There are many combinations of supply and return systems for heating the house. Each heating distribution in a private house can be classified according to several characteristics.
We offer to understand the nuances of the arrangement and operation of possible variants. Understanding the principles of design, the pros and cons of each type of distribution, will help plan the geometry of the system and its arrangement taking into account the individual characteristics of the room.
Content of the article:
- Modeling the optimal loop geometry
- Natural and forced water circulation
- Vertical and horizontal distribution
- Choice of single or two-pipe
- The use of a one-pipe system
- The use of a two-pipe heating
- Installation of a distribution manifold
- Radiator connection system
- Rules for the use of underfloor heating
- Conclusions and a useful video on the subject
Modeling the optimal geometry of the circuit
Few closed water circuits can be designed for a single private house, that will heat different rooms. They may differ considerably in the type of distribution.
The design is primarily based on the operability of the system as well as on the optimal geometry in terms of minimizing costs, ease of installation and the possibility to match the heating elements to the design of the premises.
The main objective of the heating system installed in a detached house is the full compensation of the heat loss through the building structures and openings
The distribution variant is selected in order to reduce the heat loss as much as possible. Not more than 10% of the pipeline should pass through unheated rooms
The budget of the house owners affects the choice of system. Based on financial capabilities is determined by the technical equipment of the structure, the type of coolant flow and its effectiveness
The more technical means required for the system, the more effective it is, but the more situations involving breakdowns and repairs
Selection of optimal distribution of heating for a country house should take into account the relationship of the circuit with other utilities
When designing it is necessary to clearly define the type of boiler, planned for use in heating, to thoroughly pro These may be stoves, fireplaces or gas, electric or solid fuel boilers.
The water pressure in the circuit is provided either by using circulating pumps or by arranging the system geometry to create conditions for natural circulation.
Also the hot water source may be a central heating system for several houses. In case of low head it is possible to connect circulation pumps to create additional pressure and increase the speed of fluid movement through the pipes.
Installation of a circulation pump creates sufficient pressure in the system, making it possible to use distribution variants which cannot be used with natural circulation
When choosing the natural circulation variant or the low pressure in the pipes in central heating, care must be taken to maximize the use of physical laws allowing to start and maintain the fluid movement.
A compulsory part of the distribution in this case is the acceleration manifold. It is a vertical pipe through which the hot water rises upwards, is then distributed over the heating appliances and, having lost its initial temperature, flows downwards.
The different density causes a hydrostatic pressure difference between the hot and cold liquid column, which is the driving force for the water circulation.
Gravity open system
Simple and affordable affordability
Fixtures in natural type systems
Radiator with Maevsky tap
Pump type heating heating system
Automatic air vent
Closed system air vents
Vertical and horizontal distribution
The hot water radiators can be installed in different ways. They are divided into vertical and horizontal, according to the position of the pipes (risers) that bring water directly to the radiators.
In modern houses, horizontal rather than vertical distribution of heating is used more often. The reason is that radiator layouts on different floors rarely match
Vertical schemeswith an upper hot water supply make maximum use of the hydrostatic pressure difference between the warm and cold circuit segments, so they are almost always used with natural circulation as well as low system pressures.
In addition, such circuits are operable in case of emergency pump shutdown, which may occur due to pump failure or lack of power.
Downflow plumbing is almost never used in naturally circulating heating. If there is good pressure in the system, its use is justified, as this scheme has two significant advantages over the alternative.
Benefits of the scheme:
- Shorter total length of pipes used;
- no need for a pipe in the attic or technological niches under the second floor ceiling.
The horizontal heating distribution schemeis used for single-story private houses. If a building has two or more storeys, it is often used in cases where vertical risers are undesirable from a design point of view.
Horizontal pipes, supplying and extracting water, can be smoothly integrated into the interior of the rooms as well as hidden under the floor or in niches at floor level.
