Insulation R Value

{
  "airFilmsIncluded": true,
  "asOf": "2026-10-11T14:31:36.699Z",
  "degraded": false,
  "disclaimer": "Screening signal computed from the named public source. Not financial, legal or investment advice; provided as is. Verify at the source before acting.",
  "framing": {
    "cavityR": 11.2,
    "effectiveCavityLayerR": 8.058,
    "framingFraction": 0.25,
    "framingR": 4.38,
    "lostToFramingPercent": 28.1
  },
  "heatFlowBtuPerHour": 3788.8,
  "heatFlowWatts": 1110,
  "layers": [
    {
      "layer": "drywall",
      "r": 0.45,
      "source": "table",
      "thicknessInches": 0.5
    },
    {
      "layer": "sheathing",
      "r": 0.6,
      "source": "given R",
      "thicknessInches": null
    }
  ],
  "nominalRIfNoFraming": 13.7,
  "notChecked": [
    "installation quality: gaps, compression and air leakage can cut a batt's real R-value by a quarter or more",
    "moisture, aging and temperature effects (polyiso loses R in the cold; cellulose settles)",
    "…2 more"
  ],
  "reasons": [
    "Series layers add: R_total = sum of R. A cavity with studs is combined in parallel: 1 / R_eff = (1 - f) / R_cavity + f / R_framing.",
    "R-value is resistance to heat flow (higher is better); U = 1 / R; heat flow Q = area x temperature difference / R."
  ],
  "source": "computed locally",
  "summary": "Assembly R-10.6 (U 0.095) with framing, against R-13.7 if the cavity insulation ran unbroken; framing removes 28.1% of the cavity layer's value. Heat flow through 1000 sq ft at 40 F: 3789 BTU/h.",
  "totalR": 10.56,
  "uValue": 0.0947,
  "verdict": "COMPUTED"
}

# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i 'https://home-energy-calc.x402tookit.com/insulation-r-value?areaSqFt=1000&cavity=fiberglass+batt%3A3.5&deltaTF=40&framingFractionPercent=25&includeAirFilms=true&layers=drywall%3A0.5%3B+sheathing%3A0.6r%3B+siding%3A0.6r'

# x402 v2 sends the challenge base64-encoded in the PAYMENT-REQUIRED header (v1 sends it in the body).
# To read the header:
curl -sS -g -o /dev/null -D - 'https://home-energy-calc.x402tookit.com/insulation-r-value?areaSqFt=1000&cavity=fiberglass+batt%3A3.5&deltaTF=40&framingFractionPercent=25&includeAirFilms=true&layers=drywall%3A0.5%3B+sheathing%3A0.6r%3B+siding%3A0.6r' \
  | grep -i '^payment-required:' | cut -d' ' -f2 | tr -d '\r' | base64 --decode

// npm i @x402/fetch @x402/evm viem
import { wrapFetchWithPayment, x402Client } from "@x402/fetch";
import { registerExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";

// Pays at most $0.02 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.02" });
registerExactEvmScheme(client, { signer: privateKeyToAccount(process.env.EVM_PRIVATE_KEY) });
const pay = wrapFetchWithPayment(fetch, client);

// Not sure it's safe to pay? ToolVet checks it first for $0.005. Pay for that from a separate
// client: this one is capped at $0.02 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fhome-energy-calc.x402tookit.com%2Finsulation-r-value
const res = await pay("https://home-energy-calc.x402tookit.com/insulation-r-value?areaSqFt=1000&cavity=fiberglass+batt%3A3.5&deltaTF=40&framingFractionPercent=25&includeAirFilms=true&layers=drywall%3A0.5%3B+sheathing%3A0.6r%3B+siding%3A0.6r");
console.log(res.status, await res.text());

# pip install "x402[requests,evm]"
import os
from eth_account import Account
from x402 import x402ClientSync
from x402.http.clients import x402_requests
from x402.mechanisms.evm import EthAccountSigner
from x402.mechanisms.evm.exact.register import register_exact_evm_client

# Pays at most $0.02 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.02"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))

with x402_requests(client) as session:
    res = session.get("https://home-energy-calc.x402tookit.com/insulation-r-value?areaSqFt=1000&cavity=fiberglass+batt%3A3.5&deltaTF=40&framingFractionPercent=25&includeAirFilms=true&layers=drywall%3A0.5%3B+sheathing%3A0.6r%3B+siding%3A0.6r")
    print(res.status_code, res.text)