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Merge pull request #10737 from LipingWang/IndoorGreen_Update3
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Update indoor living wall sensible heat gain calculation
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Myoldmopar authored Sep 19, 2024
2 parents cdf84cc + bd37e01 commit 80732bf
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Expand Up @@ -9,7 +9,7 @@ \subsection{Energy Balance of Indoor Living Wall}\label{energy-balance-of-indoor
Plant energy balance equation:

\begin{equation}
Q_{lw-net}+Q_{sw}+h_{ip} \cdot A_ip \cdot (T_z - T_p )-\lambda \cdot A_ip \cdot ET+Q_{cond}=0
Q_{lw-net}+Q_{sw}+h_{ip} \cdot A_ip \cdot (T_z - T_p )+Q_{cond}=0
\end{equation}

where:
Expand All @@ -27,11 +27,7 @@ \subsection{Energy Balance of Indoor Living Wall}\label{energy-balance-of-indoor
\item
\(T_p\) is the plant surface temperature (\si{\celsius})
\item
\(A_ip\) is the plant surface area (\si{\area})
\item
\(\lambda\) is the latent heat of vaporization (\si{\specificEnthalpy})
\item
\(ET\) is the evapotranspiration rate (\si{\evapotranspirationRate}).
\(A_ip\) is the plant surface area (\si{\area}).
\end{itemize}

Indoor air heat balance connects with indoor living walls through convective heat transfer, which has the opposite sign of the term in surface heat balance. Convective portion of heat gain from LED lights also contributes to zone air heat balance equation.
Expand All @@ -53,7 +49,7 @@ \subsection{Energy Balance of Indoor Living Wall}\label{energy-balance-of-indoor
\item
$V_z$ is zone air volume (\si{\volume})
\item
\(\dot Q_i\) is the convective heat from internal loads (\si{\watt})
\(\dot Q_i\) is the convective heat from internal loads including sensible heat gain from living walls (\si{\watt})
\item
\({{h_i}} {A_i}\left( {{T_{si}} - {T_z}} \right)\) is the convective heat transfer from surfaces to zone air (\si{\watt})
\item
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Expand Up @@ -2452,7 +2452,7 @@ \subsubsection{Outputs}\label{outputs-indoorlivingwall}

\paragraph{Indoor Living Wall Sensible Heat Gain Rate {[}W{]}}\label{indoor-living-wall-sensible-heat-gain-rate-w}

This output is the sensible heat gain rate from indoor living walls in W and determined by surface heat balance. Positive sign represents heat gain of living walls or heat loss of indoor spaces; negative sign represents heat loss of living walls or heat gain of indoor spaces.
This output is the sensible heat gain rate from indoor living walls in W and determined by surface heat balance. Positive sign represents heat gain of spaces; negative sign represents heat loss of spaces.

\paragraph{Indoor Living Wall Latent Heat Gain Rate {[}W{]}}\label{indoor-living-wall-latent-heat-gain-rate-w}

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11 changes: 4 additions & 7 deletions src/EnergyPlus/IndoorGreen.cc
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Expand Up @@ -363,7 +363,7 @@ namespace IndoorGreen {
ig.ZonePtr,
ig.Name,
DataHeatBalance::IntGainType::IndoorGreen,
&ig.SensibleRateLED,
&ig.SensibleRate,
nullptr,
nullptr,
&ig.LatentRate,
Expand Down Expand Up @@ -582,15 +582,12 @@ namespace IndoorGreen {
ZoneNewHum = ZoneSatHum;
}
HMid = Psychrometrics::PsyHFnTdbW(ZoneNewTemp, ZonePreHum);
ig.SensibleRateLED =
(1 - ig.LEDRadFraction) * ig.LEDActualEleP; // convective heat gain from LED lights when LED is on; heat convection from
// plants was considered and counted from plant surface heat balance.
ig.SensibleRate = state.dataHeatBalSurf->SurfQConvInRep(ig.SurfPtr) / Timestep;
ig.LatentRate = ZoneAirVol * rhoair * (HCons - HMid) / Timestep; // unit W
ig.SensibleRateLED = (1 - ig.LEDRadFraction) * ig.LEDActualEleP; // convective heat gain from LED lights when LED is on;
ig.SensibleRate = -1.0 * ig.LatentRate + ig.SensibleRateLED;
state.dataHeatBalSurf->SurfQAdditionalHeatSourceInside(ig.SurfPtr) =
-1.0 * ig.LambdaET +
ig.LEDRadFraction * 0.9 * ig.LEDActualEleP /
state.dataSurface->Surface(ig.SurfPtr).Area; // assume the energy from radiation for photosynthesis is only 10%.
state.dataSurface->Surface(ig.SurfPtr).Area; // assume the energy from radiation for photosynthesis is only 10%.
}
}

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