Is it possible to connect the underfloor heating to the return line. Connecting warm water floors to a one-pipe heating system
Question #71: I am completely confused. Answer, please, maybe not a post, but a soap. I need to mount a warm water floor system in single pipe system. I read your answers to similar questions and I have a new one.
Firstly, I still have not figured out how to connect the TP and the circulation pump to a single tube. Your post shows a drawing, but there the supply and return from the radiators and the transformer goes somewhere up and it is not clear how it closes.
Secondly, if a special module for thermoregulation is included in the TP, then how will NOT a situation arise when the circulation pump will drive the coolant, and the module will block the flow to the TP when the desired temperature is reached in the room. What will happen in this situation Alexander Answer: In general, in order for the coolant to move along the contour of a warm water floor in a one-tube heating system, it is necessary to create excess pressure in it, and this can only be done using a circulation pump, right?
And now let's consider everything in order, if the warm floor is located directly in the room where the heating boiler is installed and the circulation pump is installed on the return, then the underfloor heating circuit is connected to supply the coolant to it after the circulation pump and the output (return) from the floor circuit is connected in front of the pump. In general, it turns out that the underfloor heating circuit is connected to a single-pipe heating system in parallel with the circulation pump. In this case, the pump creates pressure in the main circuit of the heating system and in the additional circuit of the underfloor heating system.
If the boiler is powerful and the return temperature does not exceed 45-50C, then no control module should be installed.
If your underfloor heating is located at a considerable distance from the heating boiler or even on the second floor of the house, then you can connect the underfloor heating circuit as follows:
As you can see from the figure, the circulation pump is installed directly at the heating boiler, then distribution combs are installed, the underfloor heating circuit is connected in parallel to the radiators. The supply of coolant to the circuit and to the batteries is regulated using ordinary ball valves, thus establishing a comfortable temperature in the room. You can install a special connection module in the middle of the TP circuit, here in the figure that you saw, a warm floor circuit with such a module is connected in parallel to two heating batteries in a single-circuit heating system:
Since in a single-pipe heating system the underfloor heating circuit is connected in parallel either to the circulation pump or in parallel to the heating battery, when the thermostat is triggered, the coolant will pass through the heating radiators.
Another thing is if you have a single-pipe heating system in your room and only warm floors without radiators, then you need to assemble such a system:
A control module in such a system is not needed, a three-way thermostatic valve regulates the temperature of the coolant in the TP circuits, and in the event of operation, the coolant continues to circulate through the check valve using a pump in the TP circuit. Such a unit must be assembled in each room with installed underfloor heating. For construction country house or cottages, it is important not to forget that, as a rule, they are located in places where there is no water and communications. And for such a case, axial piston pumps become indispensable, which have a large reliability resource and are excellent for any latitude.
A mixing unit, or collector, in a warm water floor system is needed to adjust the temperature of the coolant. The latter is heated by the boiler according to the parameters set by the device program. Normally, the supply temperature of the heating medium is 55 °C. This is enough for the warm floor to warm up to a temperature of 30 ° C. This is the most comfortable value for the cold season.
In the presence of a collector, a high supply temperature does not play a role - the mixer itself will lower it to desired value by mixing cold water. Accordingly, if a water floor is planned without a collector, then the coolant must flow at a predetermined temperature, from which it can be concluded that a separate boiler must be installed for a warm floor without a mixing unit.
Thus, for individual radiator heating, a second boiler or a centralized common house radiator system is needed. According to state regulations, the temperature of the coolant supply to radiators is on average 70-80 ° C, which is 20 ° C higher than required for underfloor heating.
In some cases, installing a collector for underfloor heating is not justified
The main disadvantage of installing a system without a collector is the need to minimize the temperature losses of the coolant along the path “heat carrier-pipeline” and in the system itself. You also need to maintain the required temperature on the floor area. Therefore, it is recommended to consider the following requirements:
- Insulation of the walls of the room;
- Laying thermal insulation on the floor;
- Availability of high-quality window systems;
- Laying the floor in the immediate vicinity of the heating element;
- The area of the room is not more than 20-25 m 2 .
The main and common mistake when installing such a system without a manifold assembly is an attempt to install on too large an area.
