Skip to main content
Tag

temperature reset

Specious Beliefs in Code Gods

By Energy Rant No Comments
I received a lot of feedback on last week’s Code Compliance Villains, which described blunders that occurred as part of my high-efficiency boiler installation. Such mistakes would likely erode 50% of the estimated savings claimed in a deemed savings document. Efficiency issues included: Improper outdoor temperature sensor location giving false inputs to the controls. High boiler water temperature setpoints resulting in lower operating efficiency. Heat exchanger piped in parallel, rather than counterflow, resulting in higher boiler water temperatures and less efficiency. The problem with efficient equipment and energy codes is that equipment is tested in the lab, and hands are...
Read More

Indestructible Code Compliance Villains

By Energy Rant No Comments
In case you missed last week’s post, you’ll need to go back and review the setup for this week’s demonstration of code challenges and mistakes. To summarize, I have an installed ENERGY STAR-qualifying 95% AFUE[1] (efficient) boiler with a brazed plate heat exchanger, hot water reset control, and a variable firing rate that ranges from 20% to 100%. That firing range is even better than code requirements. The system is a duded-out energy code breaker in theory. Let’s look at what went wrong in order. I have a Nest cam in the backyard and a Nest thermostat for the boiler....
Read More

Code Compliance Setup – A Boiler Project

By Energy Rant No Comments
Over the last forty years, computers have become orders of magnitude more powerful while they have become much easier to use. When I was in college, mainframe IBM computers owned all the muscle of computations. I was terrified of coding and wanted nothing to do with that. Thankfully, graphical interfaces emerged to make it easy. I even conquered graduate school with Engineering Equation Solver (“do it with EES” as its creator, Professor Sandy Klein, used to say). Energy codes went completely the opposite direction, from a simple document from the IBM mainframe era (1989) to a behemoth that would break...
Read More