Eco-friendly and beautiful houses made of logs or beams are becoming more and more popular due to their affordability, speed of construction and the ability to create a unique microclimate. Such housing will provide coolness in summer and warmth in winter, if the shrinkage of the house was correctly taken into account when designing the heating system.
Options and features of the installation of heating a wooden house
High quality heating in a private house can be based on different types of heat energy sources, but it must necessarily take into account the specifics of wood, especially its tendency to cracking at high temperatures, sharp absorption and release of moisture, deformation with accelerated drying. The following can act as a heat generator:
Some options are suitable only for small buildings, others consume a lot of energy resources, others require constant monitoring and manual addition of fuel, and the fourth are distinguished by their high price and complexity in installation. For houses ranging from 80-100 sq. m, the optimal solution will be to equip a separate boiler room with the installation of a heating boiler, the use of piping, a metal chimney and aluminum or bimetallic radiators, characterized by increased heat transfer. If the house has a gas pipeline or there is the possibility of connecting to a nearby main, it is best to install gas heating equipment, which is characterized by economy, durability and high productivity.
It is important to know that in order to legalize gas heating, it is necessary to go through the approval procedures in Gaztekhnadzor. If there is no desire to clutter up the interior with sectional heaters or panels, you can use the system of “warm floors” or “warm plinth”, which will build a thermal curtain along the walls and will not let cold air into the room. But no matter what heating algorithm is implemented, it is imperative to take care of high-quality thermal insulation of the walls and roof. Then the heat will stay in the rooms for a long time, and the energy consumption will decrease to the possible minimum.
When laying communications, damage to the elements of supporting structures should be avoided so as not to disturb the uniformity of the distribution of loads on walls, floors and roofs. It is also necessary to avoid direct contact of very hot and condensed pipes with wooden surfaces. For this, both heating communications and water supply are insulated. This simple action allows you to prevent overdrying or excessive moisture of wood.
Heat carrier in the heating system of a private house
The most demanded is the hydraulic heating system, which is characterized by efficiency, ease of maintenance and a long service life. The liquid heat carrier, circulating along the circuit from the pipes, brings heat to the heating devices and returns to the boiler for heating. Water is most often used as a working medium for heating. But such a coolant is not suitable for homes that are used as temporary suburban housing for weekends or holidays. When leaving, the heat generator must be turned off. To prevent the water from freezing in cold weather and destroying pipes and radiators, you will have to regularly empty and fill the system. This is not only inconvenient and takes a lot of time, which could be spent on heating cold rooms, but also harmful to the equipment. Fresh water is rich in salts and oxygen, which are the main sources of corrosion and solid deposits on the walls of pipes and heat exchangers.
The way out of the situation will be the use of a non-toxic antifreeze based on propylene glycol as a coolant, which retains its properties under strong cooling. This working environment is designed to last up to 10 heating seasons, which fully justifies the initial cost. In this case, there is no need to fill the pipes with pure antifreeze, it is enough to use a mixture of it with water. The proportions of the composition are determined by the actual climatic conditions and the maximum winter temperature:
- up to -20C (65% water, 35% antifreeze);
- up to -25C (60% water, 40% antifreeze);
- up to -30C (55% water, 45% antifreeze);
- up to -35C (50% water, 50% antifreeze).
If the mixture for the heating system contains 55-70% antifreeze, the liquid does not freeze at temperatures below -45-65C, which is more than enough even for northern regions.
The main disadvantages of antifreeze coolant include its reduced heat capacity compared to water (by 15%), expandability, increased viscosity, fluidity and aggressiveness to rubber, due to which all detachable joints must be sealed with special stable gaskets. In addition, it is necessary to use boiler equipment, which technically provides for the use of antifreeze solution, more powerful batteries, and abandon some types of polymer and galvanized pipes. At the stage of heating design in a private house, all these points are easily solved and allow you to get a ready-to-use heating system.
Schemes and installation of heating a wooden house
Heating systems can be with natural (gravity) or forced circulation of the working medium. In the first case, the laws of gravity and the temperature difference between the heated and cooled coolant are taken into account. In the second, the liquid moves due to the pressure generated by a special circulation pump. To deliver heat to heating devices, schemes with one-pipe or two-pipe wiring are used.
To better understand the efficiency and principle of operation of a one-pipe heating system, consider its installation using the example of a wooden house with several floors. Let’s clarify right away that the presence of a single circuit provides for the rise of hot water to the highest point of the system due to its lower density and mass compared to the cooled liquid. This provides an initial impulse for gravity. Moving along the highway, the coolant sequentially passes heating devices, giving each part of the accumulated heat. The uneven distribution of heat energy between the upper and lower floors is immediately noticeable. For a small one-story wooden house, this difference is insignificant, but for spacious and tall buildings it is of key importance. The increased number of sections on radiators farther from the boiler will allow to align the temperature indicators.
