To date heat saving is an important parameter that is taken into account when constructing a residential or office space. In accordance with SNiP 02/23/2003 " Thermal protection buildings", heat transfer resistance is calculated using one of two alternative approaches:

• Prescriptive;
• Consumer.

To calculate home heating systems, you can use the calculator for calculating heating and home heat loss.

Prescriptive Approach- these are the standards for individual elements of thermal protection of a building: external walls, floors above unheated spaces, coverings and attic floors, windows, entrance doors, etc.

Consumer approach(heat transfer resistance can be reduced relative to the prescribed level, provided that the design specific consumption thermal energy for space heating is below standard).

Sanitary and hygienic requirements:

• The difference between indoor and outdoor air temperatures should not exceed certain permissible values. Maximum permissible temperature differences for outer wall 4°C. for roofing and attic flooring 3°C and for ceilings over basements and crawl spaces 2°C.
• Temperature at inner surface fence must be above the dew point temperature.

Eg: for Moscow and the Moscow region, the required thermal resistance of the wall according to the consumer approach is 1.97 °C m 2 /W, and according to the prescriptive approach:

• for home permanent residence 3.13 °C m 2 / W.
• for administrative and other public buildings, including structures for seasonal residence 2.55 °C m 2 / W.

For this reason, when choosing a boiler or other heating devices solely according to the parameters specified in their technical documentation. You must ask yourself whether your house was built with strict regard to the requirements of SNiP 02/23/2003.

Therefore, for the right choice heating boiler power or heating devices, it is necessary to calculate real heat loss from your home. As a rule, a residential building loses heat through the walls, roof, windows, and ground; significant heat losses can also occur through ventilation.

Heat loss mainly depends on:

• temperature differences in the house and outside (the higher the difference, the higher the losses).
• heat-protective characteristics of walls, windows, ceilings, coatings.

Walls, windows, ceilings have a certain resistance to heat leakage, the heat-shielding properties of materials are assessed by a value called heat transfer resistance.

Heat transfer resistance will show how much heat will leak through square meter structures at a given temperature difference. This question can be formulated differently: what temperature difference will occur when a certain amount of heat passes through a square meter of fencing.

R = ΔT/q.

• q is the amount of heat that escapes through a square meter of wall or window surface. This amount of heat is measured in watts per square meter (W/m2);
• ΔT is the difference between the temperature outside and in the room (°C);
• R is the heat transfer resistance (°C/W/m2 or °C m2/W).

In cases where we're talking about about a multilayer structure, the resistance of the layers is simply summed up. For example, the resistance of a wall made of wood, which is lined with brick, is the sum of three resistances: the brick and wooden walls and the air gap between them:

R(total)= R(wood) + R(air) + R(brick)

Temperature distribution and air boundary layers during heat transfer through a wall.

Heat loss calculation performed for the coldest period of the year, which is the coldest and windiest week of the year. In construction literature, the thermal resistance of materials is often indicated based on the given conditions and the climatic region (or outside temperature) where your home is located.

Heat transfer resistance table various materials

at ΔT = 50 °C (T external = -30 °C. T internal = 20 °C.)

Wall material and thickness	Heat transfer resistance R m.
Brick wall thickness in 3 bricks. (79 centimeters) thickness in 2.5 bricks. (67 centimeters) thickness in 2 bricks. (54 centimeters) thickness in 1 brick. (25 centimeters)	0.592 0.502 0.405 0.187
Log house Ø 25 Ø 20	0.550 0.440
Log house made of timber Thickness 20 centimeters Thickness 10 centimeters	0.806 0.353
Frame wall (board + mineral wool + board) 20 centimeters
Foam concrete wall 20 centimeters 30 cm	0.476 0.709
Plastering on brick, concrete. foam concrete (2-3 cm)
Ceiling (attic) floor
Wooden floors
Double wooden doors

Window heat loss table various designs at ΔT = 50 °C (T external = -30 °C. T internal = 20 °C.)

Window type R T q . W/m2 Q . W Regular double glazed window Double-glazed window (glass thickness 4 mm) 4-16-4 4-Ar16-4 4-16-4K 4-Ar16-4K 0.32 0.34 0.53 0.59 156 147 94 85 250 235 151 136 Double-glazed window 4-6-4-6-4 4-Ar6-4-Ar6-4 4-6-4-6-4K 4-Ar6-4-Ar6-4K 4-8-4-8-4 4-Ar8-4-Ar8-4 4-8-4-8-4K 4-Ar8-4-Ar8-4K 4-10-4-10-4 4-Ar10-4-Ar10-4 4-10-4-10-4K 4-Ar10-4-Ar10-4K 4-12-4-12-4 4-Ar12-4-Ar12-4 4-12-4-12-4K 4-Ar12-4-Ar12-4K 4-16-4-16-4 4-Ar16-4-Ar16-4 4-16-4-16-4K 4-Ar16-4-Ar16-4K 0.42 0.44 0.53 0.60 0.45 0.47 0.55 0.67 0.47 0.49 0.58 0.65 0.49 0.52 0.61 0.68 0.52 0.55 0.65 0.72 119 114 94 83 111 106 91 81 106 102 86 77 102 96 82 73 96 91 77 69 190 182 151 133 178 170 146 131 170 163 138 123 163 154 131 117 154 146 123 111

Note
. Even numbers in symbol double glazed windows indicate air
gap in millimeters;
. The letters Ar mean that the gap is filled not with air, but with argon;
. The letter K means that the outer glass has a special transparent
heat-protective coating.

