Hydronic Unit Heater
VOLCANO

Step one: determine the temperature inside the target room and its heat demand for heating purposes. Air heating is one of the most dynamic methods of heating rooms, allowing for the application of temporary (e.g. overnight) temperature lowering in the heating room and its fast heating soon before entering it. This allows for significant reductions in heat consumption, but does not require any heating power surpluses to be added to the devices for quick heating.

Step two: determine the location for the heaters and the necessary air stream range to ensure the achievement of suitable temperatures in the areas of the room you are interested in. Notice that the air speed should not exceed the permissible values in human occupancy zones or on any other sensitive areas, e.g. in the vicinity of industrial processes.

Step three: obtain information on the temperature of the heating medium available in the building.

Step four: Once you have all the above data, take the VOLCANO catalogue and look for devices which fulfill the criteria of the required air stream and required heating power, considering the possibility of work at varying outputs (first, second or third speed). Use the charts presenting air speeds in the distance function to determine the range for each device size. Alternatively, use the chart on page 18, presenting the range for limit speed of 0,5 m/s. Determine the heating power for each device speed and for various heating medium temperatures using the tables on pages 22-23.

Easy selection “shortcut”: To make your work easier, use a selection program available at: ehcad.vtsgroup.com

VOLCANO heaters equipped with AC motors have the possibility to swich between 3 speeds, and those equipped with EC motors have stepless regulation. In the unit equipped with AC motor it is performed by switching of the given winding leads with use of a simple control panel equipped with relay outputs and there is no need to use any voltage regulator. In the unit equipped with EC motor the fan speed regulation is performed by 0-10V signal. We can use either a simple wall-mounted potentiometer allowing for a stepless control of the speed, or an advanced control with microprocessor, which except for a choice of 3 programed efficiency steps, can also have numerous other functions (temperature control in the room, weekly programmable ON/OFF calendar, work parameters settings, anti-freeze modes etc.)

The main pipeline diameter should be chosen in a way, so the water flow is not higher than 2,5 m/s. It is due to a compromise between the investment costs connected with the used pipes diameters, and maintenance costs, connected with water flow resistance. We suggest the following minimum pipeline diameters depending on the quantity and type of the heaters connected to the main line according to the table on p. 20. In case of a complex installation, that is when the units are at least 40 m from the heat source, one has to correct the pipe diameters recalculating them for smaller water flow speed.

VOLCANO technical documentation contains electrical connection schemes for various work modes. It is the easiest to achieve the close of the fan together with the closing of the valve by connecting the whole unit to a power grid, protected by a redundant circuit breaker, through a thermostat. In such case one has to pay attention to the maximum thermostat input load; the load should be at least 3 (10) A per one VOLCANO unit. If the thermostat input load is too small, or the higher number of the units controlled with the use of the thermostat, one has to use an electric relay, with a coil fed from a thermostat (230V AC), work input voltage will be 230 V AC, and work input load will be adjusted to the number of VOLCANOS under control.

Yes, you can, although a heat exchanger powered by an upper manifold will be more difficult to vent. Remember to leave sufficient space for mounting a valve actuator, which should be installed on the return stub pipe

Connection of the valve with actuator to the Volcano EC controller is possible through dedicated input. This input on controller is marked as H1. On H1 input, 230 V AC voltage appears when the controller changes modes for worked mode. It transfers the 0-10V DC voltage to the fan and 230V AC voltage to actuator of the valve, which opens it.

Yes, you can. The most frequently used non-freeze medium is a water solution of ethylene glycol. The heaters mounted in VOLCANO can support up to 50% mixtures. Make sure to check, however, if other elements of the technological heat installation (valves, pump, etc.) are adapted to work on glycol mix. To do this, check the recommendations of the manufacturers of particular components used. Remember that the use of glycol mixes, which are usually characterized by higher viscosity and lower thermal capacity, compared to water, increases the resistance of heating medium flow and reduces the heating power of the device

Yes, but only when the temperature of the working medium is higher than the dew point of the cooled air, since VOLCANO devices are not equipped with drip trays and we shouldn’t lead to the condensation of humidity. To switch a VOLCANO device to the cooling function, connect an ice water installation. When there is the risk that the temperature of the working medium could fall below the dew point of the cooled air, make sure to build a drip tray and install it under the device. In this case, the VOLCANO device will be able to work with the horizontal air outlet only. The use of a VOLCANO device with vertical air outlet can result in flooding the fan motor or the space under the device, since mounting a drip tray in this position of the device is impossible.

VOLCANO is not equipped with a drip tray, which is why you should always reduce its work efficiency in the cooling mode, in order to eliminate the phenomenon of drip-trapping by the air flowing through the heat exchanger.

Yes, VOLCANO water heaters can cooperate with heat pumps. However, when selecting the size of the device, take the low temperature of the heating medium into account. We recommend the use of heaters with large heat exchange surfaces. For this type of installation, we recommend the VR3 heater equipped with a three-row heat exchanger. Make sure to check VR Mini and VR2 with two-row heat exchangers as well

Yes, there is such a possibility. One has to use H1 clamp on the controller, and for security additionally use an electric relay. On the H1 input, and then on the electric relay a 230 V AC voltage will appear when the controller turns into work mode. This way, provided the relay is correctly chosen, and can turn the circulation pump on and off.