Houses are Dumb without Smart Ventilation

Abstract

As we move to high performance housing and especially toward zero-energy homes, ventilation represents a larger and larger fraction of the space conditioning energy requirements. Ventilation standards, such as ASHRAE Standard 62.2 (or codes that use it, such as California Title 24), are typically met by continuous ventilation for their whole-house requirements, but met intermittently for their local exhaust requirements. Higher indoor air quality (IAQ) performance, as well as lower HVAC power and energy consumption, can be achieved by being smarter about how and when ventilation occurs. Numerous smart ventilation strategies are possible in high performance homes, such as increasing ventilation when the outdoor temperature is less extreme, scheduling ventilation during off-peak hours, avoiding ventilation during periods of poor outdoor air quality, and reducing whole house ventilation operation in response to incidental ventilation (e.g., bathroom or kitchen fan operation) and occupancy. Smart ventilation, in the form of a ventilation controller, can be used to implement all of these strategies and more. In this paper, we outline the theoretical requirements of a smart controller, discuss the real-world practicalities of control input options, and provide some actual examples of smart ventilation controls for residences. Ventilation controllers are flexible, and they can be used to fulfill the varied needs of building occupants, designers, policy makers, and program managers. Furthermore, as web-connected devices, the operation of a smart ventilation controller could be changed at will, in response to changes in policy, climate conditions, or grid dynamics.

Smart ventilation energy and indoor air quality performance in residential buildings: A review

“…The concept of smart ventilation was developed to ventilate properly while reducing energy loads, allow for the provision of grid services, and promote associated renewable power integration Walker, et al 2011;Turner and Walker 2012;Walker, et al 2014). The goal is to reduce the amount of energy that ventilation uses and reduce associated energy costs below that of an analogous continuously operating system while maintaining or improving IAQ.…”

“…Hybrid ventilation systems need to sense outdoor and indoor parameters and possibly ventilation system air flows in order to determine if the natural ventilation from wind pressure and stack effect is sufficient, or if a fan must be activated. This review includes results from some hybrid ventilation studies (Jreijiry, et al 2007;Turner and Walker 2013;Less, et al 2014;Chenari, et al 2016;Lubliner, et al 2016) but doesn't include an extended review of hybrid ventilation strategies in residential buildings.…”

“…Three complementary components of smart ventilation in a home can be distinguished, as suggested by Schild (2007) for DCV systems and by Walker, et al (2014) for smart ventilation:…”

“…Fan brake horsepower is roughly a square function of flow rate, meaning small reductions in flow rate translate to larger reduction in fan energy use. Even if more powerful ventilation fans must be used to meet peak airflow requirements (Smart ventilation could require an increase of 34% in fan size on average (Less, et al 2014), the fact that those peak airflows are used only if needed leads to a decrease in the energy consumption.…”

Performance based approaches in standards and regulations for smart ventilation in residential buildings: a summary review

“…The concept of "smart ventilation" more recently developed in the LBNL is another subset of smart ventilation. It was developed in order to control fans to minimize energy use (Sherman and Walker, 2011;Walker et al, 2011;Turner and Walker, 2012;Walker et al, 2014). This smart ventilation concept uses the equivalent ventilation principle (Sherman and Walker, 2011;Sherman et al, 2012) further developed in the paper, to allow for modulation of ventilation airflows in response to several factors, including outdoor conditions, utility peak loads, occupancy, and operation of other air systems.…”