As can be seen from the above table, modern double-glazed windows make it possible reduce heat loss windows almost doubled. For example, for 10 windows measuring 1.0 m x 1.6 m, savings can reach up to 720 kilowatt-hours per month.

To correctly select materials and wall thickness, apply this information to a specific example.

Two quantities are involved in calculating heat losses per m2:

• temperature difference ΔT.
• heat transfer resistance R.

Let's say the room temperature is 20 °C. and the outside temperature will be -30 °C. In this case, the temperature difference ΔT will be equal to 50 °C. The walls are made of timber 20 centimeters thick, then R = 0.806 °C m 2 / W.

Heat losses will be 50 / 0.806 = 62 (W/m2).

To simplify calculations of heat loss in construction reference books indicate heat loss various types walls, ceilings, etc. for some values winter temperature air. Typically, different numbers are given for corner rooms(the turbulence of the air that swells the house influences this) and non-angular, and also takes into account the difference in temperatures for the rooms of the first and upper floors.

Table of specific heat loss of building enclosure elements (per 1 m 2 inner contour walls) depending on the average temperature of the coldest week of the year.

Characteristic fencing Outdoor temperature. °C Heat loss. W 1st floor 2nd floor Corner room Unangle room Corner room Unangle room Wall 2.5 bricks (67 cm) with internal plaster 24 -26 -28 -30 76 83 87 89 75 81 83 85 70 75 78 80 66 71 75 76 Wall of 2 bricks (54 cm) with internal plaster 24 -26 -28 -30 91 97 102 104 90 96 101 102 82 87 91 94 79 87 89 91 Chopped wall (25 cm) with internal sheathing 24 -26 -28 -30 61 65 67 70 60 63 66 67 55 58 61 62 52 56 58 60 Chopped wall (20 cm) with internal sheathing 24 -26 -28 -30 76 83 87 89 76 81 84 87 69 75 78 80 66 72 75 77 Wall made of timber (18 cm) with internal sheathing 24 -26 -28 -30 76 83 87 89 76 81 84 87 69 75 78 80 66 72 75 77 Wall made of timber (10 cm) with internal sheathing 24 -26 -28 -30 87 94 98 101 85 91 96 98 78 83 87 89 76 82 85 87 Frame wall (20 cm) with expanded clay filling 24 -26 -28 -30 62 65 68 71 60 63 66 69 55 58 61 63 54 56 59 62 Foam concrete wall (20 cm) with internal plaster 24 -26 -28 -30 92 97 101 105 89 94 98 102 87 87 90 94 80 84 88 91

Note. In the case when there is an external unheated room behind the wall (canopy, glazed veranda, etc.), then the heat loss through it will be 70% of the calculated value, and if behind this unheated room If there is another outdoor room, then the heat loss will be 40% of the calculated value.

Table of specific heat loss of building enclosure elements (per 1 m2 along the internal contour) depending on the average temperature of the coldest week of the year.

Example 1.

Corner room(1st floor)

Room characteristics:

• 1st floor.
• room area - 16 m2 (5x3.2).
• ceiling height - 2.75 m.
• There are two external walls.
• material and thickness of the external walls - timber 18 centimeters thick, covered with plasterboard and covered with wallpaper.
• windows - two (height 1.6 m, width 1.0 m) with double glazing.
• floors - wooden insulated. basement below.
• higher attic floor.
• estimated outside temperature -30 °C.
• required room temperature +20 °C.

• Area of ​​external walls minus windows: S walls (5+3.2)x2.7-2x1.0x1.6 = 18.94 m2.
• Window area: S windows = 2x1.0x1.6 = 3.2 m2
• Floor area: S floor = 5x3.2 = 16 m2
• Ceiling area: Ceiling S = 5x3.2 = 16 m2

Square internal partitions does not participate in the calculation, since the temperature on both sides of the partition is the same, therefore heat does not escape through the partitions.

Now let's calculate the heat loss of each surface:

• Q walls = 18.94x89 = 1686 W.
• Q windows = 3.2x135 = 432 W.
• Floor Q = 16x26 = 416 W.
• Ceiling Q = 16x35 = 560 W.

The total heat loss of the room will be: Q total = 3094 W.

It should be borne in mind that much more heat escapes through walls than through windows, floors and ceilings.

