Babysense Video Monitor features a long range, so normally you should not experience range problems.
Babysense Video Monitor features a long range - 900 feet in open space. Please note that the performance in open space is different than in a residential unit, where you have numerous environmental disturbances. The open space measurement is the only method used for baby monitors, as each place of use is different. Babysense monitors should operate well in standard conditions.
Nevertheless, it depends on the distance between the first and second floors. Also, please take into account that objects that block line-of-sight between the transmitter (camera) and the receiver (Parent Unit), may reduce the range. Such objects could be: any large metal object, like metallic doors or reinforced concrete between the baby and parent unit.
The signal strength may also be reduced by other solid structures, like thick walls, or by radio or electrical equipment, such as cordless or mobile phones, TV, computers or dimmer switches. In order to minimize the environmental influences, it is recommended to keep the baby monitor (baby and parent units) at least 5ft away from these types of products.