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<DIV>I am attempting to model a water cooled VRF system for a dormitory in northern Montana. I have used Dana Troy's method for air source VRF systems several times with great success, but this is my first attempt at a water source system. The model seems to work as expected with a single speed compressor, but when I change this to a variable speed compressor, the system doesn't function properly. There is no flow in the water loop and the VRF heating energy disappears. The model still shows no unmet load hours but is clearly not operating correctly.</DIV>
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<DIV>I have done some research in the help files and the forum archives and found little help. Volume 3 of the DOE2 help file under Air-Side System Types - PVVT seems to hint at variable speed compressors being only for air cooled condenser types. The eQUEST forums have a few posts of this same question with no conclusion. What have you found? What is the best way to simulate a variable speed compressor for a water source heat pump system? Am I missing something here?</DIV>
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<DIV>Thanks,</DIV>
<DIV>Tim</DIV>
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<DIV> </DIV><PRE style="MARGIN: 0in 0in 0pt; mso-element: frame; mso-element-frame-hspace: 2.25pt; mso-element-wrap: around; mso-element-anchor-vertical: paragraph; mso-element-anchor-horizontal: column; mso-height-rule: exactly" dir=ltr class=MsoNormal><SPAN style="FONT-FAMILY: 'Arial','sans-serif'; COLOR: maroon; FONT-SIZE: 10pt; mso-bidi-font-size: 12.0pt"><STRONG>Tim Johnson, PE, BEMP, LEED AP</STRONG></SPAN></PRE><PRE style="MARGIN: 0in 0in 0pt; mso-element: frame; mso-element-frame-hspace: 2.25pt; mso-element-wrap: around; mso-element-anchor-vertical: paragraph; mso-element-anchor-horizontal: column; mso-height-rule: exactly" class=MsoNormal><SPAN style="FONT-FAMILY: 'Arial','sans-serif'; COLOR: maroon; FONT-SIZE: 7.5pt; mso-bidi-font-size: 12.0pt"><STRONG>CTA : Mechanical Engineer</STRONG></SPAN><SPAN style="FONT-SIZE: 10pt"> </SPAN></PRE><PRE style="MARGIN: 0in 0in 0pt; mso-element: frame; mso-element-frame-hspace: 2.25pt; mso-element-wrap: around; mso-element-anchor-vertical: paragraph; mso-element-anchor-horizontal: column; mso-height-rule: exactly" class=MsoNormal><SPAN style="FONT-SIZE: 7.5pt"><FONT face=Arial>DIRECT: 208.577.5645</FONT></PRE><PRE style="MARGIN: 0in 0in 0pt; mso-element: frame; mso-element-frame-hspace: 2.25pt; mso-element-wrap: around; mso-element-anchor-vertical: paragraph; mso-element-anchor-horizontal: column; mso-height-rule: exactly" class=MsoNormal><SPAN style="FONT-SIZE: 7.5pt"> </PRE><PRE style="MARGIN: 0in 0in 0pt; mso-element: frame; mso-element-frame-hspace: 2.25pt; mso-element-wrap: around; mso-element-anchor-vertical: paragraph; mso-element-anchor-horizontal: column; mso-height-rule: exactly" class=MsoNormal><PRE style="MARGIN: 0in 0in 0pt; mso-element: frame; mso-element-frame-hspace: 2.25pt; mso-element-wrap: around; mso-element-anchor-vertical: paragraph; mso-element-anchor-horizontal: column; mso-height-rule: exactly" class=MsoNormal><STRONG><SPAN style="FONT-FAMILY: 'Arial','sans-serif'; COLOR: maroon; FONT-SIZE: 7.5pt; mso-bidi-font-size: 12.0pt">CTA, Inc. </SPAN><SPAN style="FONT-FAMILY: 'Arial','sans-serif'; COLOR: #3e3e3e; FONT-SIZE: 7.5pt">|<SPAN style="mso-spacerun: yes"> </SPAN></SPAN><SPAN style="FONT-FAMILY: 'Arial','sans-serif'; COLOR: #8e0000; FONT-SIZE: 7.5pt"><A href="http://www.ctagroup.com/"><SPAN style="COLOR: #8e0000; mso-bidi-font-size: 12.0pt">www.ctagroup.com</SPAN></A></SPAN></STRONG></PRE><PRE style="MARGIN: 0in 0in 0pt; mso-element: frame; mso-element-frame-hspace: 2.25pt; mso-element-wrap: around; mso-element-anchor-vertical: paragraph; mso-element-anchor-horizontal: column; mso-height-rule: exactly" class=MsoNormal><SPAN style="FONT-FAMILY: 'Arial','sans-serif'; COLOR: #3e3e3e; FONT-SIZE: 7.5pt">1185 W. Grove St. – Boise, ID 83702<?XML:NAMESPACE PREFIX = O /><O:P></O:P></SPAN></PRE><PRE style="MARGIN: 0in 0in 0pt; mso-element: frame; mso-element-frame-hspace: 2.25pt; mso-element-wrap: around; mso-element-anchor-vertical: paragraph; mso-element-anchor-horizontal: column; mso-height-rule: exactly" class=MsoNormal><SPAN style="FONT-FAMILY: 'Arial','sans-serif'; COLOR: #3e3e3e; FONT-SIZE: 7.5pt">P: 208.336.4900 – F: 208.343.3531</SPAN></PRE></SPAN></PRE></SPAN></BODY></HTML>