Sunday, July 27, 2014

Dominion Power Rebate Program for Commercial HVAC Systems

Your contractor must be on Dominion’s approved contractor list. The performance of each contractor and project will be closely monitored. Please allow for multiple visits by Dominion’s personnel and a third party Measurement and Verification (M&V) contractor. Local governments do not qualify. Customers with single meter loads greater than 10 megawatts do not qualify. Dominion has $30 million dedicated to this program. Although it sounds like quite a bit, you can expect it to go fast in this economy.

Friday, July 25, 2014


Gas turbine generators also add to the viability of wind and solar power generation. Conventional power plants use fossil fuels to fire boilers which create steam to drive the generators. Boiler plants can take one to two days to bring on line and do not handle fluctuations in load very well. Nuclear plants are also best run at a steady load. Gas turbines can be brought on line in a little as 15 minutes and easily modulate to handle the load fluctuations that wind and solar plants are susceptible to. We also discussed PJM, the organization that manages power generation and distribution throughout our region. An upcoming AEE/NCC chapter meeting will provide additional insight into the complexities of keeping everyone’s electricity on so I will comment on that information at that time.

Thursday, July 17, 2014

Troubleshooting a Broken Thermostat

The thermostat serves as the control center for an HVAC system. When it goes bad, the entire unit follows suit. When the entire HVAC system doesn’t seem to budge, a damaged thermostat is one of the most likely causes. Here are a few troubleshooting tips.

The thermostat must be installed in the proper location. Owners need to ensure that the thermostat is installed in the correct place; for instance, a thermostat installed on a wall with high heat gain or heat loss will never work properly as it will mainly react to the temperature of the wall and not to the air indoors. Also, a thermostat exposed to direct sunlight is going to experience problems.

Is there a big hole behind the thermostat that feeds either cool or warm air drafts to the device? Virtually every thermostat is designed with a hole that lets wires in. If the wiring hole happens to be situated at the back of the component, the hole must be stuffed with insulation and covered with tape to prevent drafts from affecting the thermostat’s functions.

Checking the heat anticipator is also vital. A main part of most mechanical, non-digital thermostats, the heat anticipator needs to be set according to the amp draw on the heating control circuit. It offers a small amount of energy savings, and it also prevents thermostat overshooting as it shuts off the main burners and allows the fan to continue running and dissipating heat.

Tuesday, July 1, 2014

A Brief History of HVAC Systems

HVAC doesn’t always mean air conditioning. In fact, the acronym stands for “heating, ventilation, and air conditioning”, which covers everything related to controlling thermal comfort. HVAC systems have come a long way since their inception, and this blog post will delve into several main points of HVAC history.

1000s-1400s – During this period, the Greeks, Romans, Egyptians, Chinese, and Indians all churned up pioneering heating and cooling solutions. One notable invention was the Roman hypocaust, which is a central heating system consisted of a furnace in a basement that distributed heat throughout homes. By the 1400s, chimneys were pretty common. It is also known that Leonardo Da Vinci once built a water-driven fan to ventilate several rooms during that time.

1500s-1800s – During the 1500s, ventilating machines were extensively used in French mines to direct fresh air into the shaft. The U.S. House of Parliament also had a crude ventilation system to cool the building during sessions. By the 1800s, Benjamin Franklin introduced the world’s first stove, which also happened to be the first steam heating system.

1900s – Furnace systems with centrifugal fans, as well as high-pressure steam heating, were extensively used during this time. On the cooling side, it was mainly about Willis Carrier, the inventor of the modern air conditioner. Carrier’s invention resulted into numerous other innovations, much of which are still in use today.