And give thy kinsman his due and the poor and the son of the road; and waste not wastefully, for the wasteful were ever the devil’s brothers; and the devil is ever ungrateful to his Lord.—Qur’an 17:26 (trans. E. H. Palmer)
Programmable thermostats automatically reduce heating and cooling in your home when you do not need as much of one or the other. For example, in the summer you can adjust the temperature according to your work or vacation schedule. Hence when you are out, your house will get no or only minimal air conditioning. You can also set different temperatures for day and night. This is convenient and provides a comfortable temperature in your home. It also makes much sense to have different zones in your home. For example, you do not need to heat the bedrooms much in the winter or when some of them are not in use. Of course, it is possible to set the thermostat manually, but it is also easy to forget. You leave the house full of thoughts about where you are going, which leaves the heat or the AC running. Programmable thermostats help save energy, benefitting your wallet. But, much more important, the saving reduces energy consumption, which is essential for the environment on which we and all life depend.