Example 2

Room under the roof (attic)

Room characteristics:

• top floor.
• area 16 m2 (3.8x4.2).
• ceiling height 2.4 m.
• exterior walls; two roof slopes (slate, continuous lathing. 10 centimeters of mineral wool, lining). pediments (beams 10 centimeters thick covered with clapboard) and side partitions ( frame wall with expanded clay filling 10 centimeters).
• windows - 4 (two on each gable), 1.6 m high and 1.0 m wide with double glazing.
• estimated outside temperature -30°C.
• required room temperature +20°C.

• Area of ​​the end external walls minus windows: S end walls = 2x(2.4x3.8-0.9x0.6-2x1.6x0.8) = 12 m2
• Area of ​​roof slopes bordering the room: S sloped walls = 2x1.0x4.2 = 8.4 m2
• Area of ​​the side partitions: S side partition = 2x1.5x4.2 = 12.6 m 2
• Window area: S windows = 4x1.6x1.0 = 6.4 m2
• Ceiling area: Ceiling S = 2.6x4.2 = 10.92 m2

Next we calculate heat losses these surfaces, it must be taken into account that in this case the heat will not escape through the floor, since there is a warm room below. Heat loss for walls We calculate as for corner rooms, and for the ceiling and side partitions we enter a 70 percent coefficient, since unheated rooms are located behind them.

• Q end walls = 12x89 = 1068 W.
• Q pitched walls = 8.4x142 = 1193 W.
• Q side burnout = 12.6x126x0.7 = 1111 W.
• Q windows = 6.4x135 = 864 W.
• Ceiling Q = 10.92x35x0.7 = 268 W.

The total heat loss of the room will be: Q total = 4504 W.

As we see, a warm room on the 1st floor loses (or consumes) significantly less heat than attic room with thin walls and a large glazing area.

To make this room suitable for winter accommodation, it is necessary first of all to insulate the walls, side partitions and windows.

Any enclosing surface can be presented in the form of a multilayer wall, each layer of which has its own thermal resistance and its own resistance to air passage. By summing the thermal resistance of all layers, we get the thermal resistance of the entire wall. Also, if you sum up the resistance to the passage of air of all layers, you can understand how the wall breathes. The most best wall made of timber should be equivalent to a wall made of timber with a thickness of 15 - 20 centimeters. The table below will help with this.

Table of resistance to heat transfer and air passage of various materials ΔT = 40 ° C (T external = -20 ° C. T internal = 20 ° C.)

Wall Layer	Thickness layer walls	Resistance heat transfer of the wall layer		Resistance Air flow worthlessness equivalent timber wall thick (cm)
			Equivalent brick masonry thick (cm)
Brickwork from the usual clay brick thickness: 12 centimeters 25 centimeters 50 centimeters 75 centimeters	12 25 50 75	0.15 0.3 0.65 1.0	12 25 50 75	6 12 24 36
Masonry made of expanded clay concrete blocks 39 cm thick with density: 1000 kg/m3 1400 kg/m3 1800 kg/m3		1.0 0.65 0.45	75 50 34	17 23 26
Foam aerated concrete 30 cm thick density: 300 kg/m3 500 kg/m3 800 kg/m3		2.5 1.5 0.9	190 110 70	7 10 13
Thick timbered wall (pine) 10 centimeters 15 centimeters 20 centimeters	10 15 20	0.6 0.9 1.2	45 68 90	10 15 20

To get a complete picture of the heat loss of the entire room, you need to take into account

1. Heat loss through the contact of the foundation with frozen soil is usually assumed to be 15% of the heat loss through the walls of the first floor (taking into account the complexity of the calculation).
2. Heat losses associated with ventilation. These losses are calculated taking into account building codes(SNiP). A residential building requires about one air change per hour, that is, during this time it is necessary to supply the same volume fresh air. Thus, the losses associated with ventilation will be slightly less than the amount of heat loss attributable to the enclosing structures. It turns out that heat loss through walls and glazing is only 40%, and heat loss for ventilation 50%. In European standards for ventilation and wall insulation, the heat loss ratio is 30% and 60%.
3. If the wall “breathes”, like a wall made of timber or logs 15 - 20 centimeters thick, then heat returns. This allows you to reduce heat losses by 30%. therefore, the value of the thermal resistance of the wall obtained during the calculation must be multiplied by 1.3 (or, accordingly reduce heat loss).

By summing up all the heat loss in the house, you can understand what power the boiler and heating appliances are needed to comfortably heat the house on the coldest and windiest days. Also, such calculations will show where the “weak link” is and how to eliminate it using additional insulation.

You can also calculate heat consumption using aggregated indicators. So, in 1-2 storey houses that are not very insulated with outside temperature-25 °C requires 213 W per 1 m 2 of total area, and at -30 °C - 230 W. For well-insulated houses, this figure will be: at -25 °C - 173 W per m 2 of total area, and at -30 °C - 177 W.

