Can I use it without the chimney?

The chimney helps comply with certain distance restrictions found in urban areas. If you can place the hive more than 5 metres from a neighbour, or you have a divider (hedge, low wall, etc.) taller than 2 metres, you can install it without the chimney. Using the chimney can slightly reduce the amount of honey produced, since bees need more energy to leave the B‑BOX to forage for flowers.