Heating any medium, such as water or air, causes it to expand and become lighter. Conversely, cooling causes it to shrink and become heavier. The combination of these multidirectional physical influences forms a phenomenon called convection, which is one of the processes of heat transfer in large volumes of liquids and gases.

When a container of water is placed over a burning burner, the water above the flame absorbs energy. This energy causes water molecules to move away from each other, causing it to become less dense. Heated water rises; in the drawing, the gray paint on the bottom of the vessel makes this movement visible. At the same time, colder, denser water sinks down to take the place of the warmer water that has risen. As warm water rises, it gives up some of its energy to the surrounding water and cools slightly. Meanwhile, warmer water continues to rise, pushing layers of cooled water aside. Convection will stop only when the flame goes out and all the water reaches the same temperature.

Convection when heat is supplied

Heating the bottom of the test tube increases the temperature of the lower layers of water. As a result, warm water rises, and heavier water cold water goes down and also heats up. Over time, all the water becomes hot. Heating the upper part of the test tube leads to an increase in the temperature of only the upper layers of water, since the lighter hot water stays over cold.

Convective movement of water

Rising from the bottom of a vessel standing on a fire, the heated water gradually loses heat. Once on the surface, this water spreads outward under the influence of a rising column of warmer water. As the water cools, it becomes denser and sinks.

Convection in a gas environment

Streams of smoke make it possible to trace the formation of convective currents in the air of the room (pictures above). The process begins with warm air rising upward (left picture). Having reached the ceiling (middle picture), this air diverges to the sides under the influence of rising warmer air jets, after which, having lost heat, it sinks down to the floor and, under the influence of jets of cooled air descending from above (picture on the right), again moves to the source of heat, heats up and rises up.

Heating and cooling the air in a room

An air conditioner cools a room most effectively when placed near the ceiling (top picture below text), as the cooled air (blue in the picture) sinks down and then spreads throughout the room by convection. Conversely, the air heater works best when placed near the floor (bottom picture). Warm air (orange in the picture) rises and then circulates throughout the room.

AIR .

WHERE IT'S WARMER.

Target. Reveal that warm air is lighter than cold air and rises.

Game material. Two thermometers, a kettle with hot water.

Progress of the game. Children find out if the room is cool, where it is warmer - on the floor or on the sofa, that is, higher or lower, and compare their guesses with the readings of thermometers. Children perform the following actions: hold their hand above or below the battery; without touching the kettle, keep your hand above the water. They find out with the help of actions where the air is warmer: from above or from below (everything that is lighter rises upward, which means warm air is lighter than cold air and warmer from above).

WIND IN THE ROOM (“LIVE SNAKE”)

Target. Find out how wind is formed, that wind is a flow of air, that hot air rises up and cold air falls down.

Game material. Two candles, a “snake” (a circle cut in a spiral and suspended on a thread).

Progress of the game. An adult lights a candle and blows on it. Children find out why the flame is deflected (by the air flow). An adult suggests examining the “snake”, its spiral design, and demonstrates to the children the rotation of the “snake” above the candle (the air above the candle is warmer, the “snake” rotates above it, but does not go down, because warm air lifts it up). Children find out that the air makes the “snake” rotate, and with the help of heating devices they perform the experiment independently

An adult invites children to determine the direction of wind movement from above and below the doorway. Children explain why the direction of the wind is different (warm air in the apartment rises and leaves through the gap at the top, and cold air is heavier, and it enters the room from below; after a while, the cold air will heat up in the room, rise up and go out into the street through the gap at the top, and cold air will come in its place again and again). This is how wind arises in nature. Draw the results of the experiment.

SUBMARINE.

Target. Find out that air is lighter than water; identify how air displaces water, how air leaves water.

Game material. curved cocktail tube, plastic glasses, container with water.

