The spring is usually the season when people have the least concern for the indoor comfort in their homes. Winter cold fades, summer heat hasn’t arrived yet. The heating system turns off, the air conditioner has yet to turn on.
But this is an important time for HVAC systems—because during the period when they’re aren’t needed as much is the ideal time to have them maintained. Just the way that amusement parks use the off-season to shut down favorite attractions for the regular maintenance required to keep the rides running well and safely.