Specification Of Energy-Efficient Installation And .

usually considered conditioned spaces if they arenot thermally insulated from the occupied spacesof the dwelling.Cooling Equipment. Equipment used to providemechanical cooling for a room or rooms in abuilding.Crawl Space. A space between the ground andthe first floor of the building. Typically, crawlspaces are unconditioned.Design Conditions. The parameters and conditions used to determine the performance requirements of space-conditioning systems.Packaged Air Conditioning Equipment. Allthe cooling components are included in onecabinet, installed outdoors. Sometimes referred toas self-contained equipment.Pascal. A metric system unit of pressure, theunits for which are Newtons per square meter.There are 248 Pascals per inch of water gauge.Pick-up Time. The period of time during whichthe space heating system is increasing the temperature in a conditioned space after a manual orautomatic temperature setback.Duct Run out or Branch. A duct running froma trunk to a terminal unit (register or grille).Plenum. An air compartment or chamber towhich one or more ducts are connected and thatforms part of either the supply or return system.Pull-down Time. For space cooling, the timerequired to reduce dwelling temperature to acomfortable level after a manual or automatictemperature setup.Electric Resistance Heating. Heating by electrical resistance coils.Refrigerant Charge. The amount or weight ofrefrigerant in a compressor-based cooling system.Emergency Heat, Heat Pump. The backup heatrequired by some code jurisdictions in case ofheat pump operation failure. Requires that theemergency heat be sufficient to maintain someminimum room temperature when the heat pumpcompressor is out of operation.Refrigerant Metering Device. This devicecontrols the flow of liquid refrigerant to thesystem evaporator coil(s).Drop. For cooled air, the vertical distance between the bottom of a supply air outlet and thebottom of the air stream where it reaches its ratedvelocity, usually 50 feet per minute.Energy-Efficiency Ratio (EER). The ratio ofnet cooling capacity (in Btuh) to total electricalenergy use (in Watts) of a cooling system underdesignated operating conditions.Gas Heating System. A natural gas or liquefiedpetroleum gas heating system.Heat Pump. A space-conditioning device capable of heating and cooling by way of a refrigeration system.Heating Seasonal Performance Factor(HSPF). For heat pumps, the total heating outputof a heat pump under established test conditions,in Btu, divided by the total electric energy inputduring the test, in watt-hours.1 – Abbreviations, Acronyms and DefinitionsSaturation Temperature. Boiling point ortemperature of vaporization of a liquid.Seasonal Efficiency. The efficiency of a spaceheater averaged over the entire heating season.Annual Fuel Utilization Efficiency (AFUE) is anestimate of seasonal efficiency. Contrast this withthe steady-state efficiency, the efficiency duringburner operation.Seasonal Energy-Efficiency Ratio (SEER).The total cooling output of a central air conditioner in Btus under established test conditions,divided by the total electrical energy input inWatt-hours during the test.Space-Conditioning System. A system thatprovides, either collectively or individually,heating, ventilating or cooling to the building’sconditioned spaces.7/26/20007

Split-System Air-Conditioning Equipment. Anair conditioning (heat pump) system that has thecondenser (outdoor coil) remote from the evaporator (indoor coil).Spread. The divergence of an air stream after itleaves an outlet, usually expressed in degrees ofarc from the outlet centerline.a building, not directly or indirectly conditionedby a space-conditioning system. Examplesinclude unconditioned attics, crawlspaces, andgarages. Unconditioned spaces are usuallythermally insulated from the occupied spaces innew dwellings but may not be in existing dwellings.Steady-State Efficiency. The efficiency of afurnace during burner operation.Subcooling. The temperature of a liquid when itis cooled below its condensing temperature.Superheat. The temperature of a vapor refrigerant above its saturation change-of-state temperature.Supplemental Heat, Heat Pump. Also referredto as auxiliary heat. The additional heat requiredto heat a building when the outdoor temperatureis below the balance-point temperature. As theoutdoor temperature drops, more supplementalheat is needed. Typically provided by electricresistance heating elements.Thermostatic Expansion Valve (TXV), Cooling System. A cooling system using the TXV forregulating the flow of refrigerant into the coolingunit, actuated by the changes in evaporatorpressure and superheat of the refrigerant leavingthe cooling unit.Throw. The vertical or horizontal distance airtravels from the face of an air outlet to its ratedvelocity, usually 50 feet per minute.UL 181. UL Standard for Factory-Made AirDucts and Connectors.UL 181A. UL standard for pressure-sensitivealuminum tapes, heat-activated aluminum tapes,and mastic closure systems for use with rigidfiberglass air ducts.UL 181B. UL standard for pressure sensitivetapes and mastic closure systems for use withflexible air ducts.Unconditioned Space. An enclosed space within87/26/20001 – Abbreviations, Acronyms and Definitions

