The 28th home has officially met the Thousand Home Challenge! The POS Dream House, nestled in the Sierra Nevada foothills, is the first house in Nevada County and the eleventh home in California to meet the Challenge.
Gavin Healy and Elizabeth Dieter bought their 1880’s Victorian home in 2006.Since then they embarked on major remodeling/retrofit effort that included making structural repairs, insulating the home’s foundation, walls, and roof and totally revamping the mechanical, plumbing and electrical systems. The project has served as a living laboratory for Balance Point Home Performance with the performance of the home’s systems extensively submetered.
In November 2015, Balance Point Home Performance removed the natural gas AO Smith Vertex water heater and replaced it with a Sanden split system CO2 heat pump water heater (GAU-A45HPA) and matching 80 gallon stainless steel tank (HP31555D). This Sanden CO2 installation will be monitored by the Bonneville Power Administration and Washington State University this coming year. Info on past product evaluation results are posted here. The Sanden CO2 HPWH will be introduced to the US market as soon as it gains UL approval.
Using OPTION B, with the gas combi heating system, the home’s 1000 Home Challenge threshold was originally 7,570 kWh/year. They narrowly missed the target with the annual site energy use of 7,812 kWh. In the year since the Sanden CO2 HPWH provided space and water heating the annual site energy use dropped to 3,923 kWh! With 100% electric heat the OPTION B threshold is now 5,264 kWh/year, and Gavin and Elizabeth easily met the Challenge. Even with a warmer heating season last year, a reduction of over 50% of their total household site energy use from one intervention is very impressive. Stay tuned for the case study that details the fine-tuning that Gavin performed to optimize the combi system’s performance.
Attched is a graph showing the home’s pre (Dec. 2013 - Nov. 2014) and post (Dec. 2014 - Nov. 2015) energy performance compared to the 1000 Home Challenge thresholds.
Thanks for your encouragement and time for putting this together!
Best Gavin Healy
Wow. Spectacular usage. I'm pumped about CO2 heat pumps. =) I emailed John Miles of Sanden last week, UL listing is expected first quarter this year. They hope to bring up to 60,000 BTU models to market, enough to tackle most homes I work on in Cleveland. Way to go, Gavin!
I'm curious how close a DER I worked on came to the 1000 Home Challenge. 2000 sf, 24,000 cubic feet, 14,500 kWh. We don't have good before utilities, unfortunately. HERS dropped from 208 to 49.
I need to also know the zip code, occupancy and heating fuel use to calculate your OPTION B threshold.
44234 (Hiram OH), 3, and 100% electric. What will likely disqualify it is that it's now a commercial building, it's the environmental studies building now for Hiram College. Having an idea of what usage is required will help me understand if a client home has a shot at making it in the future, though. Thanks!
Best way to understand the 1000 Home Challenge thresholds is to sign up for the Intro to the 1000 Home Challenge webinar, this Friday, Jan 15, 1 - 2:30 Eastern time. Attached is our 1000 Home Challenge threshold calculator with the imputs from your building. For the building you described the OPTION B threshold is 7,072 kWh/year (site energy). OPTION B does not use pre-existing use. just inputs - ZIP code, occupants, floor area (FFA, not CFA),# of households, single family or not, and source of energy for heating. Given these inputs, OPTION B estimates the energy use of a very high performance building and houshold for space heating, cooling, water heating, and everything else. The threshold is the sum. You can use renewables to help meet the threshold.
What is interesting is that in the case of the POS Dream House, which used the CO2-based heat pump water heater in a combi system application, there was a significant reduction from the base year in both space and water heating (to be expected), but also "everything else". It would be great if Gavin would wiegh in here. The credit for the optimization of the space hearting distribution system should go to Balance Point Home Performance. The Sanden system is a split system - an outdoor heat pump plumbed to a water heater. There are many options, both forced air and hydronic, for getting the desired distribution of heat for space heating. However, doing this well, with care to optimize performance and efficiency is both an art and a science. In the POS Dream House, submonitoring provided the feedback to optimize the system performance..
Thanks, Linda! I am going to sic my client on it, they are one PV system away from meeting the challenge, it's one of 3 homes that I've removed the gas meter from so far. With PV, all would be good candidates. The retrofits are not truly 'deep' but they are substantial, case studies to come later this year.
To be clear, projects must have residential-type occupancy. Interested parties should participate in our Intro webinar, which is held every month. Register on the 1000 Home Challenge website (www.Thousand HomeChallenge.org) - :How to Join.
This project won't qualify, then. But 2 other ones could. I signed up for the webinar, I'm supposed to be traveling to Detroit then, I'll try and listen in!
Very impressive usage. Congrats Gavin and Elizabeth! Looking forward to the case study. Thanks Linda for all that you do.