phc April 2022 www.phcppros.com
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GEOTHERMAL HVAC
City with one of our clients in February 2022. This cooperative apartment complex in Manhattan saw that wastewater thermal energy exchange was the most cost- effective use of geothermal exchange-type heat pump technology available today to reduce greenhouse gas emissions. Whenever you take a shower, run the wash machine or dishwasher, the temperature of the water going down the drain is going to be warm, at least as warm as the indoor temperature. It even counts for flushing toilets because those flush tanks often have enough time indoors to assume room temperature. Wastewater energy exchange extracts the heat by sending wastewater through a heat exchanger, where a geothermal heat pump heats the domestic water. It can even provide space heating and cooling, or about any other heating and cooling function that may be needed. Similar to an ERV in principle, the heat going out of the building is captured and sent back to a mechanical device - in this case, a heat pump providing domestic hot water, heating and cooling. In this process, the energy stays in the building and is re-used. After noting the energy consumption in US buildings, it's easy to see that DHW runs second only to the energy consumption for heating and cooling It's important to understand some of the ways energy can be recovered. It's easy to convert waste heat, or thermal energy, to a warmer temperature by use of a fluid/water-sourced heat pump, more often called a geothermal heat pump. A GHP's job is to move thermal energy "uphill" - to increase the temperature. With 70-degree wastewater, the jump to 130+ degrees can be done efficiently, boasting a coefficient of performance of 4 or 5. A COP of 5.0 means that for every unit of electricity used, five units of heat are transferred. GHPs are the central component of the thermal extraction/rejection portion of energy recovery. They use available energy in liquids between 25 degrees and 110 degrees and can absorb or reject heat to and from them. GHPs are thermal energy pumps, concentrating heat energy through the Carnot Cycle principle, delivering final temperatures from well below freezing to more than 140 degrees for uses such as space conditioning, refrigeration or domestic hot water. Wastewater temperatures are favorable for the process of thermal transfer with GHPs. The average temperature of wastewater for all buildings/dwellings is between 65 degrees to 75 degrees, right in the middle of the highest efficiency ranges for GHPs. A GHP uses liquid (similar to the water entrained in pipes, underground or even from a sewer line) as a heat source or a heat sink. There is a lot of energy in 70-degree water, but at that temperature, the water is also able to absorb vast quantities of energy effectively. When the water is giving off heat, it's a heat source. When it's absorbing heat, it's a heat sink. Hydronic systems are amazing because they effectively channel BTUs within a pipeline, unlike air-source systems. GHPs make the magic happen by manipulating BTUs to whatever temperature is needed at the time. They are the center of the energy universe for renewable and sustainable energy systems. [Disclaimer: I'm a neutral industry consultant. This story was selected solely on its value to the industry.] l Jay Egg is a geothermal consultant, writer and the president of Egg Geo. He can be reached at jayegg.geo@ gmail.com.
MADE IN USA 2021 General Wire Spring
Operating like a check valve, the Flood-Guard will seal off water back-up from overloaded sewers. Water flows normally through the drain until the sewer backs up, then the float rises and seals off the drain until the water recedes. Installation is simple, and once in place it can prevent property damage and some very messy clean-up jobs. Learn more by calling the Drain Brains at 800-245-6200, or visit www.drainbrain.com/floodguard
Flood-Guard
STOP BASEMENT FLOODING!
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