Centralized heating repeatedly increases the cost of maintaining housing. Owners of private houses choose an autonomous method of heating. The best option for individual housing construction is the installation of the heating of a two-story private house with your own hands. Schemes, calculations and a binding of the standard project carry out independently. The heating scheme of a 2-storey private house is one of the components of the engineering part of the project.
Heat engineering calculation of the heating system of a 2-storey private house
Thermal calculation determines the operating parameters of the heating system – the total amount of heat loss in the building, equipment capacity, number of heating appliances, etc.
The power of the heat generator is calculated by the amount of heat loss at home, which takes into account:
- the area of heated premises;
- climatic conditions of the area;
- the presence and condition in which the insulation of the premises is located;
- material and thickness of external (bearing) walls, floors and floors;
- roof structure, the presence of a technical floor;
- tightness and size of windows, street (balcony) doors.
Components of the heating system of a private house
Boiler – heat generator in the heating and hot water system. Average power standard 100 W per 1 m2 the area provided that the height of the insulated room is not more than 3 meters. Provide a margin of up to 20% of the performance of the boiler for unreported losses. Hot water requires an increase in power reserve of 50%.
The summary table, with variants of typical heat engineering calculations of boiler power, allows to compare the approximate selection results and existing models of heat generators.
The boilers can run on diesel fuel, coke, coal, wood, peat, pellets, natural gas or electricity. The choice of fuel type depends on its availability. More than 70% of consumers use gas boilers. Electric boiler (convector) is considered as a backup or combined option.
Pig-iron or steel generators of thermal energy make in floor and wall execution. Stationary floor boilers are installed in a separate room, which is equipped with a boiler, an expansion tank, a chimney and a forced ventilation system (according to the standards and requirements of the gas service).
Wall-mounted gas boilers chimney and a separate room is not required. Oxygen for gas combustion is supplied through a flexible corrugated pipe. Single-circuit unit designed for heating. The use of the heating scheme of a two-story house with a double-circuit boiler provides heating and hot water supply.
Ways of transfer of heat energy of the boiler to the system: forced circulation of the coolant and natural circulation (non-volatile heating method). The design of the boiler with two circuits contains an integrated circulation pump and a closed expansion tank.
Carriers of thermal energy in the heating system: water, antifreeze or electrolyte coolant for flow type electrode boilers.
Water has a high heat capacity and density, but requires compliance with a constant temperature regime of the room in winter. Homeowners who use the house irregularly prefer antifreeze as a coolant.
The choice of the type of wiring heating and type of coolant produced at the design stage of the project. Viscosity, coefficient of expansion and heat capacity of antifreeze slow down the heat exchange process and reduce the heat removal of radiators. For the non-freezing coolant carrier, it is required to increase the power of the pumps and the flow area of the system.
Important! The presence of ethylene glycol in antifreeze limits its use in double-circuit boilers. Some additives destroy parts made of polypropylene, cast iron, non-ferrous metals, rubber.
Heating device – steel, aluminum, combined, cast iron or anodized radiator (battery), which gives off its heat and provides a favorable microclimate indoors.
Heat transfer and inertia depend on the material and dimensions of the device. The length of the battery designs is changed by adjusting the required number of sections. The air vent valve (Mayevsky’s crane) and the thermostat valve installed at the inlet of the heating medium to the heating device ensure uniform calculated heat removal. A shut-off valve on the branch pipe is required for maintenance during operation.
The places of installation of heating devices are indicated in the normative technical documentation: around the perimeter of the heated room, under the window openings, near the entrance door. A thermal curtain installed at the entrance door will not allow cold air to penetrate from the street into a residential building.
Ways of connecting radiators with risers and pipelines: one-sided, diagonal and lower connection.
The number of radiators (I) is calculated by the formula:
I = s * kone* k2* k3* kfour* 100 / P (pcs) where
S – area of the room, (m2);
P – passport value of power of one section, (W);
kone – multiplying factor for double-glazed windows;
k2 – a reduction coefficient of losses, which depends on the area of the external walls;
k3 – dependent coefficient on the construction and insulation of the roof (with or without attic);
kfour – dependent coefficient on the ceiling height (kfour = 1, with h = 2.5 m), the higher the interfloor space, the greater the correction value.
Note! The manufacturer indicates in the passport of the product the design parameters: internal volume and radiator power. Coolant consumption in the battery capacity of 7 kW – 7 liters per minute.
Pipeline transfers, distributes and returns coolant to the boiler. The directional movement of the flow slows down the rough inner surface of the pipes, changing the diameters of the flow area, turns. The magnitude of the hydraulic resistance determines the method of circulation (natural or forced).
Piping (closed loop) ensures the tightness of the system. The power of the boiler is directly proportional to the flow rate of the coolant, which determines the internal radiator volume, the capacity of the boiler heat exchanger and the filling of the pipeline sections.
In heating systems of private houses, steel seamless and polypropylene pipes with a minimum coefficient of internal resistance (roughness) are used.
Expansion tank for closed or open heating is present in all schemes of the heating system of a two-story private house. The pressure that a circulating pump or gravity forces creates in the discharge pipe changes the boiling point of the heat transfer medium. The sharp boiling of water can provoke a spontaneous surge, the release of dissolved gases and a multiple increase in volume (temperature expansion), which leads to the destruction of the components of the heating system. The expansion tank helps to avoid such problems.
The membrane divides the sealed expansion tank of the closed type into the water and air chambers. In closed-type systems, the tank is installed on the return pipe nozzle, in front of the suction nozzle of the circulation pump. Dependent layout involves raising the tank to a height of at least one meter.
An open surge tank is installed at the top of the upper (main) riser in the attic. An overflow pipe and nutrient pressure pipe are cut into the body. The design requires careful thermal insulation, since at low temperatures, an unheated tank and overflow can “thaw”. The estimated capacity of the tank (10% of the total volume of the network) provides savings of the heated coolant during overflow and air removal. The lack of an open-type expansion tank is evaporation of the coolant.
Important! In heating systems with antifreeze, expansion tanks of a closed type are installed as a coolant, which ensure tightness and preserve the original volume and properties of the coolant.
Installation stop valves in the heating system provides the ability to turn off the network area or equipment for the prevention, repair or replacement. Ball valves are installed on the risers, before and after the heating devices, pumps, manifolds, boiler, boiler.
Safety armature – check and safety valve, automatic air vent, balancing valve. They protect the pipeline from throttling flows and water hammering of the heating system (pump, radiator, boiler). The shut-off valve stops the supply of fuel when the sensors of gas analyzers are triggered, the electricity is turned off and the circulation through the heat exchanger is stopped.
Control valves (electronic or electromechanical control valve, thermostatic valve) level the indicators in the heating system.
The main condition for fittings and fittings in the heating system – the fitting must ensure proper throughput with less pressure losses and tightness of branches, turns, transitions of diameter in the pipeline.