System Using an HVAC Air Handler and Thermostat for Building Energy Loss Testing, Monitoring and Cost Control

Abstract

An improved HVAC air handler and control system adapted for measuring and monitoring operating characteristics, the leakage of supply and return ducts to which it is connected, the infiltration leakage of the building it serves, the blockage of air return paths and the watts drawn and air flow generated by its blower. Leakages are measured by blocking outlets of all supply ducts or all return ducts, opening one side of the air handler to outdoor air, running the air handler blower, and measuring the air flow. Airflow may be measured by opening or closing orifices mounted in plenums attached to the air hander or built into the air handler cabinet, or by varying the speed of the blower motor, in connection with an integrated manometer. Thermostat firmware controls all functions.

I claim: 
     
         1 . An air handler system including functions for air handler monitoring and for at least one of duct leakage and building envelope leakage testing, comprising:
 a. an air handler comprising a return orifice, an air blower, and a supply orifice;   b. a duct system comprising at least one duct, coupled with at least one orifice selected from the group comprising the return orifice and the supply orifice;   c. an outlet terminating each duct;   d. means for temporarily blocking air flow selectively through all supply outlets or all return outlets in combination with the outlets;   e. means for selectively opening the return orifice or the supply orifice to enable unrestricted movement of air from an area outside the air handler, whereby the blocking means and the opening means define a path for air with air leakage as the only remaining air flow; and   f. monitoring means adapted for measuring at least one air handler operating parameter that is correlated with a leakage air flow rate, wherein the leakage air flow rate is comprised of one of supply duct leakage, return duct leakage, building envelope infiltration and building envelope exfiltration, whereby the air handler system measures normal air handler operating parameters and duct leakage and building envelope leakage from time to time without the need for external test equipment, to aid in achieving and maintaining energy efficiency in a building and determining the need for maintenance or repairs.   
     
     
         2 . The air handler system of  claim 1 , further including:
 a. means for logging measurements generated by the monitoring means of at least one operating parameter of the air handler;   b. means for converting the logged operating parameters to at least one test result, the test result selected from the group consisting of blower static pressure under normal operating conditions, blower power under normal operating conditions, air flow rate under normal operating conditions, return duct leakage air flow rate, supply duct leakage air flow rate, total duct leakage air flow rate, predominant duct leakage air flow rate, building envelope leakage air flow rate at 50 pascals, natural building envelope leakage air flow rate, building envelope leakage air flow rate with obstacles in place, duty cycle of burners during coldest hour, and duty cycle of air conditioner during hottest hour; and   c. means for communicating current and logged test results to a user.   
     
     
         3 . The air handler system of  claim 1 , further comprising:
 a. monitoring means adapted for calculating air handler air flow under normal operating conditions from the measured operating parameter;   b. means for dividing the supply duct leakage by the air flow under normal operating conditions, whereby to derive duct leakage percentage; and   c. means for communicating the duct leakage percentage to a user.   
     
     
         4 . The air handler of  claim 1 , further including means for calculating at least one of building envelope air changes per hour corresponding to the building envelope leakage air flow rate, and building envelope leakage air flow rate in units of cubic feet per minute per square foot of conditioned floor area, in combination with the monitoring means. 
     
     
         5 . The air handler of  claim 1 , further including means for estimating building envelope leakage under natural conditions corresponding the building envelope leakage air flow rate, in combination with the monitoring means. 
     
     
         6 . The air handler system of  claim 1 , further comprising:
 a. means for logging an air handler operating parameter value, in combination with the date and time the value was logged;   b. means for storing a low threshold value and a high threshold values for the air handler operating parameter;   c. means for comparing the most recently logged value with at least one previously logged value; and   d. means for indicating to a user when the comparing results in a value higher than a stored high threshold value or lower than a low threshold value.   
     
     
         7 . The air handler system of  claim 1 , further including a capability for determining whether the systems complies with a requirement for maximum watts per cubic feet of normal air flow, comprising:
 a. means for storing the requirement for maximum watts per cubic feet per minute;   b. the monitoring means further adapted for measuring air handler air flow under normal operating conditions;   c. the monitoring means further adapted for measuring blower power consumption under normal operating conditions;   d. means for dividing the blower power consumption by the air handler air flow;   e. means for comparing the result of the division with the requirement; and   f. means for indicating the result of the comparison to a user.   
     
