AHRI GUIDELINE V SI-2011 Calculating the Efficiency of Energy Recovery Ventilation and its Effect on Efficiency and Sizing of Building HVAC Systems.pdf

1、 AHRI Guideline V (SI) 2011Guideline for Calculating the Efficiency of Energy Recovery Ventilation and its Effect on Efficiency and Sizing of Building HVAC Systems Price $10.00 (M) $20.00 (NM) Copyright 2011, by Air-Conditioning, Heating, and Refrigeration Institute Printed in U.S.A. Registered Unit

2、ed States Patent and Trademark Office IMPORTANT SAFETY DISCLAIMER AHRI does not set safety standards and does not certify or guarantee the safety of any products, components or systems designed, tested, rated, installed or operated in accordance with this standard/guideline. It is strongly recommend

3、ed that products be designed, constructed, assembled, installed and operated in accordance with nationally recognized safety standards and code requirements appropriate for products covered by this standard/guideline. AHRI uses its best efforts to develop standards/guidelines employing state-of-the-

4、art and accepted industry practices. AHRI does not certify or guarantee that any tests conducted under its standards/guidelines will be non-hazardous or free from risk. Note: This guideline supersedes AHRI Guideline V2003. For the I-P version, see AHRI Guideline V (I-P) -2011. TABLE OF CONTENTS SECT

5、ION PAGE Section 1. Purpose 1 Section 2. Scope .1 Section 3. Definitions .1 Section 4. Information Requirements .4 Section 5. General Principles .5 Section 6. Calculating the Recovery Efficiency Ratio for the Energy Recovery Ventilation Component 5 Section 7. Integrating the Efficiency of the Energy

6、 Recovery Component with the Efficiency of Cooling and Heating Equipment .8 Section 8. Calculating the Effect of Energy Recovery Ventilation on Cooling System Efficiency 9 Section 9. Calculating the Effect of Energy Recovery Ventilation on Heating System Efficiency 9 Section 10. Sizing .9 Section 11

7、. Implementation 10 FIGURE Figure 1. Generic Configuration of an Air-to-Air Heat Exchanger Used for Energy Recovery in Ventilation Applications .2 APPENDICES Appendix A. References Normative 11 Appendix B. References Informative 11 Appendix C. Sample Calculations Informative .13 Appendix D. Comparin

8、g Typical Combined Efficiency and Energy Analysis Results in a Varietyof ClimatesInformative 24 Appendix E. Rating Conversions Informative .24 TABLE FOR APPENDICES Table D1. Sample Calculation Results for Five Climates 24 FIGURES FOR APPENDICES Figure C1. Placement of Fans for a Draw-through Arrange

9、ment .18 Figure C2. Placement of Fans for a Blow-through Supply with Draw-Through Exhaust Arrangement 19 AHRI GUIDELINE V (SI)-2011_ 1 CALCULATING THE EFFICIENCY OF ENERGY RECOVERY VENTILATION AND ITS EFFECT ON EFFICIENCY AND SIZINGOF BUILDING HVAC SYSTEMS Section 1. Purpose 1.1 Purpose.The purpose

10、of this guideline is to establish a method of calculating the energy efficiency of applied Energy Recovery Ventilation components and of heating, ventilating, and/or air-conditioning systems utilizing such components at selected operating conditions. It also provides guidance on proper sizing of coo

11、ling and heating equipment when such energy recovery components are applied. 1.1.1 Intent.This guideline is intended for the guidance of the industry, including engineers, installers, contractors and users. It provides a means for calculating the impact of applied energy recovery equipment on the en

12、ergy efficiency of the heating, ventilating and air-conditioning system at a single selected operating condition. The guideline is not a rating system for Energy Recovery Ventilation (ERV) Equipment, nor does it provide a means of estimating annual energy use. 1.1.2 Review and Amendment. This guidel

13、ine is subject to review and amendment as technology advances. Section 2. Scope 2.1 Scope. This guideline applies to energy recovery ventilation component applications and combinations of energy recovery components with unitary heating, ventilating, and air-conditioning equipment incorporating mecha

14、nical ventilation with outside air. 2.1.1 This guideline applies only to energy recovery applications utilizing components tested and rated in accordance with AHRI Standard 1061 (SI) -2011. 2.1.2 Because non-certified data is required for the calculations, the results should not be considered to be

15、“certified”. Section 3. Definitions All terms in this document follow the standard industry definitions in the current edition of ASHRAE Terminology of Heating, Ventilation, Air Conditioning and Refrigeration and ASHRAE Standard 84, unless otherwise defined in this section. 3.1 Coefficient of Perfor

16、mance (COP). A ratio of the cooling/heating capacity in watts to the power input values in watts at any given set of Rating Conditions expressed in watts/watts. 3.1.1Coefficient of Performance Cooling (COPc). A ratio of the cooling capacity in watts to the power input values in watts at any given se

