Bypass section selection when installing a circulation pump

Do I need an additional pump for a double-circuit boiler Navien

After installing a condensing double-circuit boiler, many users are considering installing an additional pump in the heating system of a country house. The need to use an additional booster device is explained by the uneven heating of the living quarters of a two-story house with sufficient power of the boiler equipment.

Advice! If the drops coolant temperature at the supply and the return pipeline exceed 20 degrees, it is necessary to switch the circulation pump to an increased speed or get rid of air locks.

Installation of another pump is necessary in such cases:

1. When installing the heating of a private house with an additional circuit, or in the case when the length of the pipes is more than 80 meters.
2. For uniform supply of coolant through the heating system.

There is no need to install an additional pump if the heating is balanced using special valves. Therefore, before buying booster equipment, bleed the air from the heating radiators and add water, check the circuit for leaks using a manual pressure test pump. If, after carrying out such procedures, the autonomous heating of a private house will work normally, then another pump will not be needed.

Why do you need a hydraulic gun

If several pumps are installed in the heating system of a summer house or cottage, a hydraulic separator or a hydraulic arrow must be included in the circuit. The specified device can be operated together with a single-circuit diesel boiler or a solid fuel unit. In the latter case, the device regulates the supply of coolant in different phases (fuel ignition, combustion phase and attenuation). Installing a hydraulic arrow allows you to balance the operation of the heating system. The main tasks of the hydraulic separator are:

• Automatic removal of accumulated air;
• Capturing dirt from coolant flows.

Important! The hydraulic arrow in heating allows you to balance the operation of the system, protects it from airing, and prevents the accumulation of dirt in pipelines.Such a device must be installed without fail in the presence of several booster units

Installation nuances

When installing heating on a turnkey basis, the master plumber installs a circulation pump with a wet rotor. Such a device does not create much noise, its rotor rotates without lubrication. A coolant is used here as a coolant and lubricant. When installing pumping equipment, you need to consider the following nuances:

1. The shaft of the device that injects pressure is placed horizontally with respect to the floor plane.
2. Carry out the installation in such a way that the direction of the water coincides with the arrow on the device.
3. Mount the instrument with the terminal box up to prevent water from entering the electronics.

Important! Experts recommend installing a pump on the return pipeline of the heating system of a one-story or multi-story residential building. Despite the fact that such equipment is designed to operate in hot water with temperatures up to 110 degrees, warmer liquid in the return pipeline will only extend the service life. Installation of the unit is carried out only after draining the water from the system

In the event of a power outage, the pump will not be able to pump the coolant, so it is connected through a bypass, a strainer is installed in front of the inlet pipe to prevent scale and debris from entering the impeller. In addition, shut-off valves are provided at the inlet and outlet of the device for possible replacement and repair of the device.

Installation of the unit is carried out only after draining the water from the system.In the event of a power outage, the pump will not be able to pump the coolant, so it is connected through a bypass, a strainer is installed in front of the inlet pipe to prevent scale and debris from entering the impeller. In addition, shut-off valves are provided at the inlet and outlet of the device for possible replacement and repair of the device.

As we can see, the installation of a circulation pump requires certain skills, so the installation of this equipment should be carried out by a professional. To order the service, you can leave a request on the website or call +7 (926) 966-78-68

Where to put

It is recommended to install a circulation pump after the boiler, before the first branch, but it does not matter on the supply or return pipeline. Modern units are made from materials that normally tolerate temperatures up to 100-115 ° C. There are few heating systems that work with a hotter coolant, therefore considerations of a more “comfortable” temperature are untenable, but if you are so calmer, put it in the return line.

Can be installed in the return or direct pipeline after/before the boiler up to the first branch

There is no difference in hydraulics - the boiler, and the rest of the system, it does not matter whether there is a pump in the supply or return branch. What matters is the correct installation, in the sense of tying, and the correct orientation of the rotor in space

Nothing else matters

There is one important point at the installation site. If there are two separate branches in the heating system - on the right and left wings of the house or on the first and second floors - it makes sense to put a separate unit on each, and not one common one - directly after the boiler.Moreover, the same rule is preserved on these branches: immediately after the boiler, before the first branch in this heating circuit. This will make it possible to set the required thermal regime in each of the parts of the house independently of the other, as well as save on heating in two-story houses. How? Due to the fact that the second floor is usually much warmer than the first floor and much less heat is required there. If there are two pumps in the branch that goes up, the speed of the coolant is set much less, and this allows you to burn less fuel, and without compromising the comfort of living.