The vertical layout of the heating system
Two-pipe vertical vertical system
Performance of horizontal layout
Choice of one or two pipes or two-pipe option
The hot water supply and the chilled water outlet for a private home heating system can be made with one or two pipes. Each option has advantages and disadvantages, as well as peculiarities of use depending on the type of distribution.
In terms of interior design, the presence of a second pipe does not have any effect on the appearance of the heating system due to the lower connection option of the system to the radiators and the possibility to reduce the pipe diameters
Using a single pipe connection
The water heating scheme of a private house using one pipe for hot and chilled water outlet is called single-pipe. The main advantage of such a system is to minimize the length of the pipes.
The main advantages of the option are:
- lower purchase costs of heating system elements;
- easier and faster installation;
- lower risk of breakdown.
The main drawback of single pipe heating is the gradual reduction of water temperature that runs in series through all radiators in the circuit.
So a slightly larger surface area of the last radiators has to be used (larger number of elbows), which often negates the cost benefit of minimizing the length of the pipes.
The principle of a one-pipe heating system
The specifics of connecting heating appliances
The minimum number of pipes in the arrangement
A single pipe assembly option with top top connection
Bottom connection version of the radiator
Features for balancing the temperature in the circuit
Modification of the single pipe top connection
The single pipe heating circuit construction method
In addition Due to this disadvantage, there are limits for a single loop on the number of radiators that can be connected. If there are too many of them, the last ones along the course of the coolant flow will hardly radiate heat.
In addition, there is a problem in calculating the heat output. Here it must be taken into account that disconnecting the first radiators from the heating system leads to a higher incoming water temperature for the following devices.
It makes no sense to use one-pipe schemes with vertical bottom distribution as the pipe length will be the same as in the two-pipe version, which negates all the advantages, but leaves the disadvantages.
If the return of the heating medium follows the same route as the supply, the total length of the pipes in both variants is almost the same
The heater is generally connected via a bypass to be able to shut off either one without stopping the water circulation through the circuit.
To save on faucets, it is possible not to do bypass water through the bypass, but then you would have to stop this part of the system and drain water when the radiator needs to be replaced or repaired.
The most economical option is to use one 1.5-2 inch diameter steel pipe without heating radiators. The absence of taps and fittings makes such a system also the most practical because of the minimized risk of water leaks or bursts.
For details on the calculation of a one-pipe heating system, see this article.
Applying the two-pipe heating option
The heating circuit scheme where one pipe is used to supply hot water to the radiators and the second pipe to return chilled water is called a two-pipe system.
His main advantages are:
- the temperature of water supplied to all radiators is the same;
- disconnecting one or more radiators does not affect the temperature of water supplied to the remaining radiators;
- the limit on the number of radiators for one heating circuit depends only on the throughput capacity of the pipes.
The main disadvantage of such wiring is the slight increase of pipe metres.
This leads to some additional drawbacks:
- increasing costs for purchase and installation of heating system elements;
- complicates the integration into the interior of a private house.
The number of fittings and cocks in a two-pipe system is almost the same as in a one-pipe system.
For a two-pipe system, the total length of pipes increases by the distance between the first and last radiator. Sometimes it is negligible compared to the entire circuit length
Depending on the relative movement of hot and chilled water, two-pipe circuits are divided into two types:
through circuit. Both flows move in the same direction and thus the cycle length of the coolant turnover is the same for each radiator. In this case they are heated at the same rate when the heating system starts.
Dead end version. The direction of flow of hot and chilled water is counter-directional. The radiators closest to the boiler heat up faster.
The slower the water velocity, the more noticeable this effect, so with natural circulation, some rooms will heat up much more slowly than others.
Principle of assembly of two-pipe system
Features of two-pipe circuits
Application of thermostatic controls
Two-pipe circuit with lower distribution
For the investment in the appliance
Hidden copper pipe installations
Beam version of the two-pipe system
If a circulating pump is used or the distance between the first and the last radiator in the circuit is small, the effect of uneven heating in a two-pipe, dead-end system is unnoticeable.
Inclusion of a distribution manifold
The so called \"radial scheme\" using a distribution manifold is a popular method of water heating in the recent times.
