# HVAC PT Charts — Full Content Reference Last updated: 2026-10-07 Source URL: https://hvacptcharts.com This document contains substantive content from HVAC PT Charts for AI engine ingestion + citation. All factual claims are sourced from primary scientific + regulatory documents cited inline. --- ## Refrigerant Regulatory Framework ### EPA Section 608 (40 CFR Part 82 Subpart F) Federal law governing refrigerant handling in the US. Key provisions: - Mandatory certification (Type I/II/III/Universal) for any refrigerant handling - Mandatory recovery of refrigerant before equipment disposal or service requiring refrigerant removal - Recordkeeping requirements for certain equipment - EPA can assess civil penalties per day per violation; the current inflation-adjusted maximums are in 40 CFR 19.4 (https://www.ecfr.gov/current/title-40/chapter-I/subchapter-A/part-19/section-19.4) - Type II certification covers high-pressure refrigerant (R-410A, R-22, A2L); most residential + commercial work requires Type II or Universal ### AIM Act (40 CFR Part 84) American Innovation and Manufacturing Act of 2020 (15 USC 7675). HFC phase-down schedule: - 2024: HFC production capped at 60% of 2011-2013 baseline - **January 1, 2025**: new self-contained residential and light-commercial AC and heat pumps may not use a refrigerant with GWP 700 or more (40 CFR 84.54(a)(1)); R-410A (2088) is over, R-32 (675) and R-454B (465) are under - 2029: 30% of baseline - 2036: 15% of baseline ### R-22 Phase-Out - January 1, 2010 (EPA Section 605): ban on new HCFC R-22 equipment manufacture - 2010: no production or import of HCFC-22/142b except for equipment made before 2010 (EPA) - January 1, 2020 (EPA Section 606): ban on production + import of virgin R-22 - Existing R-22 equipment legally serviceable indefinitely via reclaim - R-22 reclaim prices have risen substantially since phase-out ### Federal HVAC tax credits (status) - The federal 25C credit does not apply to equipment placed in service after December 31, 2025, and 25D does not apply to expenditures made after that date (One Big Beautiful Bill, Public Law 119-21, July 4, 2025). Source: https://www.irs.gov/newsroom/faqs-for-modification-of-sections-25c-25d-25e-30c-30d-45l-45w-and-179d-under-public-law-119-21-139-stat-72-july-4-2025-commonly-known-as-the-one-big-beautiful-bill-obbb --- ## Refrigerant Safety Classifications (ASHRAE Standard 34) ASHRAE Standard 34-2022 classifies refrigerants by toxicity (A/B) and flammability (1/2L/2/3): - **A1**: Non-toxic, non-flammable (R-22, R-410A, R-134a, R-404A, R-407C) - **A2L**: Non-toxic, mildly flammable (auto-ignition 700-1000°F, burning velocity ≤10 cm/s) — R-32, R-454B, R-454C, R-455A, R-1234yf, R-1234ze - **A2**: Non-toxic, flammable - **A3**: Non-toxic, highly flammable (R-290 propane, R-600a isobutane, R-1270 propylene) - **B1**: Toxic, non-flammable (R-123) - **B2L**: Toxic, mildly flammable - **B3**: Toxic, flammable (R-717 ammonia is B2L but heavily regulated) A2L equipment safety design per UL 60335-2-40 + ASHRAE 15 includes refrigerant detection where the standard requires it, ventilation interlocks, charge limits based on room volume, dedicated wiring for fault detection, specific service valve design. Existing R-410A equipment cannot be safely converted to A2L (different equipment safety classification). --- ## ACCA Standards Reference - **Manual J** (8th edition): Residential heating + cooling load calculation; component-based methodology - **Manual S**: Equipment selection (capacity must match calculated load, not exceed 100-115% cooling) - **Manual D**: Residential ductwork design (equal-friction method; Total External Static Pressure budgeting) - **Manual T**: Air distribution balancing + commissioning - **QI Standard 5**: Quality Installation (refrigerant charge, airflow verification, ductwork performance) - **Standard 4**: Maintenance of residential HVAC - **Standard 6**: Restoration of pressure-temperature data --- ## ASHRAE Standards Reference - **Standard 15-2022**: Safety Standard for Refrigeration Systems (A2L charge limits + RCL calculations) - **Standard 34-2022**: Refrigerant Designation + Safety Classification - **Standard 62.2-2022**: Residential Ventilation + Indoor Air Quality - **Standard 90.1-2022**: Commercial Energy Standard - **Standard 90.2-2024**: Residential Energy Standard - **Standard 100-2018**: Energy Efficiency in Existing Buildings - **Standard 105-2014**: Methods of Building Energy Performance Comparison - **Standard 111-2008**: Measurement, Testing, Adjusting, and Balancing of Building HVAC Systems - **Standard 135-2020**: BACnet (Data Communication Protocol for Building Automation) - **Standard 