Spatio-temporal distribution of thermal parameters in sheep house with slatted floor in winter

Abstract: The slatted floor was widely used in a sheep house for cold winter at present. The objective of this study was to investigate the spatial and temporal distribution of thermal parameters in a closed sheep house with a slatted floor in winter in a cold region. Two sheep houses with slatted floors (House A and B) with the same structure were selected in the north-south direction. The manure outlet of House A was not blocked, where that of House B was blocked. The temperature and humidity in the upper space of two slatted floors were continuously and dynamically measured in time and space (horizontal and vertical). A two-month test was carried out to measure the key environmental parameters. An infrared thermal imaging device was used to systematically analyze the temperature in the lower space of the slatted floor. The results showed that: 1) There was no difference in the average daily Temperature (Ta) or Relative Humidity (RH) between two houses (P>0.05), with the Ta of -3.07 ℃ and the RH of 38.08% in House A. However, there was an increasing trend in the Ta at the fecal outlet of House B, compared with House A, revealing an average Ta of -2.76 ℃ and a maximum Ta difference of 1.05 ℃ between two houses. 2) the Ta at 1.5 m above floor (T1.5) was higher than that at floor (T0) (P>0.01) in the vertical distribution. Specifically, the difference was 1.71 ℃ in House A, and decreased to 1.35 ℃ in House B. The average T0 in House B increased by 0.49 ℃, compared with House A. In addition, the lowest T0 in House A was -7.40 ℃, and the T0 was lower than -3 ℃ for 16.0 h every day. 3) In the horizontal direction, the Ta on the south side in both houses was higher than that on the north side. s lower than -3 ℃ for 16.0 h every day. 4) From horizontal, the south-side Ta in both houses was higher than the north-side. Particularly at the slatted floor, the difference between north- and south-side Ta reached to 0.59 ℃ in House A and 0.39 ℃ in House B. Moreover, the horizontal difference of Ta was obvious in the east-west direction, showing the west-side Ta was the lowest. Particularly on the west-north side, the horizontal temperature Ta difference reached 2.11 ℃ in House A, whereas, the difference decreased to 0.92 ℃ in House B. Consequently, the Ta at the outlet on the north-west side was the lowest in both houses, where the T0 and T1.5 in House B increased by 1.33 and 0.47°C, respectively, compared with House A. 5) In infrared thermography of enclosure under the slatted floor, the Ta difference was 2.1 ℃ between the slatted floor and ditch bottom in House A, while the difference in House B dropped to 0.7 ℃. Moreover, the side wall Ta of the ditch in two houses was the lowest among all structures under floor, with -9.3 ℃ in House A and -7.2 ℃ in House B. 6) The wind chill temperature (WCT) in House B was higher than that in House A (P>0.05). The wind speed at the fecal outlet of house A was higher (P>0.05) than that of House B, reaching 0.682 m/s. The fecal outlet was sealed in a slatted-floor house, further increased the indoor Ta, while decreased both horizontal and vertical Ta difference. The finding can provide strong support to the airtightness and heat preservation at the fecal outlet when the slatted floor was used in the sheep house.