HVAC Schools and Continuing Education

To sustain a HVAC career beyond the routine installation phase you need some education. Like most jobs, HVAC combines skills, technical industry specific knowledge and problem solving. A good HVAC education will address all these areas. You do not necessarily have to go to a technical school. Learning from veterans of the industry can be more effective in teaching practical knowledge. At some point you will want to get some certifications that require training.

Even the professionals need to keep up with changes in the field. As new technologies are introduced, I like to send my Denver HVAC techs out to master them before anyone else. This gives us a cutting edge in Denver furnace repairs and sales.

Basic electrical knowledge is the foundation of air conditioning services Denver. All HVAC units use electricity in some capacity. Even pure gas heaters still need electricity to monitor flame output and manage use. Professionals that want to get and manage jobs need business, math, customer service and computer skills as well. Math is used every day on the job to determine what sized part is needed, whether that part is a whole air handler or just a replacement capacitor. It is also useful for bookkeeping - determining prices, wages and profit margins. Public speaking and customer service helps you get jobs and become respected in the community.

The premise is that you need many well rounded skills, but none of it matters if you do not have the knowledge to do your job effectively. Even a basic filter replacer or furnace repair man needs to know common problems and the science behind why the equipment does - or isn't doing what is should. With a good foundation you can work your way up to being an engineer or running your own business. However be leery of online schools. These are considered sham schools by some agencies. Completing online quizzes can never replace technical schools where you learn on the job training with your own two hands.

Local building codes can change dramatically depending on the location, but it is important to be familiar with them otherwise your construction will not pass inspection. Sometimes manufacturers have their own guidelines and it is important to receive their education because each piece of equipment operates slightly differently. Some organizations are pushing for more standardization in the industry but that has not come to full fruition yet.

While you are working your way through education, many companies would love to hire you because they know you are interested and knowledgeable in the subject. Those who cannot afford education can still start as an apprentice and have a jump on the practical knowledge side of the business. Often knowing how things work in the real world makes the concepts easier to understand once you get to the classroom.

Oil and Gas Furnaces

Gas furnaces burn fuel which can be hazardous just like any fossil fuel. Furnaces using gas or oil fuel need carbon monoxide detectors and failsafe shutoff valves to keep you safe from poisoning or fire. Modern furnaces are very well engineered and all professional HVAC technicians should install detectors as part of the heating installation.

The overall rate of failure for vents and flues is very low, but you still need to be cautious around any combustible equipment. Eventually a machine will fail, especially at the heat exchanger. Propane and natural gas are the two ways gas is used to heat your home. Some Denver heating experts prefer propane because it provides around 2.5 times as many BTUs of heating per cubic foot. Interestingly the two heating gases are delivered in different ways. Natural gas needs a pipeline to be delivered while propane is commonly bottled and trucked in. Naturally odorless and clear, they have a strong smell added to alert people of leaks.

Be careful of gas leaks as the gas will behave differently. Natural gas rises, while propane sinks and can collect on the ground. The air handler heater furnace contains a valve manifold and burners which heat up to thousands of degrees. A heat exchanger is a special device designed to withstand this heat and convert it into warm air to heat your home. The safety systems disengage the gas and keeps the fan on when the temperature has risen to a dangerous level.

Some high efficiency burners for commercial Denver HVAC have two stage furnaces which force air into the second stage like a supercharger. As the air is forced out the ventilation shaft, the fuel is burned at a very efficient rate. However two stage burners like these are only economical in large commercial applications.

Oil provides even more BTU's per volume, but as a liquid, it has a fixed volume that cannot be compressed like propane. Denver furnace repair techs like oil furnaces because they are simple and the technology has been around a while. The oil tank should be a considerable distance from the burners when doing HVAC design. The oil line and tank should be inspected for leaks, and oil furnaces need filter replacements as well. The operation of oil heaters is actually very similar to gas, except that the flue on an oil furnace needs a barometric damper to detect oil levels.

Air Handlers and Heating

Usually the air handler is the unit that provides heat, but some more advanced commercial and residential heating systems use zoning with remote heating. In this case the handler just provides air while the heaters provide zoned heat. Even inside air handlers there are multiple forms of heat energy.

