Insulation technologies

Lecture content:

1. Regulatory framework
2. Thermal insulation
3. Thermal insulation of enclosing structures
4. Modern architectural solutions
5. Active links (NPA, standards, resources)
6. Glossary
7. Questions for self-testing

1. Regulatory framework

• Laws of Ukraine:
  • “On Energy Efficiency”
  • “On Energy Efficiency of Buildings”
• Main DBN and DSTU:
  • DBN V.2.6-31:2021 “Thermal Insulation and Energy Efficiency of Buildings”
  • DBN V.2.6-33:2018 “External Wall Structures with Facade Thermal Insulation”
  • DSTU 9191:2022 “Thermal Insulation of Buildings. Method for selecting thermal insulation material”
  • DSTU-N B V.2.6-191:2013 “Air permeability of enclosing structures”
  • DSTU-N B V.2.6-192:2013 “Thermo-hygrological state of structures”
  • DBN V.1.1.7-2016 “Fire safety of construction objects”
  • DSTU B V.2.6-34, 35, 36:2008 “External wall structures with facade thermal insulation”

2. Thermal insulation

Today, Ukraine has already developed a number of standards for calculating the thermal envelope of buildings. We have quite effective state building codes, and at the same time, gradual harmonization with European standards is taking place.

The state’s course is now clear: reconstruction and sustainable development. This means that we strive for all new buildings to be both efficient and environmentally friendly. And achieving this without high-quality thermal insulation is simply impossible.

Assessment methods

Special devices help us to see exactly where a house is losing heat. These are, first of all, thermal imaging cameras and infrared thermometers. For example, a thermal imaging camera clearly shows how heat passes through the enclosing structures and exactly where energy losses occur. It records the radiation spectrum, and we can clearly see weak points.

But it is very important: the energy efficiency of a building cannot be considered fragmentarily. What is often done in our country — the so-called “patch” insulation, when only one apartment or a piece of the facade is insulated — is not only ineffective, but also a violation of the law. After all, the facade is the common property of all residents of the building. And according to the Law of Ukraine “On Energy Efficiency”, thermal modernization should be carried out comprehensively, and not partially.

Physics of processes

The efficiency of thermal energy consumption directly depends on what kind of thermal envelope the building has. For example, you can compare a house with a thermos. But there is a significant difference here: a thermos only stores heat, and the building must also “breathe”. That is, the enclosing structures must not only retain heat, but also let air through. This is necessary so that moisture does not accumulate inside. And in addition, the structures must be strong, withstand the load.

What is thermal conductivity? This is the property of a material to transfer heat from a hotter surface to a less hot one. It is characterized by the thermal conductivity coefficient. To simplify, the phenomenon of thermal conductivity is when the energy of atoms and molecules from a hotter part is transferred to a colder one.

At the same time, the same heat transfer conditions may require different thicknesses of thermal insulation material. That is why the standards provide laboratory methods for determining such indicators as thermal conductivity, heat absorption, and vapor permeability. Materials that go on sale must have quality certificates confirming these characteristics.

And here is another important thing: the material in a dry state retains heat much better than in a wet state. And we must always take into account that moisture is present everywhere – and it will necessarily penetrate through the thickness of the enclosing structure. Therefore, there is no such thing as a completely dry wall or ceiling. This must be taken into account when choosing a heater.

And the indoor microclimate is determined by two key indicators: temperature and relative humidity. According to the standards, it should be about 20°C and 55% humidity. And it is the balance of these parameters that affects the comfort in the room.

Approximate heat loss

Let’s see where exactly the building loses heat.

The main sources of loss look like this:

• Up to 15% of heat can go through the roof;
• Up to 30% through the walls;
• Windows and doors provide another 25%;
• Ventilation — also up to 30%;
• And approximately 10% is lost through the basement.

These are, of course, approximate figures. In practice, everything depends on many factors: what type of building it is, what materials are used, what is the thickness of the windows and doors, whether there is insulation and what is its thickness.

3. Thermal insulation of enclosing structures

Practical requirements

When we talk about new construction or thermal modernization projects, we must always rely on the normtive base. And here are three key documents:

• DBN V.2.6-31:2021 – “Thermal insulation and energy efficiency of buildings”;
• DBN V.2.6-33:2018 – “External wall structures with facade thermal insulation. Requirements for design, arrangement”;
• DSTU 9191:2022 – “Thermal insulation of buildings. Method for selecting thermal insulation material”.

This last standard already takes into account the European approach and is harmonized with EU standards.

