Pianos are extremely sensitive instruments.
An ideal environment for a piano would be a temperature and humidity controlled room which is away from any sunlight.
In reality it is unlikely that you would have such a room in your house. So, where possible, try to keep your piano away from radiators, air conditioning vents or any place where there are changes in temperature. For more information, contact Gideon the Piano Tuner in Finchley. I cater to clients across London.