covered are location, sizing, duct and plenumtightness, duct insulation values and maintenanceof distribution efficiency.Chapter 2 – Introduction2.1Introduction.A growing body of evidence suggests that mostheating, ventilating, and air conditioning (HVAC)equipment – both standard and high efficiency –is improperly installed, with significant adverseconsequences on residential equipment efficiency. Recent studies demonstrate that themanner of equipment installation may have agreater impact on actual equipment operationthan its efficiency rating. Improved installationpractices not only significantly increase systemefficiency, they can also enhance occupantcomfort, increase occupant health and safety,reduce equipment and maintenance costs, allowequipment downsizing, increase the installer’sprofit margin, and increase equipment life.12.2For each of the specification elements, a verification method is provided. A number of the elements only require visual verification. Others,such as furnace heat rise, require verificationwith the use of inexpensive equipment and asimple test.Finally, in some cases ( such as duct leakage)more complicated test procedures are necessaryfor proper verification. When selecting thesemore complex test procedures, the most practicaland accurate procedures were chosen for thisspecification, without losing sight of the cost oftest equipment and the relative complexity of themethods.2.3Applicability.This specification addresses the installation ofresidential space cooling, space heating and airdistribution systems. The focus is on the energyefficiency of newly installed systems and existingsystems, and the long-term maintenance of theefficiency of systems. It also addresses theinteraction of the components within systems.2.2.1 Air Conditioners and Heat Pumps.Space-cooling equipment is addressed, includingpackaged systems, split-system cooling-only andheat pumps. The major elements addressed areequipment location, sizing, coil airflow, refrigerant charge, controls and maintenance of efficiency.2.2.2 Gas Furnaces. Ducted central gasfurnaces are covered. The primary items addressed are equipment location, sizing, heatexchanger airflow, controls and maintenance ofefficiency.2.2.3 Ducts and Air Handlers. Forced-airducted distribution systems for both space cooling and heating are addressed. The major items2 – IntroductionENERGY STAR Specification forExisting Ductwork.This Specification of Energy-Efficient Installation and MaintenancePractices for ResidentialHVAC Systems, where appropriate, complieswith ENERGY STAR Specification for ExistingDuctwork. For information about this ENERGYSTAR Specification, call 888-STAR-YES or visitthe ENERGY STAR web site at www.energystar.gov.Please Note: Because the primary focus ofthis specification is installation practicesaffecting system energy efficiency, thespecification does not directly address theelements of installation that can impactoccupant health and safety. In the field,occupant health and safety should always bethe primary concern of the installing andservicing technician. It is stronglyrecommended that appropriate health andsafety testing be done as part of atechnician’s routine procedures.7/26/20009

2.4Relation of this Specification toOther Codes and Standards.This Standard is intended to meet or exceedexisting codes and regulations and to conform toaccepted building practices. It is not intended toreplace existing codes and standards. The contractor should comply with all relevant codes,standards, and manufactures’ specifications.2.5Quick Reference Tables.The following quick reference tables list theelements of this specification. The Quick Reference elements are keyed to the numbers of theSpecification text.1C. Neme, J. Proctor, and S. Nadel, National EnergySavings Potential from Addressing Residential HVACInstallation Problems (U.S. Environmental ProtectionAgency E NERGY STAR Program, 1999), pp. 1-2.107/26/20002 – Introduction