Conventionally, heat loss in a private home can be divided into two groups:

• Natural - heat loss through walls, windows or the roof of a building. These are losses that cannot be completely eliminated, but they can be minimized.
• “Heat leaks” are additional heat losses that can most often be avoided. These are various visually invisible errors: hidden defects, installation errors, etc., which cannot be detected visually. A thermal imager is used for this.

Below we present to your attention 15 examples of such “leaks”. These are real problems that are most often encountered in private homes. You will see what problems may be present in your home and what you should pay attention to.

Poor quality wall insulation

Insulation does not work as effectively as it could. The thermogram shows that the temperature on the wall surface is distributed unevenly. That is, some areas of the wall heat up more than others (than brighter color, the higher the temperature). This means that the heat loss is no greater, which is not correct for an insulated wall.

In this case, the bright areas are an example of ineffective insulation. It is likely that the foam in these places is damaged, poorly installed or missing altogether. Therefore, after insulating a building, it is important to make sure that the work is done efficiently and that the insulation works effectively.

Poor roof insulation

Joint between wooden beam and mineral wool is not compacted enough. This causes the insulation to not work effectively and causes additional heat loss through the roof that could be avoided.

The radiator is clogged and gives off little heat

One of the reasons why the house is cold is that some sections of the radiator do not heat up. This can be caused by several reasons: construction garbage, air accumulation or manufacturing defect. But the result is the same - the radiator works at half its capacity heating power and does not warm the room enough.

The radiator “warms” the street

Another example of inefficient radiator operation.

There is a radiator installed inside the room, which heats up the wall very much. As a result, part of the heat it generates goes outside. In fact, the heat is used to warm the street.

Laying heated floors close to the wall

The underfloor heating pipe is laid close to the outer wall. The coolant in the system is cooled more intensively and has to be heated more often. The result is an increase in heating costs.

Cold influx through cracks in windows

There are often cracks in windows that appear due to:

• insufficient pressing of the window to window frame;
• wear of rubber seals;
• poor-quality window installation.

Through the cracks the room constantly gets cold air, due to which drafts that are harmful to health are formed and heat loss from the building increases.

Cold influx through cracks in doors

Also, cracks appear in balconies and entrance doors.

Bridges of cold

“Cold bridges” are areas of a building with lower thermal resistance compared to other areas. That is, they transmit more heat. For example, these are corners, concrete lintels above windows, junction points building structures and so on.

Why are cold bridges harmful?

• Increases heat loss in the building. Some bridges lose more heat, others less. It all depends on the characteristics of the building.
• Under certain conditions, condensation forms in them and fungus appears. Such potentially dangerous areas must be prevented and eliminated in advance.

Cooling the room through ventilation

Ventilation works in reverse. Instead of removing air from the room to the outside, cold street air is drawn into the room from the street. This, as in the example with windows, provides drafts and cools the room. In the example given, the temperature of the air that enters the room is -2.5 degrees, at a room temperature of ~20-22 degrees.

Cold influx through the sunroof

And in this case, the cold enters the room through the hatch into the attic.

Cold flow through the air conditioner mounting hole

Cold flow into the room through the air conditioner mounting hole.

Heat loss through walls

The thermogram shows “heat bridges” associated with the use of materials with weaker resistance to heat transfer during the construction of the wall.

Heat loss through the foundation

Often when insulating the wall of a building, they forget about another important area - the foundation. Heat loss also occurs through the building's foundation, especially if the building has a basement or a heated floor is installed inside.

Cold wall due to masonry joints

Masonry joints between bricks are numerous cold bridges and increase heat loss through the walls. The example above shows that the difference between the minimum temperature (masonry joint) and maximum (brick) is almost 2 degrees. The thermal resistance of the wall is reduced.

Air leaks

Cold bridge and air leak under the ceiling. It occurs due to insufficient sealing and insulation of the joints between the roof, wall and floor slab. As a result, the room is additionally cooled and drafts appear.

Conclusion

All this typical mistakes, which are found in most private homes. Many of them can be easily eliminated and can significantly improve the energy status of the building.

Let's list them again:

1. Heat leaks through walls;
2. Ineffective operation of thermal insulation of walls and roofs - hidden defects, poor-quality installation, damage, etc.;
3. Cold inflows through air conditioner mounting holes, cracks in windows and doors, ventilation;
4. Ineffective operation of radiators;
5. Bridges of cold;
6. The influence of masonry joints.

15 hidden heat leaks in a private home that you didn't know about

Not all materials used in construction are capable of providing the required level of heat conservation for a private home. Through walls, roof, floor, window openings there is a constant heat leak. By using a thermal imager to determine which structural elements of a building are the “weak links,” through comprehensive or fragmented insulation, you can significantly reduce heat loss in a private home.

Insulate the windows

Insulation of house windows is most often carried out using Swedish technology, for which everything window sashes removed from the frames, then a groove is selected along the perimeter of the frame with a milling cutter, into which a tubular silicone seal (with a diameter of 2 to 7 mm) is inserted - this allows you to reliably seal the window ledges. Small cracks in frames, gaps between the glass unit and the frame are filled with sealant after preliminary washing, cleaning and drying the windows.

