Optimizing Whole House Deep Energy Retrofit Packages: A Case Study of Existing Chicago-Area Homes

Abstract

Improving the energy efficiency of the residential building stock plays a key role in mitigating global climate change. New guidelines are targeting widespread application of deep energy retrofits to existing homes that reduce their annual energy use by 50%, but questions remain as to how to identify and prioritize the most cost-effective retrofit measures. This work demonstrates the utility of whole building energy simulation and optimization software to construct a "tool-box" of prescriptive deep energy retrofits that can be applied to large portions of the existing housing stock. We consider 10 generally representative typology groups of existing single-family detached homes built prior to 1978 in the Chicago area for identifying cost-optimal deep energy retrofit packages. Simulations were conducted in BEopt and EnergyPlus operating on a cloud-computing platform to first identify cost-optimal enclosure retrofits and then identify cost-optimal upgrades to heating, ventilation, and airconditioning (HVAC) systems. Results reveal that prescriptive retrofit packages achieving at least 50% site energy savings can be defined for most homes through a combination of envelope retrofits, lighting upgrades, and upgrades to existing HVAC system efficiency or conversion to mini-split heat pumps. The average upfront cost of retrofits is estimated to be ~$14,400, resulting in average annual site energy savings of ~54% and an average simple payback period of ~25 years. Widespread application of these prescriptive retrofit packages across the existing Chicago-area residential building stock is predicted to reduce annual site energy use by 3.7 × 10 16 J and yield approximately $280 million USD in annual energy savings.

A Method for Determining the Relationship Between Increasing Insulation and Potential Freeze Thaw Damage in Brick Masonry Walls

“…For the second set of insulation options in Table 6 which include polyisocyanurate board (PIR), polyurethane board with capillary active channels (IQ-T), aerated concrete (AAC) and calcium silicate (CaSi) the number of freeze thaw cycles (18)(19)(20)(21)(22)(23)(24)(25)(26) and freeze thaw resistance (67% to 75%) shows a relatively large difference. The insulation values between the options are also different, the largest difference between the set being the R7.69 of the (PIR) option and R2.27 of the (CaSi) option.…”

“…Similar energy savings benefits can be found in different brick masonry housing archetypes as well. Using prescriptive retrofit strategies for pre-1978 homes in Chicago a study was able to achieve 54% site energy savings using the whole building energy simulator BEopt [18] . In another study energy retrofit strategies were implemented onto Toronto Century, Century-semi (typically 2-storey or 3strorey) and War time (1-storey bungalow) masonry homes.…”

Advancing Energy Efficiency in Developing Countries: Lessons Learned from Low-Income Residential Experiences in Industrialized Countries

“…In the United States, energy audits alone can cost program implementers between $100-$600 before any improvements are made, and typically they include a list of prioritized measures that can cost an additional $1,000-$15,000, depending on needs (Fixr 2018). These types of whole-house retrofits can lead to deep energy savings (40% or more), but the cost might be prohibitive for low-income households unless funded through ratepayer, federal, or state funds (Leinartas and Stephens 2015). At the other end of the spectrum, prepackaged measures offer low-cost saving opportunities that can be deployed at scale but might offer less energy savings.…”

Sustainability and cost assessment of coastal vacation homes for energy retrofits

“…While many different types of buildings, including single family homes (Leinartas and Stephens, 2015), multifamily homes (Goldman et al , 1988), hotels (Karagiorgas et al , 2007; Xing et al , 2015), commercial (Hou et al , 2016) and office buildings (Dascalaki and Santamouris, 2002), etc., have been studied for energy-related research, a special category of homes, the vacation rental homes have not been given much consideration. Although these homes may be thought of as similar in nature to the average single family homes, the difference may be in their size.…”