1. What is Gas Boiler Efficiency?

Definition: Boiler efficiency measures how effectively a gas boiler converts the energy in fuel into usable heat.

Purpose: It helps homeowners and engineers evaluate boiler performance, compare systems, and identify potential energy savings.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( \eta \) — Efficiency percentage (%)
• \( Q_{out} \) — Useful heat output (kW)
• \( Q_{in} \) — Energy input from fuel (kW)

Explanation: The ratio of useful heat output to energy input, expressed as a percentage.

3. Importance of Boiler Efficiency

Details: Higher efficiency means lower fuel costs and reduced environmental impact. Modern condensing boilers achieve 90-95% efficiency, while older models typically range 70-85%.

4. Using the Calculator

Tips: Enter both heat output and energy input in kW. Energy input should be equal to or greater than heat output (efficiency cannot exceed 100%).

5. Frequently Asked Questions (FAQ)

Q1: What's considered good efficiency for a gas boiler?
A: Modern condensing boilers: 90-95%, Older non-condensing boilers: 80-85%. Below 80% is considered poor.

Q2: How can I improve my boiler's efficiency?
A: Regular maintenance, proper sizing, installing thermostatic controls, and upgrading to a condensing boiler.

Q3: Why can't efficiency exceed 100%?
A: It would violate energy conservation laws. Some condensing boilers may appear >100% efficient when calculated differently (using lower heating value).

Q4: How do I find Q_out and Q_in values?
A: Q_out can be measured from heat production, Q_in is typically listed in boiler specifications (based on gas consumption).

Q5: Does this account for seasonal variations?
A: No, this calculates instantaneous efficiency. Seasonal efficiency is typically lower due to standby losses and varying loads.