What you need to know about heating and thermal modernization

Lecture content:

1. What is thermal modernization
2. Energy audit: why and what does it give
3. Building heating system
4. Heat energy accounting
5. Individual heat point (ITP)
6. Modern solutions
7. Active links (NPA, standards, resources)
8. Glossary
9. Questions for self-test

1. What is thermal modernization

Most people think that thermal modernization is only replacing windows or insulating the facade. That is, we are talking only about enclosing structures.

But in fact, thermal modernization is a much broader concept. This is a whole complex of works that are performed on a building that has already been put into operation. Its goal is to increase the energy efficiency of:

• the building itself,
• engineering systems and their elements,
• the thermal characteristics of the enclosing structures.

The level must meet not lower than the minimum requirements for the energy efficiency of buildings, defined by law.

An important nuance. There are several types of design work in construction:

• new construction,
• reconstruction,
• overhaul,
• restoration.

Thermomodernization should be distinguished from a major facade overhaul or adjustment of reconstruction. These are different concepts – both in the legal and technical sense.

Key theses

• Definition: thermal modernization is a set of works on a finished object that increases the energy efficiency of a building and its systems to the established minimum requirements.
• Mistake No. 1: reduce thermal modernization only to “window + facade”.
• Project work modes: new construction / reconstruction / overhaul / restoration. It is important to legally classify the type of work correctly.

2. Energy audit: why and what does it give

Energy audit is, in fact, the starting point for thermal modernization. It provides indicators that become the initial data for further analysis, recommendations and determination of specific types and volumes of work.

What is being assessed?

1. Enclosures

• • external walls;
  • walls bordering the parking lot;
  • combined coverings;
  • ceilings over the parking lot or driveway;
  • translucent structures (windows, facades);
  • external doors.

2. Key question: do they meet the minimum energy efficiency requirements?
3. Energy consumption of the building

• • heating,
  • cooling,
  • hot water supply,
  • ventilation,
  • lighting.

Important point

The assessment is based on two sources:

• data from metering devices,
• certification results.

And here a discrepancy almost always arises: these indicators never coincide, because certification works with calculated data, and accounting with actual data.

3. Building heating system

According to DBN V.2.5-67:2013, heating is the artificial heating of premises in the cold season to compensate for heat loss and maintain the required temperature. There is even such a thing as “average insecurity” – no more than 50 hours per year when the temperature may deviate from the norm.

The heating season begins when the temperature outside stays below 8°C for three consecutive days, and ends when it is also higher than 8°C for three consecutive days.

Why is the heating system key to energy efficiency?

• It is it that determines the temperature of the indoor air and the surfaces that surround us.
• Its condition and modernization directly affect the energy consumption of the building.

In many houses we have a legacy of a bygone era — old vertical systems. The best option for energy efficiency is to dismantle and install a new system. But in practice this is often impossible: each apartment is private property.

Main problems of old systems

• Damaged or missing thermal insulation on pipelines in unheated rooms (basements).
• System imbalance: some risers are overheated, others are underheated.
• Lack of regular flushing and quality maintenance.
• Unauthorized replacement of devices: residents change radiators to steel panel ones or add underfloor heating, without taking into account the hydraulic mode.
• Cast iron batteries are durable, but have high thermal inertia and do not meet modern energy efficiency requirements.

What to do?

• It is imperative to equip radiators with thermostatic elements – this allows you to avoid overheating and regulate the temperature in the rooms.
• Conduct system balancing:

• within the riser – pre-setting the thermostats;
• between the risers – using differential pressure regulators or flow limiters.

This allows you to equalize the temperature in all rooms.

Key conclusion: Balancing and regulating the heating system is critically important for resident comfort and for reducing energy costs.

But even the most modern equipment will not work effectively without responsible user behavior. Energy efficiency begins with a culture of energy management.

4. Heat energy metering

A very important point in the operation of the heating system is the heat metering unit. It consists of a flow meter on the supply and return lines, temperature sensors, and a heat calculator. All of this works in an integrated mode and allows you to understand how much the building actually consumes. For condominiums, this is critical – residents can see where their money is going.

Most modern meters are ultrasonic. But there is a nuance here: they should only be installed by certified specialists. If the stabilization areas are selected incorrectly, the meter will start to “lie” and count incorrectly.

Individual metering

In addition to the common unit, especially in buildings with a vertical heating system, you can do metering by apartment. The options are as follows:

• install a separate meter on each radiator;
• or use heat flow sensors mounted on the batteries. In the second case, the resident can block the radiator and pay minimally — only for the heat coming from the risers.

Patch insulation

One more point. If you insulate the house in “patches” — for example, individual apartments or only facade areas — there will be no significant savings. The figures in the heat bill will remain the same. Yes, the temperature in the apartment will rise, but there is actually no payback from such a decision.

Two key elements of successful thermal modernization

1. Resource accounting.
2. Weather-dependent regulation.

Without these things, even high-quality insulation can lose its meaning – because the savings will simply “dissolve”.

5. Individual heat point (ITP)

It is practically impossible to increase the efficiency of the heating system without ITP modernization. There must be two key elements:

• metering unit,
• weather-dependent regulation.

The old heat points had one plus – they worked without electricity. But the minus is that they are completely unregulated. The most common scheme used was a hydraulic elevator (in everyday life it is called a “basmak” or “sapog”). Yes, the system functioned without electricity, but it was impossible to influence its operation.

6. Modern solutions

Today, circulation pumps can be equipped with a frequency regulator, and this gives a tangible effect: unnecessary costs of both electricity and heat disappear.

There are two types of heating system regulation:

1. Qualitative – when the temperature of the coolant changes, that is, the temperature schedule is adjusted to external conditions.
2. Quantitative – when the flow rate changes, but the temperature difference remains constant.

Dependent and independent systems

In centralized schemes, the ability to adjust parameters is limited.

And in individual heat points, heat output can be adjusted more flexibly.

• Dependent systems are directly connected to the heating network.
• Independent systems must have a heat exchanger that hydraulically separates the heating network circuit and the house circuit.

This is a very important point: an independent system provides more control and stability, reduces risks and allows you to increase energy efficiency.

Independent connection

An independent connection to the heating system makes it possible to hydraulically separate the circuits: one from the heating network, the other from the house. This creates additional stability and control over the heating system, reduces the risk of accidents and allows you to regulate heat output more effectively.

An important step after thermal modernization

After the house has been conducted thermal modernization measures — insulated, windows replaced, heating system modernized — it is imperative to notify the heat supply organization.

Why? So that the company knows about the estimated reduction in heat consumption and can correctly adjust the supply parameters. If this is not done, the system mayIf you stay in the “old mode” and the house will simply overpay for excess heat.

Active links

• Law of Ukraine “On Energy Efficiency of Buildings” (Vedomosti Verkhovnoi Rada (VVR), 2017, No. 33, p. 359): https://zakon.rada.gov.ua/laws/show/2118-19#Text
• DBN V.2.5-67:2013 “Heating, Ventilation and Air Conditioning”: https://e-construction.gov.ua/laws_detail/3074971619479783152
• National Energy and Climate Plan 2030 (NECP): https://me.gov.ua/Documents/Detail?lang=uk-UA&id=f7088035-142e-4912-9aa0-6fe2def80c1b&title=ProektNatsionalnogoPlanuZEnergetikiTaKlimatuUkraini2025-2030
• Building Energy Efficiency Certification https://saee.gov.ua/diialnist/sertyfikatsiia-enerhetychnoi-efektyvnosti-budivel