feat: Begins manual d core models.

Sources/ManualDCore/CoolingLoad.swift

@@ -0,0 +1,13 @@
+import Foundation
+
+public struct CoolingLoad: Codable, Equatable {
+  public let total: Double
+  public let sensible: Double
+  public var latent: Double { total - sensible }
+  public var shr: Double { sensible / total }
+
+  public init(total: Double, sensible: Double) {
+    self.total = total
+    self.sensible = sensible
+  }
+}