Progress of the game. Children find out what will happen to a glass if it is lowered into water, whether it can rise from the bottom on its own. They perform the following actions: immerse a glass in water, turn it upside down, place a curved tube under it, and blow air under it. At the end of the experiment, conclusions are drawn: the glass is gradually filled with water, air bubbles come out of it; air is lighter than water - when it enters a glass through a tube, it displaces water from under the glass and rises up, pushing the glass out of the water.

STUBMARY AIR (1)

Target. Discover that air, when compressed, takes up less space; Compressed air has the power to move objects.

Game material. Syringes, container with water (tinted).

Progress of the game. Children look at the syringe, it

device (cylinder, piston) and demonstrate actions with it: press the piston up, down without water; try to squeeze the piston when the hole is closed with your finger; draw water into the piston when it is at the top and bottom. The adult invites the children to explain the results of the experiment and talk about their feelings when performing the actions. At the end of the experiment, children find out that air takes up less space when compressed; compressed air has a force that can move objects.

STUBBORN AIR (2)

Target. Find that air takes up less space when compressed. Compressed air has the power to move objects.

Game material. Pipettes, container with water (tinted).

Progress of the game. Children examine the device of the pipette (rubber cap, glass cylinder) and carry out the experiment in the same way as the previous one (squeeze and unclench the cap).

DRY OUT OF WATER

(Option 1 – Napkin in a glass)

Target.

Game material. A container of water, a glass with a napkin attached to the bottom.

Progress of the game. The adult invites the children to explain what it means to “get away with it”, whether this is possible, and to find out whether it is possible to lower the glass into the water and not wet the napkin lying at the bottom. Children make sure that the napkin at the bottom of the glass is dry. Then they turn the glass upside down, carefully immerse it in water, without tilting the glass to the very bottom of the container, actually lift it out of the water, and allow the water to drain without turning the glass over. The adult offers to determine whether the napkin is wet (not wet), explain what prevented the water from wetting it (air in the glass) and what will happen to the napkin if the glass is tilted (air bubbles will come out, and water will take its place, the napkin will get wet). Children repeat the experience on their own.

DRY FROM WATER.

(Option 2 – Flag on a block)

Target. Determine what air is taking up space.

Game material. A container with water, wooden blocks with flags, jars (the block with the flag should fit freely into them).

Progress of the game. An adult invites the children to lower the block into the water and watch it float. They find out why it doesn’t sink (wood is lighter than water), how you can drown it (lower it to the bottom), and not get it wet (put it in water, covering it with a jar). Children perform actions independently. They discuss why the block did not get wet (because there is air in the jar).

WHAT'S FASTER?

Target.

Game material. Two sheets of writing paper.

Progress of the game. An adult asks you to think about it: if you simultaneously release two sheets of paper from your hands: one horizontally, the other vertically (shows how to hold it in your hands), which one will fall faster. He listens to the answers and offers to check. He demonstrates his experience. Why does the first leaf fall slowly, what delays it (air presses on it from below). Why does the second sheet fall faster (it falls edge-on, and therefore there is less air under it). Children conclude: there is air around us, and it presses on all objects (this is atmospheric pressure).

FOCUS “WHY DOESN’T IT LEAVE?”

Target. Detect atmospheric pressure.

Game material. Glasses of water, postcards.

Progress of the game. An adult invites the children to turn the glass over without spilling water from it. Children make assumptions and try things out. Then the adult fills the glass to the brim with water, covers it with a postcard and, holding it lightly with his fingers, turns the glass upside down. He removes his hand - the card does not fall, the water does not spill out (unless the paper is completely horizontal and pressed to the edges). Why doesn’t water pour out of a glass when there is a sheet of paper under it (air presses on the sheet of paper, it presses the sheet to the edges of the glass and prevents the water from pouring out, i.e. the reason is air pressure).

HOMEMADE THERMOMETER

Target. Demonstrate how air expands when heated and pushes water out of the container.

Game material. A glass tube or refill (transparent) from a ballpoint pen, a 50-100 ml bottle, a little tinted water.

