Thermal unit scheme of the thermal unit

Optimizing comfort and energy efficiency of your home’s heating system requires an understanding of its thermal unit scheme. This plan describes how heat is generated, dispersed, and used in your home to keep it comfortable throughout the winter. Homeowners can make educated decisions about insulation, heating systems, and energy-saving techniques by understanding this scheme.

Fundamental to the thermal unit scheme is the central heating system, usually driven by a boiler or furnace. These appliances burn fuel, like electricity, natural gas, or oil, to produce heat. Depending on the configuration, the heat is then distributed throughout the house using ductwork, radiators, or underfloor heating systems.

The distribution system, control mechanisms, and heat source are important parts of the thermal unit scheme. Warmth is produced by the heat source, which could be a boiler or furnace. This heat is distributed throughout the house’s rooms and spaces by means of ducts, pipes, or other conduits. Thermostats and zoning systems are examples of control mechanisms that manage temperature and guarantee energy efficiency.

Insulation is essential to the thermal unit scheme because it maximizes energy efficiency and reduces heat loss. The workload on the heating system is decreased when walls, floors, ceilings, and windows are properly insulated to help retain heat inside the house. The efficiency of insulation is further increased by caulking air leaks and drafts, which maintains comfortable and consistent interior temperatures.

Examining the heating system’s thermal unit scheme in your house can help you understand how well it works and where it might be improved. Knowing this plan enables homeowners to make their home warmer and more energy-efficient, whether it’s by installing an energy-efficient furnace, improving insulation, or adjusting thermostat settings.

Why do you need a heat pump??

The house’s main heating unit’s input is where the heat pump is situated. Modifying the coolant’s parameters is its primary goal. To put it another way, before the coolant enters your radiator or convector, the thermal unit lowers its temperature and pressure. It is essential to prolong the life of all the heating system’s equipment in addition to preventing burns from contact with the heating element. It is especially crucial if metal-plastic or polypropylene pipes are used to distribute heat inside the home. Heat units can operate in two regulated modes:

The heating medium’s maximum and lowest temperatures in the heating pipe are depicted in these figures.

Modern standards also mandate that every heat point have a heat metering device installed. Let’s now discuss the configuration of the heating units.

How the heat unit is organized?

Generally speaking, each heat point’s technical component is created independently based on the unique needs of the client. There are various fundamental heating unit design schemes. Let’s examine each of them separately.

Heat unit on the basis of an elevator.

The simplest and least expensive scheme is the heat point based on the elevator unit. The inability to control the coolant temperature in the pipes is its primary drawback. In the event that it thaws during the heating season, this results in significant overconsumption of heat energy and inconvenience for the end user. Let’s examine the following figure to comprehend the operation of this scheme:

The heat unit might also have a pressure-reducing reducer in addition to the items mentioned above. It is mounted before the elevator on the supply. The key component of this scheme is the elevator, where the hot heat carrier from the "supply" and the cooled heat carrier from the "return" are combined. The formation of a discharge at the elevator’s outlet is the foundation for its operation. This discharge causes mixing to occur because the pressure of the heat carrier in the elevator is lower than the pressure of the heat carrier in the "return."

Thermal unit based on a heat exchanger.

You can separate the coolant from the main heating system from the coolant inside the house by connecting a heating station with a specialized heat exchanger. Coolant separation makes it possible to prepare it with the aid of specialized additives and filtration. There are numerous options for controlling the heat carrier’s temperature and pressure inside the home with this design. This enables a decrease in heating expenses. Examine the figure below to get an idea of this design.

Thermostatic valves are used in these systems to help mix the coolant. Aluminum radiators can theoretically be used in these types of heating systems, but their longevity depends on the quality of the coolant. The lifespan of aluminum radiators can be significantly shortened if the coolant’s PH is higher than what the manufacturer has considered acceptable. Since you have no control over the heat carrier’s quality, it is best to install cast iron or bimetallic radiators as insurance.

A heat exchanger can be used to connect DHW in a comparable manner. This provides the same benefits for controlling hot water pressure and temperature. It is important to note that dishonest management firms have the ability to mislead customers by slightly underestimating the temperature of hot water. Although practically invisible to the consumer, it can save you tens of thousands of rubles a month on a household scale.

Article Summary.

I gave you a brief introduction to thermal units in this article. While by no means comprehensive, this will serve as a good starting point for learning about this vast subject. I can state that, if they are connected to central heating, heat units are now installed not only in apartment buildings but also in private homes. Although there are upfront expenses associated with this solution, it will ultimately make living in a private home more comfortable. That’s all for now. Please use the social media buttons to share this article with friends and leave your questions in the comments section. Farewell!

