A combined heating scheme with underfloor heating and radiators in a private house is used for convenience and efficiency. Heating of premises is easier to regulate, in case of breakdown there is always a backup option. The correct choice of a heating unit, circuit and devices leads to energy savings and savings. The work of the system is coordinated manually or automatically.
Features and Benefits of the Combined System
The project is used in buildings for various purposes and any number of storeys with the correct selection of components and flooring. The warm floor of the first floor gives rise to thermal currents, heating the ceiling, which on the second floor serves as a flooring.
The owner chooses the optimal combination of equipment on his own, taking into account the following factors:
- needs of the house, preferences of the owner;
- fuel availability and price;
- the possibility of implementing the scheme;
- consumption of materials.
The radiator circuit reacts to a decrease in room temperature due to bad weather, creates thermal thresholds under the windows in cold weather. On cold days, batteries increase the heating of the room without raising the temperature of the warm floor to an uncomfortable state.
The main thing is heating installed in the base. Warm floors are used in the off-season, when the dwelling cools down and moisture appears.
The radiator system is switched on manually or automatically during a period of worsening weather to effectively heat the house.
Heating boiler selection
The selection of a heat source determines the connection diagram of warm floors and radiators to the boiler. The separation of the units is due to the type of fuel they consume.
Boilers are:
- solid fuel;
- gas;
- liquid fuel;
- electrical.
Solid fuel equipment has different capacities and operates on peat briquettes, coal, coke, firewood and wood waste. The efficiency of boilers is in the range of 50–70%, some models reach 80%. The units consume about 46–47 kg of fuel per square meter per year, excluding water heating, and are installed in houses from 30 to 2500 m2. A powerful chimney and ventilation is required, no installation permit is issued.
Gas units operate on bottled or main fuel. The power is from 10 to 15 thousand kW, the efficiency reaches 92–94%. Gas in the amount of 0.113 m3 is required for the production of 1 kW of thermal energy. Heats houses up to 400 - 500 m2, requires forced smoke extraction and ventilation. For the launch, the permission of the relevant authorities is issued.
Liquid fuel units use fuel oil, diesel fuel, oil processing, the efficiency is in the range of 86–92%. The consumption of liters per hour is calculated by multiplying the burner power by a factor of 0.1. The equipment smokes during operation and is installed in a room not adjacent to living rooms. Does not require permits for installation.
Electric boilers are also used in the heating system of a private house with underfloor heating and radiators and are powered by electricity. The power of equipment for housing ranges from 4 to 30 kW, the efficiency index is 87–98%.No soot, quiet operation, the boiler heats an area of up to 300 m2. Does not require ventilation and chimney equipment, it is connected to a three- or single-phase network without a permit for installation.
Choice of electric or water floor
The electrical system includes a heating element in the form of mats, film or cable, temperature sensors and a heating regulator (electronic or manual). The design does not significantly raise the floor and does not affect the height of the room. The system heats the surface evenly. The optimal mode is set using a combination of sensors and a thermostat, heating stops when the set parameters are reached.
Electric floors are mounted without additional labor costs:
- the wire is laid out on a plane;
- a concrete screed is made;
- finishing flooring is mounted.
A water-heated floor with a pipe system does not allow evenly warming up the area of the room, but its installation and operation is cheaper. Installing pipes in a screed requires more time and labor. The kit includes a circulation pump, manifold and pipes. The water system plus the screed raises the surface by 7 - 9 cm. Automatic or mechanical adjustment mode is selected.
The choice of the type of underfloor heating depends on the heating system and the capabilities of the owner. The fuel consumption for water heating of the surface is taken into account and compared with the costs for heating with electricity.
Selection of radiators
An air heat exchanger dissipates heat into the surrounding space through convection and radiation. Radiators differ depending on the material from which they are made:
- steel;
- cast iron;
- bimetallic;
- aluminum.