Progress of the game. Children look at the “thermometer”: how it works, its structure (bottle, tube and stopper); With the help of an adult, make a model of a thermometer. Make a hole in the cork with an awl and insert it into the bottle. Then they take a drop of colored water into a tube and stick the tube in so that the drop of water does not jump out. The bottle heats up in your hands, a drop of water rises up.

VERTUSCHKA

Target. Reveal that air has elasticity. Understand how air power (movement) can be used

Game material. Pinwheel, materials for making for each child: paper, scissors, sticks, carnations.

Progress of the game. An adult shows children a fidget spinner in action. Then he discusses with them why it spins (the wind hits the blades, which are turned at an angle towards it, and this causes the turntable to move). An adult invites children to make a turntable according to an algorithm, examine and discuss the features of its design. Then he organizes games with a spinner on the street; Children observe under what conditions it spins faster.

REACTIVE BALL.

Target.

Game material. Balloons.

Progress of the game. Children, with the help of an adult, inflate a balloon, lower it and pay attention to the trajectory and duration of its flight. They find out that in order for the ball to fly longer, it is necessary to inflate it more: the air escaping from the “neck” makes the ball move in the opposite side. An adult tells the children that the same principle is used in jet engines.

STRAW GIMLE.

Target. Reveal that air has elasticity. Understand how air power (motion) can be used.

Game material. Raw potatoes, two cocktail straws (for each child).

Progress of the game. Children take straws top part without covering the top hole with your finger; then, from a height of 10 cm, with a sharp movement they stick it into the potato; they observe what happened to the straw (it bent, did not stick in), take the second straw by the top, this time closing the upper hole with a finger; They also stick sharply into a potato and observe what happened to the straw (it stuck). Children find out that there is air inside the second straw that presses on the walls and prevents it from bending. Children conclude: in the first case, the air came out of the straw freely and it bent; in the second case, the air could not escape from the straw, since the hole was closed. In addition, when the potato entered the straw, the pressure increased even more, strengthening the walls of the straw.

PARACHUTE.

Target. Reveal that air has elasticity. Understand how air power (motion) can be used.

Game material. Parachute, toy men, container with sand.

CANDLE IN A JAR.

Target. Reveal that during combustion the composition of the air changes (there is less oxygen) and that combustion requires oxygen. Learn how to extinguish fire.

Game material. Candle, jar, bottle with a cut bottom.

HOW TO BLOW OUT A CANDLE FROM A FUNNEL.

Target. Identify the features of an air vortex.

Game material. Candle, funnel.

STRONG MATCH BOX.

Target. Determine the elasticity of air.

Game material. Matchboxes.

BIG - SMALL.

Target. Reveal that air contracts when cooled and expands when heated (takes up more space).

Game material. Plastic bottles with corks, balloon ik, coin.

FOCUS “DRY OUT OF WATER”

Target. Demonstrate existence atmospheric pressure, the fact that when air cools, it occupies less volume (compresses).

Game material. A plate with water covering the bottom, a coin, a glass.

WHY ARE THE QUESTIONS.

Target. Analyze and draw conclusions based on knowledge about the properties of air: warm air rises, i.e. it is lighter than cold air; air does not conduct heat well.

Game material. Tissue paper, stand with needle.

Progress of the game. An adult suggests making pinwheels from thin tissue paper: cut out a rectangle, bend it along the middle lines and straighten it again (the center of gravity has been found), place the paper on the tip of the protruding needle so that the needle supports it at exactly that point. Carefully bring your hand closer and the paper begins to rotate; move it away and the rotation stops. They conclude: the air rises from the bottom up, pressing on the piece of paper and causing it to rotate, since the piece of paper has a slope at the folds.

Olga Rogacheva
Experiments with air

Experience No. 1

Target experience air We need air to breathe. We breathe in and out air.