There are two types of heating systems - with forced and natural circulation. Systems with forced circulation cannot work without a pump, with natural circulation they work, but in this mode they have a lower heat transfer. However, less heat is still much better than no heat at all, so in areas where electricity is often cut off, the system is designed as hydraulic (with natural circulation), and then a pump is slammed into it. This gives high efficiency and reliability of heating. It is clear that the installation of a circulation pump in these systems has differences.

All heating systems with underfloor heating are forced - without a pump, the coolant will not pass through such large circuits

forced circulation

Since a forced circulation heating system is inoperative without a pump, it is installed directly into the gap in the supply or return pipe (of your choice).

Most problems with the circulation pump arise due to the presence of mechanical impurities (sand, other abrasive particles) in the coolant. They are able to jam the impeller and stop the motor.Therefore, a strainer must be placed in front of the unit.

Installing a circulation pump in a forced circulation system

It is also desirable to install ball valves on both sides. They will make it possible to replace or repair the device without draining the coolant from the system. Turn off the taps, remove the unit. Only that part of the water that was directly in this piece of the system is drained.

natural circulation

The piping of the circulation pump in gravity systems has one significant difference - a bypass is required. This is a jumper that makes the system operational when the pump is not running. One ball shut-off valve is installed on the bypass, which is closed all the time while pumping is in operation. In this mode, the system works as a forced one.

Scheme of installation of a circulation pump in a system with natural circulation

When electricity fails or the unit fails, the faucet on the jumper is opened, the faucet leading to the pump is closed, the system works like a gravitational one.

Mounting Features

There is one important point, without which the installation of the circulation pump will require alteration: it is required to turn the rotor so that it is directed horizontally. The second point is the direction of the flow. There is an arrow on the body indicating in which direction the coolant should flow. So turn the unit around so that the direction of movement of the coolant is “in the direction of the arrow”.

The pump itself can be installed both horizontally and vertically, only when choosing a model, see that it can work in both positions.And one more thing: with a vertical arrangement, the power (created pressure) drops by about 30%. This must be taken into account when choosing a model.

Principles of selection of pumping equipment

Having decided on the type of pumping unit for heating, it is necessary to correctly calculate its optimal power. It makes no sense to install a circulation pump with a large margin of power - it is more expensive and noisier during operation.

The circulation pump unit performs the following tasks:

• creates a fluid pressure that can overcome the hydraulic resistance of the heating circuit nodes;
• pumps through the pipeline the volume of coolant necessary for high-quality heating of all rooms.

To correctly calculate the power of the unit, you need to know:

• pump performance (flow rate, measured in m3 / h) - the volume of coolant that is pumped by the device in one hour;
• head (measured in meters) - an indicator that determines the hydraulic resistance overcome by the pump.

For a cottage with several floors, with complex architecture, the calculation of the power of the pumping unit must be performed by specialists. But for small houses, calculations are carried out using simple formulas and tables.

We determine the power

Standard calculation formula: Q=0.86R/TF-TR where

• Q is the pump flow rate (m3/h);
• R - thermal power (kW);
• TF is the temperature of the heat carrier (°C) in the supply pipe;
• TR is the temperature of the heat carrier (°C) on the return line at the boiler inlet.

It is difficult to determine the thermal power on your own, so it is more convenient to use ready-made solutions:

Method 1.According to European standards, the thermal power index (R) for a small private house is 100 W / m2, for a multi-storey building - 70 W / m2, for buildings with good insulation - 30-50 W / m2. These norms are suitable for Russian regions with a mild climate.

Method 2. Russian SNiP standards are calculated for a climate with frosts down to -30 ° C. The heat output indicator for one- and two-story houses of a small area is 173-177 W / m2, for houses with a height of 3-4 floors - 97-101 W / m2.