17、t of Rating Conditions expressed in watts/watts. 3.1.2Coefficient of Performance heating (COPh)A ratio of the heating capacity in watts to the power input values in watts at any given set of Rating Conditions expressed in watts/watts. 3.2 Combined Efficiency (CEF). The efficiency of a system incorpo

18、rating an ERV component with a unitary packaged air conditioner, heat pump, etc. Units vary according to the application. CEF is expressed in W/W. 3.3 Effectiveness. The measured energy recovery Effectiveness not adjusted to account for that portion of the psychrometric change in the leaving supply

19、air (Figure 1, Station 2) that is the result of leakage of entering exhaust air (Figure 1, Station 3) rather than exchange of heat or moisture between the airstreams. The equation for determining Effectiveness is given in AHRI Standard 1061 (SI), Appendix C. _AHRI GUIDELINE V (SI)-2011 2 3.4 Energy

20、Recovery Ventilation (ERV) Equipment. Units which employ air-to-air heat exchangers to recover energy from exhaust air for the purpose of pre-conditioning outdoor air prior to supplying the conditioned air to the space, either directly or as part of an air-conditioning (to include air heating, air c

21、ooling, air circulating, air cleaning, humidifying and dehumidifying) system. Also referred to as the air-to-air heat exchanger (AAHX). 3.4.1 Heat Pipe Heat Exchanger. A device employing tubes charged with a fluid for the purpose of transferring sensible energy from one air stream to another. Heat t

22、ransfer takes place through the vaporization of the fluid exposed to the warmer air stream and condensation of the fluid in the cooler air stream. 3.4.2 Plate Heat Exchanger. A device for the purpose of transferring energy (sensible or total) from one air stream to another with no moving parts. This

23、 exchanger may incorporate parallel, cross or counter flow construction or a combination of these to achieve the energy transfer. 3.4.3 Rotary Heat Exchanger. A device incorporating a rotating cylinder or wheel for the purpose of transferring energy (sensible or total) from one air stream to the oth

24、er. It incorporates heat transfer material, a drive mechanism, a casing or frame, and includes any seals, which are provided to retard the bypassing and leakage of air from one air stream to the other. 3.5 Exhaust Air Transfer Ratio (EATR). The tracer gas concentration difference between the Leaving

25、 Supply Airflow and the Entering Supply airflow divided by the tracer gas concentration difference between the Entering Exhaust Airflow and the Entering Supply Airflow at the 100% rated airflows, expressed as a percentage.(Note: This guideline assumes that the tracer gas concentration difference is

26、equal to the leakage of air from the Exhaust Airflow to the Supply Airflow. EATR, a ratio of the tracer gas, is used in the guideline formulae to represent a ratio of air flow.) 3.6 Fan/Motor Efficiency, Fan/Motor.The product of the fan efficiency and the motor efficiency including drive losses (mec

27、hanical, electrical and/or electronic as applicable) for each airstream. 3.7 Load Ratio, Y. The percentage of the system load (heating, cooling, humidification and/or dehumidification) met by the energy recovery component is designated as Y for the purposes of the calculations in this guideline. 3.8

28、 Net Effectiveness. The measured energy recovery Effectiveness adjusted to account for that portion of the psychrometric change in the leaving supply air (Figure 1, Station 2) that is the result of leakage of entering exhaust air Figure 1. Generic Configuration of an Air-to-Air Heat Exchanger Used f

29、or Energy Recovery in Ventilation Applications AAHXStation 4 Station 3 Station 2 Station 1 Leaving Supply Air (Supply Air) Entering Supply Air (Outdoor Air) Entering Exhaust Air (Return Air) Leaving Exhaust Air (Exhaust Air) AHRI GUIDELINE V (SI)-2011_ 3 (Figure 1, Station 3) rather than exchange of

30、 heat or moisture between the airstreams. The derivation of Net Effectiveness is given in AHRI Standard 1061, Appendix C. 3.9 Net Supply Air Flow, Qnet supply. That portion of the leaving supply air (Figure 1, Station 2) that originated as entering supply air (Figure 1, Station 1). The Net Supply Ai

31、r Flow is determined by subtracting air transferred from the exhaust side of the AAHX from the gross air flow measured at the supply air leaving the heat exchanger and is given by the equation: Qnetsupply= Leaving supply air flow (1 EATR) 1 3.10 Outdoor Air Correction Factor (OACF). The entering sup

32、ply air flow (Figure 1, Station 1) divided by the measured (gross) leaving supply air flow (Figure 1, Station 2). 3.11 Pressure Drop. The difference in static pressure between the entering air and the leaving air for a given airstream. 3.11.1 Exhaust Pressure Drop. The difference in static pressure