     
         8 . The air handler system of  claim 1 , further including means for estimating the costs of electricity wasted through system inefficiencies, comprising:
 a. means for storing at least one constant value selected from the constant group consisting of the marginal cost of electricity, the code requirement for ventilation, the volume of the conditioned building space, the value of heating degree days for the location of the building, the annual fuel utilization efficiency of the furnace associated with the air handler system, and the kilowatt hours needed to run the blower per therm of fuel input to furnace;   b. means for logging at least one value, the value selected from the leakage group consisting of an air handler operating parameter, return duct leakage, supply duct leakage, and natural building envelope leakage;   c. means for logging the electricity used by at least one of the air handler blower and air conditioner over a period of time;   d. means for logging the duty cycle of the blower over a period of time;   e. means for calculating the costs over a period of time of at least one test result selected from the group consisting of power wasted by at least one of total duct leakage air flow, envelope leakage due to predominant duct leakage air flow rate, and natural building envelope leakage air flow rate in excess of the code requirement for ventilation; and   f. means for indicating the calculated cost to a user.   
     
     
         9 . The air handler system of  claim 1 , further including means for estimating the costs of fuel wasted through system inefficiencies, comprising:
 a. means for storing at least one constant value selected from the group consisting of the marginal cost of fuel, the limit of duct leakage, the BTU input rate to the furnace associated with the air handler system, the code requirement for ventilation, the volume of the conditioned building space, the value of heating degree days for the location of the building, and the annual fuel utilization efficiency of the furnace associated with the air handler system   b. means for logging the use of fuel by the space conditioning system over a period of time;   c. means for calculating the cost over a period of time of fuel wasted by at least one test result, the test result selected from the group of: duct leakage above a limit, natural building envelope leakage above the code requirement, and building envelope leakage due to predominant duct leakage; and   d. means for indicating the calculated costs to a user.   
     
     
         10 . An air handler system with functions for measuring at least one of duct leakage and building envelope leakage in a building comprising:
 a. an air handler including a blower, a return orifice, and a supply orifice, at least one return outlet connected to the return orifice by means of a return duct and at least one supply outlet connected to the supply orifice by means of a supply duct, whereby under normal operating conditions a primary air flow moves from the at least one return outlet through the air handler and to the at least one supply outlet;   b. means for temporarily blocking all supply outlets or all return outlets;   c. means for selectively opening a first orifice, the orifice selected from the group consisting of the return orifice or the supply orifice, to the unrestricted flow of air;   d. means for measuring static pressure differential between the supply orifice and the return orifice;   e. means for adjustably bypassing the primary air flow through the air handler into or out of the second orifice, directing a portion of the primary air flow instead to an area outside the air handler, whereby to achieve a standard static pressure differential; and   f. means for determining leakage air flow in combination with the means for adjustably bypassing the primary air flow, whereby the duct leakage and the building envelope leakage may be measured from time to time without the need for external test equipment, to aid in achieving and maintaining energy efficiency in a building and for determining a need for maintenance or repairs.   
     
     
         11 . The air handler system of  claim 10 , wherein the means for adjustably bypassing the primary air flow through the air handler comprises a first panel that slides within a first track and a second panel that slides within a second track, the first panel regulating air flow at the return orifice and the second panel regulating the air flow at the supply orifice, whereby moving either the first panel or the second panel adjusts the quantity of air flow. 
     
     
         12 . A kit for adding at least one of duct leakage and envelope leakage testing capabilities to an air handler, comprising:
 a. at least one orifice assembly, the at least one orifice assembly including a calibration scale;   b. two static pressure probes;   c. means for attaching the at least one assembly to at least one of the return orifice or the supply orifice;   d. a manometer; and   e. means for coupling the manometer to the two static pressure probes, whereby leakage air flow may be read from the calibration scale.   
     