Method 3. The value for the calculation is selected according to the table presented, based on the characteristics of the building:

There is another method for determining the flow rate of the coolant (pump performance). The flow rate (Q) is equated to the boiler power (P). For example, 20 liters of coolant passes through a boiler with a capacity of 20 kW per minute. And each radiator with a power of 10 kW passes 10 liters of fluid per minute. To calculate the flow rate of the coolant in each heating circuit, it is necessary to sum up the indicators of all radiators and add the indicators of the pipeline. The flow rate of the coolant in the pipeline depends on its length and diameter. The smaller the diameter, the higher the hydraulic resistance. A table compiled for a standard coolant velocity of 1.5 m / s will help calculate the pipeline indicators.

Water consumption	Diameter in inches	Water consumption	Diameter in inches
5,7	1/2	53	11/4
15	3/4	83	11/2
30	1	170320	221/2

For every 10 meters of pipeline, 0.6 m of pressure is required, which is provided by the circulation pump. For example, if the length of the heating circuit is 100 m, the pump must provide a head of 6 m.

Bypass functions in the heating system

Let us clarify that a bypass is a pipeline designed to flow water around a certain section of the main line where any equipment is installed. In heating schemes, it can be found in two places:

• in single-pipe systems as a jumper on radiators;
• on the distribution manifold of water heated floors.

As you know, in a single-pipe heating system, the heat transfer of the first battery affects the operation of the next one, and so on. This applies to both vertical and horizontal layouts. If the bypass setting in the heating system is not done, then the radiators will be connected in series. As a result, the first of them will take away the maximum amount of heat, the second - all that is left, and the share of the third will fall only to the cooled coolant.

To prevent this from happening, the supply and return near each battery is connected by a jumper, whose task is to direct part of the coolant around the radiator. In this case, the principle of operation of the bypass is to transfer the same part of the heat to the near and far heaters and reduce their dependence on each other. How this is implemented can be seen in the figure:

In the heating system, a bypass is needed to evenly distribute heat across the batteries, as well as to carry out their repair or maintenance. If for some reason it is necessary to disconnect and remove the heater, then it is enough to simply close the 2 taps installed at the inlet and outlet of the coolant. Then the water will go along the bypass through the jumper.

But the bypass for heating on water floor heating collector plays a different role. Here the bypass line is part of the mixing unit with a three-way valve.The task of the node is to prepare the coolant of the required temperature for supply to the heating circuits of underfloor heating. Indeed, in these circuits, the water temperature does not exceed 45 ºС, while in the supply line it can be 80 ºС.

In normal mode, the three-way valve passes hot water from the system to the warm floor in a limited amount. The rest of the coolant passes through this automatic bypass, mixes with cold water from the collector and returns back to the boiler. Since the temperature difference between the main and the collector is significant, the bypass line is used constantly. It turns out that without it, the normal functioning of underfloor heating is impossible.

Price and recommendations

If we analyze the prices for bypass and accessories, we can conclude that they are not that big and completely depend on the region where you live. So, in Moscow you can buy for 5,000 rubles, and in Yekaterinburg for only 3,000 rubles. These amounts are simply meager compared to those that you will save on heating by using this pipe and faucets.

How to choose the right bypass?

Just follow our tips and you definitely won't go wrong:

1. Buy only certified goods.
2. Demand to show the seller a hygiene certificate.
3. Upon visual inspection, the bypass you choose should be smooth, free of any dents, chips, or corrosion.
4. If the product has threaded connections, then check whether they are easily twisted and unscrewed.
5. Welding seams must be solid, without pores.
6. After purchasing the product, always keep the receipt and the warranty card until the period specified in it expires.

Pump selection

The heating system is connected to water.The pump is usually powered by electricity, so contact with the liquid is not allowed. For this reason, all pumps for the heating circuit are divided into dry and wet.

dry type

In the dry circuit, there is a division into two sealed sections. In the first pumping part, direct contact with water is carried out, and in the second electrical part, power is supplied from the network. It is completely isolated from liquid ingress.

The advantages of dry appliances include:

• high power;
• high throughput;
• ensuring optimal pressure in the network.

Dry type products are justified in large industrial buildings. It is better not to put them in apartments due to shortcomings:

• big sizes;
• complexity of installation;
• the presence of a shaft that wears out over time and requires repair;
• noisy work.

wet type

This type of equipment is suitable for apartments, one- and two-story private houses. Wet pump device: a housing with a closed electrical part, which is connected to the pumping chamber. It carries out pumping of the coolant. Tightness is achieved by using a gasket. There are branch pipes and flanges for connecting pipes at the inlet and outlet.

