Ashutosh Banerjee
Mechanical engineer. Writes the heating cost model behind this site.
Ashutosh Banerjee, known as Ash, holds a Bachelor of Technology in Mechanical Engineering from Sardar Vallabhbhai National Institute of Technology, Surat, conferred in August 2024 with a cumulative grade point average of 9.19 on a 10 point scale.
He built HeatPumpMath after looking for a heat pump running cost calculator that would show its assumptions, and finding that none of them did. Every calculator he tried returned a number without saying what efficiency it had assumed, which fuel price it had used, or what it had left out. Those three omissions are the difference between an answer and a guess, so this site states all three on every page.
Why a mechanical engineer
The question this site answers is a thermodynamics question before it is a money question. Whether a heat pump costs less to run than a furnace turns on the coefficient of performance of a vapour compression cycle, the heating value of the fuel it is being compared against, and the efficiency with which each machine converts what it consumes into heat delivered indoors. That is undergraduate mechanical engineering, and it is the training behind this site.
What that training also supplies is the habit of stating a model's assumptions and its error bounds rather than reporting a single figure as though it were measured. Most of the disagreements about heat pump running cost are not disagreements about arithmetic. They are two people using different assumptions without either of them having written those assumptions down.
What he writes about here
- Coefficient of performance, HSPF2, and how seasonal ratings differ from what a machine does in your climate
- Why electric resistance backup heat dominates cold climate running costs
- How EIA publishes residential fuel prices, and the ways those figures are commonly misread
- The price ratio at which a heat pump stops being the cheaper machine to run
Credential
What he has not done
Ash is based in India and writes about the U.S. residential heating market from public data. He has not installed a heat pump, has not lived through a Vermont winter, and has never held a manifold gauge. This site claims no lived experience it does not have, and where lived experience is the thing that matters it cites people who have it: the twenty eight households in the dataset published their own figures, and three working HVAC contractors were asked the same question directly.
What is offered instead is a model that can be audited line by line, sourced to figures anyone can pull themselves, with the computed results published as files so the arithmetic can be checked rather than trusted.
How he handles being wrong
Every error found so far is in the corrections log with the old figure and the new one, including a gas price mistake that had flipped the verdict in fifteen states. Corrections are the fastest way to improve this site, and they are welcome at banerjeeashutosh01@gmail.com.
Elsewhere
Conflicts of interest
Ash sells no heating equipment, takes no money from manufacturers, installers, or utilities, and holds no position in any energy company. He has no client, in this field or any other, whose interests this site serves. If that changes it will be stated here and in the editorial standards before it changes anything on the site.