10 Building Science Lies to Watch out for
This past week I learned the truth about another one of many building science lies. It's the first one in my list here. Having my eyes opened to that lie made think of some of the other ones out there. …
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My Undersized Mini-Split Heat Pump in a Heat Wave
You may recall that I wrote about my undersized mini-split heat pump a couple of years ago. It's undersized compared to both the heating and cooling loads, as you can see in the table below. I'll discuss the heating performance…
Make It a Mechanical Room, Not Just a Closet
In our HVAC design work, we get sent projects where the client sometimes wants the impossible. They've read enough to know they want the mechanical systems in conditioned space, so they put a tiny little closet somewhere in the house…
Introduction to Whole-House Electricity Monitoring
Last year I bought the Emporia Vue whole-house electricity monitoring system.* This past weekend, I finally installed it. The photo below shows my electrical panel with the monitor installed. Yes, it looks like a mess at the moment. The panel…
Air Conditioner Sizing: Load Calculations vs Rules of Thumb
It's time to revisit one of my favorite topics: air conditioner sizing. Many contractors use rules of thumb to decide what size cooling equipment to install. Usually, the rule is based on the amount of conditioned floor area, and contractors…
Five Fun Facts About Dew Point Temperature
The humidity is returning for the summer here in the southeastern US. And as you may know, I don't use relative humidity to gauge how humid the outdoor air is. Why? For starters, the humidity can get up to 100%…
Efficient Hot Water Delivery With a Simple Tool
Gary Klein, a guru of efficient hot water delivery, has been pushing for change in hot water distribution systems for a long time. In recent years, he and his colleagues have developed a great tool for quantifying the efficiency of…
Converting Heat Pump Capacity Between English and Metric
Heat pumps are riding a wave of demand and curiosity lately. With all the talk of electrification and decarbonization, heat pumps are in! We specify heat pumps in most of our HVAC design jobs at Energy Vanguard. We've got them…
Can Duct Sealing Lead to Condensation?
When can doing something good for your house turn into something bad? Hmmm. There are way too many answers to that question, so let me narrow it down. Is it possible to make your ducts more airtight, a good thing,…
The Ol’ Beer Can Pressure Crunch
Air has weight. Air can move things, like giant wind turbine blades. Air can also crush things. I first got to see the power of air in my introductory physics class in college. The professor, Dr. Jeffrey Trahan, showed the…