1. What is a Heating and Cooling Size Calculator?

Definition: This calculator estimates the required HVAC system size based on the building's heating/cooling load and system efficiency.

Purpose: It helps HVAC professionals and homeowners determine the appropriate system capacity for optimal performance and energy efficiency.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• Size — Required HVAC capacity (tons)
• Load — Building's heating/cooling load (BTU/h)
• Efficiency — System efficiency rating (SEER for cooling, HSPF for heating)

Explanation: The building load is divided by the system efficiency to determine the appropriate HVAC system size.

3. Importance of Proper HVAC Sizing

Details: Correct sizing ensures energy efficiency, proper comfort levels, system longevity, and prevents short-cycling or insufficient capacity.

4. Using the Calculator

Tips: Enter the building load in BTU/h (from Manual J calculation or rule of thumb), and system efficiency (default SEER 14). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: How do I find my building's load?
A: Perform a Manual J calculation or use 20-25 BTU per sq ft for cooling in moderate climates.

Q2: What's the difference between SEER and HSPF?
A: SEER measures cooling efficiency, HSPF measures heating efficiency (heat pumps).

Q3: What's a typical efficiency rating?
A: Standard efficiency is 14 SEER, high efficiency is 16+ SEER, and 8-10 HSPF for heating.

Q4: Why is proper sizing important?
A: Oversized systems short-cycle, reducing efficiency and comfort; undersized systems can't maintain temperature.

Q5: How do I convert tons to BTU/h?
A: 1 ton = 12,000 BTU/h (the calculator automatically converts the result to tons).