Controller for hvac unit

Abstract

A controller (1) for an HVAC unit (2) for an indoor space (3) separated from an outdoor space (4) by a building envelope (5). The controller (1) comprises a power measurement device (6) for measuring an input power being delivered to the HVAC unit (2). The input power corresponds to a nominal heat transfer provided by the HVAC unit (2). An estimation module (7) calculates a target heat transfer between the HVAC unit (2) and the indoor space (3). The target heat transfer is calculated based on a heat transfer load comprising an external heat transfer between the indoor space (3) and outdoor space(4) calculated in accordance with an ambient indoor temperature of the indoor space (3), an ambient outdoor temperature of the outdoor space (4), and a thermal model (8) of the building envelope (5). A control unit (9) monitors or controls the HVAC unit (2) based on one or both of the input power and the target heat transfer.

1 . A controller for an HVAC unit for an indoor space separated from an outdoor space by a building envelope, the controller comprising:
 a power measurement device for measuring an input power being delivered to the HVAC unit, the input power corresponding to a nominal heat transfer provided by the HVAC unit;   an estimation module for calculating a target heat transfer between the HVAC unit and the indoor space, the target heat transfer calculated based on a heat transfer load comprising an external heat transfer between the indoor and outdoor space calculated in accordance with an ambient indoor temperature of the indoor space, an ambient outdoor temperature of the outdoor space, and a thermal model of the building envelope; and   a control unit for monitoring or controlling the HVAC unit based on one or both of the input power and the target heat transfer.   
     
     
         2 . A controller according to  claim 1  wherein the estimation module calculates the target heat transfer to substantially match the heat transfer load in order to maintain the ambient indoor temperature, the control unit operating the HVAC unit at an input power corresponding to a nominal heat transfer substantially matching the target heat transfer. 
     
     
         3 . A controller according to  claim 1  wherein the estimation module calculates the target heat transfer as the heat transfer load required such that the ambient indoor temperature reaches a desired indoor temperature for the indoor space over a desired adjustment time, the control unit operating the HVAC unit with an input power profile corresponding to a nominal heat transfer profile over the desired adjustment time to provide the target heat transfer. 
     
     
         4 . (canceled) 
     
     
         5 . (canceled) 
     
     
         6 . A controller according to  claim 3  wherein the control unit varies one or more settings of the HVAC unit to provide the input power profile over the desired adjustment time. 
     
     
         7 . (canceled) 
     
     
         8 . A controller according to  claim 6  wherein the control unit further comprises an infrared transmitter, the HVAC unit having an infrared receiver for receiving infrared signals from a remote control to adjust one or more settings on the HVAC unit, the control unit adjusting one or more settings on the HVAC unit by transmitting infrared signals from the infrared transmitter to the infrared receiver. 
     
     
         9 . A controller according to  claim 3  wherein the input power profile corresponds to a maximum efficiency measure over the desired adjustment time calculated on the basis of the input power and the target heat transfer. 
     
     
         10 . A controller according to  claim 3  wherein the input power profile corresponds to a minimum power cost over the desired adjustment time calculated on the basis of the input power and one or more power cost rates applicable over the desired adjustment time. 
     
     
         11 . (canceled) 
     
     
         12 . A controller according to  claim 3  wherein the desired adjustment time is an estimated arrival time of a user for arriving at the indoor space based on a current position of the user, a current speed of the user, and a current distance between the current position and the indoor space. 
     
     
         13 . A controller according to  claim 3  wherein the desired adjustment time is an estimated arrival time of a user for arriving at the indoor space selected from a database of one or more estimated arrival times each corresponding to a respective predetermined location, the estimated arrival time selected based on the predetermined location closest to a current position of the user. 
     
     
         14 . A controller according to  claim 3  wherein the desired adjustment time is an estimated arrival time of a user for arriving at the indoor space selected from a database of one or more estimated arrival times each corresponding to a respective geofence, the estimated arrival time selected based on a current position of the user reaching a said geofence. 
     
     
         15 . (canceled) 
     
     
         16 . A controller according to  claim 12  wherein the estimated arrival time is updated as the user travels. 
     
     
         17 . A controller according to  claim 3  wherein the external heat transfer is calculated in accordance with an ambient outdoor temperature of the outdoor space and predicted variations to the ambient outdoor temperature. 
     
     
         18 . (canceled) 
     
     
         19 . (canceled) 
     
     
         20 . A controller according to  claim 3  wherein the heat transfer load is updated during the desired adjustment time taking into account changes in variables used to calculate the heat transfer load. 
     
     
         21 . A controller according to  claim 1  wherein one or more input powers are deliverable to the HVAC unit, each input power corresponding to a respective nominal heat transfer provided by the HVAC unit. 
     
     
         22 . A controller according to  claim 21  wherein one or more of the respective nominal heat transfers are predetermined from manufacturer's data. 
     
     
         23 . (canceled) 
     
     
         24 . A controller according to  claim 21  wherein one or more of the respective nominal heat transfers are calculated from one or more outputs from the HVAC unit. 
     
     
         25 . A controller according to  claim 21  wherein the estimation module calculates the target heat transfer as the heat transfer load provided over a monitoring time, thereby defining an actual heat transfer, and the control unit monitors for a difference between the nominal heat transfer and the actual heat transfer over the monitoring time, the nominal heat transfer corresponding to the input power over the monitoring time. 
     
     
         26 . A controller according to  claim 25  wherein the external heat transfer is calculated in accordance with an ambient outdoor temperature of the outdoor space and actual variations to the ambient outdoor temperature over the monitoring time. 
     
     
         27 . (canceled) 
     
     
         28 . (canceled) 
     
     
         29 . A controller according to  claim 25  wherein the control unit sends an alert to a user device when the difference reaches a predetermined threshold. 
     
     
         30 . A controller according to  claim 25  wherein the control unit updates the nominal heat transfer corresponding to a respective input power to match the actual heat transfer. 
     
     
         31 . (canceled) 
     
     
         32 . (canceled) 
     
     
         33 . (canceled)