Enhanced hvac performance monitoring system and method thereof

Abstract

A system and method of monitoring the performance of a heating, ventilation, or air conditioning (HVAC) system including a controller in communication with a HVAC unit where the method includes monitoring environmental conditions using a controller. Environmental conditions, such as indoor air temperature, indoor humidity and outdoor temperature are measured and used to compute performance parameters that help diagnose HVAC performance problems. The rate of change of indoor air temperature (IATR) and rate of change of indoor humidity (IDHR) are computed and used to determine the sensible heat ratio of the cooling system. The sensible heat ratio, which may or may not be adjusted for transient startup, is used in concert with product performance data, indoor air temperature, indoor humidity, and outdoor air temperature to determine cooling system airflow.

What is claimed is: 
     
         1 . A method for monitoring performance and determining indoor air temperature change rate (IATR) and indoor air dehumidification rate (IDHR) to compute the airflow a cooling system, comprising:
 initiating a performance evaluation period through a heating, ventilation, or air conditioning (HVAC) controller communicatively coupled to the HVAC system;   monitoring the operation of the HVAC system using a monitoring system controller;   obtaining baseline data for one or more environmental factors from at least one of the following:
 the HVAC controller communicatively coupled to the monitoring system controller; 
 one or more sensors communicatively coupled to the HVAC controller; or 
 one or more databases communicatively coupled to the monitoring system controller; 
   generating IATR and IDHR values over the performance evaluation period;   generating Sensible Heat Ratio (SHR) value at intervals during the performance evaluation cycle using a performance analysis algorithm and at least one of the following environmental factors:
 cooling duty cycle; 
 obtained environmental data; 
 historical measured performance data for the HVAC system; or 
 manufacturer system performance product data; and 
   generating an airflow value for the cooling system based upon the generated SHR value.   
     
     
         2 . The method of  claim 1 , wherein the SHR value is adjusted to an equivalent steady state value based on an average system run-time per cycle to account for startup transient. 
     
     
         3 . The method of  claim 1 , wherein the SHR value is used to generate the airflow value based upon SHR values within a pre-determined range. 
     
     
         4 . The method of  claim 1 , wherein the cooling system airflow is determined using the SHR value and one or more of the following factors: measured indoor air temperature, outdoor air temperature and indoor humidity values applied to cooling system performance data. 
     
     
         5 . The method of  claim 1 , further comprising comparing the generated SHR value to the manufacturer system performance product data SHR value. 
     
     
         6 . The method of  claim 1 , wherein the IATR and IDHR values generated are related to a duty cycle of the cooling system. 
     
     
         7 . The method of  claim 6 , wherein the IATR and IDHR values are plotted over the duration of the duty cycle and an IATR 0  value and an IDHR 0  value is established utilizing a best-fit line plot of the IATR and the IDHR values at the y-axis intersection. 
     
     
         8 . The method of  claim 7 , wherein a sensible cooling capacity and latent cooling capacity value is obtained to generate one or more constants to determine the generated SHR value. 
     
     
         9 . The method of  claim 1 , wherein the measured airflow value is calculated utilizing the generated SHR value. 
     
     
         10 . The method of  claim 1 , further comprising displaying the airflow value. 
     
     
         11 . A method for determining the airflow of a cooling system using a smart thermostat, comprising:
 initiating a performance evaluation period through a heating, ventilation, or air conditioning (HVAC) controller communicatively coupled to the HVAC system;   monitoring the operation of the HVAC system using the HVAC controller;   obtaining baseline data for one or more environmental factors from at least one of the following:
 the HVAC controller communicatively coupled to the monitoring system controller, 
 one or more sensors communicatively coupled to the HVAC controller, or 
 one or more or databases communicatively coupled to the monitoring system controller; 
   generating one or more indoor air temperature change rate (IATR) values and one or more indoor air dehumidification rate (IDHR) values during the performance evaluation period;   generating a constant estimate value of absorptive properties of a condition space of the cooling system (K);   generating a constant estimate value for the product of a mass of the conditioned space and an average specific heat of the thermal mass of the cooling system (mc p );   generating a Sensible Heat Ratio (SHR) value at intervals during the performance evaluation cycle based upon the IATR value, IDHR value, K value, and mc p  value;   determining the SHR value at intervals during the performance evaluation cycle using a performance analysis algorithm using the following:   a duty cycle calculated within the performance evaluation period; and   manufacturer system performance product data;   generating an airflow value for the cooling system based upon the generated SHR value.   
     
     
         12 . The method of claim  13 , wherein mc p  value is determined utilizing an IATR 0  value during the duty cycle and the K value is determined utilizing an IDHR 0  value. 
     
     
         13 . The method of claim  14 , wherein a plurality of IATR values are plotted as a function of the duty cycle and fitting a curve to determine the IATR 0  value during the duty cycle. 
     
     
         14 . The method of  claim 13 , wherein a plurality of IDHR values are plotted as a function of the duty cycle and fitting a curve to determine the IDHR 0  value during the duty cycle. 
     
     
         15 . The method of  claim 13 , wherein the constant estimate value of K is determined by generating a IDHR 0  value by plotting the rate of change of IDHR against the duty cycle and dividing the latent capacity by the IDHR 0  value. 
     
     
         16 . The method of  claim 15 , wherein the constant value of mc p  is determined by generating a IATR 0  value by plotting the rate of change of IATR against the duty cycle and dividing the latent capacity by the IATR 0  value. 
     
     
         17 . A system for monitoring and evaluation of a heating, ventilation, or air conditioning (HVAC) system, comprising:
 a monitoring system controller having a processor and memory, communicatively coupled to the HVAC system, wherein the system controller is communicatively coupled to a network, wherein the networks is configured to communicate with one or more external sources for obtaining monitoring data including at least one of the following:   environmental information;   HVAC performance data provided by a manufacturer; or   measured HVAC data;   
       wherein the processer:
 initiates a performance evaluation period through a HVAC controller communicatively coupled to the HVAC system; 
 monitors the operation of the HVAC system using a monitoring system controller; 
 obtains a baseline data for one or more environmental factors from at least one of the following:
 the HVAC controller communicatively coupled to the monitoring system controller; 
 one or more sensors communicatively coupled to the HVAC controller; or 
 one or more databases communicatively coupled to the monitoring system controller; 
 
 generates one or more indoor air temperature change rate (IATR) and indoor air dehumidification rate (IDHR) values over the performance evaluation period; 
 generates one or more measured Sensible Heat Ratio (SHR) values at intervals during the performance evaluation cycle using a performance analysis algorithm and at least one of the following environmental factors: 
 cooling duty cycle; 
 obtained environmental data; 
 historical measured performance data for the HVAC system; or 
 manufacturer system performance product data; and 
 
       generates an airflow value for the cooling system based upon the generated SHR value. 
     
     
         18 . The system of claim  19 , wherein the processor further compares the generated SHR value and the generated airflow value to corresponding manufacturer system performance product data values to determine one or more adjustment factors for the system.