You can have electric heat strips which are like super hot ribbons to heat air with. For chemical heat, gas and oil furnaces are popular with Denver furnace services companies. Some units heat a liquid which then warms the air through a heat exchanger. Hot water coil and heat pumps are examples of this type of technology. Hot water coils usually use a fossil fuel to heat the water, while geothermal heat pumps use the energy from the ground.

Electrical energy is the most common in commercial Denver HVAC applications. Electrical energy does not waste as much energy as the combustion of fossil fuels in furnaces, however electrical is still more expensive per unit of energy than any other alternative. Electrical heaters generate heat by passing high voltage electricity though a metal resistance strip. They use a lot of energy, so you need to make sure both the electrician and Denver HVAC engineer are on the same page putting in all proper wiring and and circuit protection.

All wiring needs to be well insulated for this type of high energy electric work. You need circuit protection and fail safe breakers that will shut off in the event of a short or overheat.

Remote heating in air handlers use a switch to energize the heater when air flow is detected. This is important to have air flow to keep from wasting energy and reduce the chance of fire. This is an added risk with heaters all over the house. On the other hand, for buildings that will only need heating in certain locations, zone controls can result in significant savings. Remote heaters can even be gas duct furnaces. Zoning can be installed by a Denver furnace repair company, and they not only save money but also result in more even heating. They provide heat by burning gas in the ducts, but they also need air flow when operating.

Air Handler Fan and Heat Relays

The relay between the air handler control unit and the blower motor is called a fan or heat relay. If the thermostat fan setting is "on" then the relays do nothing but keep the fan running. Otherwise, when the air handler controller asks for heating or cooling the relay switches the fan on.

The relay allows the fan a short delay to spool up before it starts heating or cooling. This increases efficiency by allowing th blower to push already conditioned air in the ducts through before additional heating or cooling takes place. Instead of that air being wasted in the handler it is used for cooling your house.

Cool evaporator coils work best, so when the cooling cycle starts you will be operating at maximum efficiency. The cool coils can absorb more heat, according to Denver air conditioning services. Some controls use a fan limit switch to set when the unit turns on or off. The fan limit switch is used on furnaces where the fan control circuit is mounted on the heat exchanger.

The fan limit switch on these gas and oil furnaces energizes the fan when the heat exchanger reaches a certain temperature. For most thermostats, the white wire runs to the fan limit switch. It acts as a safety device, because if the burner gets too hot, the white wire will shut it off and keep the fan running to dissipate heat.

The heating relay is separate from the fan relay. The control board has several safety switches before it goes to the furnace to keep it from overheating. Electrical heaters should have a thermal safety fuse installed by a Denver furnace repair company that will physically melt and break the electrical connection if the furnace gets too hot.

Because furnaces are so dangerous, they have numerous fail safe controls, some of which may be manual reset. This means it will stop your house from burning down, but you may have to call a Denver HVAC technician to come reset the fuses. If the switch was tripped for no apparent reason, ask the technician which switch was tripped so that you will know where the problem is if it happens again. Most fuse and breaker switches can be replaced at a minimum cost.

Common Gas Furnace Parts and Problems

Old gas furnaces were pretty simple; just a burner and a fan to circulate air. Every furnace must have a few components to work properly. The first component between the gas intake and the furnace is the gas valve. Propane and natural gas valves are different because the gases have different densities. However many gas valves can be converted between the types without having to order a whole new part. Call your Denver heating company to see if this is possible. In some jurisdictions, switching or installing new components requires inspection for following the fuel-gas code. Before performing any work on a gas valve, make sure you turn off the gas lines going in and out.

The gas manifold maintains proper pressure for the burner. It is on the gas line between the gas valve and the burner. The pressure is sensitive to the type of gas and the specific furnace, so make sure you get a qualified Denver furnace repair man to set the pressure. Manifolds usually do not require much maintenance unless insects or other foreign material gets inside the gas panel.

For everyone other than HVAC specialists, the burner is the exciting part of the furnace. All burners shoot a flame into a combustion chamber that has a draft sucking air in. At high altitudes like in Denver, the size of the burner hole needs to be smaller because there is less oxygen in the fuel-air mixture at lower atmospheric pressure. If you bought your furnace somewhere else and moved to high altitude, you may have to call a Denver furnace service company to modify the burner outlets.

