Technical guides
Sizing, performance,
the engineering details.
Manual J math, cold-climate ratings, refrigerant cycles — the technical depth behind every install decision.
What are the ElectrifyAtlas technical guides?
In-depth engineering references on heat pump sizing (Manual J), cold-climate performance ratings, refrigerant cycles, and installer selection. Written to make homeowners informed buyers and to give contractors a shareable reference for clients asking how a system was sized.
About the guides
Both. The guides spell out Manual J math, AHRI certification reads, and cold-climate performance at a level that lets homeowners evaluate contractor bids on merit. Contractors use them to hand to clients who want to understand why the recommended system is right-sized.
Both. Decision guides compare ducted central against multi-zone mini-splits for common retrofit scenarios. Sizing guides work for either topology — Manual J is system-agnostic, and AHRI ratings apply to both.
Guides reference AHRI directory entries and DOE test procedures current as of 2026. When cold-climate performance standards change (e.g., DOE heat pump cold-climate specification updates), the affected guides are revised with a notice at the top.
No — the guides help you evaluate installer work, not replace it. Refrigerant handling requires EPA Section 608 certification, and most jurisdictions require a licensed HVAC contractor for permits. The guides make you a smarter buyer, not a DIYer.
Now size it
From theory to tons.
Plug your home's dimensions into the calculator for a fast Manual J approximation.