# Honeybee Tutorial 3: Energy Analysis with Open Studio

Related Tutorials

Important to note:

To continue with the Energy Analysis you should have, firstly, created a HB model based on your design following the steps described in: Honeybee Tutorial 1: Creating the HB model

For this tutorial, you can check about the general example description in: Tutorial Introduction

## Step 1C: Set Constructions & Program Type

In order to run the energy simulation with Open Studio, you should, firstly, define the thermal properties of the materials that compose each building component. Follow the steps described in:

Additionally, the internal energy loads and their corresponding schedules, related to the occupancy of the space, should be set. See a more detailed description in:

## Step 2C: Compose the HB model for the Energy simulation

#### Assign Construction set & Program type

Assign the Construction Set & Program Type to the HB Room

In this step, the HB Room as created in: Step 3A: Compose the HB Room will be used.

1. Connect the ‘constr_set’ result of the HB ConstructionSet component (as created in Honeybee Intermezzo 12) in the ‘_constr_set_’ input of the HB Room.

2. Connect the ‘mod_obj’ result of the HB Apply Setpoint Values component (as created in Honeybee Intermezzo 13) in the ‘_program_’ input of the HB Room.

Assign the Internal Mass

The internal thermal masses refer to the effect of furniture or other massive building components in the energy simulation.

1. Create a HB- Energy » Basic Properties » HB Internal Mass component.

2. In the ‘_construction’ input, connect the ‘constr’ result of the HB Opaque Construction component that corresponds to the material of the internal mass.

For this example, you should connect the result from the “Door” construction as created in Honeybee Intermezzo 12, since we are going to calculate the internal mass of wooden furniture.

Important to note: Each component corresponds to the internal mass of a specific material. If you want to calculate internal masses of more than one material, you should create different components.

3. Create a Params » Input » Number Slider component to set the ‘_geo_or_area’ input, related to the surface (in m2) of the internal mass. In this example, you should set it to 10.

#### Set Natural Ventilation parameters

Important to note:

A. To define which windows are operable, you should have set the ‘operable_’ input to True, when creating the respective HB Aperture. Otherwise, the natural ventilation will not be calculated for these apertures.

B. In this example, we are not going to calculate the mechanical ventilation. However, if you want to add it to your design, you can find the respective components on the HB-Energy » HVAC subpanel.

Apply Natural Ventilation Parameters

1. Create a HB- Energy » Loads » HB Ventilation Control component in order to set the temperature setpoints for natural ventilation, i.e. the interior and exterior temperature range between which natural ventilation can happen.

2. Create 4 Params » Input » Panel components and set:

-Min interior temperature (‘min_in_temp_’): 22

-Max interior temperature (‘max_in_temp_’): 25

-Min outside temperature (‘min_out_temp_’): 15

-Max outside temperature (‘max_out_temp_’): 30

Important to note: You should ensure that the temperature range for natural ventilation is well between the overall setpoints for heating and cooling of the room as set in Honeybee Intermezzo 13. If they overlap, two contradictory functions (e.g. heating and natural ventilation bringing cold air from outside) may happen simultaneously. Thus, the min interior temperature of natural ventilation should be approximately 2 degrees higher than the heating setpoint and the max interior temperature should be 2 degrees lower than the cooling setpoint respectively.

3. Create a HB- Energy » Loads » HB Window Opening component.

4. Connect the ‘rooms’ result of the HB Internal Mass component to the ‘_rooms’ input.

5. Connect the ‘vent_cntrl’ result from the HB Ventilation Control component to the ‘_vent_cntrl’ input.

6. Create a Params » Input » Number Slider component and connect it to the ‘_fract_area_oper_’ input. It defines the fraction of the window surface that is actually operable. For this example set it to 0.5 (50% - value for a sliding window).

#### Compose the HB Model

Composing the HB Model with the energy parameters assigned

1. Create a Honeybee » Create » HB Model component.

2. Connect the ‘rooms’ result from the HB Window Opening component to the corresponding input.

Important to note: You should connect only the ‘rooms’ result this time. If you connect any of the other inputs (e.g. some additional orphaned faces in the ‘faces_’ input), it will create an error in the energy simulation.

