Basil is installing a system in Toronto, Ontario where they are wide temperature variations. What is the TD of the system he's installing here where the outdoor design temperature is 20 f and the indoor design is 70 f

In places with cold winters, space heating systems have a fundamental role in buildings. Without them, indoor temperatures would quickly become unsuitable for human occupancy. The local weather is one of the most important factors when designing a heating system; if two identical buildings are developed in Miami FL and New York City, the heating load will be much higher for the NYC property.