Window insulation can also be done using heat-saving film, which is fixed to the window frame using a self-adhesive strip. By letting light into the room, the film reliably screens heat flows due to metallized coating, returning about 60% of the heat back into the room. Significant heat loss through windows is often associated with a violation of the frame geometry, gaps between the frame and the slopes, sagging and skewed sashes, poor-quality functioning of the fittings - to eliminate these problems, qualified adjustment or repair of windows is required.

Insulate the walls

The most significant heat loss - about 40% - occurs through the walls of buildings, so thoughtful insulation of the main walls of a private house will radically improve its heat-saving parameters. Wall insulation can be done from the inside or/and outside - the method of insulation depends on the material used in the construction of the house. Brick and foam concrete houses are most often insulated from the outside, but the heat insulation can also be laid from the inside of these buildings. Wooden houses They are almost never insulated from the interior, in order to avoid the greenhouse effect in the rooms. The outside of houses is insulated from timber, sometimes from logs.

Insulation of the walls of a house can be done using “wet” or curtain façade- the main difference between these methods is the installation principle facade cladding. When arranging a “wet” facade, a dense thermal insulator (expanded polystyrene, foam plastic) is attached to the wall, and then decorative finishing using adhesive mixtures. When installing a suspended facade, after installing the insulation (mineral or glass wool), the sheathing is installed, and then the cladding modules are fixed in its profiles. An essential element of the wall “pie” is a vapor barrier film, which removes condensation from the insulating layer, protects it from getting wet and prevents loss of insulating properties.

Insulate the roof

The roof of a house is another surface through which heat constantly escapes from the house. Depending on the material used to construct the roof deck, the roof may be more or less warm. Major insulation is usually required metal roofs from corrugated sheets and metal tiles. Roofs made of ondulin, flexible and ceramic tiles have low thermal conductivity, so the insulating “pie” for them can be thinner than in the case of metal. Similar to the technology for insulating other surfaces of the house, a vapor barrier must be included in the roof “pie”, and for effective ventilation of the under-roof space, one or two ventilation gaps are provided.

Insulate the floor

Unlike walls and window openings, heat leakage through the floor of a private house is small - approximately 10%, and if insulation is installed, it will be reduced to a minimum. The same foam, polystyrene or mineral wool, but it is also possible to use expanded clay, foamed concrete, cement-bonded particle mixtures and peat mats. An additional insulating measure in country house installation can be performed heated floors: water, cable or infrared.

Similar to the insulation of walls and roofs, a mandatory component of the floor “pie” is a vapor barrier membrane, which screens moisture-saturated steam leaking from internal space home outside. Thus, the heat-insulating layer is reliably protected from getting wet.

You are here: Home >> Insulating a house with your own hands >> How to properly insulate a house with your own hands: home insulation technology >> How does heat escape through windows?

How does heat escape through windows?

In this article we list what affects heat loss through windows. And we list this so that, when insulating windows with our own hands, we do it with an understanding of what we are doing and why.

Factors influencing heat loss through windows

So, here's what affects heat loss through windows:

• size of windows and their number (light opening area);
• window block material;
• glazing type;
• location;
• compaction

Now let’s look at each factor separately and find out what it should be optimal for.

What should the area of ​​the windows be?

Obviously, what larger area window opening, the more heat can leave the room through it. But you can’t do without windows at all... The area of ​​the windows should be justified by calculation: why did you choose this particular width and height of the window?

Hence the question: what window area is optimal in residential buildings?

If we turn to GOSTs, we will get a clear answer:

The area of ​​the window opening must provide a coefficient of natural illumination (KEO), the value of which depends on the construction area, the nature of the terrain, orientation to the cardinal points, the purpose of the room, and the type of window frames.

It is believed that enough light enters the room if the area of ​​all glass surfaces in total it amounts to 10...12% of the total area of ​​the room (calculated by floor). According to physiological indications, it is believed that optimal condition lighting is achieved with a window width equal to 55% of the width of the room. For boiler rooms, the light opening area is 0.33 m2 per 1 m3 of room volume.

Individual premises (for example, boiler rooms) have their own requirements, which you need to learn about in the relevant regulatory documents.

How to reduce heat loss with a large glass area?

Heat loss through glass can be significant, which is why heating costs are high.

To reduce heat loss through windows, special coatings are applied to the glass with one-way transmission of short- and long-wave radiation (the long-wave part of the spectrum is infrared rays emanating from heating devices, they are delayed, and the short-wave part - ultra-violet rays- skipped). As a result, in winter sunlight passes into the room, but heat does not leave the room:

And in summer it’s the other way around:

Why is multi-layer glazing more effective?

Experience shows that increasing the thickness of the air gap between the glass panes in a double sash window does not lead to an increase in the thermal efficiency of the entire window. It is more effective to make several layers, increasing the number of glasses.

