ASHRAE 90.1 热回收要求

AASHRAE Standard 90.1 是美国商业建筑的参考能源标准，其排风能量回收规则是选用热回收新风换气机时最常见的规范触发条件。本文总结了 ASHRAE 90.1-2022 适用于指定空气-空气热回收的设计人员的要求。

When Recovery Is Mandatory (Section 6.5.6.1)

通风系统必须在排风与室外空气之间进行能量回收，当 以下两者 以下条件同时成立时：

• 独立风机系统的设计送风量为 5,000 CFM (2.4 m³/s) 或以上。
• 最小新风量为 70% 或以上 的设计送风量。

这涵盖了专用新风系统（DOAS）和高密度占用的混合空气系统。较小系统也可能具备经济意义；参见 AHU 选型计算 用于盘管与转轮的一体化选型。

Minimum Effectiveness

指标	ASHRAE 90.1-2022 要求
最小能量回收率	50%（焓回收率，依据 AHRI 1060）
测试方法	AHRI 1060 / AHRI 1061
节能器旁通	Allows bypass, but flow through device ≤ 10% of design and pressure drop ≤ 0.4 in. w.c.

对于不提供主动加湿的系统，显热回收率在供热设计工况下须达到 50%，而焓回收率适用于供冷设计工况。该 焓与膜式对比 有助于选对设备以越过该门槛。

Common Exceptions

• 实验室通风柜排风及危险排风系统。
• 商业厨房含油脂的排风。
• 在潮湿气候下的除湿应用，若使用转轮会重新引入湿气。
• 能量回收会干扰空气侧或水侧节能器（受上述旁通限制约束）的系统。

当指定转轮或板式芯体时，请针对以下故障模式进行规划： 能量回收轮故障排查 — frost, seal leakage, and imbalance all erode the measured effectiveness that the code assumes.

Why It Matters for Payback

Because 90.1 sets a floor, most designers specify 60–75% effectiveness to also clear LEED 能源性能得分 并缩小制冷与供热机房规模。回收装置应作如下选型： 之前 盘管，使 DX 或加热容量按回收负荷而非原始新风负荷选型。

常见问题

When does ASHRAE 90.1-2022 require energy recovery?
When a fan system has design supply airflow of 5,000 CFM or greater and minimum outdoor airflow of 70% or more of supply.

What minimum effectiveness does the standard require?
A 50% energy recovery ratio, which is enthalpy per AHRI 1060, or 50% sensible at the heating design condition where no active humidification is provided.

Are there common exceptions?
Yes, including lab fume-hood and hazardous exhaust, commercial-kitchen grease exhaust, and cases where recovery would conflict with an economizer subject to bypass limits.

How does the requirement interact with equipment selection?
The recovery device should be selected before the coil so plant is sized on the recovered load, not the raw outdoor-air load.

常见问题

When does ASHRAE 90.1-2022 require energy recovery?

When a fan system has design supply airflow of 5,000 CFM or greater and minimum outdoor airflow of 70% or more of supply.

What minimum effectiveness does the standard require?

A 50% energy recovery ratio, which is enthalpy per AHRI 1060, or 50% sensible at the heating design condition where no active humidification is provided.

Are there common exceptions?

Yes, including lab fume-hood and hazardous exhaust, commercial-kitchen grease exhaust, and cases where recovery would conflict with an economizer subject to bypass limits.

How does the requirement interact with equipment selection?

The recovery device should be selected before the coil so plant is sized on the recovered load, not the raw outdoor-air load.