2 – IntroductionQuick Reference for HVAC Installation SpecificationAir Conditioners and Heat Pumps: Split and Packaged SystemsSection/Specification ElementSpecification ElementPotential BenefitsVerification Test orMethod3. Air Conditioners and Heat Pumps:Split and Package Systems7/26/20003.1 Selection and Sizing- Comply with ENERGY STAR efficiency guidelines.- Select for adequate and efficient sensible and latent cooling.- Use Residential Load Calculation, Manual J.- Use Residential Equipment Selection, Manual S.3.2 Placement of Equipment- Follow manufacturer s recommendations- Minimize ductwork length.- Allow sufficient access to all equipment.- Don t restrict airflow to outdoor coil.- Avoid outdoor coil locations that might be adversely affected by rain, snow,seasonal flooding, or vegetation.- 400 CFM for wet coil, 50 CFM.- 425 — 450 CFM for dry coil, 50 CFM.3.3 Indoor Coil Airflow3.4 Refrigerant Charge- Manufacturer s specification3.5 Refrigerant Lines for Split System- Insulate suction lines, not liquid lines.- Size lines and line length to manufacturer s specifications.- Limit line length.- Should be installed to continue the operation of the air handler blower for aminimum of one minute after the compressor cycles off. Not required in hot,humid climates.- Programmable thermostats should be ENERGY STAR labeled.3.6 Fan Delay Relay3.7 Cooling/Heating ProgrammableThermostat- Proper selection can increase thermalcomfort and save energy.- 2—10% savings per year are possible forsizing correctly rather than over sizing.- Also, possible reduced duct size, surfacearea, and leakage.- Not confirmed by research, but could besubstantial.- Residential Load Calculation,Manual J by ACCA.- Residential EquipmentSelection, Manual S by ACCA.- 6-10% energy savings per year for nonTXV or fixed orifice device.- 2% energy savings per year for TXV.- Duct Blower test — 3.13.1.- Supplementary Heat Test forheat pumps (temperature rise) —3.13.2.- Flow Hood test — 3.13.3.- Pressure Drop test — 3.13.4(See Text for limitations of test)- Superheat method for fixedorifice devices — 3.14.1.- Subcooling for thermalexpansion valve (TXV) devices— 3.14.2.- Weigh-in refrigerant test —3.14.4.- Visual inspection.- Improper refrigerant charge is probablythe most significant cause of loss ofefficiency.- Fixed orifice type: 10—20 % energysavings per year are possible.- TXV type: 5% energy savings per year arepossible.Increased energy efficiency due to slowedheat transfer.- Increases efficiency by purging ductworkof conditioned air and extracting maximumcooling capacity from the evaporator coil.- Savings from automatic temperaturechange can result in significant energysavings, depending on operation andclimate.- Visual inspection.- Visual inspection.- Visual inspection.11

12Quick Reference for HVAC Installation SpecificationAir Conditioners and Heat Pumps: Split and Packaged Systems (continued)Section/Specification ElementSpecification ElementPotential BenefitsVerification Test orMethod3. Air Conditioners and Heat Pumps:Split and Package Systems (continued)3.8 Indoor Heat Pump Thermostat, HeatingOperation7/26/20003.9 Air-Source Heat Pump Outdoor LockoutThermostat3.10 Heat Pump Defrost Control, HeatingOperation3.11 Access for Maintenance3.12 Maintenance Items- Should be intelligent recovery, staging, or ramping types.- Changeover from heating to cooling must be manual, notautomatic.- Thermostat must maintain a 3 degree temperature differentialbefore supplemental heat is activated.- Thermostat must have an emergency heat switch.- When a non-intelligent or non-ramping heating thermostat isused, an outdoor lockout thermostat is required. (Note:Emergency heat should not be subject to lockout).- Select model with microprocessor defrost that learns.- If defrost is a time/temperature type, set the time interval toprovide the highest operating efficiency.- Provide adequate clearance for all necessary servicing andmaintenance.- Follow the manufacturer s regularly scheduled maintenanceprogram guidelines.- Inspect the following items at servicing:Filters,Indoor and outdoor coils,Indoor coil airflow,Refrigerant change,Refrigerant lines,Air handler blower parts, andControls.- If the heat pump thermostat is not workingproperly in heating mode, the expensivesupplementary heat can be unnecessarilyactivated, resulting in wasted energy.- Visual inspection.- Without an outdoor lockout thermostat,the expensive supplementary heat can beunnecessarily activated.- Optimized defrost control increasesenergy efficiency of the equipment.- Visual inspection.- Allows proper service and maintenance,thereby ensuring the maximum efficiencyof the equipment.- Proper maintenance of equipment andcontrols will retain system efficiency andextend equipment life.- Visual inspection.- Visual inspection andmanufacturer s specifications.- Visual inspection orappropriate instrumenteddiagnostics procedure.2 – Introduction