The “classic” double frame is ineffective. And the greatest effect can be achieved with triple glazing. That is, a double-chamber double-glazed window is more effective in all respects (thermal insulation, sound insulation) than a single-chamber one.

(Chambers here are the gaps between the glasses; two glasses - one gap, a single-chamber double-glazed window; three glasses - two gaps, two chambers... etc.)

The optimal thickness of the air gap between the glasses is considered to be 16 mm.

When you are offered double-glazed windows, and you need to choose from several types, for example, from these (the numbers above the double-glazed windows are the thickness of the glass and the spaces between them):

That optimal second and third.

Well, again, you need to keep in mind the glass seal. In modern double-glazed windows, not only the number of chambers has been increased, but also the air in the space between the glasses has been pumped out, some inert gas has been pumped in instead, and the chambers are sealed.

Location of windows and heat loss through them

Window glass is almost completely transparent to solar heat, but not transparent to “black” radiation sources (with temperatures below 230 degrees).

Much more heat passes through the glass from the outside than can pass through from the inside. This one-way conductivity can lead to the fact that in winter the heating of rooms with sunny side may not require significant expenditure. In the summer, on the contrary, we get overheating of the rooms, which creates the need to cool the rooms.

The least amount of light comes from the north, northeast and northwest sides.

Conclusion: you need to take into account the location of windows and their impact on the climate in the house at the stage of designing a house. Otherwise, all that remains is to “fight” with the help of blinds, films on glass, restoration of old frames or replacing them with new ones, insulation of slopes and other measures, which will be discussed in the following articles.

Comfort is a fickle thing. Sub-zero temperatures arrive, you immediately feel chilly, and are uncontrollably drawn to home improvement. “Global warming” begins. And there is one “but” here - even after calculating the heat loss of the house and installing the heating “according to plan,” you can be left face to face with the quickly disappearing heat. The process is not visually noticeable, but is perfectly felt through woolen socks and large heating bills. The question remains: where did the “precious” heat go?

Natural heat loss is well hidden behind bearing structures or “well-made” insulation, where there should be no gaps by default. But is it? Let's look at the issue of heat leaks for different elements designs.

Cold spots on the walls

Up to 30% of all heat loss in a house occurs on the walls. IN modern construction They are multilayer structures made of materials of different thermal conductivity. Calculations for each wall can be carried out individually, but there are common errors for all, through which heat leaves the room and cold enters the house from outside.

The place where the insulating properties are weakened is called a “cold bridge”. For walls it is:

• Masonry joints

The optimal masonry seam is 3mm. It is achieved more often adhesives fine texture. When the volume of mortar between the blocks increases, the thermal conductivity of the entire wall increases. Moreover, the temperature of the masonry seam can be 2-4 degrees colder than the base material (brick, block, etc.).

Masonry joints as a “thermal bridge”

• Concrete lintels over openings.

One of the highest thermal conductivity coefficients among building materials(1.28 - 1.61 W/ (m*K)) for reinforced concrete. This makes it a source of heat loss. The issue is not completely resolved by cellular or foam concrete lintels. The temperature difference between the reinforced concrete beam and the main wall is often close to 10 degrees.

You can insulate the lintel from the cold with continuous external insulation. And inside the house - by assembling a box from HA under the cornice. This creates additional air gap for warmth.

• Mounting holes and fasteners.

Connecting an air conditioner or TV antenna leaves gaps in the overall insulation. Through metal fastener and the passage hole must be tightly sealed with insulation.

And if possible, do not move metal fasteners outside, fixing them inside the wall.

Insulated walls also have heat loss defects

Installation of damaged material (with chips, compression, etc.) leaves vulnerable areas for heat leaks. This is clearly visible when examining a house with a thermal imager. Bright spots indicate gaps in the external insulation.

During operation, it is important to monitor the general condition of the insulation. An error in choosing an adhesive (not a special one for thermal insulation, but a tile one) can cause cracks in the structure within 2 years. And the main ones insulation materials They also have their disadvantages. For example:

• Mineral wool does not rot and is not interesting to rodents, but is very sensitive to moisture. Therefore, its good service life in external insulation is about 10 years - then damage appears.
• Foam plastic - has good insulating properties, but is easily susceptible to rodents, and is not resistant to force and ultraviolet radiation. The insulation layer after installation requires immediate protection (in the form of a structure or a layer of plaster).

When working with both materials, it is important to ensure a precise fit of the locks of the insulation boards and the cross arrangement of the sheets.

• Polyurethane foam - creates seamless insulation, is convenient for uneven and curved surfaces, but is vulnerable to mechanical damage and is destroyed by UV rays. It is advisable to cover it with a plaster mixture - fastening the frames through a layer of insulation violates the overall insulation.

Experience! Heat losses can increase during operation, because all materials have their own nuances. It is better to periodically assess the condition of the insulation and repair damage immediately. A crack on the surface is a “fast” road to destruction of the insulation inside.

