建筑规范热回收要求

A跨辖区来看，建筑规范正日益 强制要求 一旦系统处理足够的外气即要求能量回收。本概述比较主要制度，使设计人员能够指定一个满足所有要求的核心。

Minimum Effectiveness by Regime

制度	触发条件	最低回收率
ASHRAE 90.1-2022 (US)	≥ 5,000 CFM and ≥ 70% OA	50% 焓 (AHRI 1060)
IECC／美国多数州规范	通过引用采用 90.1	相同的50%下限
California Title 24 (US)	高外气比、大型系统	50%以上显热，按气候调整
EU Ecodesign 1253/2014	units ≥ 30 W fan power	73% (ηt）、68% 绕管式
EU EPBD 2024/1275	2030年前实现 ZEB（政策驱动）	要求回收，而非固定百分比

Reading the Differences

• 美国规则基于以下触发： 系统规模和外气比；欧盟规则基于以下触发： 投放市场的设备 并设定绝对的73%热效率。
• California Title 24 在寒冷气候中收紧显热下限，并将回收与经济器控制挂钩。
• The EPBD does not state a percentage but makes recovery the practical path to a fossil-free, near-zero-energy building — see EPBD 零排放建筑.

One Core, Many Codes

Specifying a core at 70–75% enthalpy effectiveness clears the US 50% floor, the EU 73% Ecodesign floor, and most Title 24 climate tiers at once. Use the 试验标准 以确认数值是在正确基准上测得的，以及 ASHRAE 90.1 与 生态设计 关于具体例外情况的文章。其结果是形成一份能让大西洋两岸审核方都满意的单一规范。

Practical Specifying Strategy

The cleanest way to satisfy every regime is to specify one core at 70 to 75% enthalpy effectiveness and confirm its measured value on the relevant test basis. That single choice clears the U.S. 50% floor, the EU Ecodesign 73% thermal floor, and most California Title 24 climate tiers simultaneously, which matters for manufacturers selling across markets. The trap is mixing metrics: ASHRAE and Ecodesign both quote effectiveness but define it at different conditions and for different streams, so compare like with like using the named standard. Exceptions also vary, lab and grease exhaust are exempt in the U.S., but the EU rule is about equipment placed on the market, so a project’s exceptions should be listed explicitly. Finally, remember that effectiveness without controlled pressure drop can backfire; a core that needs a much larger fan may erase its own saving, which is why fan-power limits bind the two together.

常见问题

How do U.S. and EU recovery mandates differ?
U.S. rules trigger on system size and outdoor-air fraction with a 50% floor, while the EU rule triggers on equipment sold and sets a 73% thermal efficiency.

Can one core satisfy all jurisdictions?
Yes. A core at 70 to 75% enthalpy effectiveness typically clears U.S., EU Ecodesign, and most Title 24 tiers at once.

Why must pressure drop be considered with effectiveness?
A more effective core needing a much larger fan can erase the energy saving, which is why fan-power limits bind the two together.

What exceptions are common?
Lab fume-hood, hazardous, and grease exhaust are commonly exempt in the U.S., while the EU rule instead governs equipment placed on the market.

常见问题

How do U.S. and EU recovery mandates differ?

U.S. rules trigger on system size and outdoor-air fraction with a 50% floor, while the EU rule triggers on equipment sold and sets a 73% thermal efficiency.

Can one core satisfy all jurisdictions?

Yes. A core at 70 to 75% enthalpy effectiveness typically clears U.S., EU Ecodesign, and most Title 24 tiers at once.

Why must pressure drop be considered with effectiveness?

A more effective core needing a much larger fan can erase the energy saving, which is why fan-power limits bind the two together.

What exceptions are common?

Lab fume-hood, hazardous, and grease exhaust are commonly exempt in the U.S., while the EU rule instead governs equipment placed on the market.