Don't guess — know what your home needs
An oversized system wastes money on equipment and energy. An undersized one can't keep up. Get the real numbers before you talk to an installer.
Single Room
How much heat your room loses in winter and gains in summer — calculation for your AC unit
Takes ~5 minutes
Ideal for
Planning to buy an AC? Get the exact cooling and heating load and request a quote from installers
- Cooling & heating load calculation
- EN 12831 engineering standard
- Instant results — no signup required
Full Report
Size your heat pump for the entire building — every room, one report
One-time payment · Takes ~10 minutes
Ideal for
Choosing a boiler, heat pump, or AC — exact kW per room
- Whole-building heat loss & heat gain
- Detailed breakdown per room
- PDF report for your installer
- Shareable link
Why does this matter?
Most homeowners rely on their installer's estimate. But installers often oversize equipment "just to be safe" — which means you pay more for the unit, more for materials, and more on every energy bill for years to come. If the system is undersized, you're left with rooms that never get warm enough.
Our report gives you the exact heating and cooling load for every room, calculated to EN 12831 and ASHRAE engineering standards. Walk into any installer meeting with the numbers — and make sure you get exactly the right equipment, nothing more, nothing less.