Tuesday, August 24, 2010

Electrically Ignited Pilots in Furnaces

Standing pilot lights are quickly becoming obsolete. A standing pilot light presents fire and carbon monoxide dangers along with wasting gas. Electrical furnace starters are now standard on all high efficiency Denver heaters. With electric ignition, your furnace only uses energy when it needs it. This by itself can increase your SEER rating significantly.

The really modern systems light the burners directly. This is called hot surface furnace ignition. This means that when the thermostat calls for heat, a hot igniter above the burners heats up and then ignites the gas when it is released. Other models electrically ignite a pilot whenever heat is needed. Not only furnaces, but any kind of heater using gas flame can benefit from electronic ignition. Denver HVAC companies install electric ignition systems in boilers and water heaters as well.

An important part of the ignition system is proving the pilot or burner flame is lit. The whole system fails if the solid state controls do not know if the burner is on or not. The fail safe will shut down the system if the sensors do not sense a flame. This is because it is dangerous to leave the flame burning without regulation. It is also to prevent the heater from spewing un-ignited gas into the building. If you smell gas or your furnace has shut off unexpectedly, call a Denver furnace repairs company immediately.

Often the flame sensor is just fowled with residue and once cleaned by a HVAC tech it will operate normally. However this system is still much more reliable than a standing pilot furnace. These pilot lights blow out and need to be re-lighted manually. This defeats the purpose of the pilot being lit all the time.

Along with electronic ignition, two other ways to get the most out of your heating fuel are to get air handlers with built in induction blowers, and condensing heat exchangers. The blower forces air into the combustion chamber, which aids in both combustion and exhaust of gases. The condenser is an additional heat exchanger that takes the heat out of the water vapor byproduct of natural gas combustion. These devices save energy and also increase the air quality of the home.

Monday, August 23, 2010

HVAC Ductwork Insulation and Maintenance

Your HVAC ductwork is the series of tubes that carry treated air around the building. If you are installing a new central air or heat pump system in your house, you should make sure the ductwork that will carry your new high efficiency air conditioner is up to par with the system. As all the air flows through these ducts, any leaks or problems will ruin the effect of the whole system.

When installing or diagnosing a system for Denver HVAC repairs, a good technician will inspect all the ducts. First off he is looking to see if the existing duct system will match the new air handler that was installed. This will also show if there are any leaks or other problems. Finally, ducts should be insulated and routed in a certain way to maintain safety. This process is called checking for ductwork integrity.

The average residential HVAC system has some leakage. So you can get just as much cost saving some times in fixing the ducts as buying a new high efficiency system. If 20% of the air is leaking, then the system will have to work harder. This leads to higher bills and possible Denver furnace repairs. So do not feel shy to ask the HVAC tech to check the integrity of the ducts. It is their job after all.

In some locations your HVACR system needs special consideration. In wet areas or flood plains, the duct work needs to be water tight. After a flood, you will probably need to replace the insulation, but if the ducts were not sealed you might have to replace the ducts as well as any parts that were damaged by infiltrating water. A water tight duct is also obviously air tight.

To maintain the efficiency of this well sealed ductwork, your Denver HVAC company will install insulation around it. The insulation also serves to protect the inside of your home from the temperature variations caused by hot or cool air flowing. At these temperature change points moisture tends to accumulate. As water saturated air below the dew point gets in contact with warm beams, then it will sweat. This ruins the ducts and can cause mold and mildew problems. To counteract this make sure there is a vapor barrier between the treated air and the outside.

Tuesday, August 17, 2010

HVAC Economizers

air conditioning services denver
HVAC economizers are called DDC systems in industry parlance. DDC stands for Direct Digital Control, basically computerized controls of HVAC air handlers instead of using mechanical systems to control the use of the air handler and other components. Computer technology has been able to provide dramatic energy savings for years, but the real advance recently is the ease of use for air conditioning services Denver technicians.

Instead of being pre-installed at the factory, now your HVAC technician can modify the DDC settings on site. This is a powerful new tool for Denver HVAC companies because they can customize air handler use or program zone control by site. Economizers do need extra ductwork and equipment to maximize their efficiency. One way economizers do this is by using outside air for heating or cooling when the conditions are right. When the outside air is at a temperature compatible with your comfort settings, there is no reason to use mechanical heating or cooling to do extra work.

Commercial building codes in Colorado require a certain amount of air to be circulated through the building every hour. There is no need to treat the excess air needed beyond the heating requirements. The dampers that control this excess air are often inadequate compared to digital economizers. If not calibrated after installation, these dampers often malfunction to the point that the building owners disable the devices within a year.

A common economizer in furnaces uses the heat from exhaust flue gases to make full use of boiler energy. These units are not overly complicated but it might be easier to use a specialty furnaces services Denver company for these kinds of installations or repairs. The economizer digital controls should work directly with the HVAC control system. These new digital units spit out charts and graphs of performance and can be monitored remotely.

In order for the DDC economizer to do its job correctly, it needs inputs, or information gathering sources so it can see how the HVAC system and the interior of the building are operating. One sensor should be a CO2 sensor inside the building. This allows the air handler to decide when to operate without an air damper. When C02 is at safe levels, the system will re-condition the air, significantly saving energy venting cooled air outside. The sensor is built to override everything else for safety. Two more sensors should gather outside air temperature and humidity. One way the unit can maintain good indoor air quality is to keep the building at slight pressure. This stops air infiltration which can lead to unwanted moisture or pollutants in the building.