Table of contents

Throughout day-to-day life, you might find that most meters you can buy out in the market usually only offer temperature and humidity functionality (we’re talking about relative humidity here), but there are some temperature hygrometers that not only can monitor the two points above… but can also help you check absolute humidity, dew point temperature, and VPD(Vapor-pressure Deficit). In this blog post, we’re gonna try to give a little bit more insight into the close relationship between these factors and the level of comfort we feel. And also try to answer a few questions: where can they be used? And what can we do to make our living environment more comfortable?

Absolute humidity helps prevent seasonal viruses!

So what exactly are relative humidity and absolute humidity?
Generally speaking, when we often refer to ‘humidity’, we refer to ‘relative humidity’, which is expressed as a percentage of the humidity level of the air (measured in %RH).
Relative humidity refers to the percentage of moisture content in the air. It tells us the degree of saturation of moisture in the air, such as a relative humidity of 50% indicating that the moisture in the air is only half that of saturated water vapor.
But when it comes to humidity, there is another important indicator: absolute humidity. Absolute humidity refers to the actual amount of water contained in a unit volume of air. It tells us how many grams of water are present in the air per cubic meter or kilogram. Written as the unit g/m³.

Relying solely on relative humidity is not enough to prevent viruses!

We use relative humidity to evaluate indoor comfort in our daily life, but for health fields that need accurate control of humidity parameters, such as the diagnosis and treatment of some respiratory diseases. You will find that although relative humidity maintained indoors in winter and summer is similar, viruses always spread more in winter, and tend to disappear in summer.
An article regarding absolute humidity shows that absolute humidity is more closely related to the survival of viruses and the spread of influenza, which is more in line with its impact on seasonal transmission.
In winter when the temperature is low, most of us tend to like using indoor heating, and in the summer it’s usually the air conditioning that is the first thing to be turned on, but what happens is, you can end up making already dry air even more severe. As a result, oral and respiratory mucosal systems become dry, leading to a decrease in your body’s defense functions. And when there is less water in the air, influenza viruses are given a longer time to live, which also increases our risk of seasonal colds and viruses in winter.
Research has shown that absolute humidity is at 7g/m³ when air is particularly dry. This makes it easier for influenza to spread. Therefore, using SwitchBot Meter/Meter Plus indoors to maintain an appropriate absolute humidity value of 11g/m ³~ 17g/m ³ is a great way to minimize the survival rate of viruses at home.

Dew point temperature: helping you look after cars and water supply pipelines alike.

What is Dew Point Temperature?
The temperature reached when air is cooled to saturation under the condition of unchanged water vapor content and pressure, known as dew point temperature, abbreviated as dew point, is expressed in degrees Celsius or Fahrenheit.
Simply put, it represents the temperature at which water vapor in the air begins to condense into water droplets (dewdrops, fog, clouds). This means, if you continuously reduce the temperature of the air and the relative humidity is 100%, the dew point temperature is the temperature at which you see the first dewdrop or fog appear.
When you wake up, you might find that due to a sudden drop in temperature and an increase in humidity, water vapor in the house and near windows will condense into liquid, mist appears in the garden, dew hangs on green plants, frost covers vehicles and pipes, and so on.
We can monitor the changes in dew point temperature by placing a SwitchBot Indoor/Outdoor Thermo-Hygrometer outside during winter. When the dew point temperature is close to or below freezing point (0 ° C, 32 ° F), and relative humidity is high, you may find issues with car windshields, engines, outdoor water supply pipes, or even frost. You can cover the surface of your vehicle with antifreeze cloth in advance; it also helps avoid dew residue on walls and attics (that might lead to mold growth, deterioration of building wood, and more).

VPD, also known as Vapor Pressure Deficit, assists you in improving the growth of green plants and crops in greenhouses.

What is VPD?
Yup, I know what you might be thinking… What on earth is VPD? Well, it is the difference between the actual water content in the air and the water content that the air can hold in a saturated state at a certain temperature. It refers to the drying ability of air on plants, and how much water the atmosphere absorbs from plants. Madness!
Greenhouse growers like to use relative humidity to measure the humidity level in greenhouses. Although it is also very useful for controlling humidity, VPD is needed to measure the relative loss of water in the air for driving physiological processes such as transpiration and photosynthesis of plants.
VPD affects the opening of plant stomata. For most plants, if VPD is too low (less than 0.5kPa), plants cannot perform transpiration, and water accumulates on the leaves, leading to slower growth rate and even other problems such as mold and fungi. If VPD is too high (above 1.5 kPa), plants evaporate too quickly, causing them to become too dry and experiencing symptoms such as leaf wilt, resulting in poor production.
As such, for most plants, a suitable VPD range is approximately 0.5-1.5 kPa (kPa), and different plants also have different comfortable VPD values. This allows us to increase air moisture (such as timely watering), dehumidify, and air circulation by observing and recording changes in VPD, in order to maintain the optimal VPD range, minimize greenhouse fluctuations, and make plant growth more efficient, Better growth conditions!

Why you need a SwitchBot Meter.

Based on the article above, if you are a plant grower or a home enthusiast who is concerned about weather changes, in addition to temperature and humidity: relative humidity, absolute humidity, dew point temperature, and VPD are also important things you’ll need to take into consideration when looking to make your living environment comfortable. To obtain more comprehensive environmental data, the following may be some of the reasons why you’ll want to own a SwitchBot Meter/Meter Plus…
  • Helps monitor temperature, humidity (relative humidity), absolute humidity, dew point temperature, and VPD.
  • Can be used for temperature and humidity push notification alerts. (when paired with a SwitchBot Hub Mini/Hub 2)
  • Multiple installation methods, can be placed anywhere.
  • Can connect with other SwitchBot products to create a host of different scenes to help.

How do I display absolute humidity, dew point temperature, and VPD on my Meter/Meter Plus/Outdoor Meter via your app?

Easy, just follow this…
First,update our app here.
*Absolute humidity, dew point temperature, and VPD data can only be viewed via our app.
Once updated, can switch to displaying absolute humidity from the home page.
Just enter Preferences to change!

A little summary.

In order to ensure that the environment we live in, as well as plants and precious items, can be properly taken care of, we must do more than just make judgments based solely on relative humidity and temperature. If you want to obtain a more comprehensive and detailed idea of the environment around you, you should consider using absolute humidity, dew point temperature, and VPD as factors when looking at living in comfort more effectively, and accurately!