1、2003 GUIDELINE for AIR-CONDITIONING ) b Station 1 Station 3 Entering Exhaust Air (Return Ail;) 4 . Leaving Supply Air (Supply Air) b Station 2 Figure 1. Generic Configuration of an Air-to-Air Heat Exchanger Used for Energy Recovery in Ventilation Applications 3.5.3 Rotary Heat Exchanger. A device in
2、corporating a rotating cylinder os wheel for the purpose of transferring energy (sensible or total) from one air stream to the other. 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 fr
3、om one air stream to the other. 3.6 Exhaust Air Transfer Ratio (EATR). The tracer gas concentration difference between the leaving supply air (Figure 1, Station 2) and the entering supply air (Figure 1, Station i) divided by the tracer gas concentration difference between the entering exhaust air (F
4、igure 1, Station 3) and the entering supply air (Figure 1, Station 1) at the 100% rated air flow rate, expressed as a percentage. 3.7 FadMotor Efficieiicy, Fo,oio, The product of the fan efficiency and the motor efficiency including drive losses (mechanical, electrical and/or electronic as applicabl
5、e) for each airstream. 3.8 Net Effectiveness. The measured encrgy 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, Station 3) rather than exchange o
6、f heat or moisture between the airstreams. The derivation of Net Effectiveness is given in AM Standard 1060, Appendix C. 3.9 Net Supply Air Flow. That portion of the leaving supply air (Figure 1, Station 2) that originated as entering supply air (Figure 1, Station 1). The Net Supply Air Flow is dete
7、rmined 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: (i - EATR) Net Supply Leaving supply (Air Flow ) = (air flow 3.10 Outdoor Air Correction Factor. The entering supply air
8、 flow (Figure i, 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 between
9、 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 i, Station 1) and the leaving supply air (Figure 1, Station 2). 2 Copyright Air-Conditioning and R
10、efrigeration Institute Provided by IHS under license with ARINot for ResaleNo reproduction or networking permitted without license from IHS-,-,-AR1 Guideline V-2003 3.12 Published Rating. A statement of the assigned values of those perfonnance characteristics at stated Rating Conditions, by which a
11、unit may be chosen for its application. These values apply to all ERV Equipment of like size and type (identification) produced by the sanie manufacturer. The term Published Rating includes the rating of ali performance characteristics shown on the unit or published in specifications, advertising or
12、 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 Rating Conditions). 3.12.2 Standai-d Rating. A rating based on tests performed at Standard Rating Conditio
13、ns. 3.13 Rutirig Conditions. Any set of operating conditions under which a single level of perfomiance results, and which cause only that level of performance to occur. 3.13.1 Standard Rating Conditions. Rating Conditions used as the basis of comparison for perfonllance characteristics. 3.14 Recover
14、y Efficiency Ratio (RER). The efficiency of the energy recovery coniponent in recovering energy from the exhaust airstream is defined as the energy recovered divided by the energy expended in the recovery process. Units vary according to the application. For Combined Efficiency with EER, the RER is
15、expressed in Btu/(W.h). For Combined Efficiency with COP, the RER is expressed in WIW. 3.15 “Slzould. “ “Should“ is used to indicate provisions which are not mandatory but which are desirable as good practice. 3.16 Standard Air. Air weighing 0.075 Ib/ft3, which approximates dry air at 70F and at a b
16、arometric pressure of 29.92 in Hg. 3.17 Supply Air Flow. The measured (gross) leaving supply air flow (Figure 1, Station 2). Also referred to as the rated air flow. Section 4. Information Requirements 4.1 Net Efectiveness. Ratings of Net Effectiveness at application Rating Conditions and air flow ra
17、tes are required to perform calculations of efficiency. ARI certified ratings for Net Effectiveness are available at AN Standard 1060 Standard Rating Conditions. 4.2 Blower Power. A value for blower power input is required to perform the Combined Efficiency calculation. If manufacturers data for blo
18、wer power is not available, it may be calculated from coniponent pressure loss and FadMotor Efficiency in accordance with this section and 6.1. 4.2.1 Pi-essure Drop. Supply and Exhaust Pressure Drop values at application Rating Conditions and air flow rates are required to perform calculations of ef
19、ficiency. 4.2.2 Fan/Motor Efficiency. Values for FadMotor Efficiency may be required to calculate the RER of the coniponent as applied. FanMotor Efficiency is used with the pressure loss of the energy recovery component to determine the blower power consumed in the process of recovering energy. 4.2.
