Integrated Dehumidification Solution White Paper July 2018 An innovative approach to moisture removal for home health and humidity management Integrated Dehumidification Solution 2 Humidity Issues Impacting Building Health and Comfort Today’s highly energy-efficient homes have While high-performance homes reduce energy highly insulated enclosures and airtight use, the National Renewable Energy Laboratory construction and often require mechanical (NREL) and ventilation to bring fresh air into the indoor Department of environment. These high-performance homes Energy (DOE) conserve resources and save money on heating recognize that and cooling bills, but can suffer negative effects they also have from high humidity levels at certain times of an impact year in a number of U.S. regions. Increased on indoor humidity levels have a significant impact on environments: builders and architects, who are responsible for the health of their buildings, as well as z As homes homeowners, who seek to live in a comfortable, in humid safe indoor environment year-round. climates have Addressing the issue of high humidity requires become a basic understanding of the Home Energy more Rating System (HERS). HERS is the industry energy standard by which home energy performance efficient, is measured—much like the miles-per-gallon there is sticker on cars—giving prospective buyers and evidence homeowners an insight as to how the home that ranks in terms of energy efficiency. A lower relative number indicates a more efficient home: For humidity example, a home built to the 2006 International levels in Energy Conservation Code (IECC) will receive homes have been increasing.2 a rating of around 100, while a more recent home built to 2015 IECC would rate closer to 70. z As heating and cooling loads are shrinking, (Inefficient older homes can have a rating of supplemental dehumidification may be 3 150 or even higher.) Ultimately, the industry is required. pushing toward a net-zero trend—meaning that a home produces as much energy as it consumes through renewable resources.1 CHALLENGE Relative humidity, or the amount of water vapor minimizing these issues, including in homes in the air, is an important health variable that is that are unoccupied for extended periods. easy to overlook, yet very easy to remedy. Ideal For homeowners, high humidity goes beyond humidity is generally described as between 40 affecting the condition of their home’s interior percent and 60 percent. High-humidity indoor and furnishings: When indoor relative humidity environments present several major issues with rises above 60%, occupants of a home are regard to building health and human comfort. going to feel sticky and clammy in addition to Excessive humidity can cause problems with potentially being exposed to the harmful effects odor, mold, and mildew, and even peeling paint, of mold, mildew, bacteria, and dust mites— water damage, or loss of structural integrity making the environment particularly hazardous in the most severe cases. Developers, builders, for people with asthma and allergies. and architects all have a vested interest in 1 HERSindex.com 2 ASHRAE Research Project Report 1449-RP, “Energy Efficient and Cost Assessment of Humidity Control Options for Residential Buildings” 3 National Renewable Energy Laboratory (NREL), “Building America Roadmap Overview: Optimal Comfort Systems for Low-Load Homes” Integrated Dehumidification Solution 3 GEOGRAPHY During the warmest seasons in areas with of spring and fall, when temperatures are in the generally high humidity—such as the Gulf mid-60s and 70s, significantly lower heating Coast and Southeast U.S.—regular heat pump and cooling loads are required. The relative or air conditioning cycles efficiently maintain humidity, however, may be quite high. As a humidity levels; in the coolest seasons, when result, typical indoor moisture sources and outdoor conditions are drier, high humidity is outdoor ventilation air can cause the indoor not an issue. In the so-called shoulder seasons relative humidity to rise to uncomfortable levels. STRIKING A BALANCE Although there are a number of ways and time, and energy usage all must be balanced system types to address excessive relative against building health, human comfort and humidity, there is no silver bullet. Some existing health concerns, and even ease of use. In this solutions require additional system components white paper, we will explain how the Trane such as high-end, whole-home dehumidifiers Integrated Dehumidification Solution (IDS) uses or low-end portable units. Others rely on over- a simple but cost-effective method appropriate cooling to remove humidity from the home, for this segment—servicing an unmet need which can lead to temperature fluctuations up for architects, homebuilders, and homeowners to 3°F off a thermostat set-point, resulting in a number of geographical regions in the in increased energy usage and potential