Ideal home: calculation of heat loss at home. Reducing heat loss in the house How much heat escapes through the walls

Good afternoon to all forum participants!

We recently got our first home. Apartment in a panel building, 5th floor (last), not corner. The roof of the house was built a couple of years ago (slate). It’s warm in the entrance, there’s even a radiator hanging on the ground floor, it’s always warm. The apartment now has very old windows, the cracks were partially sealed with tape by the previous owners. The balcony (in the only room) is “glazed” (in quotes because there is no sash).

We don’t live in an apartment yet, but when we get there, it’s basically warm, and I want to immediately take off my jacket. The walls are all dry, the ceiling is dry, and the joints too. The thickness of the external walls is approximately 35 cm, the outside is lined with rectangular yellow tiles. The apartment will have electric heating and metal-plastic windows.

This is the prehistory, the conditions, so to speak. And now a few questions for people who understand insulation. I would like to minimize heating costs, what is the best way to do this initially, so as not to regret the effort, time and money spent later, or, if this question is asked differently: what needs to be done to reduce the heat loss of the apartment?

From what I read here, I realized that there is no need to take risks with insulating the apartment from the inside. However, here we are mainly talking about insulating external walls, which, directly, are in contact with the street.

Here are my thoughts, again from what I read and knew before:

1. Because Warm air rises and cold air sinks:
   • insulate the floor. Possible option: a primer, then a film (vapor barrier), then a thin roll of foam plastic and an OSB board on top;
   • install the ceiling from the roof side. The only question is how and with what?
2. Because I want to keep the room warm longer:
   • glue the wall that I have adjacent to my neighbors with the same thin rolled foam (the gluing technology is unknown to me, so if this can be done at all, please indicate/give a link/poke your nose on what and how);
   • How can I insulate the wall in the bathroom (it is in contact with the neighbor’s bathroom) and the wall that faces the entrance? As for the bathroom, I don’t have any options of my own, because... there will be tiles on top and I don’t know how to do it. As for the wall in the entrance - I have the same foam.
3. The old balcony will be completely removed, so here I also want to hear recommendations for building it again. I plan to have an iron frame, the bottom (facade) is made of ondulin (well, I like it very, very much))). But inside - the question is how to make it possible to store vegetables there (in terms of temperature and humidity), etc.?

There are several wishes, so to speak, additional conditions:

1. Taking up an already small area as little as possible;
2. It is possible to improve sound insulation: it will be easier for neighbors, and the music will sound better;
3. I have no skills for such work, but I think that my arms are still growing out of my shoulders, so I want to do it myself.

I'm looking for advice from knowledgeable people. Thanks in advance.

It is generally accepted that for central Russia the power of heating systems should be calculated based on the ratio of 1 kW per 10 m 2 of heated area. What does SNiP say and what are the real calculated heat losses of houses built from various materials?

SNiP indicates which house can be considered, so to speak, correct. From it we will borrow building standards for the Moscow region and compare them with typical houses built from timber, logs, foam concrete, aerated concrete, brick and using frame technologies.

How it should be according to the rules (SNiP)

However, the values ​​we took of 5400 degree-days for the Moscow region are borderline to the value of 6000, according to which, in accordance with SNiP, the heat transfer resistance of walls and roofs should be 3.5 and 4.6 m 2 °C/W, respectively, which is equivalent to 130 and 170 mm of mineral wool with thermal conductivity coefficient λA=0.038 W/(m °K).

Like in reality

Often people build “frame”, log, timber and stone houses based on available materials and technologies. For example, in order to comply with SNiP, the diameter of the logs must be more than 70 cm, but this is absurd! That’s why they most often build it the way it’s more convenient or the way they like it the most.

For comparative calculations, we will use a convenient heat loss calculator, which is located on its author’s website. To simplify the calculations, let’s take a one-story rectangular room with sides of 10 x 10 meters. One wall is blank, the rest have two small windows with double-glazed windows, plus one insulated door. The roof and ceiling are insulated with 150 mm stone wool, as the most typical option.

In addition to heat loss through walls, there is also the concept of infiltration - the penetration of air through walls, as well as the concept of household heat release (from the kitchen, appliances, etc.), which, according to SNiP, is equated to 21 W per m 2. But we won’t take this into account now. As well as ventilation losses, because this requires a completely separate discussion. The temperature difference is taken as 26 degrees (22 indoors and -4 outside - as averaged over the heating season in the Moscow region).

So here's the final diagram comparing heat loss of houses made of different materials:

Peak heat losses are calculated for an outside temperature of -25°C. They show what the maximum power of the heating system should be. “House according to SNiP (3.5, 4.6, 0.6)” is a calculation based on more stringent SNiP requirements for the thermal resistance of walls, roofs and floors, which is applicable to houses in slightly more northern regions than the Moscow region . Although, often, they can be applied to her.

The main conclusion is that if during construction you are guided by SNiP, then the heating power should not be 1 kW per 10 m 2, as is commonly believed, but 25-30% less. And this does not take into account household heat generation. However, it is not always possible to comply with the standards, and it is better to entrust the detailed calculation of the heating system to qualified engineers.

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To date heat saving is an important parameter that is taken into account when constructing a residential or office space. In accordance with SNiP 23-02-2003 “Thermal protection of 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 in relation to the prescribed level, provided that the design specific heat energy consumption for space heating is lower than the standard one).

Sanitary and hygienic requirements:

• The difference between indoor and outdoor air temperatures should not exceed certain permissible values. The maximum permissible temperature difference for an external wall is 4°C. for roofing and attic flooring 3°C and for ceilings over basements and crawl spaces 2°C.
• The temperature on the inner surface of the 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 a permanent home 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, to correctly select the power of a heating boiler or heating devices, it is necessary to calculate the 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 a square meter of structure 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 are talking 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.

Table of heat transfer resistance of various materials

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

Table of heat losses of windows of various designs at ΔT = 50 °C (T external = -30 °C. T internal = 20 °C.)

Note
. Even numbers in the designation of a double-glazed window 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 of walls, ceilings, etc. for some values ​​of winter air temperature. 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 m2 along the internal contour of the walls) depending on the average temperature of the coldest week of the year.

Note. If 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 there is another external 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.
• above the 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

The area of ​​the internal partitions is not included 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 sheathing, 10 centimeters of mineral wool, lining). gables (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 will calculate the heat losses of these surfaces, while 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 sloped 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 can see, a warm room on the 1st floor loses (or consumes) significantly less heat than an attic room with thin walls and a large glazing area.

To make this room suitable for winter living, 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 best timber wall should be equivalent to a timber wall 15 - 20 centimeters thick. 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.)

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 of 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, at an outside temperature of -25 °C, 213 W per 1 m 2 of total area is required, 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.

Any construction of a house begins with drawing up a house project. Already at this stage you should think about insulating your home, because... there are no buildings and houses with zero heat loss, which we pay for in the cold winter, during the heating season. Therefore, it is necessary to insulate the house outside and inside, taking into account the recommendations of the designers.

What and why to insulate?

During the construction of houses, many do not know, and do not even realize that in a built private house, during the heating season, up to 70% of the heat will be spent on heating the street.

Asked about saving the family budget and the problem of insulating the house, many ask the question: what and how to insulate ?

This question is very easy to answer. It’s enough to look at the screen of a thermal imager in winter, and you will immediately see through which structural elements heat escapes into the atmosphere.

If you don’t have such a device, then it doesn’t matter, below we will describe statistical data that shows where and in what percentage the heat leaves the house, and also post a video of a thermal imager from a real project.

When insulating a house It is important to understand that heat escapes not only through the floors and roof, walls and foundation, but also through old windows and doors that will need to be replaced or insulated during the cold season.

Distribution of heat loss in the house

All experts recommend implementing insulation of private houses , apartments and industrial premises, not only from the outside, but also from the inside. If this is not done, then the “dear” warmth to us, in the cold season, will simply quickly disappear into nowhere.

Based on statistics and data from experts, according to which, if the main heat leaks are identified and eliminated, then it will be possible to save 30% or more on heating in winter.

So, let's figure out in what directions and in what percentage our heat leaves the house.

The largest heat losses occur through:

Heat loss through the roof and ceilings

As you know, warm air always rises to the top, so it heats the uninsulated roof of the house and ceilings, through which 25% of our heat leaks.