Heat loss from the foundation

Concrete is the predominant material in foundation construction. Its high thermal conductivity and direct contact with the ground result in up to 20% heat loss along the entire perimeter of the building. The foundation conducts heat particularly strongly from basement and an incorrectly installed heated floor on the first floor.

Heat loss is also increased by excess moisture that is not removed from the house. It destroys the foundation, creating openings for the cold. Many people are sensitive to humidity thermal insulation materials. For example, mineral wool, which is often transferred to the foundation from general insulation. It is easily damaged by moisture and therefore requires a dense protective frame. Expanded clay also loses its thermal insulation properties on constantly moist soil. Its structure creates air cushion and compensates well for soil pressure during freezing, but the constant presence of moisture minimizes beneficial features expanded clay insulation. That is why the creation of working drainage is a prerequisite for the long life of the foundation and heat conservation.

This also includes in importance the waterproofing protection of the base, as well as a multi-layer blind area, not wide less than a meter. With a columnar foundation or heaving soil, the blind area around the perimeter is insulated to protect the soil at the base of the house from freezing. The blind area is insulated with expanded clay, sheets of expanded polystyrene or polystyrene.

It is better to choose sheet materials for foundation insulation with a groove connection, and treat it with a special silicone compound. The tightness of the locks blocks access to the cold and guarantees continuous protection of the foundation. In this matter, seamless spraying of polyurethane foam has an undeniable advantage. In addition, the material is elastic and does not crack when the soil heaves.

For all types of foundations, you can use the developed insulation schemes. An exception may be a foundation on piles due to its design. Here, when processing the grillage, it is important to take into account the heaving of the soil and choose a technology that does not destroy the piles. This is a complex calculation. Practice shows that a house on stilts is protected from the cold by a properly insulated floor on the first floor.

Attention! If the house has a basement and it often floods, then this must be taken into account when insulating the foundation. Since the insulation/insulator in this case will clog moisture in the foundation and destroy it. Accordingly, heat will be lost even more. The first thing that needs to be resolved is the flooding issue.

Vulnerable areas of the floor

An uninsulated ceiling transfers a significant portion of the heat to the foundation and walls. This is especially noticeable if the heated floor is installed incorrectly - a heating element cools down faster, increasing the cost of heating the room.

To ensure that the heat from the floor goes into the room and not outside, you need to make sure that the installation follows all the rules. The main ones:

• Protection. A damper tape (or foil polystyrene sheets up to 20 cm wide and 1 cm thick) is attached to the walls around the entire perimeter of the room. Before this, the cracks must be eliminated and the wall surface leveled. The tape is fixed as tightly as possible to the wall, isolating heat transfer. When there are no air pockets, there are no heat leaks.
• Indent. There should be at least 10 cm from the outer wall to the heating circuit. If the heated floor is installed closer to the wall, then it begins to heat the street.
• Thickness. The characteristics of the required screen and insulation for underfloor heating are calculated individually, but it is better to add a 10-15% margin to the obtained figures.
• Finishing. The screed on top of the floor should not contain expanded clay (it insulates heat in the concrete). Optimal thickness screeds 3-7 cm. The presence of a plasticizer in the concrete mixture improves thermal conductivity, and therefore heat transfer into the room.

Serious insulation is important for any floor, and not necessarily with heating. Poor thermal insulation turns the floor into a large “radiator” for the ground. Is it worth heating it in winter?!

Important! Cold floors and dampness appear in the house when the ventilation of the underground space is not working or not done (vents are not organized). No heating system can compensate for such a deficiency.

Junction points of building structures

The compounds disrupt the integrity of the materials. Therefore, corners, joints and abutments are so vulnerable to cold and moisture. Connection points concrete panels They become damp first, which is where fungus and mold appear. The temperature difference between the corner of the room (the junction of the structures) and the main wall can range from 5-6 degrees to subzero temperatures and condensation inside the corner.

Clue! At the sites of such connections, craftsmen recommend making an increased layer of insulation on the outside.

Heat often escapes through interfloor covering, when the slab is laid over the entire thickness of the wall and its edges face the street. Here the heat loss of both the first and second floors increases. Drafts form. Again, if there is a heated floor on the second floor, the external insulation should be designed for this.

Heat leaks through ventilation

Heat is removed from the room through equipped ventilation ducts, ensuring healthy air exchange. Ventilation that works “in reverse” draws in the cold from the street. This happens when there is a shortage of air in the room. For example, when a switched-on fan in the hood takes too much air from the room, due to which it begins to be drawn in from the street through other exhaust ducts (without filters and heating).

Questions about how not to withdraw a large number of heat outside, and how not to let cold air into the house, have long had their own professional solutions:

1. Recuperators are installed in the ventilation system. They return up to 90% of the heat to the house.
2. Getting settled supply valves. They “prepare” the street air before entering the room - it is cleaned and warmed. The valves come with manual or automatic adjustment, which is based on the difference in temperature outside and inside the room.

Comfort costs good ventilation. With normal air exchange, mold does not form and a healthy microclimate for living is created. That is why a well-insulated house with a combination of insulating materials must have working ventilation.

