1. Geo-Exchange Addison Parks and Andy Gerla

2. Summer Time Ground Temperature Constant 60 ̊ F Home walls are mainly heated from the Sun’s radiation and cooled by the convection of wind. This results in an uncomfortably warm home. Due to green initiatives, it would save money and protect the environment to cool a home through a geo-exchange system rather then a conventional AC Unit. Here we have a home resting on what are called heat pump piles. Fluid circulates through the cooler heat pump piles and then through the home to absorb the heat coming from the outside. That way the outside heat never raises the internal temperature. Preferred Temperature 72 ̊ F Outside Temperature 92 ̊ F

3. Heat Pump Piles The only energy required to run a heat pump pile is the pump situated at the top. The energy required to run the pump is minimal compared to an AC unit. Warm fluid coming from the home circulates down the center of the pipe and then returns to the home passing by the outer wall of the pipe. We will now determine how long the pile will need to be assuming T m,i = 92 ̊ F, T m,o = 61 ̊ F, r 1 =10cm, r 2 =12cm, r 3 =15cm, and the pipe is made out of a board of glass fiber.

4. Wayne in Ground Pump We will use this Wayne in Ground Pump. This pump does 6120 GPH or.00643 m^3/s. Our fluid will be water.

5. r1r1 r2r2 r3r3 L r 1 =.010m r 2 =.012m r 3 =.015m T m,i = 92 ̊ F T m,o = 60 ̊ F Table A.3 Glass fiber k=0.058 W m ̊ K = 306 ̊ K = 289 ̊ K Table A.6 Water @ 297 ̊ K k=608.8E-3 W m ̊ K µ=917E-6 Ns m3m3 Calculations It is determined that the equivalent diameter is 0.04m The Reynolds number is 202,660 and therefore turbulent. Using Seider we find Nu D is 854 h is 21673 W/m^2*K R tot is.613 K/W Therefore the required length is 20,855 meters. This length is impractical. Pr=6.3 c p =1.87kJ/kg*K

6. A more practical situation would be to decrease the size to r 1 =5mm, r 2 =7mm, r 3 =8mm. Then decrease the flow to 1.43 Gallons an hour. This results in the following: It is determined that the equivalent diameter is 0.004m The Reynolds number is 87 and therefore laminar. Nu D is 173 h is 159 W/m^2*K R tot is.509 K/W Therefore the required length is 4 meters. In conclusion, we’d determine how much heat comes from the walls and that would determine how many Heat Pump Piles a home would need. Corrected Values Pipes to Heat Pump Pile Additional pipes may be needed to remove internally generated heat.