Where Heat Pump Design Gets Fun – Manual S and Beyond with Eric Fitz

Amply is hiring! We’re looking for an awesome Senior iOS Engineer to join our small but mighty team. If you are anyone you know is interested, check out our job posting to learn more and apply. https://info.amply.energy/sr-mobile-engineer-may-2025 ---------------------------------------- Most contractors know about Manual S. Few really use it. In this episode of The Heat Pump Podcast, Amply co-founder Eric Fitz walks through Manual S in plain English—breaking down what matters, what doesn’t, and how to design heat pump systems that actually deliver comfort all year long. Using his own home in Portland, Maine as a case study, Eric explains how to interpret extended performance tables, avoid oversizing, and balance real-world tradeoffs like auxiliary heat and low load cycling. The episode also introduces Amply’s free Manual S spreadsheet tool—designed to take the math and guesswork out of equipment selection. This is a must-listen for anyone who wants to size systems with confidence, especially in cold climates where comfort and efficiency are harder to get right. Key Learnings: Manual S made simple: Four ratios are all you need Eric walks through them step by step.Low-load cycling is real: Why oversizing hurts comfort and efficiency.Forget label tonnage: It’s all about the actual performance curves.Cold-climate trade-offs: How to balance auxiliary heat and seasonal loads.New free tool: Amply’s spreadsheet automates the math – grab it here.Local expertise wins: Knowing your regional climate and electricity rates gives you a major edge. Timestamps [00:00] - Intro & Free Manual S spreadsheet [01:35] - Meet Eric Fitz & today’s goal: demystify Manual S [03:48] - What makes heat pump design so hard (and fun!) [07:00] - Why your Manual J must be aggressive [10:15] - Comfort first, efficiency second [20:00] - The 4 Manual S ratios (and how to use them) [28:15] - Getting the right performance data [36:00] - Real-world trade-offs: auxiliary heat, cycling, efficiency [44:30] - Kilowatt hours vs. energy costs: What matters to homeowners [52:00] - Wrap-up: tools, tradeoffs, and where to go from here Resources for Smarter Heat Pump Design: NEEP database: https://ashp.neep.org/#!/Amply Manual S tool: https://info.amply.energy/heat-pump-manual-s-free-toolACCA Manual S: https://www.acca.org/standards/technical-manuals/manual-s Follow the Hosts: Ed Smith: https://www.linkedin.com/in/ed-smith-5aa8716Eric Fitz: https://www.linkedin.com/in/ehfitz/Amply Energy Website: https://www.amply.energy/Amply Energy YouTube: https://www.youtube.com/@amplyenergyAmply Energy Facebook: https://www.facebook.com/amplyenergyAmply Energy Instagram: https://www.instagram.com/amply_energy/