Research & Comparison Methodology

HeatPumps.wiki separates heat-pump research into five questions:

1. What does the building need?
2. What can the equipment actually deliver?
3. What does the complete project cost?
4. What incentives genuinely apply?
5. Can a competent local contractor install and support it?

A product brochure answers only part of that.

1. Building Load Comes First

We do not recommend heat-pump tonnage from square footage alone.

For full-system sizing, we point readers toward ACCA Manual J load calculations and manufacturer performance data.

This prevents a nominal tonnage label from being confused with actual heating capacity at design conditions.

2. We Separate Seasonal and Point-Condition Efficiency

We use:

• SEER2 for seasonal cooling efficiency
• HSPF2 for seasonal heating efficiency
• EER2 for cooling efficiency at a defined condition
• COP for heat delivered per unit of electricity at a defined condition

For cold climates, we also evaluate low-temperature heating capacity.

3. Cold-Climate Evaluation

Current ENERGY STAR Cold Climate criteria are used as a minimum qualification reference.

That currently includes:

• 5°F COP
• 5°F capacity retention
• HSPF2
• SEER2
• control-verification requirements

We still tell readers to compare equipment at their local design condition where data is available.

4. Product/Brand Comparisons

Brand/model comparisons use current manufacturer technical documentation for model-specific claims.

We distinguish:

• model specifications
• category requirements
• independent datasets
• our interpretation

We do not convert a manufacturer's own specification into "independent testing."

5. Cost Methodology

We use current published cost datasets as planning evidence.

Different datasets can disagree because their:

• markets
• project scopes
• customer populations
• system types
• collection methods

are different.

We present the source rather than averaging incompatible datasets into a fake precision number. Our cost directory separates installation, replacement, running, and repair costs.

6. Calculator Methodology

Our tools display their assumptions and run locally in your browser.

Examples:

Size calculator

• known-load mode converts actual design load into nominal equivalents
• square-foot mode shows an illustrative cooling-rule budget band, not a validated building-load recommendation

Savings calculator

• converts current space-heating-only fuel use into estimated useful heat
• applies user-selected seasonal COP
• compares operating cost

Cost calculator

• uses current source-backed project benchmarks
• does not infer local labor pricing

Rebate research

• prioritizes official program resources over a national eligibility assumption
• requires a source URL and verification date for any incentive record published on the site

7. Rebate Methodology

We prioritize:

1. DOE/federal
2. state energy agencies
3. utilities
4. municipal programs
5. manufacturer programs

Aggregator data can help discover a program but should not replace the official source when the official source is available.

8. Repair Content

Troubleshooting pages distinguish:

• safe homeowner checks
• symptoms requiring professional diagnosis

We avoid detailed high-voltage or refrigerant procedures.

9. Updating Content

Pages with volatile claims include a review/update date.

High-priority update classes:

• incentives
• tax rules
• product lineups
• efficiency standards
• pricing datasets
• discontinued models

10. How "Best" Is Determined

We do not use one universal proprietary score.

"Best" depends on the stated use case.

Examples:

• severe cold
• ducted retrofit
• compact installation
• premium humidity control
• ductless zoning

This is more useful than pretending one heat pump is objectively best for every U.S. home.

Corrections and Challenges

The site currently has no editorial submission channel. When evaluating a disputed methodology choice or claim, identify the source or calculation that supports a proposed correction and preserve its assumptions.