Von Löwen Designs

Pacific Gas and Electric Company suggests that if your heating system is more than 15 years old, you should consider upgrading it for increased comfort and energy savings. What makes a newer furnace more efficient? Some older furnaces have pilot lights that burn all the time, wasting energy, while new models have electronic ignition. Even more significant is the Annual Fuel Utilization Efficiency (AFUE), which is a rating of how much energy the furnace turns into usable heat in you home. The higher the AFUE, the less energy the system will use and the less money it will take to heat your home. The AFUE of older furnaces may be as low as 50 – 70 percent.

When replacing a furnace choose an ENERGY STAR qualified furnace with an AFUE of 90 percent or higher. For a current product list of ENERGY STAR gas furnaces click here.

For ENERGY STAR qualified oil furnaces click here, and be sure to contact your local utility for information about potential rebates for high efficiency furnaces.

If your home does not already have a programmable thermostat, consider having one installed. It can be set to automatically turn the temperature up or down at programmed times. For example, delivering less heat during sleeping hours, or increasing it just before you wake up. It’s a relatively inexpensive upgrade that offers energy savings and convenience.

For a current ENERGY STAR programmable thermostat product list click here.

Design and Install HVAC System to ACCA Recommendations.

Air Conditioning Contractors of America (ACCA) has provided 5 informative manuals pertaining to residential HVAC systems. Of these ACCA manuals D, J, and S contain information that is directly relevant to HVAC system function, design and efficiency.

Manual D.

Residential duct systems have a direct and significant effect on equipment size, equipment efficiency, equipment malfunctions, envelope infiltration, operating cost, utility demand loads, vent performance, exhaust system performance, indoor air quality, ambient noise, occupant comfort and owner satisfaction. Therefore, the duct system must be carefully designed and properly installed or the potential benefits that are associated with building an efficient structure and using high efficiency equipment will not materialize.

ACCA manual D presents the methods and procedures that should be used to design residential duct systems. The subject material includes information about system selection (constant volume or variable volume), system performance characteristics, duct materials, blower performance, airside devices and duct sizing procedures. ACCA manual D also includes information about duct system efficiency and the synergistic interactions between the duct system, the envelope, the HVAC equipment, the vents and the household appliances. Indoor air quality, noise control, testing and balancing also are discussed. Other ACCA manuals that pertain to residential HVAC system design include Manuals J (loads), S (equipment selection), T (basic air distribution) and H (heat pumps).

Manual J.

ACCA Manual J is primarily a load calculation manual. The first six sections of ACCA manual J outline a simple, accurate procedure which can be used to estimate the heat loss and heat gain for conventional residential structures. Residential heating and cooling systems must be selected and designed to provide comfort conditions in all occupied spaces regardless of season. Temperature, humidity, air movement and ventilation must be controlled by the system. In addition, the system must perform these functions at maximum efficiency in order to minimize energy consumption.

The load calculation is the basis for the system design. Loads must be analyzed if the furnace, condensing unit, fans, coils, ducts, and air terminals are to be sized correctly. Comfort, efficiency and reliability are closely related to correct sizing and selection of equipment.

A load calculation must be made for each room so that the room cooling and heating requirements can be determined. This information is needed for terminal selection, fan and duct sizing. A load calculation must be made for the entire structure in order to properly size the heating and cooling equipment.

Manual S.

ACCA Manual S is a comprehensive guide for selecting and sizing residential heating and cooling equipment. ACCA Manual S documents the procedures that should be used to select and size residential cooling equipment, furnaces and heat pumps. These procedures emphasize the importance of using performance data that documents the sensible, latent or heating capacity for a wide variety of operating conditions. This manual also suggests sizing strategies for all types of cooling and heating equipment and it discusses the nuances of the presentation formats that are used by equipment manufactures.

Doing these calculations correctly and installing the system correctly and as indicated by the calculations will result in an efficient and effective HVAC system that will deliver comfort and energy savings. Insist that your HVAC contractor uses ACCA Manual S to size your unit. When contractors use rule of thumb the unit is often too big, which means greater upfront costs, higher energy bills and reduced comfort. An oversized unit will cycle on and off too quickly which does not adequately remove moisture from the air leading to mold and mildew. Manual S takes a myriad of factors into account rather than just square footage. Ask your contractor to show you the Manual S calculations for your home.

Install High Efficiency, Sealed Combustion Heating Systems.

High efficiency heating equipment increases comfort, reduces pollution, and lowers energy use and associated greenhouse gas emissions. High energy efficiency systems include ENERGY STAR qualified heat pumps. Some heating systems are designed to provide both space heating and hot water; the heat source may be a boiler, furnace, solar water heater or heat pump.

Furnaces and Boilers.

When replacing the furnace or boiler, select a sealed-combustion ENERGY STAR qualified model with 90 percent or greater AFUE (annual fuel utilization efficiency) rating.

For a current product list of ENERGY STAR boilers click here.

Sealed combustion furnaces, boilers and water heaters duct outdoor air directly into a sealed jacket around the combustion chamber so that air from inside the house isn’t used for combustion. These products also vent combustion gases directly outdoors so that they don’t pollute the home.

Heat Pumps.

In many climates and in locations where switching form electric to gas is difficult, electric air-source or ground source heat pumps are an alternative to combustion furnaces and boilers. Unlike combustion heating systems that convert fuel into heat, heat pumps use the difference between outdoor air temperatures (or ground temperatures) and indoor air temperatures to cool and heat your home. Select ENERGY STAR qualified models for better energy efficiency.

For a current product list of ENERGY STAR electric air-source heat pumps click here.

Properly sized, high efficiency heating equipment reduces heating bills and protects air quality. Sealed combustion furnaces, boilers and water heaters prevent backdrafting. This can occur when exhaust fans, clothes dryers or leaky ducts negatively pressurize a house; this negative pressure can pull carbon monoxide into the house from the furnace’s or boiler’s vent flue.

Electric heat pumps can often provide more efficient heating and cooling then standard separate furnace and air conditioning units.

Geothermal Heat Pumps.

A new ENERGY STAR specification for geothermal heat pumps went into effect on December 1, 2009. The new specification allows water-to-water GHPs to immediately be eligible to qualify for the label. On average, ENERGY STAR qualified products covered under this new specification will be over 45 percent more energy efficient than standard options.

Anticipating advances in technology in the coming years, EPA has set more stringent efficiency requirements to ensure that ENERGY STAR continues to represent top performers in this category.

New requirements for water-to-air and direct geoexchange GHP models will take effect on January 1, 2011. Even more stringent levels will go into effect for water-to-water and water-to-air models on January 1, 2012.

As of December 1, 2009 homeowners who install geothermal heat pumps with the ENERGY STAR are eligible for a 30 percent federal tax credit.

Geothermal heat pumps are similar to ordinary heat pumps, but use the ground instead of outside air to provide heating, air conditioning and, in most cases, hot water. Because they use the earth’s natural heat, they are among the most efficient and comfortable heating and cooling technologies currently available.

For a current product list of ENERGY STAR qualified water-to-air and DGX model geothermal heat pumps click here.

For ENERGY STAR water-to-water geothermal heat pumps click here.

Install Zoned, Hydronic Radiant Heating with Slab Insulation.

Instead of providing warm air via ducts, hydronic radiant heating systems circulate hot water through under-floor tubing, wall radiators or baseboard convectors. Their heat source can be a boiler, conventional water heater or solar water heater.

Hydronic radiant heating is most appropriate in cold climates or in homes where air conditioning is not needed. Design the system in accordance with Radiant Panel Association (RPA) guidelines and use an RPA-certified installer. To reduce heat loss to the ground, the entire slab should be insulated to a minimum or R-5.

Many people find hydronic radiant heating more comfortable than forced air heating. Hydronic radiant heating can provide more even heat throughout a room, reduce drafts and eliminate duct leakage. Hydronic radiant heating systems are also easily zoned, which allows residents to turn off the heat in areas of the home that aren’t being used.

Install High Efficiency Air Conditioning with Environmentally Responsible Refrigerants.

Energy-efficient air conditioning equipment saves homeowners money and reduces demand for electricity from power plants. Environmentally sound refrigerants reduce the risk of damage to the ozone layer.

Air conditioners are rated according to SEER, or Seasonal Energy Efficiency Ratio and according to EER, or Energy Efficiency Ratio. Higher SEER and EER ratings mean greater energy efficiency.

Choose an air conditioner with a SEER of 14 or higher or an EER of 11 or higher. While these units usually have higher upfront costs, they are a good investment. Many utilities offer rebates for higher efficiency units.

For a current product list of ENERGY STAR qualified central air conditioners click here.

For a current list of ENERGY STAR room air conditioners click here.

For ENERGY STAR’s handy cost savings calculator click here.

The air conditioner should have a thermostatic expansion valve (TXV), which is a refrigerant regulation device that can help ensure that the system operates at maximum efficiency over a wide range of conditions. Some air conditioning equipment comes with a factory installed TXV and others accept a TXV that can be bolted on by an HVAC contractor.

Another good strategy for energy efficiency is a zoned central air conditioning system, which allows two to four zones to be conditioned at different temperatures so only the spaces being used are cooled.

When choosing a new air conditioner, make sure it doesn’t use hydrochlorofluorocarbon (HCFC) refrigerants. HCFCs can destroy the ozone layer if the refrigerant leaks out of the air conditioner. R-22 (HCFC-22) is an HCFC refrigerant commonly used in may residential cooling systems. The federal Clean Air Act requires that HVAC manufacturers discontinue using R-22 in new air conditioners by 2010.

Some new models already use alternatives to R-22 refrigerant, including: R-410a, R-134a or R-407C. Common trade names for these refrigerants are Puron®, SUV-410A®, GENETRON AZ20®, DuraCool®, and more.

Make sure that refrigerants are handled properly; always select a reputable dealer that employs service technicians who have been EPA certified to handle refrigerants.

High efficiency air conditioners save money and energy, and reduce peak electricity demand. Installing air conditioning systems with TXV lowers utility bills and saves energy.

If the refrigerant leaks during replacement, a non-HCFC refrigerant will not damage the ozone layer.

They say a picture is worth 1,000 words, so before you leave be sure to visit Von Löwen Designs to view an assortment of refreshing examples in kitchen and bath design concepts, refined palette and interior finishes, and sustainable yet chic, green remodeling ideas that may encourage and inspire your next remodel or home improvement project.

If you stop and think about it, in a many numbers of ways, an adept designer’s skill set should be very comparable to those of a successful professor or teacher. Both having the objective to encourage and provide guidance to the student/client to get from Point A (what they know, understand and believe to be true in the present) to Point B (an advanced state of deeper understanding and knowledge to enable and support a conclusion).

I’m not sure if you will find many noteworthy educators that just stand up in lecture to simply declare B as the correct answer. Of course not, there is considerably more to it than that, and similar methods will apply to a proficient design approach.

At the outset a designer most posses a thorough understanding of Point A. Meaning: Where is your client starting from? What do they understand now? What do they believe and why do they believe it? For what information and knowledge are they ready? What are they doing now and why are they doing it that way? This comprehension of your client’s perspective can only come from doing a lot of direct questioning and careful listening, saving your own reactions and opinions until much later in the process.

Having an appreciation of Point A, the designer cannot proceed directly to a discussion of Point B and it’s objective quite yet. The designer must develop and nurture a reasoning process that initiates a focus on the differences and a journey of discovery for all parties involved. The goal here is an interactive way to guide your client, shining light on any present enigmas and facilitate those doors to be opened so that upon reflection your client will come to their own conclusion that Point B is the more suitable way to proceed. Thus avoiding the awkward and uncomfortable position of trying to convince them.

I always try to remember to ask those sometimes difficult to handle questions that initially might appear that I am literally trying to sway my client out of doing the assignment, and you know in some cases we do realize together that moving forward is not the best solution to their existing predicament. On the other hand, together we may conclude that in order to truly resolve what’s troubling them their scope of work will need to be increased, and it will be necessary to rethink the entire downstairs floor plan instead of just knocking down a single wall. You never can tell. It works both ways, but the bottom line is the result was never forced or just provided, and their commitment was achieved through reasoning and discovery by closely working together.

Have a wonderful holiday!

lars-

They say a picture is worth 1,000 words, so before you leave be sure to visit Von Löwen Designs to view an assortment of refreshing examples in kitchen and bath design concepts, refined palette and interior finishes, and sustainable yet chic, green remodeling ideas that may encourage and inspire your next remodel or home improvement project.