Outcome‐based ventilation: A framework for assessing performance,health, and energy impacts to inform office building ventilation decisions

This article presents an outcome‐based ventilation (OBV) framework, which combines competing ventilation impacts into a monetized loss function ($/occ/h) used to inform ventilation rate decisions. The OBV framework, developed for U.S. offices, considers six outcomes of increasing ventilation: profitable outcomes realized from improvements in occupant work performance and sick leave absenteeism; health outcomes from occupant exposure to outdoor fine particles and ozone; and energy outcomes from electricity and natural gas usage. We used the literature to set low, medium, and high reference values for OBV loss function parameters, and evaluated the framework and outcome‐based ventilation rates using a simulated U.S. office stock dataset and a case study in New York City. With parameters for all outcomes set at medium values derived from literature‐based central estimates, higher ventilation rates’ profitable benefits dominated negative health and energy impacts, and the OBV framework suggested ventilation should be ≥45 L/s/occ, much higher than the baseline ~8.5 L/s/occ rate prescribed by ASHRAE 62.1. Only when combining very low parameter estimates for profitable impacts with very high ones for health and energy impacts were all outcomes on the same order. Even then, however, outcome‐based ventilation rates were often twice the baseline rate or more.     

Performance of a CO2 sorbent for indoor air cleaning applications: Effects of environmental conditions,sorbent aging,and adsorption of co-occurring formaldehyde

Indoor air cleaning systems that incorporate CO₂ sorbent materials enable HVAC load shifting and efficiency improvements. This study developed a bench-scale experimental system to evaluate the performance of a sorbent under controlled operation conditions. A thermostatic holder containing 3.15 g sorbent was connected to a manifold that delivered CO₂-enriched air at a known temperature and relative humidity (RH). The air stream was also enriched with 0.8-2.1 ppm formaldehyde. The CO₂ concentration was monitored in real-time upstream and downstream of the sorbent, and integrated formaldehyde samples were collected at different times using DNPH-coated silica cartridges. Sorbent regeneration was carried out by circulating clean air in countercurrent. Almost 200 loading/regeneration cycles were performed in the span of 17 months, from which 104 were carried out at reference test conditions defined by loading with air at 25°C, 38% RH, and 1000 ppm CO₂, and regenerating with air at 80°C, 3% RH and 400 ppm CO₂. The working capacity decreased slightly from 43-44 mg CO₂ per g sorbent to 39-40 mg per g over the 17 months. The capacity increased with lower loading temperature (in the range 15-35°C) and higher regeneration temperature, between 40 and 80°C. The CO₂ capacity was not sensitive to the moisture content in the range 6-9 g/m³, and decreased slightly when dry air was used. Loading isothermal breakthrough curves were fitted to three simple adsorption models, verifying that pseudo-first-order kinetics appropriately describes the adsorption process. The model predicted that equilibrium capacities decreased with increasing temperature from 15 to 35°C, while adsorption rate constants slightly increased. The formaldehyde adsorption efficiency was 80%-99% in different cycles, corresponding to an average capacity of 86 ± 36 µg/g. Formaldehyde was not quantitatively released during regeneration, but its accumulation on the sorbent did not affect CO₂ adsorption.     

价值工程在暖通空调方案优选中的应用

本文认为方案设计是暖通空调系统设计中最复杂、难度最大的阶段,也是冷热源系统生命周期中最基础而又最重要的环节,是关系到暖通空调系统能否健康、有效运行的关键。系统方案的选择有很多方法。通过综合考虑技术,经济,环境和人文等因素,提出采用价值工程的评价方法在当前仍然是一个比较好的选择。此评价方法中功能重要程度对最终结果影响很大,不同得功能重要程度评判原则不同所得结果不同。     

暖通空调绘图表示方法分析

指出暖通空调施工图绘图表示方法迫切需要规范统一，以提高设计效率和设计质量。分析了目前暖通空调绘图表示方法的现状和发展趋势。     

空调系统生物污染防治方法概述

介绍了微生物的种类、习性特点及常用灭除方法 ,并结合HVAC系统的具体应用要求 ,探讨了空调系统可能采用的一些生物污染灭除方法。     

智能决策支持系统（IDSS）在暖通空调设计决策中的应用研究

智能决策支持系统ＩＤＳＳ是一种面向对象，运用知识、数据对人们决策过程进行支持的计算机软件系统。论述了暖通空调设计决策的意义及应用方法，讨论了建立暖通空调设计决策支持系统的几个问题，开发了一个直燃式溴化锂吸收式制冷机组的选型决策支持系统，使用表明能很好地实现对用户的选型决策支持。     

因特网在暖通空调专业上的应用

简要介绍了因特网（Ｉｎｔｅｒｎｅｔ）的概念和上网所需的计算机硬件和软件，提出了有关暖通空调专业的一些网址信息，展望了因特网在暖通空调专业上应用。     

大学建筑暖通空调设计探讨

结合大学建筑设计实例,分析了这类建筑暖通空调系统的共性及特点。总结了设计工作中的一些经验并加以探讨。     

2000年以来发布的有关暖通空调专业的部分国家标准和行业标准

列出了2000年以来发布的部分供暖供热、空调制冷、节能、通风除尘、洁净技术、计算机及网络技术、防火排烟、给水排水、减振降噪、环境保护、室内空气品质、材料与设备等标准．以及有关设计、验收规范和一些综合类标准。     

工程实践是培养学生专业能力的最好课堂

实习是培养工程专业本科生的必修环节，但长期以来暑期实习安排难和如何保证有效的实习是困扰着所有建筑环境与设备工程专业教学的一个问题。本文介绍了清华大学建筑环境与设备工程专业在教改中摸索出的经验与教学实践总结的一些经验，例如如何通过为建筑业主或使用者解决实际存在的暖通空调系统中的问题来达到培养本科生实践能力的目的等，以便与各兄弟院校进行交流，相互促进。