The electrical part is also divided into two parts. In the center is a glass, in which there are all electrical mechanisms except for the starter power piping. It is hermetically sealed outside the glass and does not come into contact with water. There is a rotor in the glass, on the shaft of which the impeller is attached. To place the glass in the coolant, an air release valve is used.

The disadvantages of the system include a decrease in efficiency.Advantages - low power consumption, simple installation and the ability to install on any section of the pipe

It is important that the glass is in a horizontal position, otherwise, when installed vertically, the mechanism will overheat and quickly fail.

Quick Tips for Mounting

Among the common options is when the heating circulation pump is installed on the bypass. It is easier to dismantle such a system if necessary, when the device is temporarily disconnected from the network. The work will require the purchase of such tools:

1. Sealant.
2. Tow or linen thread.
3. Pliers.
4. The assembly is carried out with the participation of open-end wrenches, adjustable type.

Adapters with spurs and taps are prepared separately, "American nuts" become part of the original kits

The diameter of the product and reliable material are the most important characteristics that you should pay attention to.

Actions are performed in the following order:

• Crane assembly. One belongs to a straight pipe, the other two are located at the edges of the pump. Precise welding of a fragment with a crane involves a preliminary measurement of the "return" section.
• Assemble the pump loop. So far, the nuts are only screwed on, and their tightening is pushed back to one of the finishing stages of work.
• Trying on the bypass loop. Separate markings - for places where welding to the pipe takes place.
• Welding. It is better to trust it only to masters with sufficient qualifications.
• Assemble the lower node on the return line.
• Connecting the pump to the power supply.

An arrow is always drawn on the body. It is needed to indicate where the coolant is moving. Preservation of the indicated side is ensured when the units are turned.

The pump is powered by conventional 220-volt networks.It is advised to opt for a conventional connection with a separate power line. Phase with zero and protection is required. A three-prong socket with a plug helps organize the connection of elements to each other. If there is a connected power cable, the relevance of the solution increases. The correct installation of the heating pump with your own hands is completed.

Carrying out work

Proper installation of the pump in the heating system of a private house requires performing work, observing certain installation rules. One of them is a tie-in on both sides of the ball valve circulation unit. They may be needed later when dismantling the pump and servicing the system.

Be sure to install a filter - for additional protection of the device.

Usually the quality of the water leaves much to be desired, and particles that come across can damage the components of the unit.

Install a valve on top of the bypass - it does not matter if it is manual or automatic. It is needed to bleed air pockets periodically formed in the system. Terminals should be directed straight up

The device itself, if it belongs to the wet type, must be mounted horizontally. If this is not done, only part of it will be washed with water, as a result, the working surface will be damaged. In this case, the presence of a pump in the heating circuit is useless.

Terminals should be directed straight up. The device itself, if it belongs to the wet type, must be mounted horizontally. If this is not done, only part of it will be washed with water, as a result, the working surface will be damaged. In this case, the presence of a pump in the heating circuit is useless.

The circulation unit and fasteners must be placed in the heating circuit naturally, in the correct sequence.

Before starting work, drain the coolant from the system. If it has not been cleaned for a long time, clean it by washing it several times.

On the side of the main pipe, in accordance with the diagram, mount a bypass - a U-shaped pipe section with a pump built into its middle and ball valves on the sides. In this case, it is necessary to take into account the direction of water movement (it is marked with an arrow on the body of the circulation device).

Each fastening and connection must be treated with sealant - to prevent leakage and make the whole structure more efficient.

After fixing the bypass, fill the heating circuit with water and check its ability to function normally. If errors in operation or malfunctions are found, they must be eliminated immediately.

Movement design

One of the most popular schemes for the heating system of an individual house can be called a scheme where the central water supply line is preserved, and the circulation pump is installed in a parallel pipe.

Before you make a bypass into the heating system, you should consider: the design of this device depends on its area of ​​\u200b\u200bapplication:

• near the radiator, a product is installed, consisting of a jumper, as well as 2 ball valves;
• such a device includes several parts: a circulation pump, a filter, two taps, as well as an additional tap for the main circuit;
• you can also install a pump to automatically control the temperature of the room, put in place of ball valves thermostats that turn off, if necessary, the passage of the coolant to the pump if a certain temperature is reached in the room.