In order for the cooled working medium to be able to flow back into the heat exchanger for heating by gravity, the heat generator must be placed below the level of the radiators. The use of a circulation pump eliminates this requirement and makes heating in a private house much more efficient due to the accelerated movement of the working environment.
In a simplified form, the installation of a one-pipe heating system can be described as follows:
- boiler installation;
- installation of an expansion tank and radiators;
- laying of a pipe line;
- installation of a circulation pump (if necessary);
- connection of communications to devices;
- installation of radiator valves.
To improve the performance of one-pipe heating, special jumpers are used – bypasses, which allow redirecting and redistributing the coolant flow through the riser.
A two-pipe heating system is much more efficient due to the simultaneous flow of the heated coolant into the radiators through a separate line. Having passed through the sections of one heater, the working medium immediately enters the return line and returns to the boiler.
In addition to uniform heating of all radiators, another important advantage of two-pipe heating is its variability. You can easily add new heaters and extend the lines in the desired direction. Thus, when completing a house, there is no need to replace the entire heating system.
Important nuances of organizing heating in a wooden house
As already mentioned, the main features of the installation of a heating system are associated with the use of wood as the main building material of the house. Even well-dried timber contains some moisture and dries out over time and lends itself to partial deformation. On the scale of an individual structural element, such changes can be considered insignificant. But taking into account the large areas of wall, floor and ceiling surfaces, the shifts become critical and can be tens of centimeters. The use of standard communications and rigid fasteners will lead to pipe breaks (ruptures), destruction of inter-pipe connections and insulation, and equipment damage. That is why special expansion joints are installed on the main lines, which are equipped with a corrugated surface, are resistant to dynamic loads and have the ability to compress and stretch. Sliding fittings provide freedom of movement of the pipes. Open installation of pipes often violates the overall aesthetic integrity of a wooden interior, so it is advisable to give preference to hidden laying of communications.
Pipes are laid under the floor, in the floors, behind the false walls. It is important to accurately determine the location of the piping in advance. Experts strongly recommend using collectors and equipping communications in such a way that there is not a single joint in the floors and under the floor. This leads to a slight increase in the construction budget, but completely eliminates the risk of leaks in a place inaccessible for prompt repair.
High-quality pipes made of cross-linked polyethylene or polypropylene, which are designed for trouble-free operation for up to 50 years, are used as the material for the coolant lines.
For arranging false walls that will decorate communications, you should not use soft insulation that is unable to keep its shape on its own. It is best to use special plates with a perfectly smooth fiberglass mesh coating. They are easily attached to each other due to the thorn-groove connection.
If a load-bearing beam or a wall is in the way of laying the communication, it is necessary to make a bypass turn of the pipe and in no case do not cut the wood, reducing the structural strength of the building. When laying communications under the floor, it is allowed to make holes in the logs. If there is a desire to organize a system of underfloor heating, you cannot use a monolithic concrete screed. There is a convenient Finnish technology with the installation of communications in a dry screed on a base of several layers of drywall or cement-bonded particle board. Tile adhesive is used to fill the voids.
We remember about wall shrinkage, pipe insulation, chimney and boiler room arrangement
Shrinkage of a wooden structure is a natural process of shrinking and shrinking walls due to the evaporation of moisture from the pores of the wood. The intensity of this process depends on the type of material used. Houses made of laminated veneer lumber and chamber-dried lumber are the least susceptible to shrinkage. But such materials are more expensive. Most often, affordable logs and beams of natural moisture are used, which give significant shrinkage. Before installing heating in a private house, it is advisable to let it settle for 8-12 months. If this is not possible, the installation of pipes is carried out using expansion joints and sliding fasteners.
Wood is equally adversely affected by strong thermal effects and moisture in the form of condensation on pipes, which lead to cracking, deformation, mold and rot. The most economical and correct way to eliminate these problems will be thermal insulation of highways with a special tubular material.
The chimney can become very hot during operation of the heat generator, which carries significant risks of wood fire. Therefore, it is necessary to use certified chimneys made of refractory materials with insulation. The best option is considered to be a free-standing brick pipe with its own foundation, which rises up to 2 meters above the house. This design provides excellent traction, effectively removes combustion products and reliably protects the wooden house from temperature effects.
The installation of the gas boiler must be carried out on a fireproof floor or wall base. If a solid fuel heat generator is used as a heat source, it is necessary to take care of a full-fledged boiler room in which all horizontal and vertical surfaces are not hot.