We’ve begun our second week of live online sessions of the National Home Performance Conference. Last week the focus was on our individual and collective responses to the COVID-19 pandemic. This week we’ll cover some of the more traditional aspects of home performance. It’s probably a good time to take a break from pandemics and focus on the day to day work that has made life better for countless people and will continue to do so post-pandemic—and we hope even more so.
Matt Golden, CEO of Recurve, in Mill Valley, California, began his home performance career as co-founder of Recurve—he calls it “Recurve 1.0” and his current company “Recurve 2.0)—a home performance contracting company. He shared his experience and the wisdom he gained in a decade helping run a company focused on individual homes, as a software designer, and now as a consultant to discuss, Finding the Potential in Building Performance to Maximize Grid Value, Climate Benefits, and Better Cost-effectiveness
Matt learned, among other things, that it was difficult to track progress house to house; and that, when contractors are paid through “deemed savings”, its hard to know what actual savings are realized. And some houses that we retrofit to be more comfortable may not save energy or may actually increase energy use. He used his own home as an example. “I’d like to get air conditioning, but it will make my energy bills go up.” Matt suggests we look at the biggest users, where there is the biggest chance of creating big savings; and that we look to aggregating data to provide reliable information on how much energy is saved and at what time of day, or, how the energy use effects utility load profiles. This is the kind of information of interest to utilities and this is what investors will pay for.
Right now, about one-third of the utilities in the United States have made some commitment to reduce greenhouse gases (GHG) in order to stem the worst effects of Global Climate Change. As an industry, we can align the goals of building performance with the goals of utilities, investors, and those combatting climate change. By learning the real value of what we do we can focus our efforts wisely, as well as create and manage profitable businesses.
Keith O'Hara, of Eco Performance Builders in Concord, California, and Dan Perunko, co-owner of Balance Point Home Performance, Grass Valley, California, teamed up to discuss Mini Split Heat Pump Systems, Ductless and Ducted Part 1: Design, Layout and Zoning; and Mini Split Heat Pump Systems, Ductless and Ducted Part 2: Installation Best Practices and Commissioning. These guys have been friends for a while, and it shows!
In Part 1 Keith and Dan discussed the design and layout of ducted and ductless mini-split heat pumps. Like many things, the goal of the homeowner, the home itself, and the climate determine what is the best system to use. A big challenge for any system though is correct layout and sizing. With ductless mini-splits and multiple indoor and outdoor units, it is hard to control temperature in different rooms in a house. For example, sometimes a room will call for less cooling or heating than the minimum output of the system and you can end up using energy on rooms that aren’t demanding any heating and cooling at all. And in relatively dry California, where both panelists live and work, a home’s latent heat load is small. But in other climates it is a big factor in system design.
Asked about the three most common design errors he finds in working on HVAC systems in homes, Joe says these are: systems that are designed and installed on sight, oversized equipment, and no consideration given to the building enclosure.
In Part 2, Keith discussed the prevalence of refrigerant leakage and how much it can worsen Global Climate Change. He quoted from the book with the humble title, Drawdown: The Most Comprehensive Plan Ever Proposed to Reverse Global Warming, edited by Paul Hawken (published by Penguin Books, 2017). Leaked refrigerant contributes more to carbon equivalent GHG emissions (89 Gt) than on shore wind turbines negate emissions (85 Gt). So, Keith is very concerned about testing for refrigerant leaks on the HAVC systems his company installs and retrofits. “Most of my calls from homeowners who want their HVAC systems to work have refrigerant problems.” Then there are the problems with systems delivering about half the heating and cooling that they are rated for.
This is only a sample of the kind of information and food for thought and discussion you get by participating in the live events, or by watching recordings of those sessions. See the “Live Sessions” page for access. Other “on-demand” presentations will be available for a year beginning May 18.