Patent Publication Number: US-2012031986-A1

Title: Secondary heating system controller

Description:
The present invention relates to a secondary heating-system-controller, a primary heating-system-controller in combination with such a secondary heating-system-controller, a boiler for a heating system having the secondary heating-system-controller onboard, and to a method of reducing utility costs for a heating system by using such a secondary heating-system-controller. 
     Typically a heating system comprises a gas or oil-fired boiler for heating radiators connected thereto and for supplying hot water to taps. The central heating circuit often relies on a centralised thermostat which acts as a primary controller for turning the boiler on usually two or three times a day. Once the set room temperature is reached, the thermostat turns off the boiler. If the ambient temperature drops back below the temperature set at the centralised thermostat, during an activation period, then the boiler is reactivated. 
     However, during an activation period, the boiler is put under a long sustained and often continuous demand whilst the radiators on the central heating circuit attempt to raise a room temperature around at least the centralised thermostat to the pre-set required threshold as quickly as possible. Once the centralised thermostat temperature is reached, the boiler is generally programmed to maintain for a period or overshoot this temperature by a certain margin before switching off. 
     This sustained demand and maintenance/overshoot facility all leads to significantly increased utility usage. 
     The present invention seeks to provide a solution which reduces the amount of a utility supply required for a heating system, without or substantially without impacting a heating effect perceived by a user or occupant. 
     According to a first aspect of the invention, there is provided a secondary heating-system-controller for use in conjunction with a primary heating-system-controller of a heat supply unit supplying a heating system, the secondary heating-system-controller comprising interruption means for temperature-independently periodically deactivating and reactivating the heat supply unit supplying the heating system during an activation period of the heat supply unit determined by the primary heating-system-controller. 
     Preferable and/or optional features of the first aspect of the invention are set forth in claims  2  to  13 , inclusive. 
     According to a second aspect of the invention, there is provided a secondary heating-system-controller in accordance with the first aspect of the invention, in combination with a primary heating-system-controller of a heat supply unit supplying a heating system. 
     Preferably, the secondary heating-system-controller carries the primary heating-system-controller. 
     According to a third aspect of the invention, there is provided a boiler for a heating system, the boiler comprising a secondary heating-system controller, in accordance with the first aspect of the invention, which is onboard. 
     Preferably, the boiler further comprises an onboard boiler controller, the secondary heating-system controller being integral with the boiler controller. 
     According to a third aspect of the invention, there is provided a method of reducing utility costs for a heating system by using a secondary heating-system-controller in accordance with the first aspect of the invention, the method comprising the step of temperature-independently deactivating and reactivating the heat supply unit supplying a heating system a plurality of times using the interruption means during a standard activation period of the heat supply unit. 
    
    
     
       The invention will now be more particularly described, by way of example only, with reference to the accompanying drawings, in which: 
         FIG. 1  shows a perspective view of a first embodiment of a secondary heating-system-controller, in accordance with the first aspect of the invention; 
         FIG. 2  shows an exploded view of the secondary heating-system-controller; 
         FIG. 3  shows a perspective view of the secondary heating-system-controller, a primary heating-system-controller, and a mounting plate when spaced apart; 
         FIG. 4  shows the secondary heating-system-controller and the primary heating-system-controller, when connected; and 
         FIG. 5  shows a front view of a second embodiment of the secondary heating-system-controller, in accordance with the first aspect of the invention and when provided onboard a boiler for a heating system. 
     
    
    