To keep the burners fed with air, you need some sort of ventilation system. HVAC includes not only the ducts that bring treated air around your home, but a ventilation system for the burner. The furnace needs a way to bring in oxygenated air and safely vent the burnt exhaust.

The combustion chamber is not directly connected to your heating ducts to keep you safe from dangerous exhaust. The heat from the furnace is passed onto the air through a heat exchanger. These heat exchangers are made from thick metal that can withstand the constant high heat from the burner. Heat exchangers should be regularly checked because any crack in the material can release exhaust directly into your house.

Furnace Flame Efficiency

Modern furnaces are a lot more complicated than just burning gas and air. To work properly, your furnace regulates the air-fuel mixture. Natural gas and propane used to be cheap forms of heating, but as they become more popular those days are ending. As the prices for fuel increases, the efficiency of the burn becomes more important. Natural gas is a light fuel that should burn blue. A yellow flame in a natural gas furnace probably means that it is not getting enough air. A Denver furnace repairman should be able to adjust the airflow to fix a yellow flame rather easily.

Other common problems with furnace flames are flames that flicker or roll out. An adjustment to your furnace will be necessary in most cases. The HVAC tech may have to test the actual composition of the flame with an expensive instrument called a a combustion analyzer. The analysis tells your Denver HVAC technician the temperature as well as the levels of carbon dioxide, monoxide, and oxygen given off by the flame.

Having the furnace fumes completely exhausted outside the home is very important. Carbon monoxide can lead to headaches, nausea and even death. A dirty burning furnace can have other toxic byproducts as well. Your Denver furnace repair company should do a furnace draft test to make sure your furnace is not leaking exhaust into your home.

I recommend all homes have a carbon monoxide detector installed to protect the occupants from this invisible, smell-less gas. Carbon monoxide poisoning is no joke and long term exposure can cause brain damage. Carbon monoxide basically replaces oxygen in your blood and starves your brain of oxygen. During my work in my Denver HVAC company, we usually find 4-5 homes a year that have a carbon monoxide leak, so there must be many more that are completely unaware.

If the problem with your furnace flame is the gas level and not the air mixture, your HVAC guy should do a gas pressure test. Depending on the type of fuel (natural gas, propane, or heating oil) the required pressures are different. The optimal level will lead to complete combustion of the fuel.

How to light a pilot

In my business, the pilot light is the thing that has the biggest earnings/cost ratio. Poor consumers often pay over $100 for a HVAC technician to come light their pilot. The actual time of work is usually less than one minute. Lighting a pilot light does have a small degree of risk, but the average consumer needs to know how to do it themselves so they do not have to call their Denver heating company every time the light blows out.

The pilot is a very simple device that keeps a small flame for igniting your gas furnace blowers. Sometimes the hardest part of lighting a pilot is finding it. Many people know where their thermostat is and that is the extent of their HVAC knowledge. Sometimes the pilot is deep inside of the furnace unit and you will need a long match or BBQ lighter to get the flame close enough. If the pilot does not light, then you will need to call your Denver furnace repair services company because the problem may be much larger than you expected.

If your furnace is not heating, first check where you always would: check that the thermostat is on. Then check the filter, because a clogged or nonexistent filter will damage your HVAC equipment quickly. The power to your furnace or thermostat may also be off at the circuit breaker. Then check that you have gas flowing. If you have natural gas, check the meter to make sure your gas is turned on. For propane heating, obviously check the tank pressure and valves to see if they are open. The valve at the furnace is called a gas-cock and should be parallel to the inlet or turned to "pilot" or "on" for it to work. These simple checks are the most common reason for failed furnaces, and will save you money calling the Denver HVAC company to your house to flip a switch.

Some furnaces have an intermittent pilot that works with electronic ignition. The pilot is only lit when the HVAC system needs it, and it is lit with an electronic spark. This means the pilot does not need to be lit all the time. If it does not ignite automatically, call a Denver furnace repair company and do not attempt to light it yourself.

If the pilot is manual an unlit, first turn the knob to pilot before lighting. The flow of gas for the pilot should be so low that you will not smell any gas. Natural gas rises, while propane sinks and collects along the ground. If the pilot goes out, the valve that supplies it gas will automatically close and your furnace will not work. You will need to turn or hold the knob in the pilot position to get the gas flowing again.