Panel radiators made of steel differ in average price, have a universal connection, serve 25 - 30 years. The elements are available in different heights and lengths. Steel batteries withstand a pressure of up to 8 atm, with a test indicator of 25 atm, they require a preliminary calculation of power. Elements are destroyed due to corrosion in places that have been damaged.
Old-style cast iron batteries are large and heavy, there are modern models of small sizes, developed jointly by designers and designers. Service life - up to 50 years, withstand a pressure of 6-10 atm, with a test rate of 15 atm. The elements are resistant to corrosion and are susceptible to clogging with calcium deposits.
A steel distribution manifold is installed inside the bimetallic radiators, which increases the working head up to 25 atm. The batteries are combined with different pipes and are lightweight. The cost of the elements is high, the use of antifreeze is not recommended, since leaks occur.
Aluminum batteries give off heat well, are attractive and lightweight. You can recruit a different number of sections, install in gravity heating circuits, but only in closed systems. Working pressure in the range of 7–12 atm, with a test indicator of 25 atm. Interaction with copper elements causes corrosive currents.
Which pipes are suitable for a combined heating system
Products are selected taking into account quality, cost, reliability, service life and ease of installation.
Copper pipes quickly heat up and effectively give off heat, the circuits of such elements are distinguished by excellent technical characteristics and resistance to corrosion, they have been in operation for 50–80 years. Products are expensive, installation is carried out only by specialists due to the complexity of working with copper.
Polypropylene pipes are manufactured with aluminum and fiberglass reinforcement. In the first form, the metal interlayer keeps the polymer from excessive expansion. Skill when welding is required as material delamination often occurs. Fiberglass pipes are durable and high-quality products due to their solidity.
Reinforced-plastic pipes are distinguished by acceptable performance and are used for the radiator circuit and underfloor heating. Inside there is a layer of polypropylene with smooth walls, which does not deteriorate or oxidize. Polyethylene is bonded to the aluminum pipe with an adhesive layer. Products are easily mounted and do not require special skills, pipes are bent, connections are made with press or threaded fittings.
XLPE collectors are used for underfloor heating. Tightness is achieved using press fittings that are easy to install. The material serves for a long time, has little wear and tear and conducts heat well.
Organization of installation
The difficulty is the implementation of wiring for 2 circuits with different temperatures of the energy carrier. A sequential scheme is used for connecting a warm floor and batteries from one boiler and a hydraulic arrow. The first wiring saves a resource, and the second allows the unit to work in optimal mode.
The energy carrier is supplied to the underfloor heating pipes with a low temperature compared to the radiator circuit. Heating is regulated by automatic equipment as they cool in each branch. The line is turned off by stopping the pump. Pipes for underfloor heating are chosen with a cross section of up to 20 mm to reduce the inertia of the system.
In private houses
There are basic requests for the scheme of a combined heating system with radiators and underfloor heating that require attention. The equipment is put in free access for control and repair. The risk of fire and explosion is taken into account.
Installation rules:
- The water temperature should be 20 ° C higher than the ignition limit of the substance, boiling of the energy carrier is prevented. The boiling rate depends on the head in the system. For example, at a pressure of 2 atm, water boils at + 120 ° C.
- Heating of the surface of the exposed parts of radiators and pipes should not exceed the permissible limits.
- Equipment and appliances are insulated to protect against burns, energy loss and freezing in unheated buildings.
- Hot parts are closed if they can cause ignition of gas, dust in the room.
The design, calculation and selection of the heating system remains important.
In apartments
Additionally, thermostats are used according to the number of batteries for temperature coordination. The unit's automation maintains the temperature of the energy carrier. Taps are installed on the branches of the supply line for selectively disconnecting batteries or underfloor heating circuits.
Mayevsky's cranes are installed according to the number of devices, a safety group is mounted, including an expander, a pressure gauge, a safety valve and an air vent. The radiators of the main circuit are cut sequentially in a diagonal pattern or from bottom to bottom. The horizontal level is maintained to get rid of water noise.
