With energy-consuming equipment, such as water heaters and refrigerators, we have good data on energy consumption and can set clear standards accordingly. In some product categories—clothes washers, for example—Energy Star standards were adopted because those standards provide a high enough threshold to represent just the very top segment of the product market (less than 10%). In other product categories—e.g., refrigerators and dishwashers—we set a higher threshold than ENERGY STAR: for example, exceeding those standards by 10% or 20%. With lighting and lighting control equipment, certain generic products qualify, such as compact fluorescent lamps and occupancy/daylighting controls, while in other categories only a subset of products qualify. In some cases, products that meet the energy efficiency requirements are excluded, because of evidence of poor performance or durability. Microturbines are included here because of the potential for cogeneration (combined heat and power) that they offer.
Once we’ve considered low-emitting products and those that prevent moisture problems, we also consider green ventilation products, filters, radon mitigation equipment, and other equipment and devices that help to remove pollutants or introduce fresh air. Because ventilation equipment is standard, we only recognize products that are particularly efficient or quiet or which have other benefits, such as heat recovery.
Hunter, manufacturer of ceiling, bath, and portable fans, offers two energy-efficient 91 cfm “Ultra Quiet” bathroom/utility fans. At under 1.0 sone, these fans are quiet and energy-efficient enough for continuous use as primary ventilation. Model 82031 has no light whereas 82041 contains a fluorescent fixture. These ceiling-mounted units are not for use above a shower or tub and should not be used with dimmer switches or fan speed controls.
In today's tightly sealed buildings, unless there's a central ventilation system, in-line utility fans or bathroom spot ventilators may be the only mechanical ventilation system. These fans need to be quiet to ensure they are used. A bathroom fan's noise level is measured in “sones,” with one sone being about as loud as a residential refrigerator. In-line utility fans installed remotely down ductwork are often used for bathroom, kitchen, and general ventilation and much quieter than most bathroom fans and are not tested for noise by Energy Star and the Home Ventilating Institute (HVI). Since a fan may run continuously throughout the day when used as primary ventilation, it also needs to be energy efficient.
The energy efficiency, or efficacy, of ventilation fans is measured in cubic feet per minute (CFM) of air moved per watts of energy consumed. Products listed here are certified by Energy Star and HVI to have an efficacy of 4 or greater and, in the case of bathroom fans, generate no more than 1.0 sone.
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