33、between the entering exhaust air (Figure 1, Station 3) and the leaving exhaust air (Figure 1, Station 4). 3.11.2 Supply Pressure Drop. The difference in static pressure between the entering supply air (Figure 1, Station 1) and the leaving supply air (Figure 1, Station 2). 3.12 Published Rating. A st

34、atement of the assigned values of those performance characteristics at stated Rating Conditions, by which a unit may be chosen for its application. These values apply to all ERV Equipment of like size and type (identification) produced by the same manufacturer. The term Published Rating includes the

35、 rating of all performance characteristics shown on the unit or published in specifications, advertising or other literature controlled by the manufacturer, at stated Rating Conditions. 3.12.1 Application Rating. A rating based on tests performed at application Rating Conditions (other than Standard

36、 Rating Conditions). 3.12.2 Standard Rating. A rating based on tests performed at Standard Rating Conditions. 3.13 Rating Conditions. Any set of operating conditions under which a single level of performance results, and which cause only that level of performance to occur. 3.13.1 Standard Rating Con

37、ditions. Rating Conditions used as the basis of comparison for performance characteristics. 3.14 Recovery Efficiency Ratio (RER). The efficiency of the energy recovery component in recovering energy from the exhaust airstream is defined as the energy recovered divided by the energy expended in the r

38、ecovery processis expressed in W/W. 3.15 “Should.“ “Should“ is used to indicate provisions which are not mandatory but which are desirable as good practice. 3.16 Standard Air. Air weighing 1.20kg/m3, which approximates dry air at 21C and at a barometric pressure of 101.32 kPa. 3.17 Supply Air Flow.

39、The measured (gross) leaving supply air flow (Figure 1, Station 2). Also referred to as the rated air flow. 3.18 Unitary Air Conditioner. One or more factory-made assemblies which normally include an evaporator or cooling coil(s), compressor(s), and condenser(s). Where such equipment is provided in

40、more than one assembly, the separated assemblies are to be designed to be used together, and the requirements of rating outlined in this standard are based upon the use of these assemblies in operation together. 3.18.1 Functions. Either alone or in combination with a heating plant, the functions are

41、 to provide air-circulation, air cleaning, cooling with controlled temperature and dehumidification, and may optionally include the function of heating and/or humidifying. _AHRI GUIDELINE V (SI)-2011 4 Section 4. Information Requirements 4.1 Net Effectiveness. Ratings of Net Effectiveness at applica

42、tion Rating Conditions and air flow rates are required to perform calculations of efficiency. AHRI certified ratings for Net Effectiveness are available at AHRI Standard 1061(SI) Standard Rating Conditions. 4.2 Blower Power. A value for blower power input is required to perform the Combined Efficien

43、cy calculation. If manufacturers data for blower power is not available, it may be calculated from component pressure loss and Fan/Motor Efficiency in accordance with this section and 6.1. 4.2.1 Pressure Drop. Supply and Exhaust Pressure Drop values at application Rating Conditions and airflow rates

44、 are required to perform calculations of efficiency. 4.2.2 Fan/Motor Efficiency. Values for Fan/Motor Efficiency may be required to calculate the RER of the component as applied. Fan/Motor Efficiency is used with the pressure loss of the energy recovery component to determine the blower power consum

45、ed in the process of recovering energy. 4.2.3 Determining Fan/Motor Efficiency. 4.2.3.1 When motor poweris known: MotorSAFanMotorFanMotor/FanPwrQPPwrPwr=2 Where: A/S= Air density ratio (ratio of the air density to the density of Standard Air) Fan/Motor= Fan/Motor Efficiency PFan = Total static press

46、ure across the fan, Pa PwrFan = Fan Power, W PwrMotor= Motor Power, W Q = Air flow rate, m3/s 4.2.3.2 When thefan curve is available: mdFanSAFanMotor/FanPwrQP=3 Where: d = Drive efficiency m = Motor efficiency PwrFan = Fan Power, W 4.2.3.3 When fan, motor and drive efficiencies are known: mdfMotorFa

47、n= 4 Where: AHRI GUIDELINE V (SI)-2011_ 5 f = Fan efficiency 4.3 Unitary Equipment Efficiency.The COP of the unitary equipment is required to perform calculations of CEF. Calculations at Standard Rating Conditions may be used to provide an indication of comparative performance. To characterize actua

48、l performance, application Rating Conditions should be used. System selection, fan configuration, energy recovery Effectiveness and outdoor air conditions can impact the applied COP of the unitary equipment. Changes in airflow rate, fan operating point or coil entering condition of the unitary equipment should be taken into account in calculating applied COP prior to completing the Combined Efficiency calculation. Standard Ratings COP at Standard Rating Conditions should be used when conditions (e.g. coil entering conditions and airflow rate) for the system match Standard Rating Cond