Bottom line! To reduce heat loss through ventilation ducts It is necessary to eliminate errors in air redistribution in the room. In properly functioning ventilation only warm air leaves the house, some of the heat from which can be returned back.

Heat loss through windows and doors

A house loses up to 25% of heat through door and window openings. The weak points for doors are a leaky seal, which can be easily replaced with a new one, and thermal insulation that has become loose inside. It can be replaced by removing the casing.

Vulnerable spots for wooden and plastic doors similar to “cold bridges” in similar window designs. Therefore, we will consider the general process using their example.

What indicates “window” heat loss:

• Obvious cracks and drafts (in the frame, around the window sill, at the junction of the slope and the window). Poor fit of the valves.
• Damp and moldy internal slopes. If the foam and plaster have become detached from the wall over time, then the moisture from outside gets closer to the window.
• Cold glass surface. For comparison, energy-saving glass (at -25° outside and +20° inside the room) has a temperature of 10-14 degrees. And, of course, it doesn’t freeze.

The sashes may not fit tightly when the window is not adjusted and the rubber bands around the perimeter are worn out. The position of the valves can be adjusted independently, as well as the seal can be changed. It is better to completely replace it once every 2-3 years, and preferably with a seal of “native” production. Seasonal cleaning and lubrication of rubber bands maintains their elasticity during temperature changes. Then the seal does not let the cold in for a long time.

Slots in the frame itself (relevant for wooden windows) are filled silicone sealant, better transparent. When it hits the glass it is not so noticeable.

The joints of the slopes and the window profile are also sealed with sealant or liquid plastic. IN difficult situation, you can use self-adhesive polyethylene foam - “insulating” tape for windows.

Important! It is worth making sure that in the finishing of external slopes the insulation (foam plastic, etc.) completely covers the seam polyurethane foam and the distance to the middle of the window frame.

Modern ways to reduce heat loss through glass:

• Use of PVI films. They reflect wave radiation and reduce heat loss by 35-40%. Films can be glued to an already installed glass unit if there is no desire to change it. It is important not to confuse the sides of the glass and the polarity of the film.
• Installation of glass with low-emission characteristics: k- and i-glass. Double-glazed windows with k-glass transmit the energy of short waves of light radiation into the room, accumulating the body in it. Long-wave radiation no longer leaves the room. As a result, the glass on the inner surface has a temperature twice as high as that of ordinary glass. i-glass holds thermal energy in the house by reflecting up to 90% of the heat back into the room.
• The use of silver-coated glass, which in 2-chamber double-glazed windows saves 40% more heat (compared to conventional glass).
• Selection of double-glazed windows with an increased number of glasses and the distance between them.

Healthy! Reduce heat loss through glass - organized air curtains above the windows (possibly in the form of warm baseboards) or protective shutters at night. This is especially true for panoramic glazing and severe sub-zero temperatures.

Causes of heat leakage in the heating system

Heat loss also applies to heating, where heat leaks often occur for two reasons.

• Powerful radiator without protective screen heats the street.

• Not all radiators warm up completely.

Following simple rules reduces heat loss and prevents the heating system from running idle:

1. A reflective screen should be installed behind each radiator.
2. Before starting the heating, once a season, it is necessary to bleed the air from the system and check whether all radiators are fully warmed up. The heating system can become clogged due to accumulated air or debris (delaminations, poor quality water). Once every 2-3 years the system must be completely flushed.

The note! When refilling, it is better to add anti-corrosion inhibitors to the water. This will support the metal elements of the system.

Heat loss through the roof

Heat initially tends to the top of the house, making the roof one of the most vulnerable elements. It accounts for up to 25% of all heat loss.

Cold attic space or residential attic are insulated equally tightly. The main heat losses occur at the junctions of materials, it does not matter whether it is insulation or structural elements. Thus, an often overlooked bridge of cold is the boundary of the walls with the transition to the roof. It is advisable to treat this area together with the Mauerlat.

Basic insulation also has its own nuances, related more to the materials used. For example:

1. Mineral wool insulation should be protected from moisture and it is advisable to change it every 10 to 15 years. Over time, it cakes and begins to let in heat.
2. Ecowool, which has excellent “breathable” insulation properties, should not be located near hot springs - when heated, it smolders, leaving holes in the insulation.
3. When using polyurethane foam, it is necessary to arrange ventilation. The material is vapor proof and excess moisture It is better not to accumulate under the roof - other materials are damaged and a gap appears in the insulation.
4. Plates in multi-layer thermal insulation must be laid in a checkerboard pattern and must adhere closely to the elements.

Practice! IN upper structures any gap can drain a lot of expensive heat. Here it is important to place emphasis on dense and continuous insulation.

Conclusion

It is useful to know the places of heat loss not only for arranging a house and living in comfortable conditions, but also so as not to overpay for heating. Proper insulation in practice pays for itself in 5 years. The term is long. But we’re not building a house for two years.

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