Utilization of Multiple Short Heat Consumption Measurement Method for Diagnostics of Heat Source of Existing Building: Part 2: Practical use of the Method

S t r e s z c z e n i e W artykule zaprezentowano określanie wymaganej mocy cieplnej dla diagnostyki źródła ciepła istniejącego budynku mieszkalnego. W celu zaproponowano wyznaczanie wymaganej mocy cieplnej budynku z wykorzystaniem oryginalnej metody kilkukrotnego krótkiego pomiaru zużycia ciepła w istniejącym budynku mieszkalnym z wentylacją naturalną. K e y w o r d s : Heating, ventilation; Insitu thermal diagnostics; Heat source; Thermal power of the building; Thermal characteristics; Existing residential building; Heat consumption measurements. 2/2018 A R C H I T E C T U R E C I V I L E N G I N E E R I N G E N V I R O N M E N T 99 A R C H I T E C T U R E C I V I L E N G I N E E R I N G E N V I R O N M E N T The Si les ian Univers i ty of Technology No. 2/2018 d o i : 1 0 . 2 1 3 0 7 / A C E E 2 0 1 8 0 2 7 H . F o i t , P . L u b i n a , D . T ą t a 100 A R C H I T E C T U R E C I V I L E N G I N E E R I N G E N V I R O N M E N T 2/2018 ing, compact heat distribution node located in the cellar of the building. The heat node is a two-stage switch adapted for central heating and hot water supply. In heated rooms there are no heating cost allocators or other devices that allow you to determine the amount of heat consumed for heating the rooms. 3. DETERMINATION OF THE VALUES FOR THE VERIFICATION OF THE METHOD. In order to verify the method there were determined heat loss coefficients for the buildingH TV,H rz T,H rz V, and the number of the ventilation air changes nV according to the equations from part 1. The average daily flow of internal heat gains Z was also determined. Appropriate balance equations were obtained on the basis of the measurement data for 10 days moderately varying in daily temperature, selected from the group of 20 measurement days, mostly in February 2012. The selection of 20 days was the result of available and complete measurement data for these days. Therefore optimum days (days with a significant difference in midday temperature) are not selected for the analysis of the short-term in-situ measurement method, but the ones that may frequently occur in the practical application of the method (precise weather conditions cannot be predicted on measurement days for the method). The external climate data (air temperature, relative humidity of the air, wind velocity and direction, total and dispersed solar radiation intensity on the horizontal plane, temperature of the horizon) were received from the measurements of the meteorological station that lies 10 km away from the building. The consumption of the heat supplied to the installation, the flow and return temperatures of the mains and the installation part resulted from the registration of these quantities made by means of the heat meter mounted in the node. The building's heat gain from solar radiation through the windows was determined using the SOLAR program [2]. After a preliminary analysis of the results of the check, it was assumed that the average daily heat gains flux from solar radiation contains 3/4 of the gains resulting from the radiation transmitted through the windows in the examined day and 1/4 of gains from radiation from the previous day. The estimation of an internal profit to determine the efficiency of use of the gains was conducted on the basis of the unit profits referred to 1m2 of the usable area of the building, accepted as 4.5W/m2 The average internal gains flux adopted to estimate the efficiency of gains use was 7kW, and the average daily exchange of air was 0.3h-1 for the same purpose. The efficiency of the node and installation (node, transmission, emission and regulation of heat supply) was determined on the basis of the heat losses of the node components and the installation, and the heat flux taken from the heat network as well as the efficiency of regulation and the adopted emission. Based on dependencies (23, 26), estimated U-values for partitions and windows and known building dimensions, the temperature t ** e was determined. The efficiency of using internal gains was estimated on the basis of the total heat gains of the building: u+ Z+ Z,tr (from people, appliances and solar radiation) and heat demand for compensating the heat loss of the building (penetration through partition walls and ventilation) dem, using dependency: where: u – measured, average utility heat flux for considered day, W, Z – average internal heat gains flux for considered day, W, Z,tr – average for considered day, differential heat flux from solar radiation through transparent components, The method check was performed by calculating the average monthly required power of the node on the basis of H T determined by the multiple measurement method and comparing the determined volume with the average monthly heat flux delivered to the building, measured by the heat meter at the thermal node. 4. DETERMINATION OF LOSS COEFFICIENTS AND THE NUMBER OF VENTILATION AIR CHANGES The average daily values of the used measurements for the group of 20 days accepted for analysis were presented in Table 1. When omitted in generalized balance equation the arrangement (12 – part 1) tr Z Z u dem e u , 1 φ φ φ φ η + + − − = (36) ( ) ( ) ) ( ) ( ) ( ) ( ) (