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.
Just how low the VOC level needs to be for a given product to qualify for inclusion in GreenSpec depends on the product category. For most products, we require certification to California’s health-based emissions standard, CDPH Std Method v1.1 standard (also referred to as California Section 01350), which tests a product’s resultant VOC concentrations in the space after a given period of time. For wet-applied products like paints, caulks, and adhesives, we still also look for VOC content instead of, or in addition to, verified low emissions; this is because emissions testing doesn’t adequately test initial offgassing, and VOC content is currently the only widely available proxy.
PROseal is a smooth, water-based duct sealant for low, medium, and high pressure metal duct systems. Intended for interior or exterior use, low-shrinkage PROseal remains permanently flexible and is mildew-resistant and paintable. PROseal contains 41 g/L VOCs and is also available in a fiber-reinforced formula, FIBERseal, with 21 g/L VOCs.
Duct leakage is a major problem with forced-air heating or air-conditioning systems. When ducts are run outside of the conditioned space, heating and cooling efficiencies may be cut in half due to leakage. Tightly sealed ducting is extremely important in ensuring high energy efficiency of forced-air HVAC equipment.
Experts strongly recommend flexible duct mastics—not duct tape—for sealing ducts, as mastics last longer under high temperatures. In some applications, however, the messiness of mastics can be a problem. Newer types of duct tape, such as oriented polypropylene or butyl tapes, can outlast standard cloth duct tape, but joints must still be mechanically fastened. GreenSpec lists sealants with a maximum VOC content of 50 g/L.
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