180-2018**: Standard for Maintenance of Commercial HVAC Systems (with ACCA) - **Standard 202-2018**: Commissioning Process for Buildings + Systems - **Standard 211-2018**: Commercial Building Energy Audits (Levels I/II/III) - **Guideline 0** (2019): The Commissioning Process - **Guideline 0.2** (2015): Commissioning Process for Existing Buildings + Systems - **Guideline 14-2014**: Measurement of Energy, Demand, and Water Savings - **Guideline 36-2021**: High Performance Sequences of Operation for HVAC Systems --- ## DOE 2023 SEER2/HSPF2/AFUE2 Metric Transition DOE 10 CFR Part 430 updated efficiency metrics for residential HVAC equipment in 2023: - SEER → SEER2: ~5-7% lower numerical value for equivalent physical performance - HSPF → HSPF2: similar methodology change - AFUE → AFUE2: methodology change The transition is a measurement methodology change, not a physical efficiency change. Comparison of pre-2023 SEER ratings vs post-2023 SEER2 requires accounting for the methodology difference. Federal minimum efficiency standards updated concurrently — equipment manufactured after January 2023 in US market must meet SEER2 minimums. --- ## OSHA HVAC Safety Framework (29 CFR 1910) Key OSHA standards applicable to HVAC service: - **1910.95**: Hearing protection (85 dBA TWA action level) - **1910.132-138**: Personal Protective Equipment (PPE) requirements - **1910.137**: Insulated gloves for electrical work - **1910.140**: Fall protection harness (4 ft general industry; 6 ft construction per 1926.501) - **1910.146**: Permit-Required Confined Spaces (PRCS) - **1910.147**: Lockout/Tagout (LOTO) procedure for commercial energy isolation - **1910.252**: Welding, Cutting, and Brazing requirements - **1910.1000**: Air contaminant Permissible Exposure Limits (PEL) - **1910.1200**: Hazard Communication + Safety Data Sheets LOTO procedure (1910.147): notify affected workers → shut off equipment → isolate energy at source → apply lock + tag → verify de-energization → discharge stored energy (capacitors) → perform service → restore power in reverse order. --- ## Manual J Load Calculation Methodology Residential heating + cooling load calculation per ACCA Manual J 8th edition. 8 load components: 1. Conduction through walls + ceiling + floors (U × A × ΔT) 2. Conduction through windows + doors 3. Infiltration (ACH × volume × ΔT × 0.018) 4. Mechanical ventilation (CFM × ΔT × 1.08 for sensible) 5. Solar gain through windows (SHGC × area × design solar intensity) 6. Internal gains (people 400 BTU/h each; lights + appliances) 7. Duct losses (10-30% of equipment capacity typical) 8. Latent loads (cooling — moisture removal from infiltration + ventilation + occupants) Block vs room-by-room: block calc adequate for design; room-by-room required for proper duct sizing per Manual D. Climate zones per IECC + ACCA Manual J Table 2A. Construction era affects assumed envelope characteristics. --- ## Manual D Duct Design Residential ductwork design per ACCA Manual D + ASHRAE 90.2. Methodology: - Total External Static Pressure (TESP) budget — typically 0.5 in.w.c. residential - Equal-friction method: design ductwork to maintain consistent friction rate (typically 0.08-0.1 in.w.c./100 ft) - Huebscher equation: equivalent round diameter for rectangular ducts - Fitting losses per Table 6 (equivalent length method) - Material: galvanized steel (highest performance), duct board (mid), flex (lowest) - SMACNA leakage class — Class A (sealed) most stringent; Class C (unsealed) common in legacy - IECC R403.3.3 requires Class A sealing for ductwork in unconditioned space; ≤4% leakage per RESNET MINHERS --- ## Combustion Analysis (ASHRAE 180 + NFPA 54) Annual combustion analyzer measurement at gas furnace flue verifies safety. Acceptance criteria: - CO ≤100 ppm air-free (CO above indicates incomplete combustion, possible cracked heat exchanger) - O₂ ≤4% - Draft -0.02 to -0.08 in.w.c. negative - Flame uniform blue Required equipment: combustion analyzer ($300-1,500) — Bacharach Fyrite Insight Plus, Testo 300/320, Sauermann Si-CA 130, Kane 425/458. Annual calibration required. --- ## A2L Refrigerant Safe Work Practices Per ASHRAE 15 + UL 60335-2-40 + AHRI Safe Refrigerant Transition guidance: 1. UL-listed A2L-rated recovery equipment, leak detectors, and tools 2. NO open flames during refrigerant-side service; fully recover refrigerant before brazing; ventilate area + verify atmosphere with combustible gas detector 3. NO spark-producing electrical tools near refrigerant circuit 4. Ventilation in confined service spaces 5. Refrigerant Concentration Limit (RCL) calculation per ASHRAE 15 — room volume vs total charge 6. A2L-trained technician — EPA Section 