What does Delta-T signify in hydronic balancing and why is it important?

What does Delta-T signify in hydronic balancing and why is it important?

• A. The temperature difference between supply and return water; it indicates heat transfer effectiveness and helps verify proper flow and load.
• B. The difference between outside air and indoor air temperature; irrelevant to balancing.
• C. The maximum allowed temperature in the boiler room.
• D. The delta in pressure across a valve; used to set valves.

Answer: (A)