Move: Take a glass of water, insert a straw and exhale air. Bubbles appear in the glass.

Experience No. 2

Target experience: Lead children to understanding and meaning air

Move: Make a small parachute. Show that when the parachute drops, air the dome bursts beneath him, supporting him! it, so the decrease occurs smoothly.

Experience No. 3

Target experience: Lead children to understand the characteristics air. Air is invisible, has no specific shape, spreads in all directions, has no odor of its own.

Move: Take scented napkins, orange peels, etc. and invite the children to smell the odors in the room one by one.

Experience No. 4

Target experience: Bring children to understand weight airA. Air has weight. Move: Place inflated and uninflated on the scales balloons: a bowl with an inflated balloon will outweigh

Experience No. 5

Move:Place the opened plastic bottle in the refrigerator. When it is cool enough, place a lid around its neck. inflated balloon. Then place the bottle in a bowl of hot water. Watch the balloon begin to inflate on its own. This happens because air expands when heated. Now put the bottle in the refrigerator again. The ball will go down because air shrinks when cooled.

Experience No. 6

Target experience: Help identify a property air(elasticity, understand how force can be used air(movement).

Move:The teacher invites the children to conduct experience with balloon : see how it will fly if you untie the thread that holds it in air. Children, with the help of a teacher, inflate balloon, release it and pay attention to the trajectory and duration of its flight. They find out that in order for the ball to fly longer, you need to inflate it more.

Experience No. 7

Target: Learn to reflect existing ideas in transformative activities. How can you play with the wind?

Move: Take a square sheet of paper and cut it along the pre-drawn lines. Bend the corners towards the center, where they are attached to the stick with a pin, having previously placed a small bead between the pinwheel and the stick. In order for the spinner to fulfill its function in calm weather, you need to run while holding the stick in your hands. The pinwheel spins only when there is wind.

Experience No. 8

Target: Help identify what is warm air lighter than cold and rises.

Move:The teacher invites the children to compare the temperature air in the room and near warm objects. Determine where warmer: on the floor or on the sofa? The teacher holds the thermometer on the floor and then on the sofa. Children are convinced that the higher, the warmer. Next, the teacher suggests approaching the battery. Reach above the battery, below the battery. Where is it warmer? (Warmer above the battery.)

Then the teacher suggests going to the kettle with hot water. Raise your hand and hold it above the water. Children make sure that the water vapor is hot. Warm the air is lighter than cold. Warm air rises, so it's warmer on top.

This article aims to give, in simple terms, an idea of ​​how air exchange occurs in a room, and how to influence it in order to obtain optimal air parameters. Therefore, the article makes simplifications and ignores some physical parameters. If you want precise scientific formulations, then enter the required term into the search and you will find many descriptions and data.

Part 1 - Science

To make different formulas and numbers more understandable, we will often look at them with examples. And for such examples we will use the following values:

The average room is 5 by 6 meters with ceilings of 2.5 meters.

Optimal air parameters are 18C and 60% humidity.

When talking about air in general, I will often introduce 1 meter cube of air.

A little theory

There is a certain amount of water (steam) in the air, and this amount is measured by the concept of humidity. Humidity is indicated both relatively (for example, 50-70%) and absolutely (for example, 10 grams per cubic meter). We are, of course, accustomed to the first option, but before we talk about relative humidity, we must talk about absolute humidity and its connection with air temperature.

Absolute humidity

Absolute air humidity is the amount of water (steam) (grams) in the air (1 cubic meter). And the exact amount of water in the air is called absolute humidity.

Maximum absolute humidity

It is clear that air cannot contain an infinite amount of water; there is a maximum water that air can contain, that is, 100% humidity. And this amount of water is called maximum absolute humidity.

And the air, depending on the temperature, can contain a certain amount of water (steam), and the higher the air temperature, the more water can evaporate in the air, and the lower the air temperature, the less water can be evaporated. And at sub-zero temperatures, water practically does not evaporate into the air. Therefore than colder air(below 5C) the drier it is and it doesn’t matter what the relative humidity is.

