Energy Efficiency In Maine
Team 3
This photo shows the unit in the beginning stages of fabrication. The aluminum frame can be seen as well as the wooden wall with the outdoor unit of the heat pump mounted to it. The display screen can also be seen on the right side of the unit and the casters mounted to the aluminum frame can be seen at the bottom.
The next photo shows a different view of the photo above. Once again, the outdoor unit of the heat pump can bee seen mounted to the wooden wall as well as the display screen mounted to the aluminum frame. The aluminum frame was very time consuming to fabricate, but makes the unit very light-weight for it's size.
The photo below shows quite a few components of unit in the later stages of fabrication. The indoor unit of the heat pump can be seen mounted to the left side of the wooden wall as well as the 120v AC to 240v AC transformer mounted above the outdoor unit of the heat pump on the right of the wooden wall. Also, the styrofoam board insulation can be seen being fitted into place before the walls are assembled.
The next photo shows the NEMA electrical box mounted to the top of the aluminum frame as well as the heat pump power cord and power meter wires being routed through the wooden wall. Also, this photo shows the back styrofoam board wall in place as well as the hole cut in the back wall for the exhaust fan (fan 1 of 2).
The next photo shows walls and trim mounted on the unit. In the picture the fan holes on the top and back sides of the unit can be seen as well as the NEMA box mounted on the top of the unit.
The next set of photos shows the National Instruments LabVIEW software used for the data acquisition system and control system in the unit. The photo directly below this excerpt is of the "front panel" or the display screen of the data acquisition and control systems. This display shows the temperatures on either side of the heat pump, the heat pump coefficient of performance and the cost/btu of the heat pump. It also has a dial to control the temperature of the enclosure and graphs the coefficient of performance of the heat pump.
The next picture is of the the temperature data acquisition code. Daqmx functions were used to specify the chanels and sampling rate after which a read data daqmx function is used inside a while loop to read the temperature data and then the data is manipulated to be displayed in degrees celsius and degrees fahrenheit.
The next bit of code shown is the control system for the fans. This section of code takes the temperautre data for inside the unit and compares it to the set point temperature. Then using a case structure, if the temperature inside the unit is less than the set point temperature, the fans are turned on to bring warm air into the enclosure. If the temperature inside the unit is above the set point temperature, the fans are left off to let the heat pump drop the temperature of the enclosure.
The next couple pictures show our NEMA electrical enclosure and all of the wiring for our systems. In the picture directly below this text, the relay for the fans can be seen in the bottom left of the box, the National Instruments USB Daq can be seen in the lower right of the box and the EKM Metering Power Meter can be seen directly inbetween the two. Above the power meter is a breaker swtich for the power to the fans, above that is a ground terminal for the fan power ground and above that are the terminals for the fan power and neutrual. The 120V AC power comes in from the wall outlet through the breaker and into the relay. The power then leaves the relay and is split to go to the two different fans. The relay is powered by a 5V constant signal from the NI daq and switched by a 5V switched signal from the NI Daq. Also, the yellow and brown wires going to the NI daq are the wires for the temperature sensors. The temperature sensors require a ground, a 5V input and a signal wire. Finally, the red wires and black/white twisted pair are the power and current measurements from the heat pump being input into the power meter. The output signal from the power meter is not yet wired in the picture below.
The next photo shows the final product of the heat pump demonstration unit. The display screen which is hooked up to a laptop running National Instruments LabVIEW can be seen as well as the indoor unit of the heat pump on the right side of the demonstration unit.
The final picture here shows another view of our NEMA electrical enclosure with all of the wiring completed. In this photo, the relay can be seen at the top left of the enclosure, below that is the power meter and below the power meter is the National Instruments DAQ. In this picture the output wires can be seen leaving the power meter and connecting to a NI USB-485 cable in the bottom right of the enclosure.
Final Design / Report
This section of the website outlines the final design of our project and shows all of the components during and after fabrication. Also, below this text is a link for the Final Report of our project.