THE HAYFIELD HOUSE

A Homeowner's Quest for Sustainable Building

Category: Air source heat pumps

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Air source heat pumps / Design / Heating / Insulation / Lessons Learned / Performance Metrics / Sustainable Building

It’s Important to Measure the Performance of Your Net-zero House. — I’m glad I did.

Measuring the performance (“EUI”) of your zero net-energy house is important. There is a saying, “You can’t manage what you don’t measure”. Without measuring, you don’t know how energy efficient your house is. Fortunately, I measured and found out my house wasn’t performing as expected. What did I measure? What did I find? And how did I fix the problem? The standard metric to measure the performance of a net-zero house is to calculate the energy-use intensity (“EUI”). As a refresher as to what EUI is and how to measure it, click here. Ideally, the EUI for a zero net-energy should be below15, and definitely below 20. The EUI for THE HAYFIELD HOUSE is about 15, but I wish it was even lower.– I’ll explain...

Air source heat pumps / Design / Lessons Learned

Use Outputs from Energy Modeling Software with Caution

The building of a net-zero house requires the forecasting of both the energy production and energy demands of the house. There are computer software models that can be used to make these forecasts.  However, these models can have issues.   Forecasting energy production (at least for solar panels) is generally quite accurate. However, the forecast for the energy demand of a house have high error ranges.  Part of the problem is the difficulty of predicting how an owner will actually use the house.  For example, one owner might be frugal in his energy use, while the other owner turns up the heat to 75 degrees. Over-all, the models have a wide error range with a bias to over-estimating energy use.  For example, Applied Energy Volume...