与其他建筑通风策略相比，按需控制通风（DCV）系统具有一些优势，因为它们可以保持空间的可接受室内空气质量（IAQ），同时降低建筑通风的总体能耗。在选择DCV传感器时，考虑它们的性能和成本是很重要的。在过去几年中，低成本传感器的可用性有所增加。然而，在DCV内使用目前可用的低成本传感器的可行性是一个需要进一步研究的领域。 本文的工作重点是评估当前低成本二氧化碳（CO2）传感器在可控环境下用于DCV的可行性。验证了三种低成本CO2传感器模型的性能，以确定它们在控制DCV方面的适用性。初步测试显示，三个传感器中的一个存在不可接受的误差。该传感器采用微热板技术进行气体传感，未进行详细测试。详细测试的两个传感器使用非色散红外（NDIR）技术。 第一个NDIR传感器（A型）的精度令人满意；一些传感器测量值与剂量浓度的偏差超过100 ppm，但仍保持在150 ppm以内。传感器模型A的非线性度大于模型B，但可接受，与最佳拟合线性线的最大偏差在55至92 ppm之间。A型传感器的重复性是可以接受的；当测量相同的CO2浓度时，三天试验期间的传感器测量值始终在100 ppm范围内。 事实上，记录的最大不可重复性为73 ppm。A型传感器的滞后特性令人满意；当从不同方向接近相同的CO2浓度时，大多数传感器测量值都在100 ppm以内，所有传感器测量值都在150 ppm以内。然而，A型传感器有漏报CO2浓度的倾向，如果传感器未校准或控制算法中未考虑漏报的倾向，这可能会降低室内空气品质。传感器模型A持续少报二氧化碳的减少幅度较大，这可能会导致DCV系统提前关闭，可能会对室内空气质量产生负面影响。 第二个NDIR传感器（B型）的精度优于A型，被认为是可以接受的。传感器测量值始终在剂量浓度的100 ppm范围内。B型传感器确实有过度释放二氧化碳浓度的趋势，这可能会导致比理想情况更多的能耗；然而，由于传感器的精度更高，预计影响较小。B型传感器的非线性度令人满意；与最佳拟合线性线的最大偏差在30至55 ppm之间。 B型传感器的重复性令人满意；当测量相同的CO2浓度时，在三天的测试中，除一个传感器测量值外，所有传感器测量值均在100 ppm以内。B型传感器的滞后异常；当从高浓度或低浓度接近相同的CO2浓度时，传感器测量值通常在20 ppm以内，并且始终在60 ppm以内。发现B型传感器适用于DCV。这项工作表明，每台售价27加元（20美元）的超低成本二氧化碳传感器可能不适合DCV，但价格太低- 成本为80加元（60美元）的二氧化碳传感器可能适合开发用于管理室内二氧化碳浓度的低成本控制器和传感器包。引用:2020年虚拟会议技术论文

Demand-controlled ventilation (DCV) systems have someadvantages over other building ventilation strategies, as theycan maintain acceptable indoor air quality (IAQ) of a spacewhile reducing the overall energy consumption of buildingventilation. When selecting sensors for DCV, it is important toconsider their performance and cost. Over the past severalyears, there has been an increase in the availability of low-costsensors. However, the feasibility of using the currently availablelow-cost sensors within DCV is an area that requiresfurther investigation. The focus of the work presented in thispaper is to evaluate the feasibility of current low-cost carbondioxide (CO2) sensors for use in DCV using a controlled environment.The performance of three low-cost CO2 sensormodels was verified to determine their suitability in the controlof DCV. Preliminary testing revealed unacceptable inaccuracyin one of the three sensors. This sensor uses micro-hotplatetechnology for gas sensing and was excluded from detailedtesting. The two sensors tested in detail use nondispersiveinfrared (NDIR) technology.The accuracy of the first NDIR sensor (model A) was satisfactory;some of the sensor measurements deviated from thedosed concentration by more than 100 ppm, but remainedwithin 150 ppm. The nonlinearity of sensor model A wasgreater than model B but was acceptable—the maximum deviationfrom the linear line of best fit ranged between 55 and92 ppm. The repeatability of sensor model A was acceptable;sensor measurements during the three days of testing werealways within 100 ppm when measuring the same CO2 concentration.In fact, the maximum recorded nonrepeatability was73 ppm. The hysteresis of sensor model A was satisfactory;most sensor measurements were within 100 ppm and all werewithin 150 ppm when measuring the same CO2 concentrationwhen approached from varying directions. However, sensormodel A had a tendency to underreport CO2 concentrations,which could reduce IAQ if the sensors were not calibrated orif the tendency to underreport was not considered in the controlalgorithm. Sensor model A consistently underreporteddecreasing CO2 at a larger magnitude, which would likelycause the DCV system to turn off sooner than desired, potentiallynegatively impacting IAQ.The accuracy of the second NDIR sensor (model B) wasfound to be better than model A and was deemed acceptable. Thesensor measurements were always within 100 ppm of the dosedconcentration. Sensor model B did have a tendency to overreportCO2 concentrations, which could result in more energy consumptionthan ideal; however, the impact is expected to be low due tothe better accuracy of the sensor. The nonlinearity of sensor modelB was satisfactory; the maximum deviation from the linear line ofbest fit ranged between 30 and 55 ppm. The repeatability of sensormodel B was satisfactory; all but one of the sensor measurementsduring the three days of testing were within 100 ppm whenmeasuring the same CO2 concentration. The hysteresis of sensormodel B was exceptional; sensor measurements were typicallywithin 20 ppm when measuring the same CO2 concentrationwhen approached from either high or low concentrations andwere always within 60 ppm. Sensor model B was found to be suitablefor use in DCV.This work shows that ultra low-cost CO2 sensors in thearea of $27 CAD ($20 USD) each may not be suitable for DCV,but that low-cost CO2 sensors in the area of $80 CAD($60 USD) could be suitable for developing a low-cost controllerand sensor package for managing indoor CO2 concentrations.