This method of distribution works safely only with good water pressure in the system, therefore it is not used for natural circulation.
Beam distribution involves connecting each radiator (or a small group of them) directly to a distribution manifold distributing hot water and collecting chilled water
Beam radiator connection system
The most uniform and controlled division of the heating medium flow to the heating appliances can be achieved by using a distribution manifold.
The device includes two combs, one in which the hot water comes from the boiler and is distributed to the radiators, and the other in which the cooled water returns and is routed back to the boiler.
The radiators are connected through a distribution manifold in parallel, so that the temperature difference between the heating medium and the radiators is kept to a minimum.
This greatly facilitates the design of the radiators as well as making it possible to easily adjust the capacity of each radiator during operation.
Heating system manifold group
The working principle of the manifold type
Prevalence of two-pipe solutions
Specification of the arrangement of radiant systems
Laying heating pipes in screed
Breather valves on distribution pipes
Supply pipes in the bathroom
House-made distribution pipes
A second very important advantage of such distribution is the possibility to control the heating water to all appliances from one place. The manifold is placed in a special cabinet with access to indicators and controls: valves, cocks and pumps.
It is convenient from the position of home climate control and allows the radiators to fit more easily into the room interior.
The maximum length of water inlet and outlet pipes to the radiators should be considered a drawback of systems with a manifold heating distribution scheme. This option is the most expensive in terms of the cost of circuit elements and the most difficult to install, and also requires some qualification.
The use of a manifold to connect heating devices of various types requires a good understanding of water heating and sometimes hydraulic calculations for normal functioning of such systems
As a rule, pipes in the radial heating wiring are installed in the floor screed. This means that it is necessary to design and install such a system during the construction or major renovation of a private house.
Collector version to connect the radiators or change the geometry of the circuits in rooms with an already carried out internal repair is quite difficult. This is the second significant disadvantage of this type of wiring.
Rules for using underfloor heating
A comfortable and very popular way to heat living spaces is to install underfloor heating. If the area to be heated is small, you can get by with a single pipe placed in the floor screed.
Hot floor heating via a distribution manifold is the only option for heating large areas in this way
For large areas a single pipe cannot be used for the following reasons:
- the amount of heat supplied will not be sufficient to heat the entire room, in addition this heating will be uneven;
- when long, there is a strong hydrodynamic resistance to the fluid flow, which leads to excessive energy consumption to create pressure and increases the risk of water breakdown at connections.
Hence, when the floor heating area is large, the use of several pipes is not an option but a necessity.
In this case the connection is made via a distribution manifold.
Floor heating manifold
Metalloplastic and copper pipes
Filling the screed over the heating circuit
Often the manifold is equipped with a mixing unit, to regulate the temperature of the water supplied to the underfloor heating pipes. The fact is that for heating radiators, as a rule, a liquid with a temperature range of 70-80°C is used, while the floor heating needs about 40°C.
Temperature regulation via a mixer is reliable, which is very important because exceeding the temperature can cause significant deformation of the floor covering: linoleum, laminate or parquet.
Conclusions and useful video on the topic
Scheme representation of heating distribution in a large area two-story house. Two-pipe cross and dead-end system and underfloor heating connected via manifolds. Excluding the conflict of circulation pumps with a hydrostretch:
Louvered circuit for heating a two-story building. Since the finishing has not yet been done, the entire distribution is clearly visible. Nuances of laying pipes on the floor under a concrete screed:
The opinion of a practicing master installer of heating systems on the various schemes used in private homes. An overview of the pros and cons of natural circulation, one-pipe, two-pipe cross and dead-end, and manifold wiring:
The presented wiring for house heating are typical and can be modified to take into account the geometry of the premises, the required temperature values or other factors. The laws and basic provisions of physics, hydraulics, materials science and other disciplines must be observed when modifying the schemes.
In case of complex or non-standard tasks, it is better to contact specialists, because the redesign of heating systems can come out even more expensive than their modeling and installation.
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