20、3 Determining Fan/Motor Efjciency. 4.2.3.1 When motor power is known: where: PNPS = 1 Air density ratio (ratio of the air density to the density of Standard Air) FadMotor Efficiency 746 6356 Total static pressure across the fan, in H20 Fan Power, W Motor Power, W Air flow rate, cfm 4.2.3.2 When the
21、fan curve is available: where: T)d = Drive efficiency rl ni = Motor efficiency PwrFan = Fan Power, Hp 3 Copyright Air-Conditioning and Refrigeration Institute Provided by IHS under license with ARINot for ResaleNo reproduction or networking permitted without license from IHS-,-,-AR1 Guideline V-2003
22、 4.2.3.3 When fan, motor and drive efficiencies are known: where: qf = Fan efficiency 4.3 Uizitaiy Equiyinerzt Efficieizcy. The EER or COP of the unitary equipment is required to perfomi calculations of CEF. Calculations at Standard Rating Conditions may be used to provide an indication of comparati
23、ve performance. To characterize actual perforinance, application Rating Conditions should be used. System selection, fan configuration, energy recovery Effectiveness and outdoor air conditions can impact the applied EER of the unitary equipment. Changes in air flow rate, fan operating point or coil
24、entering condition of the unitary equipment should be taken into account in calculating applied EER prior to completing the Combined Efficiency calculation. Standard Ratings - EER at Standard Rating Conditions should be used when conditions (e.g. coil entering conditions and air flow rate) for the s
25、ystem match Standard Rating Conditions for thc unitary equipment. Application Ratings - EER at application Rating Conditions should be used if conditions (e.g. coil entering conditions and/or air flow rate) vary from Standard Rating Conditions for the unitary equipment. 4.4 Load Ratio, Y. The percen
26、tage 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. The system load is the suni of the building load and the ventilation load. AAHX net capacity System net c
27、apacity Y= 4 Section 5. General Principles 5.1 Geiier-al Priizciyle. The general principie of all efficiency calculations is to determine the energy input or cost for a given useful energy output. In the case of ERV equipment, this is the recovered space conditioiiing energy divided by the power use
28、d to recover that energy. This can be expressed as a Recovery Efficiency Ratio (RER): Net conditioning energy recovered Total electric power consumed RER = 5 where the net space conditioning energy can be either heating, humidification, cooling, dehumidification or a combination thereof and the tota
29、l electric power consumed includes the power required to move air through both sides of the AAHX as well as any additional power, such as the wheel drive motor in a Rotary Heat Exchanger. The power required to move air through the AAHX is a function of the Supply and Exhaust Pressure Drop values thr
30、ough the AAHX, as well as the FadMotor Efficiency of the air-moving device. The power required to rotate a Rotary Heat Exchanger can be measured directly. Section 6. Calculating the Recovery Efficiency Ratio for the Energy Recovery Ventilation Component 6.1 Calculatiizg the RER for the Eizergy Recov
31、ery Device. Consult manufacturers data for infomiation on fan power consumption or pressure loss for the component. The RER is calculated in Equations 6a, 6b and/or 6c: Enettotal niin (h -h3) PWrblwr pwrcomp RERToial = 6a 6b 6c where: CP hl h3 me 1 min = Specific heat of air, Btu/lb.“F Total enthalp
32、y of the entering supply air, Btu/lb (Figure I, Station 1) = Total enthalpy of the entering exhaust air, Btu/lb (Figure 1, Station = 3) = Mass flow rate of the entering exhaust air, Ibh (Figure 1, Station 3) The lesser of ni, and me, lb/h = 4 Copyright Air-Conditioning and Refrigeration Institute Pr
33、ovided by IHS under license with ARINot for ResaleNo reproduction or networking permitted without license from IHS-,-,-AR1 Guideline V-2003 Mass flow rate of leaving supply air, lb/h (Figure 1, Station 2) Direct power input to the AAHX component, not included in blower power, W Sum of the blower pow
34、er for both the supply and the exhaust airstreams, W (represents the additional fan power imposed by the introduction of the energy recovery component into the two airstreams; may be obtained from actual blower power from manufacturers data) Q .AP Fan/Motor where: 7 C = Required unit conversion cons
35、tant AP = Pressure loss of the component for the supply and exhaust airstreams, in H20 Note: Other alternatives (such as comparison of operating points on a fan curve) that accurately characterize the additional fan power required by the component are acceptable means of obtaining blower power. Dry-
