nadish21's profile - activity

Hello,

I am trying to simulate the HVAC System of a small house with a PTAC or Packaged Rooftop Air Conditioner. Generally when the HVAC system works in a real life scenario (i.e. for a small house) the Heating or Cooling Coil or the Fan consumes a constant electric power whether they are working on Part load or Full load conditions. But in the system I am trying to simulate ,Although regulated by a sophisticated Energy Management System Control (With the help of @Ivan Korolija), The Output of the Electric Equipment has a varying Power Consumption. How can I get rid of this problem?

Background of the question: For the Same problem there were experiments conducted a few years back on a small House' s HVAC system. The power consumption was almost constant. Hence for my research I am trying to simulate the exact same conditions.

I am sharing the links of IDF File and the Excel Results File here. Anyone can excess them on google drive (no sign in would be required.

Link for Excel Results File:

Excel Results File

Link for The IDF File

IDF File

I would be extremely grateful for any help that can be rendered to tackle this issue. Thank you in Advance.

Nadish

Hello,

I have a confusion regarding the modeling of HVAC system for a single thermal zone. My simulation is for a single small House (although its template is not available in EPlus, but I am using the Midrise Apartment's template) with a single HVAC unit. I am not sure if the Air Terminal:Single Duct: Uncontrolled Object is enough to ensure that the Conditioned air from the HVAC unit is reaching Equally to all the Rooms in my Thermal Zone. I have not set up any duct work or other objects for the HVAC system manually.

I am Attaching the IDF file for a sample simulation. I would appreciate any help in this matter.

Sincerely,

Nadish Anand

IDF Link

I am trying to Determine the Effects of Wind Speed on my Simulation. For this I would need to Frequently change the Zone Outdoor Air Wind Speed. Can I do this by an EMS code? or Do I need to Modify the Weather data file every time with the desired Wind Speed?

Any Help will be greatly appreciated.

Sincerely,

Nadish Anand

Hello,

I am trying to simulate a small house in the OpenStudio Template of "Midrise Apartment". I am having troubles in ascertaining how the Thermostat behaves according to the provided Temperature values and the selected schedule set. I do not know what schedule set do I need to select in order for My HVAC System to Keep on heating the thermal zone till a particular set temperature say T is reached and as soon as T is reached the HVAC turns off. When the Temperature drops to T-1 deg F the HVAC should turn on automatically. Further, is such a setting possible in OpenStudio, if so can I get a detailed documentation of the Thermostat schedule sets of OpenStudio, if Not can anyone guide me how to realize this appropriately using Energy+ as I am referring to Energy+ documentation now.

Any help will be greatly appreciated.

Thank You.

The Following Part is for my pre-latest questions on the data which the EMS program generates when the IDF is ran through Energy Plus.(@Ivan Korolija)

The Following is the link to the Excel Results File file:

Excel Results File-pre Latest

The Following is the Link to the IDF file:

IDF File

The following are the Latest files (@Ivan).

Latest Excel Results File:

Excel File_Latest

Latest IDF File:

IDF_Latest

While making geometry in SketchUp, and using an OpenStudio Template for the model, can we specify the wall thicknesses for both of interior and exterior walls?

Or do we need to construct the geometry as we do in Autocad or some other Architecture related software?

If so will OpenStudio apply the default construction sets of the Template to this Geometry?

I downloaded Sketchup alongwith Openstudio 1.5.3 more than a month ago. Now I am not able to use SketchUp because 1 month free trial has expired. I do not understand this. Do we need to Buy SketchUp if we need to use it with OpenStudio, or has NREL procured a Key for Sketchup which I do not know about. Previous Versions of SketchUp worked for more than a month and I was never Asked to Buy an Product.

Hello,

I am wondering if there are two different time steps (one for Plant i.e. HVAC and the other for the Zone) in EnergyPlus? if not is there a response time for the Plant to start Circulating conditioned air? if there is a response time How can I control it?

Any help will be greatly appreciated.

Sincerely,

Nadish Anand

Update:

Hello Amir and Eric, I am referring to the Following Data Plot:

Zone Air Temperature-1 min. Timestep

Zone Air Temperature Detailed

This is the plot of the Zone Air Temperature Data I have obtained from my EnergyPlus Simulation. I have an EMS Code that Controls the HVAC Operation with a Offset Temperature from the Heating and Cooling Setpoints. The offset Temperature here is 0.6 deg.C and the Heating Setpoint is 21.1 deg.C. Now as you can see from the plot the HVAC system is not starting operation as soon as (21.1-0.6) = 20.5 deg.C is hit by the Zone Air temperature. It takes a while (1-3 mins.) to start operation. I am wondering why this behavior is experienced and hence my earlier question.

Thank you once again.

Nadish

Hello Mr. Ringold,

Thank you for your Answer. It was really helpful. I however have one more followup question. Is there a sub 1 minute level timestep in EnergyPlus. The simulation that I am Running uses a 23 kW heater. In 60 seconds (1 min.) it should add around 1.38 million Joules to the system. However in some timesteps when the heater is turning On/Off it is adding Heat Below this value. Which leads me to believe that there are certain calculations which are done below the 1 minute level. If it were a minute, the heat addition for that timestep should be 1.38 Million Joules.

Nadish

Hello,

I am Trying to simulate a normal HVAC system with a Fan, Electric Heating Coil and a Cooling Coil. I get energy added by the heater in a timestep as below its addition capacity, as if the Heater was operating for a fraction of a Minute. Is this possible in EnergyPlus? Since the minimum Timestep is 1 minute how could this behavior take place?

Any Help will be greatly appreciated.

Sincerely,

Nadish Anand