United States. Although it is primarily targeted discomfort. Ultimately, each moisture-removal toward energy-efficient homes, Trane IDS can solution comes with pros and cons, and factors be incorporated into any home in which value- such as initial cost of ownership, payback oriented humidity control is desired. Integrated Dehumidification Solution 4 How The Trane Integrated Dehumidification Solution Works IDS takes a practical approach to the excessive- With IDS, home temperature is maintained humidity problem, pairing a specialized without over-cooling. A heater located within Trane thermostat with compatible Trane air the variable-speed air handler is an independent conditioning units, heat pumps, and variable- operating feature/mode and can be activated speed air handlers. When needed, home when too much humidity is detected, even if occupants can set the thermostat control to cooling is not needed. The result is a more three levels of dehumidification (low/medium/ predictable lowering of humidity all while high), depending on the comfort level desired. maintaining home comfort levels. When too much humidity is detected in the house, the IDS will run for a defined amount In basic terms, the IDS uses the of time out of each hour. (Note: To adhere to dehumidification function of the cooling coils code requirements, IDS is only available when in conjunction with the warming function of the system is in cooling mode. See Appendix for electric heat in order to remove moisture while additional detail.) maintaining neutral, comfortable temperatures within the home. 1 ndoor idiy ee inree de o inern ore or oi ir rog in ro e oide 1 2 ero dee idiy eeed e ere reerene o o edi or 4 ig deending on deired oor ee nd ond 2 e ye o rn on ooing 5 eeri e nd e rie eed ir 3 nder 5 er reded 3 e ye oiy idiy in e oe e ene e need o reoe ero onine o oire nd e ooed ir onior idiy ee nd e oer e eeri eing e r onino n eeen iin e ir nder ere i oiy nd i red o e e iro den o eerre o e oe 4 e ir nder en reen ny oire on e roiding onino oor ire e drier ondiioned oi or in e drin n ro ir rogo e oe ie reeoring nd eing oere inroded ino e oe IDS System Components Unique XL824 or XL1050 Control Outdoor Variable Speed Heat Pump or Indoor Mechanical Ventilator Air Conditioner Air Handler (not required in all homes) Integrated Dehumidification Solution 5 Why Trane IDS is Needed and the Benefits It Provides The market needs a technology that will provide year-round comfort in energy-efficient homes at the lowest upfront cost. There are two specific customer groups that can benefit from incorporating Trane IDS into their HVAC systems: RESIDENTIAL BUILDERS/ARCHITECTS The home construction industry is acutely aware of the problems caused by high indoor humidity levels, both from the perspective of homeowner satisfaction as well as the health of their buildings when vacant, prior to purchase. For those designing and building residential homes, Trane IDS represents a cost-effective option for basic dehumidification, given the low initial price and simple, fast installation. z Numerous builders and architects have requested Trane’s assistance to address these concerns. Trane IDS provides a value-oriented, integrated solution that makes financial and practical sense: z Lower initial cost of systems, due to use of existing Trane HVAC units that are compatible— rather than having to purchase separate equipment and accessories. z Similarly, use of those familiar product lines simplifies installation, minimizing labor costs and time on-site. z Effective removal of humidity from vacant homes protects their investment from hazards of mold, mildew, and odors, as well as the resulting callback issues. z More comfortable indoor climates result in increased homeowner satisfaction. HOMEOWNERS Occupants of energy-efficient homes need fresh air, but they also want to be comfortable and protected from issues such as mold, mildew, and odors. During winter and summer in humid regions of the United States, HVAC units effectively remove moisture from the air. During the shoulder seasons, when temperatures are moderate and homes require less heating or cooling, indoor humidity can rise to uncomfortable levels. For value-minded homeowners, Trane IDS provides several advantages: z Low initial cost of ownership. (See additional discussion below.) z Whole-house dehumidification through existing ductwork. z Creates more comfortable environment. z Mitigates health issues from mold and mildew. z Ease of use—interaction done with familiar thermostat programming via simple user interface offers low- medium-high levels, keeping relative humidity under 60% and as low as 45%4. z No maintenance required beyond regular servicing of the standard equipment. 4 The relative humidity in individual homes will vary based on outdoor conditions and installation. If more specific set points are desired, another solution—such as a whole-house dehumidifier—may be recommended.