To produce house roof insulation and reduce heat loss to a minimum, you need to use roof insulation with a total thickness of 200mm to 400mm. The technology for insulating the roof of a house can be seen by enlarging the picture on the right.

Heat loss through walls

Many will probably ask the question: why is there more heat loss through the uninsulated walls of the house (about 35%) than through the uninsulated roof of the house, because all the warm air rises to the top?

Everything is very simple. Firstly, the area of ​​the walls is much larger than the area of ​​the roof, and secondly, different materials have different thermal conductivity. Therefore, when building country houses, first of all you need to take care of insulation of house walls. For this purpose, insulation for walls with a total thickness of 100 to 200 mm is suitable.

To properly insulate the walls of a house, you must have knowledge of technology and special tools. The technology for insulating the walls of a brick house can be seen by enlarging the picture on the right.

Heat loss through floors

Oddly enough, uninsulated floors in a house take away from 10 to 15% of the heat (the figure may be higher if your house is built on stilts). This is due to ventilation under the house during the cold period of winter.

To minimize heat loss through insulated floors in the house, you can use insulation for floors with a thickness of 50 to 100 mm. This will be enough to walk barefoot on the floor in the cold winter season. The technology for insulating floors at home can be seen by enlarging the picture on the right.

Heat loss through windows

Window- perhaps this is the very element that is almost impossible to insulate, because... then the house will look like a dungeon. The only thing that can be done to reduce heat loss by up to 10% is to reduce the number of windows in the design, insulate the slopes and install at least double-glazed windows.

Heat loss through doors

The last element in the design of a house through which up to 15% of heat escapes is the doors. This is due to the constant opening of the entrance doors, through which heat constantly escapes. For reducing heat loss through doors to a minimum, it is recommended to install double doors, seal them with sealing rubber and install thermal curtains.

Advantages of an insulated house

• Cost recovery in the first heating season
• Saving on air conditioning and heating at home
• Cool indoors in summer
• Excellent additional sound insulation of walls and ceilings and floors
• Protection of house structures from destruction
• Increased indoor comfort
• It will be possible to turn on the heating much later

Results for insulating a private house

It is very profitable to insulate a house , and in most cases it is even necessary, because this is due to a large number of advantages over non-insulated houses, and allows you to save your family budget.

Having carried out external and internal insulation of the house, your private home will become like a thermos. Heat will not escape from it in winter and heat will not come in in summer, and all costs for complete insulation of the facade and roof, basement and foundation will be recouped within one heating season.

For the optimal choice of insulation for your home , we recommend that you read our article: Main types of insulation for the home, which discusses in detail the main types of insulation used to insulate a private home outside and inside, their pros and cons.

Video: Real project - where does the heat in the house go?

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 load-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 structural elements.

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 with adhesive compositions of 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.

Reinforced concrete has one of the highest thermal conductivity coefficients among building materials (1.28 - 1.61 W/(m*K)). 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 an additional air layer for heat.

• Mounting holes and fasteners.

Connecting an air conditioner or TV antenna leaves gaps in the overall insulation. The through metal fasteners 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. Yes, and the main insulation materials 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 the basement and improperly installed heated floors 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 thermal insulation materials are also sensitive to humidity. 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 wet soil. Its structure creates an air cushion and well compensates for ground pressure during freezing, but the constant presence of moisture minimizes the useful properties of expanded clay in 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, at least a meter wide. 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 - the 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). The optimal thickness of the screed is 3-7 cm. The presence of a plasticizer in the concrete mixture improves thermal conductivity, and therefore the transfer of heat 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. The joints of concrete panels become damp first, and fungus and mold appear there. 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 sub-zero 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 the interfloor ceiling when the slab is laid across 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).

The questions of how not to remove large amounts 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. Supply valves are being installed. 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 easily be re-glued to 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 are 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.

The cracks in the frame itself (relevant for wooden windows) are filled with silicone sealant, preferably 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 a 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 of the 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 retains 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 over the windows (possibly in the form of warm baseboards) or protective roller 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.

• A powerful radiator without a 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.

A cold attic or residential attic is 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 it is better not to accumulate excess moisture 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 overhead structures, any breach can remove 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 in order to equip your home and live 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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