I would set up an HVAC system that can maintain both temperature and humidity. Make sure you can maintain both set points for all simulations. Then use the predicted load variables to calculate Load SHR. You can do this by zone, or sum these values for the entire building.
Output:Variable,*,Zone/Sys Sensible Load Predicted,Hourly;
Output:Variable,*,Zone/Sys Moisture Load Rate Predicted,Hourly;
You will need some additional math for this.
For example, a spreadsheet calc may look like this:
IF(Zone/Sys Sensible Load Predicted < 0, IF(Zone/Sys Moisture Load Rate Predicted < 0, calculate the Cooling Load SHR,1),IF(Zone/Sys Sensible Load Predicted > 0,IF(Zone/Sys Moisture Load Rate Predicted < 0,calculate Heating Load SHR,1,x))
Remember the psychormetrics of calculating SHR. If heating and dehumidifying, the SHR could be > 1 or < 0. A room air dehumidifier has an SHR close to 2.
Look at the upper left hand corner of this psyc chart.
http://www.heatpipe.com/ProductsServices/forengineers/psychrometric_chart.pdf
On 6/6/2011 9:45 AM, Michael Grant wrote:
Hey everyone,
I know it’s been a while, but going over this subject again, does anyone know how I can get the annual sensible heat ratio (sensible load/total load) of a building (typical is around 0.7)? I’m trying to study the building’s characteristics through infiltration, occupancy, and solar gains.
Thanks,
Michael Grant, MIT
Engineering | Systemair Inc.
(T) 1-506-743-9500
From: EnergyPlus_Support@xxxxxxxxxxxxxxx [mailto:EnergyPlus_Support@xxxxxxxxxxxxxxx] On Behalf Of Richard Raustad
Sent: April-29-11 10:41 AM
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
Subject: Re: [EnergyPlus_Support] Total Building Sensible and Latent Energy
I don't know of any report variables that provide actual total or latent energy provided to the zone. Those existing report variables are related only to sensible energy provided to the zone and includes more than what comes through the zone inlet nodes (e.g. baseboards, room dehumidifiers, etc.). Also remember that these report variables are only related to the "load" when the thermostat set point is met (i.e., if you provide more or less sensible capacity to a zone than is required to meet the set point, it's not really the load). The "load" related to both the thermostat and humidistat set points can be viewed using:
When a zone thermostat is present:
HVAC,Average,Zone/Sys Sensible Load Predicted [W]
HVAC,Average,Zone/Sys Sensible Load to Heating Setpoint Predicted [W]
HVAC,Average,Zone/Sys Sensible Load to Cooling Setpoint Predicted [W]
When a zone humidistat is present:
HVAC,Average,Zone/Sys Moisture Load Rate Predicted [kgWater/s]
HVAC,Average,Zone/Sys Moisture Load Rate Predicted to humidifying setpoint [kgWater/s]
HVAC,Average,Zone/Sys Moisture Load Rate Predicted to dehumidifying setpoint [kgWater/s]
On 4/29/2011 8:24 AM, Michael Grant wrote:
Hey everyone,
Is there a place in a model where I can have energy plus spit out a building’s total sensible and latent load?
Is my only option under “Output:Variable,*,Zone/Sys Sensible Cooling Rate,hourly;” and “Output:Variable,*,Zone/Sys Sensible Heating Rate,hourly;” ?
Thanks,
Michael Grant, MIT
Engineering | Systemair Inc.
(T) 1-506-743-9500
--Richard A. RaustadSenior Research EngineerFlorida Solar Energy CenterUniversity of Central Florida1679 Clearlake RoadCocoa, FL 32922-5703Phone: (321) 638-1454Fax: (321) 638-1439 or 1010Visit our web site at: http://www.fsec.ucf.edu
-- Richard A. Raustad Senior Research Engineer Florida Solar Energy Center University of Central Florida 1679 Clearlake Road Cocoa, FL 32922-5703 Phone: (321) 638-1454 Fax: (321) 638-1439 or 1010 Visit our web site at: http://www.fsec.ucf.edu UCF - From Promise to Prominence: Celebrating 40 Years
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