NCC 2022 Volume One - Building Code of Australia Class 2 to 9 buildings
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44

Specification 44 Calculation of heating load limit, cooling load limit and thermal energy load limit

Specification 44 Calculation of heating load limit, cooling load limit and thermal energy load limit

This Specification contains the method of calculating the heating load limit, cooling load limit and thermal energy load limit for compliance with J1P2 and H6P1.

To clarify the methodology for calculating the heating, cooling, and thermal energy load limits with J1P2 and H6P1.

Specification 44 provides a calculation method for the purposes of assessing compliance with J1P2 and H6P1. The load limits in Specification 44 are based on climate factors and floor area. By defining the load limits based on climate factors, cooling, heating and thermal load limit can be determined for any climate.

The heating load limit of a space, measured in MJ/m2.annum, is equal to the greater of—

  1. 4; and
  2. ((0.0044×HDH)−5.9)×FHMathType@MTEF@5@5@+= feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaaiikaiaacI cacaaIWaGaaiOlaiaaicdacaaIWaGaaGinaiaaisdaiiaacqWFxdaT caWGibGaamiraiaadIeacaGGPaGaeyOeI0IaaGynaiaac6cacaaI5a Gaaiykaiab=Dna0kaadAeadaWgaaWcbaGaamisaaqabaaaaa@4874@  
    , where—
    1. HDHMathType@MTEF@5@5@+= feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamisaiaads eacaWGibaaaa@3857@  
      = the total annual heating degree hours of the building location; and
    2. FHMathType@MTEF@5@5@+= feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamOramaaBa aaleaacaWGibaabeaaaaa@37B8@  
      = the area adjustment factor for the heating load limit, determined in accordance with Table S44C2.
Table S44C2 Area adjustment factors for the heating load limit
Total area of habitable rooms (AH) Area adjustment factor (FH)
≤ 50 m2 1.37
> 50 m2 to ≤ 350 m2
(5.11×10−6)AH2−(3.82×10−3)AH+1.55MathType@MTEF@5@5@+= feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaaiikaiaaiw dacaGGUaGaaGymaiaaigdaiiaacqWFxdaTcqWFXaqmcqWFWaamdaah aaWcbeqaaiab=jHiTiab=zda2aaakiab=LcaPiaadgeadaWgaaWcba GaamisaaqabaGcdaahaaWcbeqaaiab=jdaYaaakiab=jHiTiab=Hca Oiab=ndaZiab=5caUiab=Hda4iab=jdaYiab=Dna0kaaigdacaaIWa WaaWbaaSqabeaacqGHsislcaaIZaaaaOGaaiykaiaadgeadaWgaaWc baGaamisaaqabaGccqGHRaWkcaaIXaGaaiOlaiaaiwdacaaI1aaaaa@5449@
> 350 m2 0.84

To detail the calculation of the heating load limit of a space.

In S44C2, the heating load limit of a space is expressed in Megajoules per square meter per annum (MJ/m2.annum). The limit is determined by taking the greater of two values: the first is a fixed value of 4 MJ/m2.annum, and the second is calculated using a formula. This formula incorporates two variables: the total annual heating degree hours specific to the building's location, and an area adjustment factor for the heating load limit, which can be obtained from Table S44C2 based on the total area of the habitable room.

(1) The cooling load limit of a space, measured in MJ/m2.annum, is calculated in accordance with the following formula:

CLL=(5.4+0.00617×(CDH+1.85DGH))×FCMathType@MTEF@5@5@+= feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaam4qaiaadY eacaWGmbGaeyypa0JaaiikaiaaiwdacaGGUaGaaGinaiabgUcaRiaa icdacaGGUaGaaGimaiaaicdacaaI2aGaaGymaiaaiEdaiiaacqWFxd aTcaGGOaGaam4qaiaadseacaWGibGaey4kaSIaaGymaiaac6cacaaI 4aGaaGynaiaadseacaWGhbGaamisaiaacMcacaGGPaGae831aqRaam OramaaBaaaleaacaWGdbaabeaaaaa@52BC@  