In understanding the thermal unit scheme of a heating system for your home, it"s essential to grasp the basic setup. Essentially, the thermal unit scheme is the blueprint for how your heating system operates. It outlines the flow of heat throughout your home, from the source of heat—like a furnace or boiler—to the various rooms. Think of it as a roadmap that guides the warmth from where it"s generated to where it"s needed most. This scheme typically includes components like pipes, radiators, vents, and controls, all working together to distribute heat efficiently. By understanding this scheme, homeowners can better maintain and optimize their heating systems for comfort and energy efficiency, ensuring cozy winters and lower utility bills.

What is a heating system elevator unit?

Powerful boiler houses or CHP systems supply heat to office buildings, multi-story buildings, high-rises, and a wide range of other consumers. It can be challenging to modify even a fairly basic autonomous system in a private home, particularly if errors were made in the design or installation. However, a large boiler house or cogeneration plant’s heating system is unimaginably more complicated. Each consumer has a different pressure in the heating pipes and a different amount of heat consumed, and there are numerous branches from the main pipe.

Since pipeline lengths differ, the system should be built to ensure that even the furthest-flung consumer gets enough heat. The reason behind the coolant pressure in the heating system becomes evident. As a circulation pump, pressure is generated by the central heating main and drives water through the heating circuit. When a consumer’s heat consumption varies, the heating system shouldn’t become out of balance.

Furthermore, the system’s branching shouldn’t have an impact on the heat supply’s efficiency. To ensure stable operation of a complex centralized heating system, each facility must have an automated heating system control unit or an elevator unit installed in order to prevent mutual influence.

Thermal distribution point of the building

One of the three temperature modes for boiler operation is advised by heat engineers. These regimes have been used in practice for many years after being initially computed theoretically. They guarantee the most efficient transfer of heat over long distances with the least amount of loss.

Boiler thermal regimes are defined as the ratio of the supply temperature to the "return" temperature:

1. 150/70 – supply temperature is 150 degrees and return temperature is 70 degrees.
2. 130/70 – water temperature 130 degrees, the temperature of the "return" 70 degrees;
3. 95/70 – water temperature is 95 degrees, "return" temperature is 70 degrees.

In actuality, the value of the winter air temperature determines which mode is used for each unique location. It should be mentioned that using high temperatures—particularly 150 and 130 degrees—to heat rooms is prohibited in order to prevent burns and major repercussions in the event of depressurization.

Because of the high pressure inside the pipelines, the water does not boil because its temperature is higher than its boiling point. Thus, for a given building, it is imperative to lower the temperature and pressure and provide the required heat extraction. The heating system’s elevator unit, a unique piece of heat engineering machinery housed in the heat distribution center, is tasked with handling this duty.

Design and principle of operation of the heating elevator

The node connecting the supply and return pipes is the focal point of the heating network pipeline, which is typically located in the basement. This is a mixing unit for heating a house, an elevator. The elevator is produced as a steel or cast iron structure with three flanges installed. The working principle of this traditional heating elevator is founded in the laws of physics. A diffuser, a mixing chamber, a receiving chamber, and a nozzle are all located inside the elevator. A flange is used to connect the inlet chamber to the "return".

The water that has been superheated enters the elevator inlet and travels through the nozzle. Bernoulli’s law states that as the nozzle narrows, the flow velocity increases and the pressure decreases. The elevator’s mixing chamber is filled with mixed water from the "return," which is drawn into the area of lower pressure. In addition to lowering the temperature to the appropriate level, water also lowers pressure. The elevator doubles as a mixer and circulation pump at the same time. This is a quick explanation of the elevator’s working principle in a building’s heating system.

Schematic diagram of the heat distribution unit

The house elevator heating nodes are responsible for controlling the coolant supply. The heating unit’s primary component, the elevator, requires plumbing. Because the regulating apparatus is susceptible to dirt, there are dirt filters in the piping that are linked to the "supply" and "return" ports.

This elevator has a device that can move the gate valve’s throttle needle in an emergency or for preventive maintenance:

• mud filters;
• pressure gauges (at the inlet and outlet);
• temperature sensors (thermometers at the elevator inlet, at the outlet and at the "return");
• Gate valves (for preventive or emergency work).

Although this is the most basic version of the coolant temperature regulation scheme, it is frequently utilized as the thermal unit’s primary component. The basic unit elevator regulates the coolant’s temperature and pressure in the circuit to heat any buildings or structures.

Benefits of using it to heat big items, homes, and skyscrapers:

1. failure-free operation, due to the simplicity of construction
2. low price of installation and component parts;
3. absolute energy independence;
4. significant saving of coolant consumption up to 30%.

Though there are unquestionable benefits to utilizing an elevator for heating systems, there are drawbacks as well:

• the calculation is made individually for each system;
• a mandatory pressure drop in the heating system of the object is required;
• if the elevator is unregulated, it is impossible to change the parameters of the heating circuit.

