# Modeling Heat Consumption of an Office Building During COVID-19 Restrictions
## 3 Case Study  
A multi-story building with 3471 m\({}^{2}\) of internal floor area and a typical geometry for offices in Omsk, Russia, was chosen for a base case study. Offices are open from Monday to Saturday; Sunday is a day off. According to the description of envelope performance, the considered building belongs to the archetype of a high-insulation house from the 2000s featuring heavy structures. The high-insulation case corresponds to a concept of the modern highly energy-efficient building (B-grade) and has been designed according to the national codebooks in 2012 with an annual heat demand of about 218 kWh/m\({}^{2}\). To compare, in Denmark, the yearly energy consumption of 160 kWh/m\({}^{2}\) is already associated with the low-insulation archetype and corresponds to buildings constructed in the 1980s, which are characterized by relatively poor energy performance [13]. All the studied scenarios were based on hourly and daily (weather-dependent) schedules created considering actual energy demand profiles in the Omsk DH system. The building is located in Omsk, Russia, a city within a continental climatic zone characterized by cold winters and moderately warm summers. The region experiences significant temperature variations, with annual sunlight hours averaging around 2000 to 2200 h, depending on specific meteorological conditions. The building is oriented with its longer facades facing east and west, optimizing daylight exposure for the office spaces during working hours. Nearby structures and vegetation are sparse, with no significant trees or buildings casting prolonged shadows on the facade. This unobstructed exposure to sunlight ensures that solar gains are a relevant factor for energy modeling and conservation strategies within the study. To compare, [PERSON] et al. [13] did not follow the case study approach and did not focus on the behavior of an office building. They presented a total of 144 different versions of the single-family house, which had been generated with variations of four building parameters. However, the same considerations, such as the thermal inertia of envelopes, internal heat gains, thermal performance of a building, and type of SH system, were under study in that paper. The U-values were constant at 1.31 W/mK for the wall and 0.75 W/mK for the roof and accounted for 0.75 W/mK and 5.20 W/mK for the floor and glazing, respectively. To compare with [PERSON] et al. [13], the U-values were assumed to depend on temperature but specifically fixed at 0.22 W/mK for temperatures below 16 \({}^{\circ}\)C, constant at 0.18 W/mK for temperatures above 28 \({}^{\circ}\)C, and vary linearly from 0.22 W/mK to 0.18 W/mK within the temperature range of 16 \({}^{\circ}\)C to 28 \({}^{\circ}\)C.  
Most offices have one exterior wall (up to 50.8 m\({}^{2}\)), with up to 60% of the window area. Skylights are only relevant for top-floor rooms as these are the only types of roofs exposed to the external environment. The building was assumed to have two types of offices, small and large, with total floor areas of 40 and 104 m\({}^{2}\), respectively. Thermal bridging at element junctions was 5.5 W/K. The number of taps in each bathroom was detailed in a building plan. The building was equipped with a range of measurement and monitoring equipment. The building DH substation had primary and secondary supply and return temperature sensors, all components of a Vzlyot TSR heat meter, each with an accuracy of \(\pm\)0.5 \({}^{\circ}\)C. A heat meter also had an in-built ultrasonic flow rate meter with an accuracy varying between 0.05 and 0.48 m\({}^{3}\)/h. The heat meter recorded the building's energy consumption, with a data resolution of 1 h. Regulation and control valves manufactured by Danfoss (AVTB series) were used for precise temperature management. The characteristics and manufacturers are aligned with standard industrial-grade components typically used for DH systems in similar applications. The offices also had sensors to monitor and control the indoor environment.