(2) In the formula at (1)—

  1. CLLMathType@MTEF@5@5@+= feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaam4qaiaadY eacaWGmbaaaa@385E@  
    = the cooling load limit (MJ/m2.annum); and
  2. CDHMathType@MTEF@5@5@+= feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaam4qaiaads eacaWGibaaaa@3852@  
    = the total annual cooling degree hours of the building location; and
  3. DGHMathType@MTEF@5@5@+= feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamiraiaadE eacaWGibaaaa@3856@  
    = the total annual dehumidification gram hours of the building location; and
  4. FCMathType@MTEF@5@5@+= feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamOramaaBa aaleaacaWGdbaabeaaaaa@37B3@  
    = the area adjustment factor for the cooling load limit, determined in accordance with Table S44C3.
Table S44C3 Area adjustment factors for the cooling load limit
Total area of the habitable rooms (AH) Area adjustment factor (FC)
≤ 50 m2 1.34
> 50 m2 and ≤ 200 m2
(1.29×10−5)AH2−(5.55×10−3)AH+1.58MathType@MTEF@5@5@+= feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaaiikaiaaig dacaGGUaGaaGOmaiaaiMdaiiaacqWFxdaTcaaIXaGaaGimamaaCaaa leqabaGaeyOeI0IaaGynaaaakiaacMcacaWGbbWaaSbaaSqaaiaadI eaaeqaaOWaaWbaaSqabeaacaaIYaaaaOGaeyOeI0Iaaiikaiaaiwda caGGUaGaaGynaiaaiwdacqWFxdaTcaaIXaGaaGimamaaCaaaleqaba GaeyOeI0IaaG4maaaakiaacMcacaWGbbWaaSbaaSqaaiaadIeaaeqa aOGaey4kaSIaaGymaiaac6cacaaI1aGaaGioaaaa@529B@
> 200 m2 and ≤ 1000 m2
(3.76×10−7)AH2−(7.82×10−4)AH+1.12MathType@MTEF@5@5@+= feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaaiikaiaaio dacaGGUaGaaG4naiaaiAdaiiaacqWFxdaTcaaIXaGaaGimamaaCaaa leqabaGaeyOeI0IaaG4naaaakiaacMcacaWGbbWaaSbaaSqaaiaadI eaaeqaaOWaaWbaaSqabeaacaaIYaaaaOGaeyOeI0IaaiikaiaaiEda caGGUaGaaGioaiaaikdacqWFxdaTcaaIXaGaaGimamaaCaaaleqaba GaeyOeI0IaaGinaaaakiaacMcacaWGbbWaaSbaaSqaaiaadIeaaeqa aOGaey4kaSIaaGymaiaac6cacaaIXaGaaGOmaaaa@529A@
> 1000 m2 0.71

To detail the calculation of the cooling load limit of a space.

S44C3 describes how to calculate the cooling load limit of a space, also in MJ/m2.annum. The cooling load limit is calculated using a formula that incorporates several variables. These include the total annual cooling degree hours and the total annual dehumidification gram hours, both specific to the building's location. Additionally, the area adjustment factor for the cooling load limit is determined using Table S44C3.

(1) The thermal energy load limit of a space, measured in MJ/m2.annum, is calculated in accordance with the following formula:

TLL=19.3HLL+22.6CLL−8.4Tr+10.74−15MathType@MTEF@5@5@+= feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamivaiaadY eacaWGmbGaeyypa0ZaaSaaaeaacaaIXaGaaGyoaiaac6cacaaIZaGa amisaiaadYeacaWGmbGaey4kaSIaaGOmaiaaikdacaGGUaGaaGOnai aadoeacaWGmbGaamitaiabgkHiTiaaiIdacaGGUaGaaGinaaqaaiaa dsfadaWgaaWcbaGaamOCaaqabaGccqGHRaWkcaaIXaGaaGimaiaac6 cacaaI3aGaaGinaaaacqGHsislcaaIXaGaaGynaaaa@512B@  

(2) In the formula at (1)—

  1. TLLMathType@MTEF@5@5@+= feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamivaiaadY eacaWGmbaaaa@386F@  
    = the thermal energy load limit; and
  2. HLLMathType@MTEF@5@5@+= feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamisaiaadY eacaWGmbaaaa@3863@  
    = the heating load limit; and
  3. CLLMathType@MTEF@5@5@+= feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaam4qaiaadY eacaWGmbaaaa@385E@  
    = the cooling load limit; and
  4. TrMathType@MTEF@5@5@+= feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamivamaaBa aaleaacaWGYbaabeaaaaa@37F0@  
    = the annual average daily outdoor temperature range.

To detail the calculation of the thermal energy load limit of a space.

S44C4 outlines the calculation of the thermal energy load limit, which is also measured in MJ/m2.annum. This is calculated using a formula that considers both the heating and cooling load limits previously calculated, as well as the annual average daily outdoor temperature range. Each of these elements forms part of the formula stated in this provision for determining the thermal energy load limit for a space.


Using the calculation method in Specification 44 is only necessary when developing a Performance Solution that assesses compliance directly against J1P2 or H6P1.