Estimation Of The Seasonal Demand For Cooling Based On The Short-Term Data

Abstract

In accordance with the requirements of the Directive on the energy performance of buildings [1], the energy performance of a building based on measurements may be an alternative for a computational one. In practice, it is important that the method should be relatively simple, based on short-term measurements in the real object. The annual heat consumption for heating and ventilation in reference climatic conditions is the basic component of the energy performance of buildings. The annual energy consumption for cooling and ventilation in public utility and office buildings in reference climatic conditions is the additional component. A b s t r a c t The paper analyzes the possibility of using the energy signature method based on the linear regression to determine the seasonal energy demand for cooling and ventilation in the office building. The "extended" energy signature method (H-m method) was described and applied. In accordance with Standard (EN 15603) the estimation of energy consumption for cooling can be performed for a period shorter than the entire season, but data range must be appropriate to obtain the correct accuracy of the results. The presented analysis concerns the uncertainty of estimation the seasonal demand for cooling and ventilation of the building based on monthly and 14-day data. The objective was to choose the shortest possible time period in order to obtain proper accuracy. It has been shown that the H-m method cannot be used to estimate cooling demand based on short-term (monthly or 14-days) data due to unacceptable uncertainty of results.S t r e s z c z e n i e W artykule przeanalizowano możliwość zastosowania metody sygnatury energetycznej opartej na regresji liniowej do wyznaczania sezonowego zapotrzebowania na energię do chłodzenia i wentylacji w budynku biurowym. Przedstawiono i zastosowano skorygowaną metodę sygnatury energetycznej (metodę H-m). Zgodnie z normą (EN 15603) szacowanie zużycia chłodu może być wykonywane dla okresu krótszego niż cały sezon, ale zakres danych musi być odpowiedni dla uzyskania właściwej dokładności wyników. Przedstawiona analiza dotyczy niepewności szacowania sezonowego zapotrzebowania budynku na chłód na podstawie danych miesięcznych i 14-dniowych. Celem był wybór najkrótszego możliwego do zastosowania metody okresu czasu, w którym uzyskuje się odpowiednią dokładność. Wykazano, że metody H-m nie można zastosować do szacowania zapotrzebowania na chłód na podstawie danych z krótkich okresów (miesięcznych, czy 14-dniowych), ze względu na nieakceptowane niepewności uzyskanych wyników.K e y w o r d s : Cooling; Energy demand; Energy performance; Energy signature; Linear regression; Office building.

Case Study of Thermal Diagnostics of Single-Family House in Temperate Climate

“…determination of seasonal energy demand for cooling based on short measurements was also shown [38]. On-site measurements of energy consumption for heating and DHW installations were presented in [39,40].…”

“…On-site diagnostics of mechanical ventilation systems and of cooling sources for air conditioning systems in office buildings were also presented in [36,37]. The determination of seasonal energy demand for cooling based on short measurements was also shown [38]. On-site measurements of energy consumption for heating and DHW installations were presented in [39,40].…”

Comprehensive On Site Thermal Diagnostics Of Buildings – Polish Practical Experience

“…H-m method is based on linear regression between H-which is the ratio of the average power delivered to the building in a given day to the difference of internal and external temperature, and the value of m which is a "meteorological" variable defined as the ratio of the solar irradiance to the difference of internal and external temperature, according to EN 15603:2008). In the paper [13] the possibility of using the H-m method in the office building was analyzed. It has been shown that the determination of energy consumption for cooling in the cooling season is possible only based on the cooling power measurements in the building in the entire cooling season.…”

On-Site Thermal Diagnostics Of Cooling Sources For Air Conditioning Systems In Office Buildings

“…As a result, there has been a need for on-site diagnostics of air conditioning installations, which should include energy efficiency assessments whether it meet the requirements of the building. [4,7,8] and in the current paper, • the on-site the diagnostics of indoor environment quality, the results are presented in [4,9], • the measurement based drawing up of energy performance certificates, the results are presented in [4,[10][11][12][13]. Full diagnostics is understood as a combination of inspection and diagnostic measurements.…”

“…Results of the cooling source diagnostics were used to determine the energy performance of a building based on measurements [13].…”