Here is a graph of maximum absolute humidity at different temperatures:

As you can see, the higher the temperature, the more water can evaporate in it.

Relative humidity

The ratio of absolute humidity and the maximum possible absolute humidity at a specific temperature is called - Relative humidity. That is, if at 18C the maximum absolute humidity (per m3 of air) is 15.4 grams (can be seen from the graph above), then for 60% relative humidity there should be 9.2 grams of water (per m3 of air). Because 9.2/15.4 is 60%.

Now knowing this, we can explain why relative humidity drops when the air warms up. With heating, the moisture capacity (maximum absolute humidity) of the air increases, but the amount of water in it (absolute humidity) remains the same, so the ratio of water to maximum decreases. For example, if the air in your room is 0C and the humidity is 100% (4.8 grams per m3 of air), then if you heat it to 18C, your relative humidity will be 31% (4.8/15.4)

Also, knowing the exact grams of water in the air gives us an idea of ​​how much water needs to evaporate in it to achieve optimal humidity.

For example, let's take an average room and optimal temperature. As we said earlier, at an air temperature of 18C and a humidity of 60%, this is 9.2 grams of water per cubic meter. And if your room is approximately 5x6m with ceilings of 2.5m and if you optimal temperature(18C) and humidity (60%) then you have approximately (multiply 5 x 6 x 2.5 x 9.2) 690 grams of water (steam) in the air in your room. And if you have a humidity of 20% at 18C in the same room, then you have approximately 230 grams of water in the air, and to achieve the optimal one you need to evaporate (690-230) 460 grams of water in the air. Good household humidifiers release approximately 350 grams of water per hour. This means you will need about an hour and a half of humidification to get the humidity optimal. (But we’re getting ahead of ourselves; we’ll get to practice later.)

*If mathematics is not “close to you in spirit,” then don’t be upset, you don’t need to memorize all these numbers at all, the main thing is to have a general idea of ​​what we’re talking about.

Let us repeat once again everything that needs to be extracted from the theory:

• absolute humidity this is the exact amount of water (steam) in the air
• maximum absolute humidity this is the maximum possible amount of water in the air relative to a certain air temperature
• relative humidity This is the ratio of absolute humidity to maximum absolute humidity.
• The higher the air temperature, the more water in it can evaporate
• the lower the air temperature, the less water can evaporate in it
• When heated, the amount of water in the air does not change, but the moisture capacity of the air changes

Seasons or air outside the window

Of course, depending on the time of year, the air outside our window is different.

In summer, the air is hot and humid (in the heat, even at 20% relative humidity, there is quite a lot of water in the air), in winter, it is cold and dry (as we said earlier, in the cold, water in the air practically does not evaporate, so it is always dry in the cold), in spring and in autumn it is cool and humid.

But relative to our room and optimal conditions, the air outside the window can be divided not into seasons, but into differences in temperature and humidity. That is, warmer, or colder, or drier. And most often we are concerned about 2 conditions, these are:

• when the air outside the window is warmer/hotter (mostly summer), hereinafter abbreviated as Summer
• when the air outside the window is cold and dry (mostly winter), hereinafter abbreviated as Winter

And in the practical part of the article we will write about these two states.

About the room

Which air goes down and which air rises?

It is widely known that warm air is lighter than cold air, which is why the temperature on the ceiling is higher than on the floor. But humid air is lighter than dry air, so the humidity on the ceiling is higher than on the floor. As a result, the air on your floor is colder and drier than on the ceiling, where it is warmer and more humid.

What is the difference in humidity and temperature from ceiling to floor?

This depends on many parameters, ceiling height, room size, location of the heat producer (heater), moisture producer (humidifier), heat transfer, moisture transfer, air flow directions (ventilation, ventilation), etc. But in general there are 2-4 degrees and 5-10% humidity. But with intense exchange of air, heat, humidity (for example, a window is open, heating, fan, humidifier/evaporative cooler is running), and high ceilings, the difference can reach 5-10 degrees and 10-30% humidity.

It should also be noted that the temperature from the heater to the window also differs by 5-10 degrees, or even more.

Ventilation

This seemingly simple, understandable procedure, when examined in detail, brings significant changes to the air we create in the room. When airing, not only the air in the room is purified, but also an intense exchange of heat and moisture occurs, and after airing, all our efforts to create optimal air can be nullified.

But it’s also impossible without ventilation, so in the practical part we will discuss how to carry out 3 important procedures: ventilation, thermoregulation, moisture regulation, without compromising other air parameters.

In fact, in our rooms there is a constant exchange of air with the outside environment (unless, of course, your room is hermetically sealed and neither windows nor doors are ever opened), in some rooms there is more, and in others less. For this, there are even special measurements of how many times the air is completely renewed per hour. If 1 is once, if 2 is twice, and if 0.5 then only half of the air is renewed in an hour. If all your windows and doors are closed, then for your room this indicator is close to 0.1, and if you have everything open, then the indicator is close to 3-4.

With a sick child, it is advisable to have this indicator be at least 1. But this is very difficult in winter, since humidifiers cannot humidify the entire room in an hour (we are getting ahead of ourselves again).

Part 2 - Practice

Now let's move from theory to practice. The recipes given here try to teach you to think creatively in relation to living conditions, and adapt them to your needs and conditions.

Our goal

Under any conditions outside the window, provide yourself and your child with optimal air parameters - about 18C and 50-70% humidity (or in an average room have about 500-700 grams of water evaporated in the air). With minimal effort, minimal cost and maximum convenience. By priority:

• clean air comes first
• air temperature comes second
• air humidity is in third place

General

The effect on the air can be divided into 2 parts:

• active correction to achieve optimal parameters
• passive maintenance of optimal air parameters

That is, first we actively turn on all the forces at full power to achieve optimal air parameters as quickly as possible, and then reduce the influence to the minimum necessary so that optimal air parameters are maintained.

Tools

To influence the air we have the following tools:

Air conditioner

• cost: high
• temperature: cooling high
• humidity: dries out
• ventilation: low
• noise: low
• service: rare
• mobility: no

Evaporative cooler

• cost: low
• temperature: cooling normal
• humidity: high humidity
• ventilation: high
• noise: medium
• service: daily
• mobility: high

Ultrasonic humidifier

• cost: low
• temperature: no effect
• humidity: medium humidity
• ventilation: none
• noise: very low
• service: daily
• mobility: high

Stove/battery

• cost: moderate
• temperature: warms
• humidity: dries out
• ventilation: none
• noise: very low
• service: rare
• mobility: no

Air purifier/washer

• cost: high
• temperature: no effect
• humidity: medium humidity
• ventilation: none but cleans the air with filters
• noise: very low
• service: daily
• mobility: high

Fan

• cost: low
• temperature: no effect
• humidity: no effect
• ventilation: high
• noise: medium
• service: rare
• mobility: high

Steam generator

• cost: average
• temperature: slightly warm
• Humidity: Moderately moisturizing
• ventilation: none
• noise: low
• service: daily
• mobility: high

In this part, we will begin to practically apply our knowledge in the fight for optimal air parameters.

Room approach

The room approach to providing air is a fairly common method; it teaches us how to create the necessary air in a room. And first we need to study this approach too.

in autumn And in the spring in general, nothing needs to be done, just open the windows, the air is normal during the day, and cool and humid at night, everything is ventilated without cost, without effort.

A in summer The big problem is cooling, since the humidity is okay. For cooling, the most effective thing is air conditioning, but it is very expensive. And if you can afford it, then having at least 1 air conditioner won’t hurt, because in many diseases cool air is critical, and in the summer it can be a salvation from the heat.