The shut-off valves are a ball valve, as well as a check valve, the need for which in the heat supply system is justified. A non-return valve can replace a faucet. When the circulation pump is turned on, the valve is closed. If the power fails, the check valve will open automatically, allowing the system to switch to natural circulation.

Therefore, it is important to correctly select both the bypass design and the shut-off valves. When there is no valve, the pump is turned on along a small circuit of the system formed by a pipeline and a bypass. The check valve device requires a ball to cover the pipe lumen and a plate with a spring

The installation of such a valve in the heating system is due to its advantages, because it works without the presence of a person. When the circulation pump is turned on, the water pressure closes the valve

The check valve device requires a ball to close the pipe lumen and a plate with a spring. The installation of such a valve in the heating system is due to its advantages, because it works without the presence of a person. When the circulation pump is turned on, the valve closes under water pressure.

However, in terms of reliability, the valve is still inferior to the valve, since abrasive impurities are present in the coolant.

Experts recommend using only a high-quality valve from trusted manufacturers, since if the ball valve leaks, repairs will not help it.

Mounting the device

Installing a bypass in the heating system does not cause any particular difficulties; you can do it yourself

It is only important to adhere to a few requirements:

• select the bypass section, which will be smaller than the diameter of the supply and return, so that, if necessary, the water flow rushes around the battery;
• the device should be mounted closer to the heater and farthest from the riser;
• it is necessary to place an adjusting valve between the radiator and bypass inlets;
• instead of ball valves, thermostats can be used, thanks to which the process of removing the heat carrier can be automated;
• when using a product made by oneself, before installing a bypass in the heating system, it is necessary to carry out welding work;
• when installing the device, it must be mounted near the boiler in such a way as to prevent overheating of the pump.

Bypass - such a seemingly simple detail, is important in order for the heating work in an individual house to be as useful as possible. It allows not only to simplify, when necessary, the repair of the radiator, but also to achieve savings in heating costs by 10%. If the selection and installation of the device is done correctly, all requirements are taken into account, then the operation of the heating equipment will not cause unnecessary trouble to the owners

If the selection and installation of the device is done correctly, all requirements are taken into account, then the operation of the heating equipment will not cause unnecessary trouble to the owners.

How to choose a water pump for home heating

The pump for heating in a private house is selected according to several main parameters:

• performance and pressure;
• rotor type;
• Power consumption;
• Control type;
• Heat carrier temperature.

Let's see how water pumps are chosen for heating a private house.

performance and pressure

Correctly made calculations will help you choose the unit that best meets your needs, which means it will help save the family budget.

The performance of an electric water pump is its ability to move a certain amount of water per minute. The following formula is used for calculation - G=W/(∆t*C). Here C is the thermal capacity of the coolant, expressed in W * h / (kg * ° C), ∆t is the temperature difference in the return and supply pipes, W is the required heat output for your home.

The recommended temperature difference when using radiators is 20 degrees. Since water is usually used as a heat carrier, its heat capacity is 1.16 W * h / (kg * ° C). Thermal power is calculated for each household individually and is expressed in kilowatts. Substitute these values ​​into the formula and get the results.

The head is calculated according to the pressure loss in the system and is expressed in meters. Losses are calculated as follows - losses in pipes (150 Pa / m), as well as in other elements (boiler, water purification filters, radiators) are considered. All this is added and multiplied by a factor of 1.3 (provides a small margin of 30% for losses in fittings, bends, etc.). There are 9807 Pa in one meter, therefore, we divide the value obtained by summing up by 9807 and we get the necessary pressure.

Rotor type

Domestic heating uses wet rotor water pumps. They are characterized by a simple design, minimal noise and maintenance-free operation. They are also characterized by small dimensions.Lubrication and cooling in them is carried out using a coolant.

As for dry-type water pumps, they are not used in home heating. They are bulky, noisy, require cooling and periodic lubrication. They also need periodic replacement of seals. But their throughput is large - for this reason they are used in heating systems of multi-storey buildings and large industrial, administrative and utility buildings.

Power consumption

The most modern water pumps with energy efficiency class "A" have the lowest power consumption. Their disadvantage is the high cost, but it is better to invest once in order to get reasonable energy savings. In addition, expensive electric pumps have a lower noise level and a long service life.

