New Refrigerants are (Almost) Here - What You Need to Know
暖通空调行业正开始向2020年《2021十大正规彩票平台》要求的新制冷剂过渡, 会逐步减少使用现有类别的制冷剂，并对冷气机及热泵所使用的制冷剂订立新的规定. 新型制冷剂比现有制冷剂对全球变暖的影响更小.
As part of this transition, the U.S. 美国环境保护署(EPA)已经为需要使用新制冷剂的新设备设定了过渡日期, commonly referred to as A2Ls.
1月6日以后生产的住宅和轻型商用空调和热泵. 1, 2025, must use the new refrigerant. 在此日期之前制造的设备有一年的安装宽限期，即1月1日. 1, 2026, installation deadline.
For products that do not require field assembly, such as window air conditioning units, 该规则将最终销售日期确定为制造合规日期(1月1日)后三年. 1, 2028, sale deadline — without a compliance date for installation.
EPA正在评估仅将容量为65的可变制冷剂流量(VRF)系统的过渡日期延长一年,000 BTU/h (19 kW) or more.
现有的空调和热泵设备不受EPA法规的约束，并且可以在设备使用寿命结束时继续使用. 用于维修和维修的部件也不受EPA法规的约束. The supply of R-410A, R-134a, 在可预见的未来，即使到下一个十年的中期，总体产量和进口量下降，满足维修需求的其他制冷剂仍将可用, 就像20世纪90年代和21世纪初之前的制冷剂过渡一样.
How A2Ls are Different
All refrigerants are required to be classified by toxicity and flammability. a2l保留了与其前身(R-410A)相同的毒性名称-无毒。. However, the flammability has been reclassified as Class 2L (lower flammability), compared to Class 1 (no flame propagation) for R-410A.
A2L refrigerants require redesign of the HVAC equipment. 重要的是，房屋建筑商积极开始计划过渡, 与供应商和安装商合作，确保在接下来的几个月里有足够的设备管道，避免潜在的瓶颈, delays and last-minute change orders. 每个设备制造商都有自己的推出策略和时间表, but these changes are imminent and will happen over the coming months.
To address the slight increase in flammability, equipment manufacturers are adding safety features to equipment, revising transportation and handling procedures, and updating installation instructions.
Primary mitigation measures for the building include:
- 通过使用压力和真空方法加强对制冷剂管路的测试，将制冷剂泄漏的风险降至最低, requiring specific joint types, and requiring nail plates at framing members where lines running through, and
- 在可能发生泄漏的情况下，将建筑物内的制冷剂浓度控制在可燃性限值以下.
In many cases, 设备制造商将在空气处理机组中安装一个泄漏检测传感器，并通过编程激活主风扇，使空气在整个家中快速循环，以降低制冷剂浓度. 其他安全策略包括使用同样由泄漏传感器激活的关闭阀，旨在限制可能泄漏的制冷剂的数量. For systems without leak detection sensors, the quantity of the refrigerant in the system, including the lines, 将需要更仔细地确定尺寸，以使制冷剂泄漏到最小的空间(e.g.系统直接服务的(如浴室)不会超过规定的浓度限值.
其他文件要求包括设备上的永久标签，列出安装系统的公司和安装的制冷剂的重量.
Although there are several A2L refrigerants approved for use, 你在市场上应该期待的两种主要制冷剂是R-32和R-454B. 每个设备制造商都将指定其设备使用哪种制冷剂.
Multifamily Buildings
对于多户建筑，制冷剂管路穿透防火地板组件, 建筑规范可能要求将制冷剂管线放置在防火竖井中或实施其他消防安全措施. Developers should coordinate designs with their MEP firms. The shaft requirements can impact plan layouts and architectural designs.
Centrally Ducted System vs. Mini Splits
不同的缓解策略将被指定为中央管道系统与. mini splits. Again, 建筑商应联系供应商获取信息，并遵循安装说明，确保实施所有必要的安全措施，以便在制冷剂泄漏的情况下不超过浓度限制.
Design Software
用于确定设备尺寸和能源建模的软件程序应使用A2L制冷剂的新设备的最新规格.
What Should Home Builders Do Right Now
Have a transition plan in place that achieves the following goals:
- Coordinate a switch-over timeline with vendors and installers
- 确保切换前现有设备和切换后新设备有足够的管道(旧设备和新设备不兼容，除非制造商特别说明)
- Coordinate with your mechanical system designer (for multifamily buildings, evaluate if a fire-rated shaft is required)
- 确保您的暖通空调承包商了解新的安装要求和将安装在您家中的特定设备的安全措施
- 确保从制造商那里获得安装说明，以便在您的家中安装特定的设备
- 在整个过程中协调所有相关方并建立直接的反馈循环
Building Code Updates
关于A2L制冷剂在每个州的建筑规范状态的信息可以使用这个找到 interactive map from the Air-Conditioning, Heating, and Refrigeration Institute (AHRI).
Additional Resources from EPA, AHRI and ICC
Technology Transitions HFC Restrictions by Sector | US EPA
Frequent Questions on the Phasedown of Hydrofluorocarbons | US EPA