Important! It is necessary to calculate the length of the circuit and its layout in such a way that the return temperature of the heating medium is not too low. Otherwise, a large amount of condensate will form on the boiler heat exchanger, which will lead to a quick breakdown of the device.
However, some craftsmen argue that in a situation where the “return” will be cold in any case, the installation of a condensate boiler can save. It has a high efficiency and such a device is not afraid low temperatures for heating.
Ways to install a warm floor without a collector
H2_2You will need the following materials and devices:
- Pipeline;
- Accessories for the pipeline;
- Boiler;
- Three-way thermostatic valve;
- Pump assembly.
Some try to use the easiest installation method - to embed the underfloor heating system directly into the central heating system. However, this approach threatens with serious breakdowns of the pipeline, because. the temperature for the radiators is much higher than that needed for the floor. Also, when such a homemade device» supervisory authorities, the owner of the apartment faces serious penalties and an order to completely dismantle the warm water floor.
2 options for laying the pipeline without a collector are preferred: a snail and a snake. Moreover, both schemes should consist of a double pipeline: 2 parallel loops to the warm floor - supply and return.
The advantage of the "snake" is that it is possible to distribute the heating zones. For example, bypassing furniture or plumbing. The advantage of the "snail" is a more uniform heating of the entire area.
After laying the pipeline, it must be connected to the boiler. First you need to calculate the power of the pump. The following formula is used:
G \u003d Q X 0.86 / Δt,
where G is the system capacity (l/h),
Q - system power (W),
0.86 - conversion factor to Kcal/h,
Δt - supply-return temperature difference (°C).
The pump is needed to ensure the speed of movement of the coolant through the pipes. Depending on the type of pump, it can be controlled either manually or automatically. The device is mounted on the supply pipeline. In a system without a mixing unit, the pump device is located under the boiler. The circuit between the pipeline with the pump and the boiler closes the three-way thermostatic valve.
In order for the underfloor heating to work stably without installing a mixing unit, you should choose a high-quality powerful boiler. Electric or gas, it doesn't really matter. The main thing is that the power of the device should be designed specifically for the designed underfloor heating. Masters recommend choosing models with a pump.
Mounting the valve for a system without a manifold
The valve is installed on the pipe with the supply coolant, a jumper is mounted to the return flow. The purpose of the three-way thermostatic valve is to regulate the temperature of the coolant that is supplied to the pump. In fact, this is a mixer, inside of which a temperature-sensitive element is located.
The valve protects the system from overheating, and in the event of a breakdown and cessation of the return flow, it automatically shuts off the supply. Also, the valve eliminates the possibility of reverse flow of the supply flow. Thus, the valve partially takes on the role of a collector.
If the floor area is large and there are serious heat losses on the "return", it is recommended to install a valve at the cold inlet end. Due to this, excessive condensate will not form in the heat exchanger.
Installation of a warm floor without a pump and a mixing unit
The need to install a pump is eliminated if the heating boiler is equipped with a powerful circulation pump, and the heating area is minimal. The main advantage of a boiler with a built-in pump is a well-chosen equipment. That is, you do not need to choose a boiler according to the individual characteristics of the pump, it is enough to determine its total power.
Today we will consider different options for connecting a warm floor to a home heating system. TP can be either the only source of heating, or combined with a high-temperature system, while the piping is performed in different ways.
How to connect a TP without batteries
TP connection diagram, in which the temperature of the coolant is controlled by the boiler.
If the TP is the only source of heating in the house, then the connection of the underfloor heating to the heating system depends on . If you have a modern boiler, sharpened for low-temperature systems, then the installation of the circuits is carried out directly through the manifold. That is, you let the flow from the heater directly into the collector comb. Do the same with the reverse flow - direct it directly to the boiler. Thus, the coolant passes through a large circulation circle.
If it is impossible to accurately set the temperature on the boiler, or if you want to play it safe so that someone does not accidentally set the boiler to the maximum, then in the scheme for connecting the underfloor heating to the heating system, a mixing unit must be provided. It is placed in front of the collector. The main task is to mix the supply and return to the set temperature.
The scheme of how to make underfloor heating from water heating with a mixing unit:
- We bring the flow from the boiler through the sump into the three-way thermostatic valve, and the branch pipe from the TP return is also supplied to it. The return is divided into two streams by a tee;
- a pump is placed behind the thermostatic valve - if the pump in the boiler is not enough;
- from the pump, the coolant goes to the supply manifold, on which manual thermostatic valves are installed;
- flow meters should be on the return comb.
Be sure to install automatic air vents on collector group. Two are better: on the supply and return comb.
In principle, this is sufficient for the normal operation of the TP. Now let's look at how to properly connect a warm floor if there are temperature sensors in each room that are connected to servos through a thermostat. The servomotors are mounted on thermostatic valves that are screwed into the seats on the return flow manifold. In this case, it is also necessary to install a bypass with a bypass valve. It is needed to continue the circulation in a small circle in the event that the TP rings are blocked by servos.
There is one subtle point here, how to connect a warm floor to the heating system - when the coolant goes through the bypass in a small circle, there is a risk of water leakage from the return of the general (large) system. Therefore, you need to install a pump of less power than in the boiler, or play it safe by installing a check valve behind the pipe (when viewed from the collector) that supplies chilled water to the mixing unit.
Connection diagram for batteries and one TP circuit
TP can be cut into the supply line through a tee. Be sure to put a mixing unit.
Often a warm floor is combined with conventional batteries. Consider how to connect a water-heated floor to a common circuit if we have only one circulation ring. In this case, we don't need to change two-pipe system heating on beam (collector). TP can be inserted into the supply line in the same way as radiators, that is, through a tee. In the same way, the return line also crashes.
To reduce the temperature to the required level, you need to make a mixing unit. In this case, the pump is not required, since it will be either in the boiler or in front of it on the return line common system(after ). No flow meters, air vents or other control elements are needed. It is enough to put a three-way thermostatic valve and, of course, as with every radiator, shut-off valves.
How to connect batteries and several TP circuits
Combined TP connection scheme (two-tube and manifold).
Now let's figure out how to connect a warm floor with radiator heating if we have several TP loops. In this case we can:
- make a beam system with two collectors;
- make a combined system - a two-pipe supply to the radiators and a collector to the TP.
In the first case, we bring the supply to the collector group. We have a separate circuit with a coolant temperature set on the boiler (60-70 degrees, and if , then all 85). The TP circuit must be connected to the second manifold through the mixing unit. Circulation pump can be installed on each collector group separately or one for the entire heating system, but more powerful. The combined system consists in the fact that the TP circuit is connected to a two-pipe system as another heat exchanger. And then the nozzles are brought to the collector through the mixing unit.
How to control the temperature
The thermostat can be directly connected to the actuator.
There are two options for controlling the temperature of the warm floor:
- through the mixing unit;
- through servos.
If you regulate the temperature of the coolant through the mixing unit, then the degree of heating of all rooms without exception changes. In this case, the air temperature depends on the area of \u200b\u200bthe room and the wiring diagram, in other words, the thermal power of the circuit. Make it so that different rooms was the desired temperature, it is not possible.
If you want to set the degree of heating of each room yourself, then servo drives are installed on the collector group.
These are electric taps that shut off the circulation of the coolant when necessary. The thermostat sends commands to the servo, and it knows when to do it by receiving data from temperature sensors that control:
- the degree of heating of the screed;
- degree of air heating.
Practice shows that you need to put the sensors in the screed. You set the temperature to 28 degrees and wait for the system to stabilize. Based on the thermometer readings, make adjustments. Yes, in this way the system will work without taking into account weather conditions, but it is still almost impossible to achieve full automation of temperature control in the room with water TPs. The circuit is very inert, if you put an air temperature sensor, the drops will be very sensitive, since the screed heats up for a long time and cools down for a long time
First launch of TP
Underfloor heating is very convenient.
It remains to figure out how to turn on the warm floor. The first start can be carried out only after the screed is completely dry - this is about a month. First, the system is filled with water. This is done manually by means of a pressure pump or via a pre-wired inlet to the water circuit.
The methodology is as follows:
- open all air vents and all valves;
- the circuit is filled with coolant;
- when water begins to ooze from the air valves, they overlap;
- installed temperature regime at the mix node;
- then the boiler is turned on.
As the coolant heats up, air will come out of it, so it will need to be bled. After several cycles of heating the coolant, the system stabilizes and you just have to adjust hydraulic resistance on different circuits of the TP by flow meters. As you operate, you will make adjustments to the temperature of the coolant.