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Posts tagged dew point temperature
Navigating the HVAC Refrigerant Transition and the Promise of Hydronic Systems for Future-Ready Architecture
Navigating the HVAC Refrigerant Transition and the Promise of Hydronic Systems for Future-Ready Architecture

The global heating, ventilation, and air conditioning (HVAC) industry is undergoing a significant transformation driven by the phasedown of high-Global Warming Potential (GWP) refrigerants, primarily Hydrofluorocarbons (HFCs). This shift, mandated by international agreements like the Kigali Amendment and domestic legislation such as the U.S. American Innovation and Manufacturing (AIM) Act, presents both substantial challenges and unique opportunities for the Architecture, Engineering, and Construction (AEC) industry.

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Heat Pumps, HVAC, High Performance Homes, Indoor Air Quality, Electrification, Building Enclosure, Architectural Design, CodePositive EnergyHVAC refrigerant transition, high-Global Warming Potential (GWP) refrigerants, Hydrofluorocarbons (HFCs), Kigali Amendment, U.S. American Innovation and Manufacturing (AIM) Act, supply chain disruptions, refrigerant costs, technical training, mildly flammable refrigerants, hydronic systems, air-to-water heat pumps, ground source heat pumps, water as heat transfer medium, building performance, global HVAC refrigerant landscape, Montreal Protocol, ozone-depleting substances (ODS), chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), HFC phasedown, U.S. ratification of Kigali Amendment, HFC consumption reduction, global warming mitigation, low-GWP technologies, HFC Allocation Program, Allocation Framework Rule, GWP limit of 700, R-410A systems, refrigerant leak detection, refrigerant reuse, reclaimed and recycled HFCs, leak repair, recordkeeping, reporting, labeling, automatic leak detection (ALD) systems, reclaimed HFCs for servicing, cost of compliance, A2L-class refrigerants, R-454B, R-32, refrigerant flammability, safety protocols, certified HVAC technicians, ACCA A2L training, ASHRAE Standards, UL Safety Standards, refrigerant types comparison, R-22, R-290 (Propane), R-744 (CO2), R-717 (Ammonia), AEC industry challenges, project timelines, supply chain constraints, refrigerant shortages, material scarcity, A2L safety training, regulatory compliance and enforcement, EPA regulations, state-level regulations, equipment availability and compatibility, refrigerant recovery machines, hydronic system types, radiant systems, baseboard heating, chilled beam systems, snow melt systems, AWHPs principles, AWHPs benefits, GSHPs principles, GSHPs advantages, ground loop, ground temperature stability, GSHP design considerations, GSHP energy savings, Investment Tax Credit (ITC), Inflation Reduction Act (IRA), technology neutral homes, renewable electricity sources, building envelope performance, HVAC system sizing, thermal insulation, high-performance glazing, air leakage, whole building design, commissioning, thermal performance, airtightness, passive building principles, Phius (Passive House Institute US), continuous insulation, thermal bridging, condensation prevention, super-insulation, minimal space conditioning system, moisture management, dew point temperature, latent loads, dedicated outdoor air system (DOAS), dehumidification, smart controls, material selection for radiant cooling, wall design for hydronics, floor design for hydronics, ceiling design for hydronics, building physics, heat transfer processes, moisture dynamics, indoor air quality, economic benefits of hydronic systems, operational cost reductions, energy efficiency, high-efficiency circulator, VRF system comparison, DX unit comparison, water source heat pumps, lifespan of hydronic systems, maintenance costs, environmental impact of hydronics, decarbonization, solar thermal, geothermal energy, strategic design for sustainable HVAC.
Rethinking Moisture Control: The Primacy of Air Tightness Over an Outdated Fixation on Vapor Barriers in Building Envelope Design
Rethinking Moisture Control: The Primacy of Air Tightness Over an Outdated Fixation on Vapor Barriers in Building Envelope Design

For decades, the architecture and construction community has engaged in a persistent debate surrounding the role and necessity of vapor barriers in building envelope design. This discussion, while touching on critical aspects of moisture control, has often been characterized by an overemphasis on the ability of specific materials to resist vapor diffusion, sometimes to the detriment of addressing more significant moisture transport mechanisms. Within the building science community, however, the principles governing moisture movement are largely considered settled science. It is well-established that air leakage, rather than vapor diffusion, is the predominant pathway for moisture transport through most wall assemblies.

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Building EnclosurePositive EnergyVapor Barriers, Air Barriers, Building Envelope, Building Science, Moisture Management, Dehumidification, Durability, Resiliency, Air tightness, vapor barriers, moisture control, building envelope design, moisture transport mechanisms, air leakage, vapor diffusion, air barrier systems, historical context of vapor barriers, evolution of vapor barrier science, bulk water intrusion, capillary action, air-transported moisture, defining air barriers, defining vapor retarders, air permeance, water vapor permeance, dew point temperature, energy efficiency, indoor air quality, building durability, acoustic control, continuity of air barrier, dedicated dehumidification, climate-specific vapor control, reservoir claddings, solar-driven inward vapor drive, ventilated rainscreen, "smart" vapor retarders, moving forward with air tightness, recommendations for architecture and construction, building codes and standards, quality assurance/quality control