     Referring firstly to  FIGS. 1 to 4  of the drawings, there is shown a first embodiment of a secondary heating-system-controller  10  which comprises a, typically moulded plastics, two part housing  12  defining an enclosable cavity  14  therewithin, a PCB  16  mounted in the cavity  14  having a control circuit  18  and a timer  20  thereon, a user interface  22  at a front exterior surface of the housing  12  which is in electrical communication with the timer  20 , and a primary heating-system-controller input element  24  for receiving a primary heating-system activation signal and a primary heating-system deactivation signal from a primary heating-system-controller  26 . 
     To energise the secondary heating-system-controller  10 , a battery compartment  28  having a removable access cover  30  is provided at a rear of the housing  12 . At least one battery  32 , preferably being rechargeable, is receivable in the battery compartment  28 . 
     The user interface  22 , in this embodiment, comprises two spaced rotary potentiometers  34  provided at or adjacent to an uppermost edge of the housing  12 . However, any suitable user interface  22  can be provided, and for example it may be digital and/or electronic with push buttons. 
     Positioning the user interface  22  towards an upper edge of the housing  12  provide space on the exterior front surface for a support  36 . The primary heating-system-controller input element  24  is an electrical connector which also defines an engagement element  38  for releasably engaging the primary heating-system-controller  26 . The primary heating-system-controller input element  24  is positioned appropriately as necessity dictates on the support  36  so that the primary heating-system-controller  26  can be in electrical communication with the secondary heating-system-controller  10  whilst being carried in a piggyback manner by the housing  12 , as shown in  FIG. 4 . 
     The primary heating-system-controller input element  24  is effectively an intercept element so that heating system activation and deactivation signals outputted by the primary heating-system-controller  26  are directly inputted to and only to the secondary heating-system-controller  10 . The control circuit  18  thus controls a main heating unit  40  of the heating system, typically being a gas or oil-fired boiler, accordingly. In the case of the secondary heating-system-controller  10  receiving an activation signal from the primary heating-system-controller  26 , the control circuit  18  activates the main heating unit  40  in a normal manner. 
     A user utilises the user interface  22  to set the timer  20  to provide an activation timing signal for a predetermined period within a user-selectable range, for example, from 5 minutes to 45 minutes. As an example, the user may select 30 minutes. 
     The user also utilises the user interface  22  to set the timer  20  to provide a deactivation timing signal for a predetermined period within a user-selectable range, for example, also from 5 minutes to 45 minutes. As an example, the user may select 15 minutes. 
     The activation timing signal is thus outputted by the timer  20  to the control circuit  18 , which thus controls the main heating unit  40  of the heating system to remain on. Following expiry of the user-selected activation period, the timer  20  outputs the deactivation timing signal to the control circuit  18 , which thus temperature-independently controls the main heating unit  40  of the heating system to switch off even though a deactivation signal has not yet been sent by the primary heating-system-controller  26 . Following expiry of the user-selected deactivation period, the timer  20  again outputs the temperature-independent activation timing signal to the control circuit  18 , which thus controls the main heating unit  40  of the heating system to switch on. This process is repeated until the deactivation signal is outputted by the primary heating-system-controller  26  to the primary heating-system-controller input element  24 , and the control circuit  18  thus controls the main heating unit  40  of the heating system to turn off. 
     The secondary heating-system-controller  10  thus utilises the residual heating effect of the heating system, via the already heated water in the system and the heated radiators, to continue supplying heat energy to the environment whilst the main heating unit  40  is switched off for a short period by the secondary heating-system-controller  10 . Once switched back on by the activation timing signal being supplied to the control circuit  18 , the main heating unit  40  again heats and circulates the heat transfer liquid in the central heating system until the next deactivation timing signal is outputted. 
     Therefore, although a heating demand placed on the main heating unit  40  may be greater, it is so for a plurality of shorter periods between the output of an activation signal and a deactivation signal from the primary heating-system-controller  26 . As a consequence, an actual ‘ON’ time of the main heating unit  40  is significantly reduced, thus markedly decreasing an amount of utility supply, such as gas or electricity, utilised, and a period of maintenance/overshoot heating is also reduced. Substantial cost savings can thus be obtained by the user without or substantially without any noticeable diminished heating effect, and a reduction in environmentally damaging emissions and carbon footprint can be achieved. 
     Ideally, the main heating unit  40  will not remain deactivated by the secondary heating-system-controller  10  for too long, otherwise the heat transfer liquid and radiators or other heat transfer devices will undesirably cool too much. This will lead to a user or occupant noticing a lack of heating and the ambient environment around the centralised thermostat or local thermostats struggling to reach the required temperatures in the main activation period provided for by the primary heating-system-controller  26 . 
