Negative Ions aka Anions

Negative Ions aka Anions

The best negative ion generators will list their ion output in the millions per second and specifically state that they don’t produce ozone (or under the safe 0.05 ppm CDC limit). If they don’t, then consider them suspect.

We are using computers more and more in our daily life. Unfortunately, they are strong emitters of harmful positive ions that can make us tired, tense and irritable.

Positive ions generated from your PC or laptop may even affect your respiratory and immune systems.

Seasonal Changes

The air is full of negative ions in springtime, and not in the winter


Columbia University studies of people with winter and chronic depression show that negative ion generators relieve depression as much as antidepressants.

Showering can be cure

Every home has a built in natural ionizer - the shower.

Further reading:

WooW! Dear Mark: What Are the Health Benefits of Negative Ions?

Dr. Oz’s Foolproof Fixes to Bust Your Bad Mood | The Dr. Oz Show

LightAir v2

Air ioniser - Wikipedia

Negative Ions Benefits For Your Health | Negative Ionizers

Negative Ion Light Bulb?

Air Quality

The Window is your true friend but trust it with wisdom. It actually doesn’t need to be open for a long time 10-20min per session, 3-4 times per day during winter. In summer I personally leave some windows always open.


Snake Plant (Sansevieria trifasciata) – See the Air Sanseverija (indijansko pero, svekrvin jezik)

Air Purifiers

Air Purifiers Comparison 2016Q2 – See the Air

Cvijeće | Najbolja biljka za spavaću sobu – svekrvin jezik

Homes and Houses: Do ionizing fans really work to purify the air? - Quora

Measuring Air Quality

Particle Counting Smart Air China

Foobot, Awair, AirMentor, Netatmo: exactly the same Sharp dust sensor

Volatile organic compounds (VOCs) are organic chemicals that have a high vapor pressure at ordinary room temperature. Their high vapor pressure results from a low boiling point, which causes large numbers of molecules to evaporate or sublimate from the liquid or solid form of the compound and enter the surrounding air, a trait known as volatility. For example, formaldehyde, which evaporates from paint, has a boiling point of only –19 °C (–2 °F).

Volatile Organic Compounds' Impact on Indoor Air Quality | Indoor Air Quality (IAQ) | US EPA

Air Quality Laser Sensonrs:

  • Sharp’s GP2Y1010AUOF dust sensor for real-time detection Are in essence identical GP2Y1010AU

  • Plantower PMS3003 Wifi Connected to internet? Build an air quality monitor |

Sensing the Air Quality: Research on Air Quality Sensors Air Quality Devices – Comparison 2016 Q1 – See the Air PM2.5 Device Comparison – See the Air

In-the-Air-Challenge:   Air Quality Sensor Box | element14 | In the Air Design Challenge

Temperature & Humidity Sensors

  • Sensirion (Swiss Company), models DHT11 (Temperature) and DHT22 (Humidity)

I have bought:

Vson Technology Co., Ltd. - Smart Cup,Wireless Laser Pointer for PPT

Air Quality Guide for Particle Pollution AQI Calculator: Concentration to AQI

Particle Pollution (PM) SEPA, državna mreža automatskih stanica za praćenje kvaliteta vazduha

When to open windows?

The only consistent high quality air window was from about 05 to 10 in the morning (AM).

Air Quality Tester Manual

Model: WP6910 Air Quality Tester


Standard display shows, top to bottom:

HCHO = Formaldehyde in mg/m3
PM2.5 = see below
TVOC = Total Volatile Organic Compounds = Gases (Benzene) in mg/m3

HCHO and TVOC are in mg/m3 So we must multiply with 1000 to get μg/m3, if needed. Example: 0.290 mg/m3 = 290 μg/m3 (x 1000)

What are PM?

On pressing Fn, it will display top to bottom: PM1 / PM2.5 / PM10, where PM1 is the smallest and most dangerous particles. See:

Good PM values are:

PM1   < 25 µg/m3,
PM2.5 < 25 µg/m3,
PM10  < 50 µg/m3

What is HCHO?

HCHO: Formaldehyde is a colorless, strong-smelling gas. It is used to make building materials and household products. Formaldehyde is used to make walls, cabinets, and furniture.

Smoking, pressed wood, and particle board have all been shown to be sources of formaldehyde.

Low risk (Good): 0.01 ppm = 0.0125 mg/m3
Mid risk  (Avg): 0.1 ppm = 0.125 mg/m3
High rish (Bad): 1 ppm = 1.25 mg/m3

If your reading falls into the intermediate range, your risk of irritation from formaldehyde exposure is lower, but it is still important to take steps to reduce your formaldehyde exposure.

To simplify: HCHO over 0.10 mg/m3 is bad. Over 0.30 mg/m3 is ALARM!

Conversion factors:

1 ppm = 1.25 mg/m3
1 mg/m3 = 0.8 ppm (at 20 °C and 1013 hPa)

What is TVOC?


HCHO/TVOC must be calibrated. On fresh air (outdoor) for around 10 minutes, and then press middle button for 3 seconds. HCHO outdoor is usually 0. PM must not be calibrated - it is laser particle counting.

date 01. Jan 0001 | modified 28. May 2021
filename: Health - Air Quality & Filter