We executed an evaluation on the energy performance of buildings under recommendations for Pandemic (COVID-19).
by Fernando Cabrera*
Introduction: During the COVID-19 pandemic, different official entities have given recommendations regarding the procedures for re-entry to buildings by their workers, which is why, from our perspective, we will analyze the impact (favorable or unfavorable) of these recommendations from global energy consumption.
We will take as a basis those given by REHVA (Federation of European Heating, Ventilation and Air Conditioning Association) in "How to operate and use facilities in the building to prevent the spread of coronavirus (COVID-19) (SARS-CoV-2) in the workplace", and to make comparisons, we will simulate a 10-story office building in the city of Bogotá in Colombia.
Scenario
By reducing the number of people working in order to achieve the recommended distance of 2 meters, this will reduce energy consumption by half.
Base Building
Generalities: The building taken as a study base is a building of 10 floors, where the first floor is considered as a Lobby of entrance to the building, there is additionally a block of elevators, bathrooms and stairs on each floor; finally, the rest of the floors are considered as offices of the open type.
Figure 1. Simple Three-Dimensional Model of the building
Characterization of the building
Geographic Location:
Bogotá: Latitude: 4.7
Longitude: -74.13
Elevation: 2458 m
Time Zone: -5
Schedule
Figure 1. Percentage of People on a normal day:
Figure 2. Percentage of Normal Daylight Utilization:
Figure 3. Percentage of Use of Electrical Equipment on Normal Day:
Figure 4. Percentage of Infiltration on Normal Day:
Relevant Data (Current Post COVID Gains and Densities)
- Heat gain per person: 132 W/people
- Occupancy density per Area (office): 0.018581 people /ft2
- Occupancy density per Lobby Area: 0.009290 people /ft2
- Lighting Density per Area (office): 2 W /ft2
- Lighting Density per Area (Lobby): 1.17 W /ft2
- Lighting Density per Area (Stairs): 0.54 W /ft2
- Equipment Density per Area (office): 0.355 W /ft2
- Equipment Density per Area (Lobby): 0.035 W /ft2
Relevant Data (Construction)
Exterior Walls
Ceilings
Floors
Glasses
Simulation
In our conventional building (Pre Covid) we have the following load profile:
Figure 2.
Some of the important considerations when performing the Post COVID simulation are the following:
The air conditioning systems do not change, so with 50% occupancy, the systems must adjust their operation to that gain and their energy consumption is subjected to analysis in this scenario.
We will not change our usage profile, nor lighting density, assuming that there is no dimerization of the systems
If there is a reduction in equipment consumption.
Figure 3.
Under this first scenario of decrease in occupancy our consumption would go from 975,581 kWh in the year to 624973.57 kWh. This is a 36% annual reduction in electricity consumption.
Next scenarios
Possible scenarios to consider for future studies
The implementation of 100% Outdoor Air systems, because the document suggests that the air is not returned to the machine, as well as the ignition of the systems prior to the use of the spaces
If an additional ventilation system is implemented that has filter boxes and accessories such as Ionization, plasma, UV lamps, what will this imply in energy consumption?
Model this characterization in other cities to analyze the feasibility of implementing these measures.
Author: Fernando Cabrera, Mechanical Engineer, FCK Engineering Consultant. (www.fckingenieria.com). Email: [email protected]
