Analysis of environmental conditions in two different Compost Bedded Pack Barn systems for dairy cattle

R.R. Andrade¹, I.F.F. Tinôco², F.A. Damasceno³, D.A. Valente², C.E.A. Oliveira², V.C. Oliveira², G. Rossi⁴ and M. Barbari⁴

¹Federal University of Goiás, Department of Biosystems Engineering, College of Agronomy, BR74690-900, Goiânia, Brazil
²Federal University of Viçosa, Engineering Department, BR36570-000 Viçosa,
Minas Gerais, Brazil
³Federal University of Lavras, Engineering Department, BR37200-000 Lavras, Minas Gerais, Brazil
⁴University of Florence, Department of Agriculture, Food, Environment and Forestry, Via San Bonaventura 13, IT50145 Firenze, Italy
*Correspondence: matteo.barbari@unifi.it, rafaella.andrade@ufg.br

Abstract:

The objective of this study was to analyse and compare the thermal environment of dairy cattle facilities in an open compost bedded pack barn (CBP) with natural ventilation and closed CBP (without thermal insulation) and climate control system. The research was conducted in a property located in Zona da Mata, Minas Gerais, Brazil. During the summer and for different periods of the day, the following average environmental variables observed inside the facilities were measured: dry bulb temperature, relative humidity and Temperature and Humidity Index (THI). The results were submitted to an analysis of variance to determine the significance of the variables in the different treatments. It was found that the closed and climate control system CBP promoted greater control of the facility’s internal microclimate, registering smaller thermal amplitudes and a greater reduction in the animals’ exposure time to stressful thermal conditions, compared to the CBP with natural ventilation. However, during summer afternoons, comfort indices indicated moderate stress. It is concluded that the closed CBP, regarding the analysed variables, indicated potential use, provided that a careful study of the climate of the region is carried out before implementation, the factors related to the ambient conditioning and better insulation of the construction are adjusted. The climatic variables inside the open CBP indicated a high stress condition for the animals, suggesting the placement of positive pressure fans and sprinklers properly distributed in the feed alley, to guarantee benefits to the entire area of the animal housing.

Key words:

animal welfare, Housing systems, livestock farming, mechanical ventilation, thermal environment

Mechanical ventilation with a heat recovery system in renovated apartment buildings

E. Kamendere¹,*, A. Zandeckis¹, A. Kamenders¹, J. Ikaunieks² and C. Rochas¹

¹Institute of Energy Systems and Environment, Faculty of Power and Electrical Engineering, Riga Technical University, Kalku street 1, LV-1658 Riga, Latvia; *Correspondence: edite.kamendere@rtu.lv 2Ekodoma Ltd., Noliktavas Street 3, LV-1010 Riga, Latvia

Abstract:

Renovation of existing buildings offers a great opportunity to reduce energy consumption, but often it also reduces indoor air quality, as buildings which were originally designed for natural ventilation are made highly air tight. A solution to the problem would be a mechanical ventilation system, but several problems are experienced when implementing it – no place for installing air ducts, cold air inflow or additional energy needed for incoming air preheating. Ventilation using heat recovery units is the one method out of many other energy saving measures. The advantage of using heat recovery units is energy saving, and as a result, savings on costs of the operation of the ventilation system. This paper describes the renovation carried out in 4-storey apartment buildings. In the course of the study, two buildings were analysed, both belonging to the series buildings of the Soviet Era (103 series), built in 1970 using the same materials, the same construction solutions. The renovation was carried out by one company, using the same materials and the same renovation principles for both buildings. The only difference after the renovation is that a new centralized mechanical ventilation system with a heat recovery unit is installed in one of the buildings, while in the second building the natural ventilation system is preserved. The arrangement of the mechanical ventilation system is rather innovative as the ventilation ducts in the building for fresh air supply are integrated into the facade’s insulation layer and enter the living room through the wall directly behind heating radiators. The main questions studied in the course of the research are the efficiency of the mechanical ventilation system heat recovery, the building’s air tightness, and the overall system efficiency.

Key words: