CIRCULATION LAB

Purpose of Lab

The purpose of this lab is to prove that the addition of our prototype would not upset the balance of the existing HVAC systems and could be implemented in almost any system. This lab is designed to measure variables such as the ones mentioned prior whilst also powering our test UV light to see if inserting it affects any variables. Our hypothesis is that if our prototype is added to the existing HVAC system, no variables that keep the balance of the HVAC system will be affected.

Outlined Procedure

Procedure I

Step 1: Install software mentioned in materials list and test for functionality for both software and Arduino hardware mentioned. Also test UV light for functionality. Be aware of safety precautions for being exposed to UVC light.

Step 2: Leave both the model HVAC system and UV light off. Initiate Arduino sensor software and Monitor variables in the test room for approximately 5 minutes or until variable levels become stabilized.

Step 3: Once stable, let the sensor run for 15 minutes and monitor measurements throughout the allotted time. Record data for any significant changes.

Step 4: Run chi square tests for goodness of fit to find if data truly affected variables in system.

Procedure II

Step 1: Find the pitch of the based on the marketed items listing description.

Step 2: Use the pitch of the to calculate the complete column length of the fan. (Complete column length – the complete length of air that the fan pushes within a minute) Use the equation: Complete column length = pitch of fan * rpm of fan

Step 3: Calculate the volume of air the fan pushes within a minute using the following equation:

Cubic Feet per Minute (CFM) = pi * fan radius^2 * complete column length

Step 4: Use the calculated cubic feet per minute in substitution for Q, volumetric flow rate, in the following equation to find the air changes per hour that the system imposes upon the HVAC system: Air Changes Per Hour (ACPH) = (60*Q)/(Volume of the room)

Our Equipment

Arduino IDE software (above)
Classroom diorama with Arduino sensor in right corner (below)

UV-C lights between two fans (below)

3D printed duct with motorized fans inside (above)
Arduino sensor (below)

UVAP on HVAC

How our prototype affected static variables in the HVAC system:

Humidity was measured in relative humidity which measures water-air mixture. Humidity also changed by very small intervals. The lowest percentage was 33.15% and the highest percentage was 33.23%. So, the range was smaller than a 10^th of a percentage, and at its highest, the humidity was only 0.05% higher than the average humidity of 33.23%.

Pressure was at a constant of 88.29 kilopascals.

Gas was measured in kiloohms which measures the concentration of gas in a room. If the resistance increases, the concentration of gas is decreasing. If the resistance decreases, the concentration of gas is increasing. As can be seen in the graph above, minimal changes are made throughout the time the system was running. The minimum kohm amount was 11.31 kohms while the maximum was 11.49 making a range of only 0.18 kohms.

The temperature was measured in degrees Celsius. The lowest temperature was 28.44 degrees while the highest was 28.52 degrees. The test had a range of 0.8 degrees Celsius (1.44 degrees Fahrenheit).

Lab Conclusion

It was found that the UV light implemented into the model HVAC system did not interfere with the balance of the of the existing HVAC system. Through testing it was found that the variables in the system changed negligibly, and to further prove its insignificance, a chi square test for goodness of fit was run of each variable. With a p value of 1, a null hypothesis would fail to be rejected. There was no evidence that installing our UV light into an HVAC system would change any variables.

Implementing our UV light prototype would be an effective way to clear out bacteria in an HVAC system while not being intrusive on the existing system.

Lab Report

CircleLabWriteUp.docx

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