#### Visualize & Check the HB Model

Visualize & Check the attributes assigned

In order to quickly check the attributes that are assigned to each face:

1. Create a Honeybee » Visualize » HB Label faces component.

2. Connect the ‘model’ result from HB Model to the ‘_hb_objs’ input.

3. Create a HB-Energy » Basic Properties » HB Face Energy Attributes component and select the attribute what you will show. For this tutorial, select the Construction attribute.

4. Create a Params » Input » Panel and connect it to the ‘sub_faces_’ input. Write True if you want to label the window instead of the opaque surfaces.

## Step 3C: Create & Run the Open Studio simulation

#### Import the Weather Data

Importing the EPW weather data for Amsterdam

You can import and extract the respective EPW weather data by following the steps in this section of the Ladybug Light Analysis tutorial (only this sections is needed for this tutorial and not the whole Ladybug Light analysis!) :

Following these steps (and selecting the Amsterdam weather data in the EPW map), you should have the components as shown in the image.

It is important to make sure that the EPW file we are using is of good quality and does not miss any data. See how you can check the quality of the EPW file in:

Important to note: In case you have already imported the EPW weather data for the Point-in-Time simulation or the Annual Daylight simulation, you can use the same component.

#### Set the Simulation Parameters

Parameters for Open Studio Energy Simulation

1. Create a HB- Energy » Simulate » HB Simulation Output component.

2. Create a Params » Input » Panel component and set it to True. Connect it with all the ‘zone_energy_use_’, ‘hvac_energy_use_’, ‘gains_and_losses_’, ‘comfort_metrics_’, ‘surface_temperature_’, ‘surface_energy_flow_’ inputs.

Important to note: These inputs correspond to the values which are going to be calculated through the energy simulation. If you do not set an input to True, then the respective values are not going to be calculated and you will get no result for them after the simulation.

3.Create a HB- Energy » Simulate » HB Simulation Parameter component.

4. Connect the ‘sim_output’ result of the HB Simulation Output component to the ‘_output_’ input.

5. Define the north of the location. In this tutorial, the north vector will be set along the positive direction of the Y axis, facing the opposite direction of the aperture normal. Create a Vector » Vector » Unit Y component and connect the ‘unit vector’ result to the ‘north_’ input.

6. In the ‘_run_period_’ you can define the analysis period for the simulation. You can follow a similar approach as the one described in Honeybee Intermezzo 9. In this tutorial, we will run the simulation for the whole year (default option).

7. By browsing your mouse over the rest of inputs, you can see which other parameters can be specified. You can find the respective auxiliary components for each of them on the HB-Energy » Simulate subpanel.

#### Run the Energy Simulation

Set-up for Open Studio Energy Simulation

1. Create a HB- Energy » Simulate » HB Model to OSM component.

2. Connect the ‘model’ output of the HB Model component to the ‘_model’ input.

3. Connect the ‘epw_file’ output of the LB Download Weather component to the ‘_epw_file’ input.

4. Connect the ‘sim_par’ output of the HB Simulation Parameter component to the ‘_sim_par_’ input.

5. Create a Params » Input » Boolean Toggle component and connect it to the ‘_write’ & ‘run_’ inputs of the HB Model to OSM component.

6. Double-click the Boolean Toggle component in order to set it to ‘True’ and run the simulation.

## Step 4C: Post-processing the results

Important to note: Some of the components may give ‘Empty Generic Data parameter’ as a result or appear to have a value of 0 although this does not seem realistic. The problem is either that the respective components are not added in the first phase (for our example, there is no HVAC system added in the HB model so the mechanical ventilation load will appear as 0) or that the respective calculation is not set to "True" on the HB Simulation Output component.

Here, the values regarding heating & cooling are going to be extracted, as well as the lighting & equipment energy needed in kWh, the heat loss / gain due to natural ventilation and the solar & internal heat gains.

