The Impact of Deep Energy Renovations on Indoor Air Quality and Ventilation in Irish Dwellings

Achieving energy-efficient dwellings has become a vital part of the global climate action plan to reduce energy usage and carbon emissions. Deep energy retrofits (DER) can help reduce residential energy use significantly. However, evidence on how DER impacts on indoor air quality (IAQ), and consequently, occupant health, is scarce. More in-depth analysis of IAQ data before and after energy retrofits is essential to understand the indoor environmental challenges of adopting energy efficiency measures.

The combined effects of temperature and humidity on initial emittable formaldehyde concentration of a medium-density fiberboard

Individual effects of temperature and humidity on formaldehyde emissions from manufactured fiberboards have been studied previously, but their combined effects and possible correlation with initial emittable concentration (C0) of building materials have not been reported yet. This paper investigated their combined effects on C0 theoretically from microcosmic perspective. Total formaldehyde content related to humidity and formaldehyde molecular phases affected by temperature in the porous material were considered.

The effect of humidity on formaldehyde emission parameters of a medium-density fiberboard: Experimental observations and correlations

Initial emittable concentration (C0), diffusion coefficient (Dm) and partition coefficient (K) are the three key emission parameters determining formaldehyde emissions from “dry” building materials. Previous studies of humidity effect on formaldehyde emissions were mainly focused on the analysis of steady-state emission rates or concentrations, whereas humidity effects on emission parameters were seldom discussed.

Ventilation and Measured IAQ in new US homes

As newer homes are being built tighter than the existing housing stock, questions have been raised about the concentrations of pollutants of concern in new homes and how mechanical ventilation systems can address this issue. This study measured pollutants of concern in 70 new homes with mechanical ventilation in California, USA and compared the results to a previous study of home without mechanical ventilation. The key pollutants were measured using both time-integrated and time-resolved over a one-week period and included formaldehyde, PM2.5 and NO2.

Trade-offs between ventilation rates and formaldehyde concentrations in new-build dwellings in the UK

The current policies and regulatory frameworks in the construction sector aim to improve energy efficiency of new buildings whilst maintaining acceptable level of indoor environmental quality (IEQ) including indoor air quality (IAQ). In practice, however, there are often important trade-offs between these objectives. The aim of this paper is to investigate the concentrations of volatile organic compounds (VOCs) in a recently built residential block in the UK and the potential trade-offs between ventilation rates and VOCs.

New release! AIVC Contributed Report 18

We are pleased to announce the release of AIVC Contributed Report 18: Ventilation and Indoor Air Quality in New California Homes with Gas Appliances and Mechanical Ventilation!


CR18: Ventilation and Indoor Air Quality in New California Homes with Gas Appliances and Mechanical Ventilation

Substantial energy is used to condition the air that enters California homes through leaks in the building envelope and ductwork - typically about a third of all heating and cooling. Reducing this through air sealing is essential to California achieving zero energy homes. However, this outdoor air also dilutes pollutants emitted inside homes and contributes to a healthy indoor environment and acceptable indoor air quality (IAQ). To address this IAQ issue, California’s Title 24 Building Standards have required mechanical ventilation in new homes since 2008.

Field measurement of carbonyl compound and particles in South Korea residential spaces

In Korea, a large amount of fine dust and carbonyl compounds is generated during cooking in the kitchen. The purpose of this study is to select 20 apartment houses and measure contaminants that are generated during cooking in apartment houses in Korea. The measurement result showed that 15 out of 20 apartment houses exceeded the guidelines for PM10 based on its peak concentration. The concentration of carbonyl compounds was measured in the descending order of acrolein (270.0㎍/m3), formaldehyde (239.5㎍/m3) based on its average concentration.

Assessing Occupant and Outdoor Air Impacts on Indoor Air Quality in New California Homes

In 2008 the State of California adopted new building codes that required the use of mechanical ventilation systems in homes that meet the requirements of ASHRAE Standard 62.2. The standard requires both a dwelling unit mechanical ventilation system and exhaust fans in kitchens and bathrooms. A field study was undertaken to evaluate the IAQ and ventilation performance of homes built to these requirements. For ventilation system performance, the airflows of all mechanical ventilation systems were measured and their use was monitored for a one-week period.

Characteristics on indoor air pollutant emission from wood-based flooring by environmental-friendly natural adhesive using CNSL

To discuss the reduction of formaldehyde and volatile organic compound (VOC) emissions from engineered flooring, cashew nut shell liquid (CNSL)-formaldehyde (CF) resin and CF/PVAc resin were applied for the maple face of the veneer bonding on plywood. The CF resin was used to replace urea-formaldehyde (UF) resin in the formaldehyde-based resin system in order to reduce formaldehyde and VOC emissions from the adhesives used between the plywoods and fancy veneers. For the CF/PVAc resins, 5, 10, 20 or 30% of PVAc was added to the CF resin.