All figures are the manufacturer's published sound pressure level at 1 metre, on the lowest realistic real-world setting for that model. Grouped by roughly the size heat pump your home might actually need, same tiers as the Size Comparison tool.

Figures are taken from each manufacturer's published specifications and may vary by exact model, revision, or operating condition. They typically run louder on the coldest days, when the unit works hardest. Real-world in-situ noise can differ from lab-tested figures. The everyday comparisons on the scale (traffic, conversation, a fridge) are approximate, illustrative reference points, not acoustic measurements. Always confirm the real number with your installer, and see our FAQ on choosing a quieter model.