Geothermal Heat Pumps Have Lower Lifecycle Costs

Qualified geothermal heat pumps have traditionally used 30 percent less energy than standard heat pumps, but with the recently developed ENERGYSTAR specification that went into effect in December 2009 the efficiency should improve to 45 percent. Though more expensive to purchase than standard options, the difference will most assuredly by paid back over time through reduced energy costs. Any residential customer who installs a properly qualified geothermal heat pump is eligible for a 30 percent federal tax credit.

Geothermal Heat Pump Sizing and Installation

In order to ensure comfort and projected savings, residential customers are advised to use a contractor who is knowledgeable of the practices necessary to custom fit these specialized heating and cooling systems to homes. Some key items of concern include:

• Sizing of the Equipment: In order to properly size the equipment, consider heat losses during cold weather and heat gains during warm weather. Though a factor, neither the square footage of a residence nor the size of existing equipment should be primary determinants in determining the proper size. Over-sized equipment can create discomfort, excessive noise and shorten the life of the equipment; and undersized equipment will negatively impact the efficiency of air distribution and likewise, accelerate wear on system components (resulting in earlier failure).
• Sealing of Insulating of Ducts: In conjunction with installing the geothermal heat pump, the contractor should test the air ducts to identify and seal leaks. The sealing is typically done using mastic, metal-backed tape, or aerosol-based sealing. In some cases, it may be advised to replace or add ducts and if the number of supply registers or return air grilles in a residence is insufficient, it may be necessary to add ducts to accommodate this need. If these additional ducts must be located in an unconditioned space (e.g. attic or crawlspace), insulation should be applied.
• Checking and Correcting of Airflow: The contractor should ensure an optimal air flow for comfort, savings and preservation of the equipment by testing the air flow (particularly after duct leakage repairs have been made).
• Charging Refrigerant: Recognizing that incorrect refrigerant levels can lower efficiency by between 5 and 20 percent and lead to premature failures ( and especially costly repairs that could have been prevented), a contractor will typically use super-heat, sub-cooling or weigh methods to verify that the proper level of refrigerant has been put in the system.
• Placing Equipment: Manufacturer’s installation instructions typically provide the best guidance in determining the optimal location for equipment. Common sense suggests that indoor equipment should be installed in conditioned spaces (or well-insulated), and outdoor components should be located out of the sun and outside areas with a lot of debris. Also, installation should be in easily accessible for maintenance purposes and there should be sufficient clearance to allow free airflow around the equipment.

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