New Home Construction & Performance Compliance
Integrating ThermoDrain into new residential construction is the most cost-effective mechanical upgrade available to meet strict IECC building codes, lower HERS® Index scores, and satisfy Net-Zero targets. Operating with zero moving parts, zero electrical power, and zero maintenance, this passive energy recycling system delivers lifetime utility savings and enhanced hot water capacity to homebuyers while protecting builder margins.
US Builder Portal: HERS Index & State Code Compliance
Drain Water Heat Recovery (DWHR) is the most cost-effective mechanical upgrade to drop RESNET HERS® Index scores, secure Section 45L Federal Tax Credits ($2,500–$5,000 per home), and meet aggressive IECC 2021/2024 state stretch codes. Explore hard-cost comparisons and certified HERS modeling parameters for the ThermoDrain TDX Series.
Secure Your 45L Federal Tax Credit ($2,500 – $5,000 per home)
To qualify for the $2,500 ENERGY STAR® or $5,000 DOE Zero Energy Ready Home (ZERH) federal tax credits, your HERS Index score must drop. As building envelopes tighten, domestic water heating has become the second-largest energy load in the home. A ThermoDrain unit preheats cold incoming water, instantly dropping a home's HERS score by 1 to 3 points, providing the exact margin required to pass federal certification modeling without blowing your framing budget.
State-Specific Energy Code Highlights
While DWHR improves HERS scores nationwide, several progressive states explicitly recognize or mandate Drain Water Heat Recovery in their building codes and utility frameworks.
Washington State (WSEC)
Under the Washington State Energy Code (Table R406.3), builders must accumulate strict energy credits for permitting. Installing a ThermoDrain directly awards mechanical points under the Water Heating options, allowing builders to avoid cost-prohibitive building envelope upgrades.
Massachusetts (Stretch Codes)
With the state's aggressive Specialized Opt-In Code demanding HERS 42 or lower, DWHR reduces the heavy electrical load on Heat Pump Water Heaters. Furthermore, the Mass Save® program frequently offers direct utility rebates to builders for DWHR installations.
Colorado (IECC Amendments)
Municipalities like Denver and Boulder have adopted strict IECC 2021/2024 amendments pushing Net-Zero readiness. In Colorado's cold climate, ThermoDrain drastically cuts peak winter water heating demand, securing compliance without upsizing electrical panels for heat pumps.
Cost Comparison: Dropping Your HERS Score by 1 to 3 Points
| Compliance Strategy | Typical Added Cost / Door | Framing & Structural Impact | Lifecycle & Maintenance |
|---|---|---|---|
| Triple-Pane Window Package | $5,500 – $11,000 | Heavy frames, structural bucking | 15–20 year seal warranty |
| Exterior Continuous Insulation (R-5+) | $6,000 – $9,500 | Extended jambs, rainscreen modifications | Inspection-critical detailing |
| High-Tier Heat Pump Water Heater | $2,500 – $3,500 | Draws ambient heat, cooling conditioned space | 10-year life, compressor noise, filters |
| ThermoDrain TDX Series | $750 – $1,150 installed | Zero framing changes. Fits in standard 3" chase. | 30+ year lifespan. Zero moving parts. |
National HERS Rater Modeling Reference Inputs
Provide this table to your RESNET HERS Rater (for Ekotrope, REM/Rate, or EnergyGauge). To ensure maximum point reduction, the system must be installed in an Equal Flow configuration (preheated water feeds both the water heater and the cold inlet of the primary shower mixing valve).
📊 Energy Advisor Deep Dive: Read our complete breakdown on modeling the TDX3240B in Ekotrope & REM/Rate to maximize Section 45L tax credits.
| Parameter |
TDX Compact TDX3240 (Starts at $185 USD) |
TDX Builder Pro TDX3350 (Code Standard / 45L) |
TDX Net-Zero Pro TDX3615 (High-Yield ZERH) |
|---|---|---|---|
| Approx. Equipment Cost | ~$185 USD | ~$325 USD | ~$525 USD |
| Target Application | Low-clearance, budget-focused builds | Production single-family baseline | DOE ZERH, luxury multi-bath |
| Nominal Stack Height | 24.0 inches (61.0 cm) | 35.0 inches (88.9 cm) | 61.5 inches (156.2 cm) |
| Drain Stack Diameter | 3.0 inches (76 mm) | 3.0 inches (76 mm) | 3.0 inches (76 mm) |
| Connection Standards | 3/4" (19 mm) PEX (ASTM F1807 / F1960) | 3/4" (19 mm) PEX (ASTM F1807 / F1 |