About Our Engineering Platform
Precision Hydronic Engineering Without the Sales Pressure
The Boiler Size Calculator platform was founded by independent chartered heating engineers frustrated by the widespread oversizing of residential boilers. Most commercial installer quote tools intentionally hide the underlying thermodynamics, using multi-step marketing funnels to sell oversized, expensive boilers.
Our Engineering Mission
Our mission is to provide 100% free, transparent, and mathematically rigorous sizing calculations for homeowners, heating engineers, architects, and landlords across both metric (kW) and imperial (BTU/hr) markets.
Key Calculation Standards We Adhere To:
- CIBSE Domestic Heating Design Guide: Chartered Institution of Building Services Engineers emitter standards and distribution losses.
- BS EN 12831-1: Energy performance of buildings — Calculation of design heat load.
- ACCA Manual J & Manual S: North American residential load calculation and equipment selection criteria.
- MCS Standards: Microgeneration Certification Scheme heat loss methodologies.
Technical Review Board
JD
James Davies, CEng MCIBSE
Lead Heating Systems Engineer & ReviewerChartered building services engineer with over 18 years in residential HVAC design, low-temperature emitter modeling, and Building Regulations Part L compliance.