Demonstration Installation:
  Heat Pump, Pennsylvania State Park

Where
The Pennsylvania Department of Conservation and Natural Resources selected Little Buffalo State Park Visitors Center in Newport, PA, as the site for a PaceController demonstration installation.

When
September/October 2005, consisting of:

  • One week of pre-installation baseline monitoring (9/14–9/20)
  • PaceController installation on 10/3/05
  • One week of post-installation monitoring (10/3–10/10)

What
Little Buffalo's Visitors Center receives heating and cooling from a large (13 ton capacity), approximately 2-year-old Carrier ground source heat pump. Two PaceControllers were installed on the heat pump—one on the compressor side and one on the auxiliary electric heat bank.

Top Line Results
This cooling-season demonstration installation showed a weather-corrected average electric demand reduction of 27.6%, with full maintenance of indoor temperature and humidity controls. The resulting projected savings are enough to pay for both PaceControllers installed in less than 2 years.

Demonstration Protocol
Demonstration phases would include:

  • 3-phase power monitoring of the Carrier heat pump
  • Temperature and relative humidity dataloggers installed in two visitors center interior locations:
    • Seminar room
    • Park manager's office
  • Ambient temperature datalogging, outside on the center's radio antenna mast to provide a correlation check with National Weather Service and other weather station data used in analysis
  • Logging of thermostat settings

Local Temperature Data:
Correlation Check with Local Weather Stations
With the datalogger set up on the radio mast outside the Visitors Center, temperature data were taken from 9/14–20, and data were compared on a day-average basis with temperature data from two Harrisburg weather stations. An average of the two Harrisburg stations' data was used for analysis at Little Buffalo.

Click here to view the site temperature readings and the day-average readings from all three locations.

Baseline Period Weather at Little Buffalo, 9/14–20
Data from the Harrisburg National Weather Service station showed higher average temperatures at the beginning of the observation period and cooler temperatures later in the week. However, cooling operation from the heat pump was still required.

Click here to view climatology data for the pre-installation measurement period.

Seminar Room Inside Temperature and
Relative Humidity Data, 9/14–20
The datalogger was placed about 8 feet up on a wall ledge. The data indicate indoor temperatures are reasonably well controlled around the thermostat set point of 72°F, with inside relative humidity (RH) in the room averaging around 56%—typical inside HVAC target is 50%.

Click here to view data from the seminar room for the pre-installation measurement period.

Park Manager's Office Data, 9/14–20
Datalogger was placed on an interior wall cabinet, at a height of about 4 feet. The data show that indoor temperature is about the same as the seminar room—average 72°F and relative humidity 56%.

Click here to view data from the park manager's office for the pre-installation measurement period.

Heat Pump 3-Phase Current Draw Data
without PaceController 9/14–20
Heat pump shows intervals of significantly extended run time, especially during hotter periods at the beginning of the observation period. For example, on 9/15, the unit ran continuously from 11 a.m. to 3 p.m.

Click here to view amp usage data during the pre-installation measurement period.

PaceController Installation Notes, 10/3/05

  1. PaceControllers were installed on the compressor and on the electric auxiliary heating elements in the standard configuration for heat pumps over 3–4 tons.
  2. During the installation, it was observed that the heat pump was only operating on the second stage, and that the first stage showed indication of icing.
  3. The heat pump's panel filters were found to be very dirty and were replaced, after which the heat pump operated normally on its two stages, as it had during the period 9/14–20.
  4. After the PaceControllers were installed and set, the three-phase power metering was replaced and restarted for the one-week post-installation datalogging.

Inside Temperature and Relative Humidity
Data Reports With PaceController, 10/3–10/05
Data show that indoor temperatures and RH were generally controlled as before the PaceController installation. A higher indoor RH on 10/7-8 was during a heavy local rainfall—a total of 5+ inches per the National Weather Service-Harrisburg, with outside average RH of 94%-95%.

Click here to view temperature and relative humidity data during the PaceController-installed measurement period.

Weather at Little Buffalo during Post-Installation Period, 10/3–10/05
Data from the Harrisburg National Weather Service station showed daily high temperatures in the high 70s up to 80°F, until a heavy rainfall on 10/7 and 10/8 dropped temperatures significantly for the rest of the week.

Click here to view climatology data during the PaceController-installed measurement period.

Heat Pump Three-Phase Current Draw Data with PaceController (10/3–10)
The current-draw data show clearly how the PaceController paces the heat pump compressor to maintain thermostat set points well, while still eliminating wasteful excess run time; also clear is the effect on compressor operation of the rainfall on 10/7-8 and subsequent temperature drop, which must be corrected for in the before/after data analysis.

Click here to view amp usage data during the PaceController-installed measurement period.

Heat Pump Energy Analysis
Analysis of the average pre-installation and PaceController-installed power demand shows a net demand reduction of 27.6%, after accounting for the increased heat pump load in the pre-installation case arising from higher ambient temperatures and the lower load arising from lower humidity.

Click here to view the heat pump analysis statistics.