2 – IntroductionQuick Reference for HVAC Installation SpecificationGas FurnacesSection/Specification ElementSpecification ElementPotential BenefitsVerification Test orMethod- Proper selection can increase thermalcomfort and save energy.- Over sizing a furnace by more than 1.4times can lead to loss in seasonal efficiency,higher equipment cost, comfort sacrificesdue to short cycling, and prematuredegradation of the furnace and/or ventsystem.- Can save as much as 2% per year inenergy costs.- Residential Load Calculation,Manual J.- Residential EquipmentSelection, Manual S.- Increases efficiency by purging ductworkof conditioned air.- Visual inspection and test withuse of a thermometer.- Increases efficiency by purging ductworkof conditioned air.- 1-3% energy savings per 8-hour setback,depending on climate.- Proper adjustment of the anticipator cansave as much as 2% annual energy use.- Allows proper service and maintenance,thereby ensuring the maximum efficiencyof the equipment.- Proper maintenance of equipment andcontrols will retain system efficiency andextend equipment life.- Visual inspection.4. Gas Furnaces7/26/20004.1 Selection and Sizing- Comply with ENERGY STAR efficiency guidelines.- Select for adequate heating capacity and blower performance.- Use Residential Load Calculation, Manual J.- Use Residential Equipment Selection, Manual S.4.2 Heat Exchanger Temperature Rise/Airflow- Temperature rise across the heat exchanger should be withinthe manufacturer s specifications.- If manufacturer s specifications are not available, use attemperature rise between 40 and 70 degrees.- Set the blower-on and blower-off temperatures according to themanufacturer s specifications.4.3 Blower Thermostat Control4.4 Fan Delay Relay4.5 Programmable Thermostat4.6 Thermostat Anticipator Control4.7 Access for Maintenance4.8 Maintenance Items- Should be installed to continue the operation of the air handlerblower for a minimum of one minute after the burner cycles off.- Programmable thermostats should be used and should beENERGY STAR labeled.- Space heating thermostats should have anticipators as a feature.- If anticipator is adjustable, make sure it is set correctly.- Provide adequate clearance for all necessary servicing andmaintenance.- Follow the manufacturer s regularly scheduled maintenanceprogram guidelines.- Inspect the following items at servicing:Steady-state efficiency test,Filters,Gas manifold pressure,Orifices sizing,Heat exchanger temperature rise,Cooling evaporator coil,Blower thermostat control,Air handler blower parts, andControls.- Temperature rise test.- Duct Blower test — 4.9.1.- Flow Hood test — 4.9.2.- Visual inspection.- Visual inspection.- Visual inspection.- As necessary.13

14Quick Reference for HVAC Installation SpecificationDucts and Air HandlersSection/Specification ElementSpecification ElementPotential BenefitsVerification Test orMethod5. Ducts and Air Handlers5.1 Duct Location5.2 Duct System Design- All ducts should be located within the conditioned spaceswhenever possible.- No ducts in exterior wall cavities.- Always install ducts, don t use building cavities.- No panned floor joists.- Don t use crawl spaces as plenums.- Use Residential Duct System, Manual D, 1995 edition or later.7/26/2000- Reduces conduction and air-leakagelosses.- Visual inspection.- If ducts are not sized large enough topermit adequate airflow, system efficiencycan be adversely affected.- Can save 15% in energy costs per year fornew

6 7/26/2000 1 – Abbreviations, Acronyms and Definitions Chapter 1 – Abbreviations, Acronyms and Definitions Abbreviations and Acronyms ACCA – Air Conditioning Contractors of America. AFUE – Annual fuel utilization efficiency. ARI – Air-Conditioning and Refrig