Pump functions when arranging water heating floor
The question is whether the pump is needed for warm water floors, is solved at the design stage. The desire to reduce the installation system due to the refusal of this equipment significantly reduces the efficiency of the water circuit functioning, even if the need to install pipes with a calculated inclination is taken into account.
This is due to a sufficiently large total length of the mounted pipeline, as well as the frequent occurrence of air traffic jams. For this reason, specialists are recommended to equip the water heating system by the pump.
Pump selection according to specifications
Usually, circulation pumps are used for floor heating design, such as in the photo. Characteristics of these aggregates Maximum compliance with the requirements.
You should know how to calculate the pump power for a warm floor correctly to purchase the desired model.
Q. fluid flow in cubic meters within an hour;
T ° Pr. t. the temperature of the water temperature in the feed pipe;
T ° Obr. T. The magnitude of the fluid temperature at the output.
If the installation of several contours is designed when laying the design, then you need to find out the total value, taking into account each of them.
According to experts, for a separate room, it is better to equip the autonomous heating system of the floor surface, as a result of which it appears to save the heat economically. It will be possible to adjust the condition of the microclimate, depending on the purpose of one or another room, and make the design work more reliable.
The difference between the water temperature in the heating circuit at the entrance to it and the outlet depends on the parameter range:
- Pipeline length. The longer the contour will be, the greater area it should heat. This means a significant consumption of thermal energy, and the temperature indicators at the inlet and outlet will be very different;
- Quality of arrangement of thermal insulation. If the technology has been broken during the creation of the system, the heat loss during the operation of the warm floor will be achieved by high numbers. This is especially true for the premises located on the lower floor, since incorrectly made heat insulation will contribute to the consumption of a significant amount of energy for soil heating. Excessive heat loss lead to an increase in the load rendered on a circulation pump for a warm floor.
- Climate in the zone of home. The north of the region, the more significant the power supply should be at the heating system and circulating unit. Manufacturers advise them to choose them with an indicator, equal to 20-25%.
Another important value for determining how to choose a circulation pump for a warm floor is the head of the coolant stream. Its must be enough to overcome the hydraulic resistance of water in the system. The index of the hydrosistration from the length of the contour, the cross-section of pipes for water, the velocity of the fluid.
By purchasing the pump, you should pay attention to the fact that the above-mentioned parameters are specified in the accompanying documents.
With independent arrangement of the system to calculate the head of the coolant, the formula is used:
P. hydrosistant on one meter contour;
L is the length of the longest contours along with control systems;
To. The coefficient of the recommended power supply of the device.
After all the data becomes known, go to the choice of the optimal pump model.
On film heaters
The calculation of the amount of infrared film is carried out much easier and reduces to the selection of heating material in size and specific heat transfer:
- Calculate the need for room in thermal energy (section The first of this publication).
- Sketch the room layout with stationary furniture. Calculate the size and quadrature of the free plot.
- Warm floor floors unfold with an indentation from the walls of 15-20 cm. Draw these stripes on the sketch and take their dimensions from free space.
- The last task is to arrange the infrared film of the required total power on the remaining plot. Choose in the manufacturer catalog Rolls of the desired width and heat transfer.
Circulating Pump Basics. How a pump works HVAC heating pump working principle
Reference. Film of the well-known brand Caleo is able to give from 130 to 230 W per 1 m² of heating element. Width. 50, 80 and 100 cm.
Consider that the thermal film is allowed to cut only across, focusing on special lines (interval. 250 mm). Neighboring canvases can be placed in either the estimated interval, but not. For a bedroom from our example, the amount of film is considered as follows:
- Required heat transfer outdoor circuit. 1.08 kW. If you take a product with heat transfer 130 W / m², you will need 1080/130 = 8.3 m² of film heater. Taking into account stock. 9 m².
- Roll width. 0.5 m. To score 9 squares, you need to take a film with a length of 18 m.
- Since the bedroom remains free of 15 m², this type of heater is quite suitable.
When installing the circulation pump, the rotor should be positioned so that it is in a horizontal position. The arrow, which is drawn on the housing, must coincide with the direction of fluid movement. After installation works, the coolant access opens, then the screw for air removal opens. If the device is located vertically, the performance will not be reduced, but the power decreases by an average of 20%.
Installing the pump for a warm floor, depending on the calculated connection scheme, or on the feed pipe, or on the return pipe:
- In case of finding a circulation pump on the feed pipe, the device must be located after the mixing unit;
- In case of finding a pump on a return pipe, specialists talk about its high efficiency.
The owners of boiler equipment sometimes arises the question of whether warm floors are possible without a pump? This option is possible. But the effectiveness of a warm floor will be questionable and need to take into account individual nuances when installing such a system.
The pumping node for a warm floor is considered in the following video.
