IES-VE User Forum

Hi, Sorry for the very long post.I am trying to simulate a building in a tropical humid climate. I have adjusted the BTM in the following manner. My location does not have a weather file in ASHRAE database. Therefore, I have placed a .EPW weather file in the shared content. Then in Aplocate, I have used the ‘Set Location Only’ and selected the weather file from ‘Simulation Weather Data’.
But when I run simulation in Apachesim, the total energy and natural ventilation remains static throughout the simulation period. The NV value is zero. I don’t understand what is going wrong.
I have selected the windows in edit selection opening types and assigned the types of opening.
I have run the simulation with following model links: Suncast, Macroflow, Auxilary Ventilation and Natural ventilation.
It would be really kind if you please look at my BTM set-up below and give me some suggestion.
Best regards

Model Set-up for Tropical Warm-Humid Climate:
Building Template Manager:
General > Default

Construction>
o External Wall> Material ID: [BRCK0000] Description: Brickwork (Outer Leaf),Thickness: 0.220 m
o Glazing> Material ID: [EXTW] Description: CLEAR FLOAT 6MM
o Rest of the item is selected as default

Thermal>
o Building regulations> Heated or occupied room
o Room conditions>
• Heating> Heating Profile> Off continuously
• DHW> Consumption> Independent Profile
>Pattern of use> Off continuously
• Cooling> cooling profile> Off continuously
• Plant (auxiliary energy)> Off continuously
Rest of it is set as default.
o System>
• HVAC system> None
• Auxilary vent> None
• DHW system> None
Rest of it is set as default.
o Internal gain>
 Fluorescent Lighting: Max sensible-6 W/m2,Max power- 6 W/m2, Rad Frac-.45,Fuel- Electricity, Variation- on continuously, Dimming- on continuously
 People: Max sensible-90 W/person, Max Latent Gain-60 W/person , Occupancy- 10 m2/person ,Variation- on continuously,
 Miscellaneous: Max sensible-10 W/m2, Max Latent Gain – 5 W/m2, Max power- 15 W/m2, Rad Frac-.5, Fuel- Electricity, Variation- on continuously

o Air Exchanges> Infiltration

Macroflow>
o Opening Types> Modified Opening
 Exposure Type> High-rise semi-exposed wall h/H=0.4
 Opening category> Window/door-side hung
 Openable area> 90%
 Max Angle Open> 90 Deg
 Proportions> 1=<Length/ Height<2
 Equivalent orfice area> 94.355% of gross
 Crack Flow Coefficient> .15
 Crack Length>0
 Opening Threshold> 24
 Degree of Opening> on continuously

Yikes! A few comments...

Constructions - Setting constructions in the BTM doesn't assign them to your spaces unless you're extruding all spaces after setting up the templates. You need to actually assign them in Apache using the "assign constructions" tool.

Thermal & System templates - All of your profiles are set to "off continuously" which will have zero heating, cooling, and (mechanical) ventilation during your simulation. This may be what you're intending..

Internal Loads - If the variation profiles for all of your gains are set to "on continuously," you are simulating 100% of the specified load during every time step (i.e. constant load).

Based on that information, of course you're not going to see variation in energy consumption! You have zero heating, cooling and ventilation, and all your internal gains are set up to be constant.

The simulation SHOULD, however, be calculating natural ventilation airflow through spaces and the resulting air temperature in each. I'm not sure what "NV value" you are talking about. The values you're probably looking at are referencing the natural ventilation air exchanges that you can set up as a profile in BTM - NOT the nat vent flows calculated with Macroflo. I'm not a Macroflo expert, so I'd recommend you read through the user guide to figure out how to view the natural ventilation values you're looking for.

OMG! I really didn't expect an answer at this hour! I am so happy that your answer has clarified some major confusions. Firstly none of my changes in BTM is actually assigned to the project! Secondly, continuous internal gain.But I didn't find another place to assign internal gain other than BTM. Anyway, the confusion still remains with Macroflow. Since I am trying to model a free-running building, all the mechanical systems are turned off. I hope this is OK. But, I believe natural ventilation will still take place inside the rooms and I wanted to see the result in Vista> selected room> ventilation> natural ventilation. Should I be looking into Macroflow internal ventilation, that is also zero. This means my windows are not actually open! I have read the user guide couple of time, but I think I am still missing something!

Is there a chance that a Macroflow expert might look into this!

Thank you so much again for answering so promptly!

Best regards.