Heat Pump Clothes Dryer Presented on April 23, 2008 By Brian Pollica Michael Hildenbrand

Product Background The clothes dryer is one of the most common appliances in a typical household. A typical family of 3 can do an average of 6 loads in the dryer in a typical week. The energy put into a dryer is not completely utilized by the dryer, thereby exhausting a certain amount of energy to the atmosphere. If the energy can be calculated and captured, the energy savings to the home owner may be significant.

Design Considerations Capture the heat exhausted to do one of the following:  Condition the air to heat a building  Utilize a heat exchanger to: Preheat water to reduce hot water heater costs, or Preheat the inlet air to reduce energy usage by the dryer  Utilize a heat pump to re-circulate the exhaust air

Calculations Air Conditioner SEER = BTU / W*H COP = SEER / 3.792

Solution Heat Pump Clothes Dryer Re-circulation of exhaust air Temperature and Humidity sensors Condensation control Interface with Dryer controls for shut offs and heat control

Condenser Coils Evaporator Coils Dryer & Heating Element Compressor Expansion Valve DAQ Temperature sensor Humidity sensor Temperature sensor Humidity sensor Heat Pump System Overview

Front panel

Back Panel

Temperature Sensor Circuit LM335 The voltage out is 3V which is obtained using the voltage divider circuit created by the 1K resistor and the LM335. The LM335 operates at the 3V level and will change the output voltage by a few hundred mV depending on the surrounding temperature, as the temperature goes up the output voltage will go up and vise versa as temperature goes down.

Humidity Sensor Circuit

Organization (Planning)‏

Budget DescriptionProject CostActual AC UnitDonated$ Dryer UnitDonated$ Temp SensorsDonated$ $7.35 Humidity Sensor $7.92 each (2)‏ Lab ViewAvailable$2499 PolycarbonateDonatedunavailable Total$49.76$ Duct work and hardware – Appliance cord – 8.47

Summary/Conclusions The heat pump is much too low for this application.