Prices Inc. VATPrices Ex. VAT
November, 2017

Warm air space heaters or hot water fan heaters (they are know by many different names) are ideal for heating large spaces in a variety of environments. The list is exhaustive and VPS Industrial Heating have sold this heating equipment to: Warehouses, factories, garages, retail outlets, zoo enclosures, gymnasiums, public halls plus many more. Not all customers fully understand the various options that they have for controlling their fan coil heaters, so hopefully this article will attempt to explain the available options.

1. No Controls

The heater is connected to a heating source and a power supply. When heat is pumped to the heater the coil heats up and radiates heat. When the power is switched on the fan will blow through the coil and heat up the room. The fan would always run at the same speed. In the case of the 3 stage fans, the speed would be selected according to how its wired ( low, medium or high). The single stage fans would run at maximum speed. When the power is switched on the and heat is still being put through the unit, heat will continue to be radiated into the space. Conversely, if the power is switched to the fan and no heat is being  pumped through the coil the fan coil will blow unheated air into the space which can be useful to increase comfort levels during warm weather.

2. Two-Port Zone Valve Only

If the heating circuit is heating other devices apart from the hot water fan heater, it would be better to fit a 2 port zone valve which in turn can be fitted on the pipe feeding the heat into the fan coil heater. This can be wired so that whenever the fan coil heater is switched on the 2 port zone valve opens and warm air will be blown into the heating space. Alternatively, the 2 port valve can be wired separately. This would enable the fan to operate without any heat and uncooled air would be blown into the space.

3. 3-Stage Speed Controllers with Thermostat

This device only works with the 3 stage fans (please see below for the fan speed controllers for other fan types) This device gives capability as follows: Heating or Cooling can be selected via a switch. Heating When the fan coil heater is being used for heating the device gives the following options which can be selected manually: On/Off – This will switch the fan on the fan will operate and if fitted the 2 port valve will operate allowing heat to be fed into the coil. Speed Control – The speed of the fan can be adjusted between low, medium and fast speeds. Thermostat – The desired temperature can be selected on the thermostat. The fan will operate until the desired temperature is achieved and the fan will then switch off. If a 2 port zone valve is fitted, this will also close. Cooling In warmer weather the heating circuit will normally be turned off. (i.e. no heat available in the pipe work). Selecting Cooling de-activates the thermostats allowing the fan to operate regardless of the temperature.

4. Fan Speed Controller – 5 Speed

We have a range of these controllers and it is important to pick the correct size unit depending on the size of the unit (or if multiple units are to be controlled). Please call us first (0141-459-3141) for technical advice. These speed controllers can be fitted to all our hot water fan coil heaters. They give the ability to select speeds 1 to 5. They can be used in conjunction with a 2-port valve which will ensure that the heating circuit to the coil is shut down when the fan is switched off. The 2-port valve could be wired separately which would allow the fan coil heater to be used as a fan only during warmer weather. If the heating circuit is off, then the fan can be used on its own without heating regardless of how the 2-port valve is used.

Fitting this into the circuit will shut the fan down when a pre-set temperature is achieved. These can be used in conjunction with a 5-speed controller and/or a 2-port zone valve.
Fitting this device provides a mechanism for time and temperature control. Set what time you want a pre-set temperature to be achieved. For example, you might want a temperature of 20 degrees to be achieved when people are using the space and outside these times select a temperature that provides frost protection. These can be used in conjunction with a 5-speed controller and/or a 2-port zone valve. Could also be used with the 3-speed controller with the thermostat disabled by selecting “cooling”  
We are happy to explain all these options in more detail. Call us on 0141 459 3141 or send any questions to