An alternative to air conditioning is an evaporative cooler (there is a separate article on this device, link below). The cooling power is a few degrees lower than that of an air conditioner, but it is quite sufficient to save you from the heat, and its very strong advantage is that it immediately humidifies the room, and also ventilates, and is very economical, and costs several times less than an air conditioner.

in winter everything is much more complicated, we are dealing with dry cold air. And inside the room, thanks to uncontrolled heating, it is dry and hot. By opening the window you can still cool the room, but humidifying it is a big problem. Of course, you've probably read how to turn off the heating, install a regulator, close the windows, use an ultrasonic humidifier, etc. And if you do all this and have no problems, then congratulations to you. Although you will still have some problems with ventilation, overall you will cope well with the winter.

But here I would like to talk about an alternative method of air regulation. This is again the previously mentioned Evaporative Cooler. The peculiarity of the operation of this device is that the hotter and drier the air, the more effectively it humidifies it and at the output an almost stable temperature of 18-23 C is formed (the exact temperature depends on the power of the device and the heat/dryness of the air). And if such a cooler is placed next to the heater, then it will draw in all the hot air and release cooled, moist air.

The most important thing is that the device requires open windows (or at least a window) so that excess moisture can escape. So by balancing the heater, evaporative cooler and opening the window, you can create heat and moisture exchange in the winter so that you have cool, moist and ventilated air in your apartment.

Of course, depending on your room, heating location, windows, and evaporative cooler model, you will have to organize air exchange differently. There are no universal formulas, but if you experiment a little and measure temperature and humidity at different angles, you will find your optimum through trial and error.

So all you need is an evaporative cooler, and if possible, an air conditioner. Of course, no one forbids you to have a regular ultrasonic humidifier.

Personal approach

This approach is not very common among climate methods. It is not aimed at organizing optimal air throughout the room, but at organizing it exactly where it is needed, that is, under the nose of the child (and parents). In principle, we don’t need optimal air near the closet or bedside table; we need the right air right under the child’s nose, and what happens in the other corners of the room is not important.

It should be clear from the description that this is a very economical method. And we mainly talk about air during sleep. We do not need measurements at different points in the room in order to maintain optimal air parameters throughout the room, but only need measurements close to the child (and parents).

Spring, autumn, summer this approach is almost no different from the room approach. And here in winter there are differences (there are also differences when the child is sick). Let’s assume that you don’t have the means and ability to insulate the heating, install a regulator, buy an evaporative cooler, etc., but you need to provide optimal air for your child. Then you will need any cheap air humidifier (can be found for $10-30), the heating is working, open the window so that the temperature is balanced somewhere between the window and the heating at the desired 18C (if it gets colder, then close the window, and if it gets hotter, then open it slightly window, find a balance where the incoming cold from the window is compensated by the heat from the heating). Place the child's bed between the heating and the window where the air is balanced at 18C, this is usually 2-3 meters from the window. And if you place it right under the window, it is better for the child to wear a hat, because up to 50% of the heat is lost from the head, and cold winds on the head will not do any good. Place a humidifier nearby so that the mist from the humidifier reaches the child’s nose with the required percentage of moisture. This usually happens within a radius of a meter, and if a cheap humidifier, even half a meter.

And now you get the desired temperature, humidity and ventilation even in winter and at almost no cost.

If you want to arrange optimal air for yourself, then also lie down next to the child, where the desired temperature is reached and the humidifier is working. Well, or install another such humidifier for yourself.

To find balance, also do not forget about the height of the child; remember, according to the theory, the higher, the warmer, the lower, the colder.

Also, regardless of the method of providing air, remember that the optimal air should go directly into the child’s nose, and if you cover the child’s nose with a blanket, he will breathe warm air from under the blanket and all efforts to provide air will lose meaning. Therefore, it is best to dress the child’s top warmly and cover the blanket to the waist/chest.