Tag Archives: HVAC

The Psychrometric Chart Explained

Green Building

The Psychrometric Chart Explained

Originally published on June 13, 2018 by BNP Media through the Building Enclosure Blog. It is one of the intimidating charts for any building design professional: the psychrometric chart. At first blush, the “psych chart” looks very complicated. There are layers of axes and curved reference lines. However, a closer examination will reveal that – at its essence – the chart is visually conveying the answers to two related questions: How much sensible (dry-bulb) heat is in the air? (See….

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Gauging the Seasonal Efficiency of Air-Source Heat Pumps

Green Building

Gauging the Seasonal Efficiency of Air-Source Heat Pumps

Originally published on February 23, 2015 by BNP Media through the Walls & Ceilings Blog. Recently, I was working on an energy model for a high-performance housing prototype. Mostly, I apply energy modeling to non-residential structures. I did not have a coefficient of performance (COP) at my fingertips for the air-source heat pump (ASHP) used in my baseline model. In this context, the COP is the ratio of the amount of thermal energy (heat) delivered by a heat pump to….

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