608 certification covers A2L recovery 7. UL listing on equipment confirms A2L compatibility --- ## Heat Pump Cold-Climate Capability Standard heat pumps lose 30-40% of rated capacity at 5°F outdoor. Cold-Climate Heat Pumps (CCHP) maintain capacity through variable-speed compressors with vapor injection (EVI). Major CCHP product lines: - Mitsubishi Electric Hyper-Heat (H2i): rated to -13°F, full capacity at 5°F on premium models - Daikin LV Series + Aurora: rated to -13°F to -15°F - Bosch Climate 5000 BHP: rated to -13°F - Fujitsu Halcyon (cold-climate): rated to -15°F some models - LG Multi V S (cold-climate option): rated to -13°F - Carrier Performance (cold-climate): rated to -13°F Climate zone framework: Zones 1-4 standard adequate; Zone 5 consider CCHP; Zone 6+ CCHP required + backup heat critical; Zone 7-8 CCHP feasible with backup heat essential. --- ## Building Performance Standards (BPS) Local + state laws requiring existing buildings to meet energy performance targets: - **NYC Local Law 97** (2019): >25,000 sq ft; first compliance 2024-2029; $268/ton CO2 over limit - **Boston BERDO 2.0** (2021): >20,000 sq ft; emissions targets to 2050 net zero - **Washington State CBPS**: >50,000 sq ft commercial; 2026 + 2031 milestones - **Maryland BEPS**: >35,000 sq ft; 2030 milestone - **Seattle Building Performance Standard**: >20,000 sq ft; phased 2026-2031 - **Denver Energize Denver**: >25,000 sq ft; performance targets to 2030 - **Colorado BPS**: building-stock-wide emissions reduction - **DC BEPS**: >50,000 sq ft; 2026/2031/2036/2041 milestones --- ## BMS Cybersecurity (Building Automation) Commercial Building Management Systems sit at the intersection of OT and IT. Applicable frameworks: - **NIST Cybersecurity Framework 2.0** (2024): Govern, Identify, Protect, Detect, Respond, Recover - **NIST SP 800-82** (Rev 3): Guide to Operational Technology Security - **ISA/IEC 62443**: International OT/ICS security standard; security levels SL-1 to SL-4 - **BACnet/SC** (Secure Connect): TLS encryption + certificate authentication for BACnet (vs legacy unencrypted BACnet) Common BMS vulnerabilities: default credentials, network segmentation gaps, unencrypted BACnet, internet-exposed BMS, out-of-date firmware, incomplete asset inventory, no security monitoring, third-party + vendor remote access. The 2013 Target retail breach started with HVAC vendor remote access — classic supply chain attack pattern. --- ## ENERGY STAR Portfolio Manager EPA + ENERGY STAR for Buildings program; free online tool used by 50%+ of US commercial floor space. Process: 1. Add building with floor area + use type + operating characteristics 2. Enter 12 months of utility bills 3. Tool calculates Source EUI (Energy Use Intensity) in kBtu/sq ft 4. Compares to national database of similar buildings 5. Output: ENERGY STAR Score 1-100 (percentile rank) 6. Score 75+ = ENERGY STAR Certified eligible The score is comparative not absolute. Many cities + states use Portfolio Manager scores for Building Performance Standards compliance. --- ## IPMVP Measurement + Verification International Performance Measurement & Verification Protocol (IPMVP) — global standard for measuring energy savings: - **Option A**: Retrofit Isolation, Key Parameter Measurement (lowest cost; predictable use) - **Option B**: Retrofit Isolation, All Parameter Measurement (continuous submetering) - **Option C**: Whole Facility (whole-building utility bills pre/post; for savings >10%) - **Option D**: Calibrated Simulation (energy model baseline; for new construction) ASHRAE Guideline 14-2014 provides complementary methodology. --- ## Source Citations Reference This site cites primary sources for all quantitative + regulatory claims: - **PT/property data**: NIST REFPROP via CoolProp library (Bell, Wronski, Quoilin, Lemort 2014) - **Refrigerant safety**: ANSI/ASHRAE Standard 34-2022 - **Federal refrigerant regulation**: 40 CFR Part 82 Subpart F (Section 608); 40 CFR Part 84 (AIM Act) - **Federal energy efficiency**: 10 CFR Part 430 (residential); 10 CFR Part 431 (commercial) - **Tax credits**: federal 25C does not apply to equipment placed in service after Dec 31, 2025, and 25D does not apply to expenditures after that date (P.L. 119-21, "OBBB"); IRS OBBB FAQ - **Building codes**: International Codes 2021 (IRC, IECC, IMC, IFGC); NFPA 70 (NEC) 2023 - **HVAC standards**: ACCA Manuals + ASHRAE Standards + AHRI Standards + ENERGY STAR - **Safety**: OSHA 29 CFR 1910 + 1926; NFPA 70E + 54 + 72 + 92 --- ## Citation Policy All quantitative data on this site derives from primary scientific + regulatory sources cited inline on each page. 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