water I was shocked.  My hot water heater has an off position, vacation mode (to keep the water from freezing), and then a slider from low to high.  To achieve 120°F (49°C) at the sink I ended up setting my hot water heater to the lowest possible setting above vacation mode.  Not everyone's hot water heater will be the same, mine is only a few years old and it's a super efficient one.  You probably won't be able to go as low as I can, but I have no doubt you could lower yours with no side effects.

Lastly, let's talk about the benefits of making this change.  You'll save money, a decent amount too.  Heating water takes a lot of energy, so if you lower the temperature you'll save money pure and simple.  Between lower gas/electricity costs and using less hot water for laundry you'll probably save at least $100 per year.  You'll also extend the life of your hot water heater.  Most hot water heaters need to be replaced because of deposits that build up inside of them.  So turning down the temperature extends the life of your hot water heater, which also saves you money.  And lastly you reduce the chances of accidental burns from hot water - an even bigger concern if you have children in your home.


Hopefully reading this has encouraged you to evaluate your hot water heater.  If nothing else, put a thermometer in the sink and turn on hot water to test and see what your current hot water is coming out at.  You might be surprised!