COP and EER Calculator

Calculate energy efficiency of heating/cooling systems.

The COP and EER Calculator is a free tool designed for construction professionals and enthusiasts. Calculate energy efficiency of heating/cooling systems. Instantly get the required materials broken down by purchase units, with an option to add a wastage allowance so you never run short on site.

Inputs

Result

How to Use This Calculator

Measure the room area in m² and clear ceiling height in meters.
Indicate the predominant orientation of the space.
Enter the thermal transmittance values for walls and roof (U in W/m²K).
Enter interior and exterior design temperatures.
Click 'Calculate' to get thermal load and recommended equipment power.

Frequently Asked Questions

How many BTU do I need per m²?

As a rule, estimate 100–150 W/m² (350–500 BTU/m²) for hot climates and 75–100 W/m² for temperate climates. This calculator accounts for orientation and insulation.

What is the difference between heating and cooling calculations?

For heating, heat loss in winter is calculated (ΔT between indoor and outdoor). For cooling, summer heat gain is calculated, which includes solar radiation.

How often should air conditioning equipment be serviced?

Filters should be cleaned every 3 months and replaced annually. A full service (refrigerant, heat exchanger) should be done every 2–3 years by a certified technician.