C***********************************************************************
  
      SUBROUTINE TYPE10(TIME,XIN,OUT,T,DTDT,PAR,INFO,ICNTRL,*)
  
C ----------------------------------------------------------------------
C
C       TYPE 10 : HOT WATER COIL MODEL (CROSSFLOW)
C       DERIVATIVES CHANGED FOR TRNSYS USE - 6-22-95
C***********************************************************************

      DOUBLE PRECISION XIN,OUT
      REAL    PAR,K1,K2,NTU
      INTEGER INFO
C     INTEGER IOSTAT
C     LOGICAL FLO1,FLO2,TEM1,TEM3,FRZDE
      DIMENSION  XIN(8),OUT(4),PAR(5),INFO(15)
C     DIMENSION  IOSTAT(8)
  
C*    COMMON  /PROPER/ RHOA,RHOW,CPA,CPW
C*    COMMON  /SOSCOM/ RTOLX,ATOLX,XTOL
      COMMON  /SIM/ TIME0,TFINAL,DELT,IWARN

C  The RHOA,RHOW,CPA,CPW properties @300 K, 1 atm
C  The units are:
C      RHOW - kg/m^3
C      CPA,CPW   - kJ/kg-K
      DATA  RHOW,CPA,CPW /999,1.007,4.179/

      P2= XIN(1)
      W1= XIN(2)
      T1= XIN(3)
      T2= XIN(4)
      P4= XIN(5)
      W2= XIN(6)
      T3= XIN(7)
      T4= XIN(8)
  
      UA=  PAR(1)
      K1=  PAR(2)
      K2=  PAR(3)
      VOL= PAR(4)
      TCON=PAR(5)
  
      IF (W1.LT.1.E-5) W1=0.                      ! added 2/24/94
      IF (W2.LT.1.E-5) W2=0.

C     FLO1=(IOSTAT(2).LT.-1).OR.(IOSTAT(2).EQ.2)
C     FLO2=(IOSTAT(3).LT.-1).OR.(IOSTAT(3).EQ.2)
C     TEM1=(IOSTAT(6).LT.-1).OR.(IOSTAT(6).EQ.2)
C     TEM3=(IOSTAT(7).LT.-1).OR.(IOSTAT(7).EQ.2)
C     FRZDE=FLO1.AND.FLO2.AND.TEM1.AND.TEM3
      S=1.
      IF (W1.NE.0.) S=SIGN(1.,W1)
      P1=P2+S*K1*W1**2
      S=1.
      IF (W2.NE.0.) S=SIGN(1.,W2)
      P3=P4+S*K2*W2**2
      C1=CPA*W1
      C2=CPW*W2
      RATE=0.
      IF (TCON.GT.0.) RATE=RATE+1./TCON
      IF (VOL.GT.0.) RATE=RATE+W2/(RHOW*VOL)
      CMIN=AMIN1(C1,C2)
      CMAX=AMAX1(C1,C2)
      IF ((C1.LE.0.).OR.(C2.LE.0.)) GOTO 1000
      NTU=UA/CMIN
      ETA=NTU**0.22
      R=CMIN/CMAX
      E1=0.
      E2=0.
      A=R*NTU/ETA
      IF (A.GT.20.) GOTO 2000
      E1=EXP(-A)
2000  A=ETA*(1.-E1)/R
      IF (A.GT.20.) GOTO 2001
      E2=EXP(-A)
2001  EFEC=1.-E2
      T2S=T1+EFEC*CMIN*(T3-T1)/C1
      T4S=T3-C1*(T2S-T1)/C2
      GOTO 3000
1000  T2S=T1
      T4S=T3
3000  IF (RATE.LE.0.) GOTO 4000
      DT2DT=(T2S-T2)*RATE
      DT4DT=(T4S-T4)*RATE
*BECAUSE DERIVATIVES CALCULATED IN MAIN HVACSIM+ ROUTINE, WE HAVE APPROXIMATED
*IT WITH THE CODE BELOW.  CLG + NJB      
* T4 OUT = T4OLD + dT/tau*(Twss - twout)
      IF(INFO(7).EQ.-1) THEN
         OUT(1)=T2
         OUT(2)=T4
         T4OLD=OUT(2)
         T2OLD=OUT(1)
      ENDIF
      IF (INFO(7).EQ.0.0) THEN
         T4OLD=OUT(2)
         T2OLD=OUT(1)
      ENDIF
      T4=(DELT*T4S + TCON*T4OLD)/(TCON + DELT)
      T2=(DELT*T2S + TCON*T2OLD)/(TCON + DELT)
C     IF (ABS(DT2DT).LT.ATOLX) DT2DT=0.0      ! added 2/24/94
C     IF (ABS(DT4DT).LT.ATOLX) DT4DT=0.0

C     OUT(1)=DT2DT 
C     OUT(2)=DT4DT
      OUT(1)=T2
      OUT(2)=T4
      OUT(3)=P1
      OUT(4)=P3
C     IOSTAT(1)=0
C     IF ((ABS(T2S-T2).LE.RTOLX*ABS(T2)+ATOLX).AND.FRZDE) IOSTAT(1)=1
C     IOSTAT(2)=0
C     IF ((ABS(T4S-T4).LE.RTOLX*ABS(T4)+ATOLX).AND.FRZDE) IOSTAT(2)=1
C     IOSTAT(3)=1
C     IOSTAT(4)=1
      RETURN 1
  
4000  OUT(1)=T2S
      OUT(2)=T4S
      OUT(3)=P1
      OUT(4)=P3
  
C     DO 10 I=1,4
C        IOSTAT(1)=1
C  10    CONTINUE
  
      RETURN 1
      END