     Similarly, the main heating unit  40  will, ideally, not remain activated by the temperature-independent secondary heating-system-controller  10  for too long, since a maximum or optimum thermal capacity of the heat transfer liquid and radiators or other heat transfer devices will have been reached and will simply be unnecessarily maintained by the main heating unit  40 . This will lead to unnecessary usage of the utility supply. 
     Thus, it is important for the user or occupant to adjust the timer  20  to best suit their needs. 
     It is common for the primary heating-system-controller  26  to be spaced from the main heating unit  40 . Typically, the primary heating-system-controller  26  includes a main thermostat to regulate the ambient temperature of a particular room. Such a primary heating-system-controller  26  usually includes a mounting plate  42  or bracket which may be hard wired to an onboard controller of the main heating unit  40 . In this case, the secondary heating-system-controller  10  includes an electrical connector  44  which enables connection to a connector  46  on the mounting plate  42 . The primary heating-system-controller  26  is then releasably mountable to the housing  12  of the secondary heating-system-controller  10  via the primary heating-system-controller input element  24 . 
     Instead of being hard wired, the primary heating-system-controller  26  may be in wireless communication with the onboard controller of the main heating unit  40 . In this case, the secondary heating-system-controller  10  may include a wireless receiver and a wireless transmitter. The primary heating-system-controller input element may be dispensed with. A frequency of a wireless transmitter of the primary heating-system-controller  26  is changed to match that of the wireless receiver of the secondary heating-system-controller  10 , and a frequency of the wireless transmitter of the secondary heating-system-controller  10  is set to that of the onboard controller of the main heating unit  40 . Wireless communication and control via the secondary heating-system-controller  10  is thus possible. 
     Referring to  FIG. 5 , a second embodiment of the secondary heating-system-controller  10  is shown. In this embodiment, rather than being separate, the secondary heating-system-controller  10  is provided onboard with the onboard controller  48 , which may thus be or include the primary heating-system-controller  26 , of the main heating unit  40 . In this case, it is preferable to integrate the secondary heating-system-controller  10  with the onboard controller  48 . However, they may be separate units which communicate with each other. 
     Although the interruption means described above comprises a control circuit, timer, and primary heating-system-controller input element, it may be feasible to have additional or alternative elements for periodically deactivating and reactivating the heating system during an activation period of the heating system determined by the primary heating-system-controller. 
     Furthermore, the secondary heating-system controller may include a supplementary controller which enables overriding of the present condition of the secondary heating-system controller. For example, if the secondary heating-system controller has cycled the main heating unit into a temperature-independent deactivation condition, but the environment becomes too cold for the occupant, the supplementary controller can be utilised to reactivate the main heating unit earlier than the set period of the secondary heating-system controller. The supplementary controller may include a wireless remote control unit by which the occupant can control the secondary heating-system controller and, in particular, the override function remotely. The supplementary controller can also be used vice versa if the occupant feels the room is too warm. 
     Preferably, the secondary heating-system controller also includes a thermostat, or makes use of a thermostat of the primary heating-system controller, to override the set period for deactivation of the main heating unit if a room temperature falls below that set by the thermostat, thereby causing automatic reactivation prior to the set period for deactivation expiring. The thermostat mentioned above may be remote from the housing of the secondary heating-system controller, thus communicating wirelessly or by hard wiring, or may be housed therein. 
     It is thus possible to provide a secondary heating-system-controller for use in conjunction with a primary heating-system-controller of a heating system, which is simple and cost-effective to produce. The secondary heating-system-controller utilises interruption means for intercepting an activation signal and a deactivation signal of the primary heating-system-controller, and during an activation period determined by the primary heating-system-controller temperature-independently controlling the main heating unit to deactivate and reactivate, preferably a plurality of times. It is thus possible to reduce a total ‘on’ time of the main heating unit during an activation period dictated by the primary heating-system-controller, whilst making use of residual heat within the heat transfer liquid and radiators or other heat transfer devices connected to the main heating unit. Utility costs, along with environmentally damaging emissions, associated with the running of the main heating unit can thus be reduced. 
     The embodiments described above are provided by way of examples only, and various other modifications will be apparent to persons skilled in the art without departing from the scope of the invention as defined by the appended claims.