5) Control Systems

Heating Systems Layout

The underfloor heating pipe loops are installed in continuous lengths, starting and finishing at flow and return connections on the manifold. Each room or loop can be individually controlled by means of a room thermostat wired to an actuator on the return connection. The flow through each loop can be balanced by a regulating valve on the flow connection.

There are a number of methods for controlling the water temperature and flow in an underfloor heating system. The fundamental question is whether or not the system requires temperature control for each individual loop.

Individual Zone Control

In residential projects where temperature is desirable for each room (and a Part L Building Control requirement for sleeping areas where the heat source is not a heat pump) temperature control is achieved via a room thermostat wired to an actuator on the manifold. The actuator is also connected to a wiring centre. As the room temperature drops, the room thermostat sends a signal to the actuator that is signalling for heat. This signal activates the manifold pump and the boiler sends hot water to the manifold.

With regard to individual zone control, the decision has to be made as to which type of thermostats is required and if combined control of both hot water for underfloor heating and domestic hot water is required:

 

  • Dial Thermostats 
  • Programmable Thermostats (Slimline/ Touchscreen)
  • Wireless Thermostats (Slimline/ Touchscreen
  • Remote Access - Central Control & Telephone remote control 
  • Remote Access - Internet Heating Control/ PC Controlled
  • Time Clocks
  • Fan Thermostats 
  • Eight zone wiring centres - Heatmiser / Drayton 
  • Two channel time clocks 
  • Termec Dial Thermostats (hard wired) 
  • Tamperproof Thermostats (hard wired)
     

 

System Components

For easy to follow guidance on how the systems work, click this image to connect to an excellent demonstration on the Heatmiser UK website - then click "How it Works" ...

 

 

 

HEATMISER PRODUCTS

 


MANUAL DIAL THERMOSTATS
(Click Image for details) 

 

 

SLIMLINE THERMOSTATS
(Click Image for details) 

 

 

TOUCHSCREEN THERMOSTATS
(Click Image for details)

 

 

 

WIRELESS SLIMLINE THERMOSTATS
(Click Image for details)

 

 

 

WIRELESS TOUCHSCREEN THERMOSTATS
(Click Image for details)

 

 

 

TIME CLOCK & PROGRAMMERS
(Click image for details) 

 

 

FAN THERMOSTATS
(Click image for details)

 

 

CENTRAL CONTROL - PHONE
(Click image for details)

 

 

INTERNET CONTROL
(Click image for details)

 

 

PC CONTROL
(Click image for details)

 

 

 

WIRING CENTRES
(Click image for details)

 

 

 

EIGHT ZONE WIRING CENTRES – DRAYTON
(click image for details) 

 

 

 

EMMETI PRODUCTS

 

 

TERMEC DIAL THERMOSTATS (HARD WIRED)
(click image for details)

 

 

 

 

TAMPERPROOF THERMOSTATS (HARD WIRED)
(click image for details)

 

 

 

 

 

WIRING CENTRES
(Click image for details 230V and 24V) 

Example System

The two pictures above are of a controls system that we put forward for flats.

Components – each apartment has a two channel programmer, one channel for hot water and the other for heating. The heating channel can be either timed or left on constant.

Each apartment has one programmable thermostat to be situated in either the hallway or living area. This thermostat can be programmed with an ‘On’ required temperature and also an ‘Off’ required temperature. This will give the apartment a night set back facility.

Other components include a standard dial thermostat in all other areas to be controlled – bedrooms, kitchens etc. A central wiring centre and individual loop actuators will be fitted on each manifold.

General Connection – the two channel programmer will be wired so as to supply or interrupt the UFH wiring centre power. The wiring centre will receive signals from the thermostats and in turn operate the relevant individual loop actuators, which will be wired to the correct terminals inside the wiring centre. When all thermostats are satisfied or powered off, the wiring centre will close the hot water supply valve via a relayed signal wire.

Operation – with the time clock set on constant, the programmable thermostat should be set to the desired times and temperatures – e.g. 21 deg C from 6am – 9am and 21 deg C from 4pm to 10pm. During the time when it is off, 9am – 4pm and 10pm – 6am, the temperature should be set between 14 deg C and 16 deg C, this will ensure that the air temperature does not drop below the set point. This should ensure the screed retains heat and will have a rapid warm up time.

During the ‘On’ time of the programmable thermostat, the dial stats can be set to achieve the desired temperature. During the programmable stats ‘Off’ period, should the air temp dip 0.5 deg C below the set back figure, the programmer will bring the heating on temporarily and allow the dial stats to operate. When the air temp has increased to 0.5 deg C above the set back temperature, the system will be turned off. The dial stats will not override the programmable stats.

Having the two channel time clock enables the owner to shut down the whole heating system at the touch of a button – to be used for holidays and other extended periods of absence.

 

LARGE AREA TEMPERATURE CONTROL

For large areas requiring a uniform temperature, such as sports halls, it is not necessary to have individual loop temperature control. In these circumstances all the loops are required to be operated at the same time.

One thermostat is required per manifold along with a 2 way zone valve that has the affect of acting as a large actuator. Individual actuators are not required on the manifold and neither is a wiring centre required.

The zone valve is fitted on the primary flow and each manifold is controlled by one thermostat and the ports on the manifold are left fully open.

The zone valve is wired to the thermostat – when the thermostat calls for hot water, the zone valve opens and at the same time it sends a signal to the boiler to send hot water.

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