Ground Source Heat Pumps (GSHP) and many Air-Source Heat-Pumps (ASHP) via “mini-splits” are almost always the most cost-effective options for multi-family building heating and cooling; and they have become even more affordable because of an act of Congress. It may be surprising, but the U.S. Congress passed legislation in February 2018 through the Bipartisan Budget Act of 2018 which reinstated the tax credit of geothermal heat pumps to § 25D of the Internal Revenue Code.
The property credit provides a 30% tax credit for residential systems (including multifamily properties up to 3 stories with central domestic water heater or up to 5 stories with individual domestic water heating) placed in service by 12/31-2019. It decreases to 26% between 12/31/19 and 1/1/2021 and 22% between 12/31/2020 and 1/1/2022. Significantly, the American Recovery and Reinvestment of 2009 repealed a previous limitation on the use of the credit for eligible projects which are also supported by “subsidized energy financing.” For projects placed in service after December 31, 2008, this limitation no longer applies.
With that news, Lightly Treading has been able to work on two multifamily projects which were/are built with high quality building science at their core which included Ground Source Heat Pump heating and cooling without a back-up boiler for heating nor back-up air-conditioning condensers for cooling. The first project, Solaire a multifamily project with its 252 units plus a clubhouse and outdoor swimming pool, was completed in 2015. The second project, Elements at Prairie Center project is nearly completed now (summer of 2018), both by C & A Companies, are examples of apartments which are built to meet the need for affordable living spaces for a wide spectrum of middle and working income tenants. They are most remarkable however by accomplishing this while also doing a wonderful job of delivering high performance. These market-rate spaces have or are achieving ENERGY STAR certification, and, in the case of Elements, it is also achieving compliance with EPA Water Sense certification.
Focusing on the ENERGY STAR certification, they have done so with:
· R-40+ cellulose attic insulation
· Thorough air-sealing including spray foam on the rim joists of each floor,
· Blown cellulose insulation (R-20) in the 2x6 walls constructed following the principles of advanced-framing
· ENERGY STAR windows (image below),
· R-10 slab-edge insulation
· All of this resulting in air-tightness with an average Natural Air Change/Hour rate of 0.17
· High-efficiency central domestic water heating equipment
They topped off all this high-quality construction specifications by installing Ground Source Heat Pumps (GSHP) with 320 feet of heat-exchange tubing in 10 vertical bore holes per building. These GSPH systems provide all the space heating and cooling for the 254 units at Solaire and 291 units at Elements at Prairie Center as well as common areas.It was the GSHP which has provided the defining detail which resulted in 175 units at Solaire in 2014 and 2015 and 78 units from the 5 completed buildings at Elements at Prairie Center in 2017 being eligible for the $2,000/unit federal tax credit for building at least 50% better than the 2006 IECC heating& cooling performance standards. This has meant $506,000 in tax credits for C & A companies thus far from these two projects! They will certainly earn more tax credits if Congress renews the law, which expired at the end of 2017.
Lightly Treading collaborated with C&A Companies and their GSHP consultant: Conald Frank with SMC Geothermal, to adjust the specifications before construction. We were then the 3rd party inspectors and quality assurance verifiers through construction of both of these projects.
Following the completion of Solaire, SMC Geothermal monitored one of the units; a 1040 sq. ft. 2 bedroom/bath with 2 people living in it who have been keeping their thermostat at 73 degrees in winter and 72 degrees in summer. Even with these settings being 5 degrees warmer in winter and 4 degrees cooler in the summer than is recommended, the unit has been averaging $8.67/month for heating or cooling! This is 61% better than the same unit built with the common practice heating/cooling system with a power-vented water heater (0.67 EF) and air-conditioning via a 13 SEER system delivering heat through a fan-coil and ductwork distribution system.
Since Solaire was built there have been even further advances in pump efficiency for both GSHP and ASHP, further improving potential savings by 10% or more for future projects. This coupled with the federal tax credits and substantial credits from United Power, the local electrical provider makes it MUST-DO to at least seriously evaluate GSHP & ASHP heating/cooling systems for every future multi-family project.
Contact Paul Kriescher (303-733-3078, x301 or firstname.lastname@example.org) at Lightly Treading to learn more and how we can evaluate the cost-effectiveness of a GSHP or ASHP system as part of an overall sustainability plan for your future project!