Control type

Through a special application, you can get information about the operation of the device wherever you are.

Typically, the adjustment of rotation speed, performance and pressure is performed by a three-position switch. More advanced pumps are endowed with electronic control systems. They control the parameters of heating systems and save energy. The most advanced models are controlled wirelessly, directly from your smartphone.

Heat carrier temperature

Water pumps for heating a private house differ in their operating temperature range. Some models can withstand heating up to + 130-140 degrees, this is exactly what should be preferred - they will cope with any thermal loads.

As practice shows, operation at the maximum temperature is possible only for the shortest time, so having a solid supply will be a plus.

Other characteristics

When choosing a water pump for heating, it is necessary to pay attention to the maximum operating pressure for the selected model, the installation length (130 or 180 mm), the type of connection (flanged or coupling), the presence of an automatic air vent. Also pay attention to the brand - in no case do not buy cheap models from little-known developers. The water pump is not the part to save on

The water pump is not the part to save on.

How to put the circulation pump on heating

Many people face the need for self-installation of the circulation pump. There are usually two reasons - either the boiler does not initially include a pump (and it is irrational to change pipes for products with a large cross section), or its power is not enough to evenly heat all the rooms through which the heating circuit is laid.

For example, if a heated extension (garage or otherwise) was erected after the residential building was built and inhabited. How to properly install a pump that circulates the coolant through the heating system, what to foresee - there are many questions during the installation process. This article will give detailed answers to the most typical of them.

Features and rules for installing the pump

Pipes of the heating system are laid according to various schemes. For the circulation pump, there is no difference where it is installed - on a vertical "thread" or horizontal.

The main thing is that the product is connected correctly.This is where a typical mistake is often made, which consists in the fact that the inlet and outlet pipes are interchanged.

How not to confuse if they are visually indistinguishable - neither in thread, nor in cross section?

There is an arrow on the pump body. She is clearly visible. It shows the direction of movement of the coolant. Therefore, its pointed tip points to the outlet pipe. This means that it is necessary to install the circulation pump in the heating system so that it faces the boiler with this side. In addition, the device passport (and it is necessarily attached) shows the recommended scheme for its installation.

Regardless of the specifics of the pump installation (spatial orientation), a prerequisite is the horizontal position of the rotor. This is also indicated in the passport.

When installing a circulation pump, in most cases a bypass is installed. Its purpose is clear - to ensure the movement of the coolant along the circuit, even if the pump is out of order or it needs to be temporarily dismantled. For example, for maintenance. Here, too, opinions differ. Some believe that the pump should be installed correctly on the pipe, others - on the bypass. What to be guided by?

Since after the pump stops working, circulation will be provided either by the device installed in the boiler or by the temperature difference (in non-volatile systems), it is necessary to create the most favorable conditions for the movement of the coolant. Therefore, when the device is turned off, it must go through the pipe, directly, bypassing the bypass. The pictures explain everything.

This installation option (on the bypass) is implemented for heating systems that are mounted for non-volatile boilers, that is, as "self-flowing".

With this installation of the pump, it is possible to organize automatic switching of the circulation from the bypass to the direct "thread". It is enough just to put a non-return valve ("petal") instead of a ball valve mounted on a pipe.

When the pump stops, the pressure in the system will drop, this valve element will open, and the movement of the fluid will continue, but already directly. Moreover, the time for such a switch is minimal, therefore, such a modification of the circuit will not affect the heating efficiency and the operating mode of the boiler.

A good solution for owners of private buildings. After all, this is a rare case when there is always someone in the house. Even a person who has gone on a well-deserved rest does not constantly sit “within four walls”, but is away on various business. It is precisely at this time that problems with en / supply may arise.

In a circuit that is designed for forced circulation, there will be no "self-flow" of the coolant by definition. At least due to the lack of the required slopes of the "threads".

This means that the pump can be placed directly on the pipe, since the installation of a bypass in this case makes no sense. But it is necessary - between the boiler and the expansion tank.

The position of the cleaning filter relative to the circulation pump (another controversial issue) depends on the characteristics of the heating circuit:

• If the system is open, then before the device, but on the bypass.
• In cases with solid fuel boilers - in front of the valve (3-way).
• In pressure systems, the "mud collector" is installed before the bypass.