Editorial Policy

Who writes this site

btuwise is published by Honeygoat GmbH and edited by Christoph Ballmer, who is responsible for the content. The team's background is web development, data and content — it builds calculators and research-based buyer's guides. The people behind the site are introduced on the About page.

Being straight about that matters more than sounding authoritative: btuwise is a research and software publisher, not an HVAC contracting business. Nobody on this team is a licensed HVAC contractor, a professional engineer, or a licensed financial adviser. What the site contributes is transparent method and carefully sourced numbers — the load calculation that binds your installation, and the quote that binds your budget, come from a licensed professional.

Where the numbers come from

• Capacity and efficiency specs — manufacturer specification sheets, submittal data and published performance tables (BTU ratings, SEER2, HSPF2, rated capacity at low ambient temperature), together with AHRI-listed performance data where available.
• Sizing factors — the BTU-per-square-foot baseline and the climate, ceiling height, insulation, sun-exposure, occupancy and kitchen adjustments follow long-established HVAC rule-of-thumb practice, applied in the open so you can see each step. They approximate an ACCA Manual J calculation; they do not replace one.
• Cost ranges — a synthesis of contractor-published pricing, national and regional cost surveys, retail equipment pricing, and the ranges that actually recur across multiple independent sources. Where sources disagree we say so and give the range rather than a false single figure.
• Incentives and regulation — primary sources: IRS guidance on the Energy Efficient Home Improvement Credit, ENERGY STAR certification criteria, EPA Section 608 rules, and the utility or state program in question.
• Running cost — the calculator applies your own electricity rate to the system's rated efficiency. It is arithmetic on your inputs, not a claim about your bill.

How the calculators are built

All four calculators — BTU sizing, installed cost, running cost and financing — are our own code, running entirely in your browser. That has two consequences worth stating plainly.

• The method is visible. Each tool shows the factors it applied and how it reached the result, so you can check the reasoning rather than trust a black box.
• The math is tested. The underlying factors live in a single data file and the calculations are verified against worked examples before a tool goes live, and again whenever the factors change.

The financing calculator uses standard amortization — the same formula a lender uses — on the amount, APR and term you enter. It is a payment estimator, not a loan offer, and no APR shown on this site is an offer of credit.

How recommendations are chosen

The "best" pages rank equipment on published, checkable criteria: capacity range, SEER2 and HSPF2 efficiency, documented performance at low ambient temperature, whether the system is genuinely homeowner-installable, zone support, warranty terms and street price. Each pick states what it is best for, because the honest answer to "what is the best mini-split" depends on the room, the climate and the budget.

Two rules apply to every recommendation:

• A commission never buys a placement. No manufacturer, retailer, contractor network or lender can pay to be listed, ranked higher, or described more favourably. Where a partner relationship exists, it is disclosed, and it has no bearing on the ranking.
• Sizing comes before shopping. A correctly sized budget unit outperforms an oversized premium one, so the site sizes first and recommends second — including when the conclusion is that a cheaper unit is the right one.

Recommendations are based on published specifications, manufacturer documentation and aggregated owner and installer feedback. btuwise does not operate a physical test lab and does not carry out its own instrumented performance testing, and the site does not claim otherwise.

Advertising and independence

btuwise is free to read because advertising, affiliate commissions and referral fees pay for it. Paid links carry an "Ad" label and a sponsored link attribute, ad slots are labelled "Advertisement", and the full commercial picture is set out in the Advertising & Affiliate Disclosure.

Advertisers have no sight of, and no say over, editorial content before publication.

Accuracy, corrections and updates

Prices, product lines, efficiency ratings and incentive programs change, and pages are reviewed and revised as they do — with particular attention to cost ranges and to any figure tied to a tax credit or utility program.

When something is wrong, it gets corrected rather than quietly removed: substantive corrections are made to the page itself. If you spot an error — a spec that has changed, a cost range that no longer matches your market, a calculation that looks off — send it to info@btuwise.com. Corrections from readers and installers are genuinely welcome, and a message naming the page and the problem is enough.

The limits of this site

Stated once, clearly, because it matters more than anything else on this page: every figure btuwise produces is a planning estimate. Size your system with a licensed HVAC contractor's Manual J calculation, budget it from written quotes, and have refrigerant work done under EPA Section 608 certification and electrical work by a licensed electrician. The Terms of Use set this out in legal form.