[BLDG-SIM] Radiant Slabs in eQUEST and LEED

Gaurav Mehta gmehta75 at gmail.com
Mon Nov 19 22:29:21 PST 2007


Radiant Slabs in eQUEST and LEEDIn most of the projects that we have dealt with in the Pacific Northwest, where there has been no cooling proposed and hence no chiller in the central plant and the air handler includes only hot water coils to tamper the outside air for ventilation. In these situations, I have modeled a hydronic radiant floor heating using a Unit Ventilator, by setting the fan power kw/cfm as 0.0000 and including a baseboard at the zone level. 

Moreover, as per LEED protocol one has to model cooling even when no cooling has been proposed, i create a dummy zone and assign a PSZ system with DX coils and hot water coils and then in the outside air tab of the Unit Ventilator select the PSZ system from the drop down list in 'Outside Air from System'. 

Since an FPH system doesn't allow outside air to be simulated, would require some work around to account for the outside air loads (which would be minimum ventilation required for IAQ) on the zone with radiant floor heating. However, the approach described above takes into account the outside air loads and also includes a cooling system that is similar to the baseline system in most cases (PSZ-AC with DX coils for cooling). In case, the central plant includes a chiller and/or baseline system includes chilled water coils, I would use the Four Pipe FC.

Any thoughts on this approach?


Thanks.


Gaurav Mehta,

Sustainable Building Analyst,
Stantec



  ----- Original Message ----- 
  From: Vikram Sami 
  To: BLDG-SIM at gard.com 
  Sent: Monday, November 19, 2007 14:30
  Subject: [BLDG-SIM] Radiant Slabs in eQUEST and LEED


  I'm doing an ECB documentation for a LEED 2.1 project using eQUEST. Around half of the building uses hydronic radiant floor heating. I am trying to model this in eQUEST. 

  From past threads, suggestions I have come across are: 
  1. Lower the Space temperature to 68F. 
  2. Using the FPH system in eQUEST. This doesn't allow for cooling however, and uses no fans (we still have air supply in our building). 

  3. Andrew Craig suggested inputting the capacity of the radiant system as an internal energy source. (This is great because it allows the fans to cycle on/off and maintains the cooling side. It doesn't calculate heating loads on the radiant slab though)

  What I plan to do is use the FPH system and setback the thermostat to 68F in these spaces. This will allow me to calculate the heating energy on the radiant coil. I then plan to use Andrew's "internal energy source" method to calculate the airside system loads, and add the FPH heat load to that. 

  Does this seem like a reasonable method to model this? 

  Vikram Sami, LEED AP 
  Direct Phone 404-253-1466 | Direct Fax 404-253-1366 

  LORD, AECK & SARGENT ARCHITECTURE
  1201 Peachtree Street NE, Suite 300, Atlanta, GA 30361 
  Responsive Design · Technological Expertise · Exceptional Service 
  www.lordaecksargent.com 

  Please don't print this email unless you really have to. 
  One tree makes 16.67 reams of copy paper or 8,333.3 sheets
  ~Conservatree, September 2002





==================
You received this e-mail because you are subscribed 
to the BLDG-SIM at GARD.COM mailing list.  To unsubscribe 
from this mailing list send a blank message to 
BLDG-SIM-UNSUBSCRIBE at GARD.COM


===========================
You received this e-mail because you are subscribed 
to the BLDG-SIM at GARD.COM mailing list.  To unsubscribe 
from this mailing list send a blank message to 
BLDG-SIM-UNSUBSCRIBE at GARD.COM
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.onebuilding.org/pipermail/bldg-sim-onebuilding.org/attachments/20071119/b301eba1/attachment-0002.htm>


More information about the Bldg-sim mailing list