36、bulb temperature of the entering supply air, OF (Figure I, Station I) Dry-bulb temperature of the entering exhaust air, OF (Figure 1, Station 3) Net Effectiveness (sensible, latent, or total, as applicable), as defined in AM Standard 1060 and determined in accordance with AM Standard 1060 Humidity r
37、atio of the entering supply air, Ib (water)/lb (dry air) (Figurel, Station 1) Humidity ratio of the entering exhaust air, Ib (water)/lb (dry air) (Figure 1, Station 3) Section 7. Integrating the Efficiency of the Energy Recovery Component with the Efficiency of Cooling and Heating Equipment 7.1 CEF
38、can be defined on a coniparable basis to existing EER and COP ratings, based on the performance of the individual coniponents. The basic principle (illustrated here for the cooling case) is: Net cooling delivered Total electric power consumed cooling, + cooling, + cooling,-, + cooling, power, + powe
39、r, + power,-, + power, CEF = 8 - When an AAHX is combined with a unitary air conditioner, the AAHX provides a portion of the system cooling capaciy and the vapor compression cycle of the unitary air conditioner provides the rest. Consistent with the basic principle, Net cooling capacity Total electr
40、ic power consumption EER = 9 The cooling system Combined Efficiency (CEFcool;,g) of a unitary air conditioner with an AAHX cooling component can be defined as: AAHX net cooling capacity + unitary net cooling capacity 1 Oa - CEFling - AAHX electric power consumption + unitary electric power consumpti
41、on The heating system Combined Efficiency (CEFheating) of a unitary air conditioner with an AAHX heating component can be defined as: AAHX net heating capacity + unitary net heating capacity 10b - CEFheating - AAHX electric power consumption + unitary electric power consumption Section 8. Calculatin
42、g the Effect of Energy Recovery Ventilation on Cooling System Efficiency 8.1 Calculating the EfSect of the ER V on Cooling Systein CEF. The CEFCooling is calculated from the RER of the AAHX (RERAAHx) and the EER of the packaged equipment (EERunitaq) according to the following expression: 5 Copyright
43、 Air-Conditioning and Refrigeration Institute Provided by IHS under license with ARINot for ResaleNo reproduction or networking permitted without license from IHS-,-,-AR1 Guideline V-2003 where: AAHX net cooling capacity system net cooling capacity Y, = (from 4.4) and RER is expressed in Btu/(W.h).
44、8.2 Note that RER can be calculated on the basis of total energy recovery, latent recovery or sensible recovery Effectiveness. The selection of the RER basis will depend on the analysis being conducted: use total for cooling and deliuniidification, latent for dehumidification only and sensible for c
45、ooling without dehumidification. Section 9. Calculating the Effect of Energy Recovery Ventilation on Heating System Efficiency 9.1 Calculating the Eflect of ERV on Heating Systeni CEF. Tlie CEFheating is calculated from the RER of the AAHX (RERAAHX) and the COP of the packaged equipment (COPu,ita,)
46、according to the following expression: 1 - +(l-Yh)iCoPnitary CEFiieating - y / RERAAHx h where: AAHX net heating capacity system net heating capacity (from 4.4) YI, = and RER is expressed in W/W. 9.2 Note that RER can be calculated on the basis of sensible recovery, latent recovery or total energy r
47、ecovery Effectiveness. The selection of the RER basis will depend on the analysis being conducted: use sensible for heating only, latent for humidification and totai for heating and liuiiiidification. Section 10. Sizing 10.1 Sizing. In evaluating the impact of energy recovery on CEF, it is important
48、 to recalculate the system size based on the load reduction provided by the energy recovery component at design conditions. Comparisons of systems with and without energy recovery should take this into account. 10.2 Methods. Equipment should be sized with load reduction provided by energy recovery a
49、t design conditions. If not already accounted for in equipment selection, HVAC equipment should be reselected in accordance with 10.3. 10.3 HVAC Equipnzent Load Reduction Factor-. An estimate of the reduction in equipment size is provided by the capacity of the energy recovery component at design conditions according to the expression: Equipment capacity capacity with 12 energy recovery Section 11. Implementation 11.1 Coizditioizs. This guideline may be used to coinpare efficiencies of different
