public enum HVACSystemSize: Double, Codable, Equatable, Sendable {
  case one = 1
  case oneAndAHalf = 1.5
  case two = 2
  case twoAndAHalf = 2.5
  case three = 3
  case threeAndAHalf = 3.5
  case four = 4
  case fourAndAHalf = 4.5
  case five = 5
}