Important to note:

A. The values regarding heating will always be positive and the values regarding cooling will be negative.

B. In this example, the heating & cooling loads refer to the total energy that needs to be added or removed from the room. In case there was a detailed HVAC system added, it would refer to the total electric energy needed for it.

1. Create a HB- Energy » Result » HB Read Room Energy Result component.

2. Connect the ‘sql’ output of the HB Model to OSM component to the ‘_sql’ input.

3. Create a HB- Energy » Result » HB Thermal Load Balance component.

4. Connect the ‘model’ output of the HB Model component to the ‘_rooms_model’ input.

Important to note: Connect the HB model component as it was created it in Step 2C: Compose the HB model for the Energy simulation.

5. Connect the ‘cooling’, ‘heating’, ‘lighting’, ‘electric_equip’, ‘people_gain’, ‘solar_gain’ and ‘nat_vent_load’ results of the HB Read Room Energy Result component to the respective inputs of the HB Thermal Load Balance component.

6. Create a Ladybug » Visualize Data » LB Hourly Plot or a Ladybug » Visualize Data » LB Monthly Chart component to visualize the data per hour or per month respectively. Connect the ‘balance’ or ‘norm_bal’(normalized by the floor area) result to the ‘_data’ input.

You can see the resulting Map by clicking on the LB Hourly Plot or LB Monthly Chart component. The graph will appear on your Rhino scene.

If you want to bake the graph: Right-click on LB Hourly Plot/LB Monthly Chart » Bake.

#### Zone Sizing

To define the necessary equipment capacity, it is more common to use the heating & cooling loads calculated for the Heating & Cooling Design day, i.e. the days that refer to the worst case scenario in terms of the building’s energy needs.

Heating & Cooling per Design Day - Graphs

1. Create a HB- Energy » Result » HB Read Zone Sizing component.

2. Connect the ‘zsz’ output of the HB Model to OSM component to the ‘_zsz’ input.

3. Create a Ladybug » Visualize Data » LB Hourly Plot component and connect the ‘cooling_load’ or ‘heating_load’ result to the ‘_data’ input.

You can see the resulting Map by clicking on the LB Hourly Plot component. The graph will appear on your Rhino scene.

If you want to bake the graph: Right-click on LB Hourly Plot » Bake.

Important to note: Since the values that we take this time refer only to the hours of one day, it only makes sense to use the LB Hourly Plot and not the LB Monthly Chart.

#### Thermal Comfort

Thermal Comfort Indicators - Graphs

These indicators refer to both the actual comfort (mean air temperature, mean radiant temperature - considering the radiant heat transfer from the human body - and mean relative humidity) and likely comfort (operative temperature - calculated taking into account all the aforementioned actual comfort indicators).

1. Create a HB- Energy » Result » HB Read Room Comfort component.

2. Connect the ‘sql’ output of the HB Model to OSM component to the ‘_sql’ input.

3. Create a Ladybug » Visualize Data » LB Hourly Plot or a Ladybug » Visualize Data » LB Monthly Chart component to visualize the data per hour or per month respectively. Connect the data from all the different results to the ‘_data’ input.

You can see the resulting Map by clicking on the LB Hourly Plot or LB Monthly Chart component. The graph will appear on your Rhino scene. If you want to bake the graph: Right-click on LB Hourly Plot/LB Monthly Chart » Bake.

#### End Use Intensity

End Use Intensity

It is an indicator of the energy efficiency and is calculated as the sum of all the energy needs of the building divided by the gross floor area. The acceptable values differ based on the use of the building.

1. Create a HB- Energy » Result » HB End Use Intensity component.

2. Connect the ‘sql’ output of the HB Model to OSM component to the ‘_sql’ input.

3. Create a Params » Input » Panel component and connect it to the ‘eui’ output. This will give you the total End Use Intensity Value.

4. Create 2 Params » Input » Panel components and connect it to the ‘eui_end_use’ and ‘end_uses’ output. These panels will give you the different end uses and the values that correspond to them.