Elevator with automatic regulation

There are elevator designs available today that allow for electronic regulation of the nozzle cross-section. There is a mechanism in such an elevator that moves the throttle needle. It modifies the nozzle lumen, which modifies the heat transfer medium’s flow rate. The lumen can be adjusted to alter the water’s movement speed. This causes a change in the mixing coefficient between the hot water and the water from the "return," which raises the coolant’s temperature in the "supply." It is now evident why water pressure is necessary for the heating system.

The coolant supply and pressure are controlled by the elevator, and the coolant’s pressure controls the flow of the heated circuit.

Basic faults of the elevator unit

Even something as basic as an elevator unit can break down. Analyzing the pressure gauge readings at the elevator unit’s control points can reveal faults:

1. Malfunctions are often caused by dirt and solids in the water clogging the pipes. If there is a drop in pressure in the heating system, which is much higher before the strainer, then this malfunction is caused by the clogging of the strainer, which stands in the supply pipeline. The dirt is discharged through the downpipes of the strainer, cleaning the screens and internal surfaces of the device.
2. If the pressure in the heating system fluctuates, the possible causes may be corrosion or clogging of the nozzle. If a nozzle failure occurs, the pressure in the heating expansion tank may exceed the permissible pressure.
3. There is a possible case when the pressure in the heating system increases, and the pressure gauges before and after the strainer in the "return" show different values. In such a case, the return strainer must be cleaned. The drain taps on it are opened, the mesh is cleaned, and the dirt from inside is removed.
4. If the nozzle size changes due to corrosion, the heating circuit is vertically unbalanced. The radiators will be hot downstairs and not hot enough on the upper floors. Replacing the nozzle with a nozzle with a calculated value of diameter eliminates such a malfunction.

Distributing devices

The elevator unit, complete with all of its plumbing, can be thought of as a discharge circulation pump that feeds coolant into the heating system at a specific pressure.

The best course of action in cases where the object has multiple floors and consumers is to allocate the entire flow of the heating medium to each individual consumer.

The manifold, also known as the comb for the heating system, is designed to solve such tasks. One way to visualize this device is as a vessel. The elevator outlet feeds the heating medium into the tank, where it exits under pressure through a number of outlets.

As a result, the heating system distribution comb permits the individual consumers of the object to be disconnected, adjusted, or repaired without interrupting the heating circuit’s operation. The mutual influence of the heating system branches is eliminated by the manifold’s presence. In this instance, the pressure at the elevator outlet and the radiators’ pressure match.

Three-way valve

When it becomes necessary to split the coolant flow between two users, a three-way heating valve that functions in two ways is utilized:

• constant mode;
• variable hydro mode.

A three-way valve is installed in the heating circuit where it might be necessary to split or stop the water supply entirely. Brass, cast iron, or steel make up the valve’s material. A ball, cylindrical, or conical shut-off device is located inside the valve. The three-way valve on the heating system can function as a mixer based on the connection, and the tap has a tee-like appearance. There is a large range of variation in the mixing proportions.

The main purposes of the ball valve are:

1. temperature regulation of warm floors;
2. regulating the temperature of the radiators;
3. heating medium distribution in two directions.

Shut-off and regulating valves are the two varieties of three-way valves. Although they are practically equivalent in theory, three-way shut-off valves make temperature regulation more challenging.

Schematic diagram of an elevator heating unit

In central heating systems, the heat carrier travels via the heating unit and then directly to the radiator sections in each apartment and room. The water in this unit is heated to the design temperature, and the heating elevator circuit’s proper operation maintains equilibrium. This elevator is located in the basement of any multi-story building that is heated by a central mains supply.

It’s essential to have effective insulation and heating in your house for comfort, energy conservation, and environmental sustainability. The thermal unit scheme, which offers an organized method of controlling heat distribution throughout the home, is essential to reaching these objectives.

Homeowners can learn how different parts of their heating system interact by comprehending the thermal unit scheme. Every component, from radiators to boilers, has a distinct function in preserving ideal interior temperatures and reducing energy waste.

The thermal unit scheme’s adaptability to various heating systems and home designs is one of its main features. The concepts of the thermal unit scheme apply regardless of whether you have a conventional central heating system or use alternative techniques like underfloor heating. This allows for customized solutions to meet a range of needs.

Putting the thermal unit scheme into practice not only improves comfort but also lowers costs in the long run. Improved heat distribution and decreased heat loss allow homeowners to lower their energy costs while maintaining a constant temperature throughout the house.

Furthermore, by keeping heat from escaping through floors, roofs, and walls, investing in adequate insulation enhances the efficiency of the thermal unit scheme. By maximizing the heating system’s efficiency, this integrated approach creates a more environmentally friendly and sustainable home atmosphere.

To sum up, the thermal unit scheme provides a thorough framework for attaining effective insulation and heating in residential buildings. Homeowners can minimize their environmental impact and create comfortable, energy-efficient living spaces by implementing its principles into their heating systems.