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Issue
#9 |
Welcome to the HVAC issue of the Affordable Energy News, an information source to help you make homes more affordable through energy efficiency. Aimed at the affordable housing market within Southern California Edison's service territory, this newsletter seeks to provide up-to-date information on energy efficiency topics such as funding sources, technologies, training, and case studies. | |
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In this issue... Efficient Heating, Ventilating and Air Conditioning (HVAC) Equipment Correctly Sizing an Air Conditioner Proper Duct Design and Installation AHEEA Handbook: Your Guide to Energy Efficiency in Affordable Housing Energy Efficiency Programs and Incentives
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Efficient
Heating, Ventilating and Air Conditioning (HVAC) Equipment
Purchasing a heating and cooling system for new and existing multifamily homes represents a major cost decision. Since the lifetime cost of running heating and cooling equipment can surpass the cost of the equipment itself, it pays to get the selection right the first time. When high efficiency equipment and distribution systems are combined with efficient building envelope measures and an accurate building load calculation, mechanical equipment can be properly sized, and result in significant cost savings. The most typical systems found in multifamily buildings are:
Electric resistance
heating and Packaged Terminal Air Conditioners (PTACs) are the least
efficient equipment, while a heat pump or split system can be made
highly efficient. The simplest approach
to improving equipment efficiency is to choose ENERGY
In Resources for HVAC
selection Consortium
for Energy Efficiency’s (CEE) Directory of California
Energy Commission Appliances Database www.energy.ca.gov/efficiency/appliances/ Correctly
Sizing an Air Conditioner Oversizing an air
conditioner is a costly mistake, both in the inflated first cost of
equipment and also in the extra cost to run the oversized equipment.
When HVAC equipment is oversized, there is a significant efficiency cost
because the equipment is cycling on and off more often. This
increases wear and tear on the equipment, which reduces life expectancy
and increases maintenance costs. In addition, oversized equipment can
cause uncomfortable drafty conditions and unnecessary noise. Conversely, right-sized systems provide even heating and cooling, and quiet operation. Properly sized equipment can reduce energy usage by as much as 35%.[1] Rightsizing an air conditioner starts with an Air Conditioning Contractors of America (ACCA) Manual J, or an American Society of Heating Refrigerating and Air Conditioning Engineers (ASHRAE) approved equivalent calculation. This calculation will accurately determine the space heating and cooling loads taking into account climate conditions, orientation, and building material properties. Once the maximum heating and cooling loads have been determined, the equipment is sized to meet those loads.
Proper
Duct Design and Installation
HVAC equipment
efficiency is only part of the equation for an energy efficient HVAC
system. No matter how efficient the equipment is, if the
distribution system is not also well designed and operating properly,
then the HVAC system as a whole will not be efficient. Air
distribution systems, e.g. a ducted system with a fan that blows warm or
cool air through the ducts, are common because they are low cost and can
perform double duty for heating and cooling (triple duty if used for
outside air ventilation also). Unfortunately, these systems when poorly
installed, and located outside of conditioned space, can lose over 30%
of the energy consumed by the equipment that is conditioning the space. Duct Design and
Installation Tips:
Ventilation
It is important to note
that there is a balance between energy savings and adequacy of indoor
air quality. High ventilation rates will result in increased energy
consumption due to the effort needed to heat/cool the larger quantity of
outdoor air before it is supplied to the dwelling unit. Having a very
low ventilation rate, however, may result in poor indoor air quality,
commonly known as the ‘sick building’ syndrome. It is important that
the supply ventilation air spreads throughout the dwelling unit. It is
also important to maintain pressure inside the house that is as close as
possible to the outdoor air pressure. Ventilation can be
natural or mechanical. Natural ventilation may require some
occupant interaction – such as opening and closing windows, or it may
utilize mechanically controlled openings. Mechanical ventilation
utilizes fans to achieve “forced” air exchange. This is a more
energy intensive process but must be weighed against indoor air quality
concerns.
AHEEA Handbook: Your Guide to Energy Efficiency in Affordable Housing Download a free color copy today at www.h-m-g.com/aheea, or send an e-mail request to aheea@h-m-g.com for a black and white hard copy. Energy Efficiency Programs and Incentives For information on SCE's multifamily affordable housing incentive programs, please see programs and contact information below: New Construction: For information
on SCE's California New Homes Program, please visit www.h-m-g.com/multifamily/CANHP
or contact Colin Jessop at 760-436-7005 or Rehabilitation of Existing Buildings:
For information on SCG/SCE's Designed for Comfort Program, please visit www.DesignedforComfort.com
or contact Elizabeth McCollum at 760-436-7001 or Affordable Housing Design Assistance
and Charrettes: For more information on SCE's Affordable Housing
Energy Efficiency Alliance, please visit www.h-m-g.com/multifamily/aheea
or contact Julieann Summerford at 760-436-7002 or
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This program is funded by California utility ratepayers and administered by Southern California Edison Company under the auspices of the California Public Utilities Commission, through a contract awarded to Heschong Mahone Group. California customers who choose to participate in this program are not obligated to purchase any additional services offered by the contractor. The trademarks used herein are the property of their respective owners. SCE reserves the right to modify or discontinue this program at its discretion or by order of the CPUC. Este programa es financiado por los usuarios de las compañías de servicios públicos de California y es administrado por Southern California Edison Company bajo los auspicios de la Comisión de Servicios Públicos de California mediante un contrato con Heschong Mahone Group. Los contribuyentes de California que decidan participar en este programa no están obligados a comprar ningún servicio adicional ofrecido por el contratista. Las marcas registradas usadas aquí son propiedad de sus dueños respectivos. SCE se reserva el derecho a modificar o interrumpir este programa a su criterio o a pedido de la CPUC. If this newsletter was
forwarded to you, and you wish to subscribe click here to send email. Heschong Mahone Group, Inc. 144 West D Street, Suite 24, Encinitas, CA 92024 |
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