A few months ago I wrote about air-source heat pumps (ASHPs) in cold climates, and I promised more info on how to select the right systems and get the best performance. Below are some things we’ve learned from our work with ASHPs in the Northeast; much of this is based on the results from a study supported by the DOE Building America program. To be clear, we’re talking about inverter-driven (variable-speed) heat pumps in residential applications during heating season. Cooling is certainly important also, but we’ve been more focused on the heating performance, especially at lower temperatures. Read more
In the first two entries of this series (Part One | Part Two), we explored advanced controls for electrically heated buildings; combined heat and power systems; upgraded atmospheric boilers and ventilation systems. For the final installment of SWA’s Favorite Multifamily Retrofits, we’ll examine the ins-and-outs of stand-alone energy storage. Read more
I’ll save the long-winded introduction and get straight to the facts. Based on New York City’s publicly available Local Law 84 (LL84) benchmarking data for 2015, hotels emit 32% more greenhouse gas (GHG) per square foot than the average for all buildings. I also want to qualify this by making a few statements about the data:
- There are 13,973 buildings on the Department of Finance list; of which 2,353 did not comply with LL84 or are not required to comply.
- We removed the outliers. Weather-normalized source energy use intensity (EUI) over 550 and under 100 (kBtu/ft2) typically indicates erroneous data. Most likely either the building’s benchmarking activities or report filed with NYC were completed incorrectly.
- A significant portion of the list comprises the buildings with erroneous data: 4950. Seems a little crazy, no? Leaving us with a good topic for another day….
- For clarity, that means we analyzed the remaining 6,654 buildings.
The good news – for the sake of this post – is that the hotel market had one of the higher rates of correctly reported compliance data. Out of 187 buildings, 143 reported with numbers that were in a normal range. The average for the sector however, reflects EUI and GHG emissions per square foot that are much higher than other similar building types. Multifamily buildings, for example, have an average of 42% lower GHG emissions/ft2 than hotels (see table below). Read more
In partnership with the District of Columbia’s Department of Energy & Environment (DOEE) and the Institute for Better Communities (IFBC), SWA is implementing DC’s first multifamily housing energy and water challenge.
What is the POWER DOWN DC Challenge?
POWER DOWN DC is a 4 month building-to-building, education focused competition in Washington, DC with a goal of empowering building residents and staff to change behavior and reduce overall energy and water usage. Residents compete as a building team against other apartment buildings to hit a reduction target and strive to make the greatest overall reduction.
Driving Savings through Friendly Competition
The basic concept is simple: bringing people together for friendly competition is more likely to encourage meaningful action than simply providing information about energy and water efficiency alone. By joining the competition, participants try to reduce their own energy and water use and help members of their apartment community do the same. Residents will be encouraged to make a commitment to efficiency and take simple steps every day that collectively will have a big payoff. Actions like turning off lights, fixing a leak, and taking shorter showers, multiplied across dozens of apartment units will have quick results. In DC, residential buildings make up 20% of total energy use and 23% of total water use. If all multi-family residents take action, we can save 83,000,000 kilowatt hours (KWH) of energy, 96,000,000 gallons of water, and $31, 400,000 dollars annually. Small steps = big savings.