     
         13 . A method for monitoring an air handler and measuring at least one of duct leakage and building envelope leakage, comprising the elements of:
 a. providing an air handler including a blower, a return orifice and a supply orifice, and at least one supply or return duct, each of the ducts coupled with an individual dedicated outlet, whereby, under normal operating conditions, air is moved from one or more outlets connected to the return orifice to one or more outlets connected to the supply orifice;   b. alternatively temporarily blocking all the outlets terminating supply ducts or all the outlets terminating return ducts;   c. opening an orifice of the air handler to the unrestricted flow of air, whereby the blocking action and the opening action define a path for air with leakage as the only remaining air flow;   d. running the air blower; and   e. during the running of the air blower, measuring at least one operating parameter of the air handler that is correlated with the leakage air flow, whereby duct leakage and building envelope leakage may be measured from time to time and the air handler monitored without the need for external test equipment, to aid in achieving and maintaining energy efficiency in a building and determining a need for maintenance or repairs.   
     
     
         14 . The method of  claim 13 , further including the elements of:
 a. providing a display;   b. logging measurements of the operating parameter, in combination with the measuring action, together with the date and time of the measurement in a log record;   c. under control of a user, retrieving a selected past log record;   d. converting the operating parameter from the retrieved log record to a test result; and   e. displaying the test result to a user.   
     
     
         15 . The method of  claim 13 , further including the elements of:
 a. logging measurements of the operating parameter, in combination with the measurement action, together with the date and time of the measurement action in a log record;   b. comparing the most recently logged measurement with at least one previously logged measurement; and   c. indicating to a user when the comparing action results in a value higher than a high threshold value or lower than a low threshold.   
     
     
         16 . The method of  claim 13 , further comprising the elements of:
 a. providing a programmable thermostat that measures the energy use of the components of the space conditioning system that the programmable thermostat controls;   b. logging the energy use of a plurality of components of a space conditioning system over a period of time;   c. estimating the costs of space conditioning over a period of time by means of a formula involving the energy use of the plurality of components and the cost of energy;   d. estimating the cost of at least one leakage, the leakage selected from the leakage group consisting of return duct leakage, supply duct leakage and total duct leakage by means of a formula including the leakage and the logged cost of space conditioning; and   e. indicating to a user by means of the programmable thermostat at least one estimate selected from the estimate group comprising an estimate of the costs of space conditioning over a period of time, and an estimate of the cost of the at least one leakage.   
     
     
         17 . The method of  claim 13 , further including the elements of:
 a. converting the operating parameter to building envelope air flow to the air flow estimated to occur under natural circumstances; and   b. indicating the estimated air flow under natural circumstances to a user.   
     
     
         18 . The method of  claim 13 , further comprising the elements of:
 a. providing a programmable thermostat that measures the fuel use of the space conditioning system and stores the cost of fuel and parameters needed for calculation of natural envelope leakage;   b. measuring the fuel use of the components of the space conditioning system over a period of time by means of the programmable thermostat;   c. estimating the cost of fuel used in space conditioning over a period of time by means of a formula including a fuel use value and a cost of fuel value;   d. converting the operating parameter to the natural envelope leakage of the building envelope;   e. estimating a cost of natural envelope leakage by means of a formula including the natural envelope leakage, the cost of fuel and a plurality of parameters needed for the calculation of natural enveloped leakage; and   f. communicating to a user by means of the programmable thermostat at least one estimate selected from the estimate group comprising the estimate of cost of fuel used in space conditioning over a period of time and the estimate of the cost of natural envelope leakage.   
     
     
         19 . A method of measuring at least one of duct leakage and building envelope leakage, comprising the elements of:
 a. providing an air handler including a blower, a return orifice and a supply orifice, and at least one supply duct or return duct, each of the ducts coupled with an individual dedicated outlet, and an electronic device controlling at least the blower of the air handler, the device including a user input device and a display;   b. enabling a user to select by means of the user input device a leakage test shown in the display;   c. prompting a user to block all supply outlets or all return outlets and to open the return orifice or the supply orifice to the unrestricted flow of air;   d. running the blower;   e. measuring at least one air handler operating parameter that is correlated with a leakage air flow rate;   f. converting the air handler operating parameter to at least one test result; and   g. showing the test results in the display.