Standard circulation pump for water heat and its device
The device provides a uniform redistribution of the coolant in a closed circuit, maintains constant pressure in the system. The application of the device significantly increases the efficiency of the warm floor system, excluding the coolant stagnation in long pipeline circuits.
The standard device is essentially a conventional circulation pump consisting of the following basic elements:
- Case. the main element of the device that is performed from high strength materials. Usually hulls are made of various metals: stainless steel, bronze, cast iron. Separate modern devices use plastic housings.
- Pipes or flanges are located on the housing and provide a connection with introductory and output pipes.
- The blade impeller ensures the movement of the coolant due to its rotation. Made from metals, plastic and modern technopolymer material, which is almost no wearing.
- The electric motor is usually placed on the side of the case and activates the impeller.
Circulating pump device for a warm floor
Circulation pumps should be fixed so that the rotor is located in a horizontal state. If the shaft is located vertically, power loss will be up to 40%.
The main characteristics of circulation pumps
Determining criteria when choosing an aggregate for water heat are the indicators of its performance and pressure.
The productivity of the unit is calculated in cubic meters (liters) per hour. In normal mode, the unit for 1 hour should pump a coolant, exceeding 3 times the volume of the entire warm water floor system. The productivity of the unit should be the higher, the greater area of laying the heated floor pipeline. Performance reserve should be 15-20%. This will increase the life of the unit and prevents the problems associated with weak heating during the cold period.
The pressure issued by the aggregate, the second important indicator. It should be sufficient to overcome all the bottlenecks and bends of the pipeline to deliver the coolant to the most remote points of the room. The calculated productivity should remain unchanged. For domestic use, it is usually enough to use a unit with pressure up to 6 m water column.
How to choose a unit for calculating pressure?
Since the hydraulic resistance of all elements of the system is overcome by pressure, these indicators should be taken into account:
- The material and diameter of the pipe affect the resistance, is contained in the instructions for the aggregate;
- the increase in resistance to the valve. 1.7;
- coefficient resistance on reinforcement and fittings. 1.2;
- Resistance coefficient on the mixing unit. 1.3.
How to calculate the heating circulation pump from the boiler power
It often happens that the boiler is purchased in advance, and the remaining elements of the system are chosen later, focusing on the power indicators of the heating device declared by the manufacturer. Often, the circulation pump is bought to upgrade heating systems with natural circulation to ensure the possibility of accelerating the movement of the coolant.
If the boiler power is known, the formula is used: Q = N / (T2-T1)
T2. water temperature in degrees Celsius at the outlet of the boiler (entrance to the system);
How to choose a pump for a warm floor
It is recommended to take into account several criteria:
- Specifications (it is necessary to make preliminary calculations according to the formulas described above and determine the appropriate model).
- Pump body material. better cast iron, stainless steel or organic polymers. These materials serve longer thanks to high anti-corrosion properties.
- The presence of a built-in thermostat allows you to protect the impeller from scale and sediments, which are formed due to the effects of hot water.
- The brand is the greatest reliability of Germany (WILO) and Denmark (Grudofs). Budget options with optimal price / quality ratio. Poland (DAB) and China (Sprut). Italian manufacturers (Lowara, Pedrollo) and Japanese brand EBARA are also popular.
- Floor pump speed mode. usually models operate at 3 speeds, which is especially convenient for a large area of heating, as well as 2-3-storey houses.
Types of pumps
For heat heating, the same pumping units are used as for conventional circulation heating systems. According to the principle of action they are centrifugal. The basis of the structure. the impeller (impeller), fixed on the drive shaft in the body of the housing.
The impeller is equipped with spiral blades. The working chamber has two outputs: suction and discharge. When the impeller is rotated from the electric motor due to the configuration of the working chamber, the volume in the zone of each blade increases.
This creates a vacation, and the fluid from the receiving channel is absorbed into the working chamber. Here it is fond of rotating blades, and approaching the outlet, under the action of centrifugal force is thrown into the pumping channel. There are only 2 types of pumps:
The first execution is a tandem consisting of a housing with an impeller and a separate electric motor, rotating the impeller shaft directly or through the coupling. In this case, the engine rotor does not contact with the liquid, and its insulation from the working medium is provided with a radial seal (rubber rings or cuffs). There are monoblock aggregates. The advantages of the “dry” rotor:
The pump with a “wet” rotor is a monoblock design that combines the electric motor and the impeller. over, only the engine stator is isolated from the liquid medium, and the rotor rotates on the sliding bearings directly in the working fluid, which performs the function of the lubricant simultaneously. Advantages of “wet” execution:
- Less efficiency (about 50%). It is explained by the fact that the rotor during rotation overcomes the viscous resistance of the medium.
- Sensitivity to the presence of saline solutions (during breaks in the operation of the salt are deposited in the gaps of bearings).
For warm floors of individual housing, the “wet” pumps are most suitable: