Overview of mixing units for UFH

First of all, underfloor heating (UFH) is associated with pipes, insulation and manifolds. Pump-mixing units are not always remembered. Someone because of misunderstanding how to set up, where to put, and most importantly why? Someone because of the high cost. However, this site - the basis of panel heating. Let's look at the options for units that are on the Ukrainian market.

Pict.1 Mixing unit of TM-3 FIV

Functionality

Floor heating is a type of low-temperature system. For a number of reasons, the water must be supplied to the pipelines with a temperature below 55 ° C. In our country, "warm floors" are often combined with radiator heating. The latter works with a heat carrier with a high temperature (above 55 ° C). This is where the pumping and mixing unit (MU) finds itself. It produces a decrease in the temperature of the water to the calculated value for underfloor heating. By mixing two streams - hot (from the main pipe of the heating system) and cooled (more often from the return highway after passing the “warm floor” loops).

Consider the scheme of the MU on the example of the equipment of the German company TECE.

Pict.2 The scheme of the mixing unit

The entrance and exit to the main heating system is located below. Supply line - A, reverse - B. The head regulator is a thermostatic valve (2) with a thermal head (4). With the help of the latter, regulation of the supply of hot water to UFH system is carried out. The setting range is 20 ÷ 55 ° C. Control takes place according to the temperature of the mixed water that enters the loops of underfloor heating. A remote thermal head sensor (6) measures it.

The circulation of water in a small circuit ("warm floor") creates a pump (5). The inlet of mixed water to the manifold (8), the output from the circuits - (9). To remove air in the upper part of the unit is placed manual air vent (7). The mixing of two streams - the feed from the heat generator (boiler) (A) and the reverse from the underfloor heating (9) occurs in the lower left part. A balancing valve (3) regulates the amount of cooled water entering the mix.

Approximately according to this scheme, all pump-mixing units work.

Kinds

All MUs can be divided into several categories.

Depending on the mounting base of the circulating pump used:

- for the pump of 130 mm;

- for the pump of 180 mm;

- universal.

Depending on the working body:

- with thermal head;

- with a three-way mixing valve.

By the presence of a bypass line:

- with bypass;

- without bypass.

By thermal power:

- low-power (up to 15 kW);

- high power (more than 15 kW).

By type of input / output main pipes:

- bottom-down;

- with a side occasion, etc.

By design, the groups differ from each other. However, many products are similar. Therefore, I will show you the range and divide them into categories. In which will be located similar products.

  

MU with one-way connection from below

This includes the MU TECEfloor (art. 77450000) discussed above. In addition, a complete equivalent - Fluvia MPG-10-B-W from Uponor. As well as another subtype - FIV TM-3 and AquaHit MU.301.

For all these groups, the inlet and outlet of the coolant in the high-temperature circuit are located below.

Pict.3 Groups with one-way bottom connection

Regulation of temperature happens at the expense of the thermal head. Mixing occurs at the bottom of the group. At the top is a thermometer. It shows the temperature of the mixed water. Also installed at the top of the air vent - manual (TECE, Uponor) and automatic (FIV, AquaHit). Assembly length of the pump - 130 mm. MU of AquaHit has the ability to also use a 180 mm pump, due to sliding fasteners.

The FIV and AquaHit groups have an integrated bypass line and plated with a nickel.

The TECE and Uponor groups can adapt to a manifolds with different center-to-center distances from 206 to 239 mm.

When selecting, it is also important to pay attention to the maximum thermal power of MU.

Pict.4 Technical information

MU with lateral versatile connection and thermal head

This subtype is one of the most popular in Ukraine. It is in the assortment of Gross, Sandi Forte, Fado, AquaWorld, etc. It is obliged to popularity of ease of installation and low cost.

Pict.5 MU of Fado

Regulator - thermal head with remote sensor (1). It is completed with two thermometers, which show the temperature of mixed water (3) and the temperature of the return line of UFH (6). To prevent the flow of hot water into the return manifold, a check valve (5) is located inside the mixing unit.

The group is equipped with a bypass line (4). It is necessary to protect the pump from overheating in case of overlapping of all circuits (for example, with actuators). Bypass will pass a small circulating ring. The amount of water passed into it is adjusted using the valve (2).

There is an even cheaper modification - without a bypass.

Pict. 6 Technical information

MU with lateral one way connection

There are the German brands - Watts (ISOTHERM), Oventrop (Regufloor) and Kermi (xNet Standart). Connection is from the side (top and bottom). The regulating mechanism is a three-way mixing valve. One of the most compact versions of MU.

Pict.7 Unit of Watts

Convenience is the versatility of the installation - even with the valve down or up. To protect against overheating, MUs are equipped with an electric overhead regulator. At increase of the limiting value of the temperature of water for the underfloor heating system - the sensor switches off the pump. Mixing occurs at the installation site of the three-way valve. The design provides a bypass line.

Pict.8 MU with lateral one-way connection

To set the temperature of the mixed water, use the stick (Watts) or thermal head. When you turn the knob on mixing unit Watts ISOTHERM, the built-in pin clicks when you increase / decrease the value by 1 ° C. The remote sensor from the thermal head is not placed inside the case as in the previous versions, but is superimposed on top. The maximum power of such groups is no more than 15 kWt.

Pict.9 Technicla info

Combined mixing units

Differ in some complexity of a design, but more exact hydraulic control. In this category, I put:

- Valtec CombiMix, TechnoMix and ValMix;

- Fado SG21;

- Luxor GM 1192;

- Giacomini R557R-1.

Its beauty lies in the simple connection of two collector units (main heating system and heated floor) in one group.

Pict. 10 Combined mix unit

As can be seen in Figure 10, the MU is located in the center of the manifolds group. On the left are the high temperature circuit manifoldss. Through it, the hot water (red line) falls on the MU, where it mixes with the cooled (blue line). Coming from the loops of panel heating. Part of the "return" from the warm floor bypass goes immediately to the return manifold (blue line) of the high-temperature circuit. Mixed water flows through the low-temperature contour feed manifold (yellow line).

Regulator - thermostatic head. Included are thermometers, air vent (mostly automatic), drainage taps with fittings (to fill the floor heating system with heat carrier), mixing valve (2) (pict. 11, right), bypass control valve (11), ball valves (6) (pict.11, right) (to shut off the flow and uninstall the pump), etc.

For Giacomini R557R-1, two types of pumps can be used - 130 and 180 mm. As standard, the kit includes a longer bypass tube. For the pump 180 mm. It can be shortened for the second option.

Pict.11 Operation scheme

According to the range of MU TM Valtec. The brand has 3 very similar options - CombiMix, TechnoMix and ValMix. In addition to the difference in price (listed from the most expensive to the cheapest), the difference is in the configuration. The last two MUs are completed with one manual air vent and one drain valve. CombiMix - two automatic air removal and two drain valves. ValMix is not equipped with a thermal head.

SG21 from Fado - Valtec CombiMix analogue. Luxor has a slightly different location of the outputs under the manifolds and the location of the thermal head, but it functions the same.

Pict.12 Range of combined MUs

Pict.13 Technical information

Separate mixing units

Here it means that the unit consists not of one integral body, but of several.

Pict.14 Pump module for floor heating M054 from ICMA

One part - to connect the circulation pump. The second is a mixing valve with a thermal head and a bypass line.

In the first part are placed - the valve for the suppression of air, the connector under the remote temperature sensor, drain valve, thermometer. They are located on opposite sides of the low-temperature circuit manifold.

Representatives are ICMA M054 and Valtec DualMix. Although the same ICMA has several different modifications of this group - M055 (with a pump); M058 (pump part only, no bypass, versatile bottom connection); M059 (like M058, only one-way connection is lower), etc.

In my opinion it is not very convenient for installation - when it is necessary to assemble the MUs from different parts. Increases installation time. But on the other hand - a large heat output, high operating temperature and pressure (10 bar).

Pict.15 Separate MUs

These mixing units are suitable for pumps with an installation length of 130 mm.

Pict.16 Technical information

Other MUs

There are also many other options that are not included in my classification, but used in Ukraine. Among these can be distinguished Herz, Danfoss, Kan-therm. All regulators - thermostatic valve with thermal head. At Herz, the MU already installed in the manifold. This shortens the assembly length of the entire group. The bypass made in the form of a copper pipe.

Pict.17 Mixing groups Herz, Danfoss, Kan-Therm

All designed for pump 130y assembly length.

Pict.18 Technical info

As a result, I would like to say that it is so important which pumping and mixing module you choose. It is important that there is an understanding of why it is needed and how to install it. To simplify the last point, I post here links to instructions for installing and configuring different mixing units.

Yes, it will be warm in your home)