Sites that review home equipment normally establish trust by owning the equipment. This one cannot, does not, and is not going to pretend otherwise. What it offers instead is a method you can audit, and this page describes it plainly enough that you can catch us if we fail to follow it.
We do not own or test the products we write about. We reproduce what manufacturer manuals, published standards and federal guidance actually say, link every source, and show the arithmetic in the open so you can check it. Where two published sources disagree, we publish both and say so rather than picking the one that reads better.
No page here issues an engineering determination of its own. That is not modesty, it is the whole editorial method, and it produces a specific shape of sentence.
| What we will not write | What we write instead |
|---|---|
| You need a 40 A breaker and 8 AWG wire. | Harvia's manual specifies 40 A for 8 kW at 240V [linked]. The NEC continuous-load rule would give 45 A. Confirm it with your inspector. |
| This filter removes lead. | NSF/ANSI 53 covers lead reduction. Ask for the performance data sheet line that names lead, because certification is per contaminant, not per product. |
| This purifier covers 1,500 sq ft. | At 200 cfm, that claim works out to one air change an hour. EPA's own table implies about five. |
Manufacturer documentation, published standards and government guidance contradict each other more often than anyone admits, because they are written by different people for different purposes. Nobody is lying; they simply never meet. Finding those seams needs reading, not a laboratory, which is why a site with no products can do it.
Four we have documented so far, each checkable against the sources on its page:
Every calculator here runs entirely in your browser. There is no server, no account, no email capture and no analytics inside them — whatever you type stays on your device because there is nowhere for it to go. Each one shows the arithmetic it used, links the source of every constant, and marks any figure that is an assumption rather than a published value.
They are also free to embed on any site, with no permission needed and no attribution required beyond the link the embed already carries. A calculator that reproduces published figures and shows its working is only worth anything if people can check it, and that is easier if it travels.
Every page carries a review date and a source list. When a manual we cite is revised, a standard changes or a jurisdiction adopts a new code edition, we revise the page and change the date. If you find a figure here that does not match the source we linked, that is a defect and we want to know about it — being checkable is the entire proposition, and a site that resents corrections has abandoned it.
Affiliate links. If you buy something after following one, we may earn a commission at no additional cost to you. That disclosure sits above the fold on every page rather than in the footer, because a disclosure you have to hunt for is not a disclosure.
The conflict of interest that creates is real and worth naming: we are paid when you buy, which is a reason to tell you to buy. The defence against it is structural rather than a promise about our character. Every recommendation traces to a published source you can open in another tab, the arithmetic is on the page, and several pages here end by telling readers that the answer is a range hood, or finding the moisture, or a laboratory test — none of which pay us anything.