Now about materials. In Ukraine, mineral wool and foamed polymers are most often used for building insulation – these are various foam plastics, expanded polystyrene. If we talk about safety, mineral wool is the best choice. It “breathes” well, lets moisture through. But polymer insulation is more airtight: it simultaneously retains heat and blocks steam, actually also performing the function of waterproofing.

There are several important requirements for the enclosing structures themselves:

• the building must be in satisfactory condition in general;
• the foundations and supporting elements must withstand not only the existing, but also additional loads from the insulation;
• sanitary and hygienic standards must be taken into account.

In particular, the temperature on the inner surface of the walls should not differ from the temperature in the room by more than 4 °C in residential buildings and 5 °C in public buildings.

An important concept here is the dew point. This is the minimum temperature at which moisture begins to condense. If the structure freezes and the dew point is inside the wall, moisture appears there, and with it fungus and mold. This is not only harmful to the structure, but also dangerous to health. Therefore, modern houses are designed to avoid such situations.

Design practice

From the point of view of the heating season, Ukraine is divided into two temperature zones. In the north, the heating period is longer, in the south – shorter. This also leads to the calculation standards. The minimum permissible heat transfer resistance is determined for each zone. That is, which walls, enclosing elements or translucent structures must provide this indicator.

And importantly: energy efficiency requirements are gradually increasing. Each new stage of building codes makes the standards more stringent – both builders and designers must take this into account.

Internal insulation in modern houses is strictly prohibited. It can be used only in cases of old buildings or for specific types of buildings, and only when the work is performed by highly qualified specialists. Otherwise, the consequences will be negative – condensate, fungus, mold.

There is also such a thing as non-standard heat-conducting inclusions. They always require modeling using two-dimensional temperature fields. Some of these solutions can be found ready-made – in reuse projects.

If we talk about external insulation, then there are two options: plaster facade and ventilated facade.

Plaster facade is a more standard and practical solution. But here it is very important that the insulation is glued correctly: tightly, hermetically, without cavities inside. There must be a layer of wind barrier.

A ventilated facade is more complex to perform, and the presence of a reinforcing mesh is mandatory there. Most often it is a fiberglass mesh, on top of which a primer and decorative painting are applied. And here the main thing is that all materials are securely connected – then the structure will work as a single integral element.

4. Modern architectural solutions

Modern architectural solutions have become much stricter. If we are talking about installing windows, then the entire structure must be sealed – there should be no visible seams. Protruding elements – cornices, balcony slabs, canopies – must be insulated. As well as corners or other protrusions, because these are the areas of greatest heat loss.

A separate problem is gas pipes and cables. In practice, moving them 5-10 centimeters from the wall is more expensive than insulating several floors. Therefore, designing the transfer of communications in the process of thermal modernization often turns into a difficult task.

The modern approach requires that window structures be installed in a layer of insulation. This allows you to create a uniform thermal field and avoid cooling the structure. If the windows remain recessed, then the slopes must be covered with insulation, otherwise we will get additional heat leakage.

And one more point. If you do not insulate balcony slabs or window structures, do not make a reinforcing layer, then over time this leads to problems. The plaster begins to crack, moisture gets inside, and as a result, the facade begins to peel off and crumble.

Control over the condition of the enclosing structures in residential buildings is carried out by the residents themselves, and in public facilities – by the administration. And here it is important to mention the “eVidnovlenie” program. This is a state initiative that provides for the provision of financial assistance to the owners of damageddamaged housing for repairs. Also, within the framework of the program, you can receive housing certificates for the purchase of new housing to replace the destroyed one.

Active links

• Law of Ukraine “On Energy Efficiency” (Vedomosti Verkhovna Rada of Ukraine (VVR), 2022, No. 2, Art. 8): https://zakon.rada.gov.ua/laws/show/1818-20#Text
• Law of Ukraine “On Energy Efficiency of Buildings” (Vedomosti Verkhovna Rada of Ukraine (VVR), 2017, No. 33, Art. 359): https://zakon.rada.gov.ua/laws/show/2118-19#Text
• DBN V.2.6-31:2021 “Thermal insulation and energy efficiency of buildings”:
  https://e-construction.gov.ua/laws_detail/3075196638495507996
• DBN V.2.6-33:2018 “External wall structures with facade thermal insulation”: https://e-construction.gov.ua/laws_detail/3075201563413710205?doc_type=2
• DSTU 9191:2022 “Thermal insulation of buildings. Method of selecting thermal insulation material”: https://eurobud.ua/wp-content/uploads/2023/05/dstu-9191-2022-teploizolyacziya-budivel-metod-vyboru-teploizolyaczijnogo-materialu-dlya-uteplennya-budivel.pdf
• Program “eRecovery”: https://erecovery.diia.gov.ua/