The present invention relates to techniques for adjusting environment, and has an object to obtain a favorable sleeping state while looking at an image projected on a display such as a television. To attain the object, an environment adjustment system mainly includes an air conditioner (1) and a display (2). The air conditioner (1) includes a temperature adjustment control part (11), a transmission part (12), and a temperature adjustment part (13). The display (2) includes a projection control part (21), a reception part (23), and a projection part (24). The temperature adjustment control part (11) causes the transmission part (12) to transmit a control instruction (S21) to the display (2). The control instruction (S21) causes the display (2) to control the color tone of an image. The reception part (23) receives the control instruction (S21) transmitted from the air conditioner (1), and the projection control part (21) causes the projection part (24) to display an image with a color tone having a calming effect based on the control instruction (S21). After that, the temperature adjustment control part (11) causes the temperature adjustment part (13) to lower ambient temperature.
