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Gas Furnaces


A furnace works to keep a home warm in the winter and plays a critical part in the operation of an air conditioning system. Furnaces produce heat through the combustion of natural gas in the furnace's burner. The heat produced from this process then passes through a heat exchanger. Air from your home's return air ducts is blown over the heat exchanger, thus warming the air. The furnace's blower then blows the warmed air into the ductwork, which carries and disperses the warmed air throughout the home. During warmer months, the blower inside a furnace continues to circulate return air throughout the home — only this time, the return air has been cooled by being blown over the indoor coil portion of the home's split-system air conditioning system. A condensing coil is typically installed on top of the furnace.

What does AFUE mean?

AFUE stands for Annual Fuel Utilization Efficiency. In layman's terms, a furnaces AFUE rating equals the amount of gas a furnace uses. The rest of the gas the furnace doesn't use goes out the chimney. So the 80% AFUE furnaces use 80% of the gas you're paying for and waste the other 20%. 90% AFUE furnaces waste 10% of the gas you're paying for and 95% AFUE furnaces waste 5% of the gas you're paying for. If your existing furnace is 15 years old, chances are it is probably about 65% to 70% AFUE. 20 year old furnaces can be as low as 60% AFUE or less.

80, 90 or 95% AFUE furnace?

The biggest difference between the 80% and 95% AFUE furnaces is the amount of gas they waste. The 80% furnaces waste 20% of the gas you pay for. The 95% Plus furnaces only waste about 5% of the gas you pay for (this percentage depends on the make, model and brand of furnace you purchase). They are called 90% Plus furnaces because they are 90% or more efficient. Some manufacturers offer furnaces with higher efficiencies than others. Another difference between the 80% and 90% Plus furnaces is the way the exhaust leaves the house. The 80% furnaces still use a traditional metal pipe for their exhaust. If your furnace is currently being vented into a brick chimney and you decide to purchase an 80% furnace, you will need to protect the chimney with an aluminum liner (if it does not already have one - most don't). The 90% Plus furnaces use a PVC pipe for their exhaust. This PVC pipe usually exits the home through the closest side wall. The 90% Plus furnaces do require a drain for the condensation that is created in the exhaust pipe.

Air Conditioners

When the air conditioner is properly matched with aevaporator coil or air handler...

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Gas Furnaces

A furnace works to keep a home warm in the winter and plays a critical part in the operation of an air conditioning system.

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Evaporator coils

Installing the correct indoor or evaporator coil is essential for getting the highest performance and comfort from your central...

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Air Handlers

An air handler is a device used to condition and circulate air as part of a heating, ventilating, and air-conditioning (HVAC) system.

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Heat Pumps

A central heat pump helps maintain comfortable temperatures inside your home and reduces humidity levels year-round.

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Mini Splits provide ductless air-conditioning and a quiet solution for cooling and heating problems.

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PTAC (Package Terminal Air Conditioner) Air Conditioning units are air conditioners that are designed to control the comfort level of a single room.

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Packaged Units

Engineered with a variable speed motor, the 15GCSX takes comfort technology to new heights...

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TM Mechanical Company, Inc | 7059 Commerce Circle, Suite A, Pleasanton, CA 94588 | License # C-20: 961018

AC Repair Pleasanton California | AC Service Pleasanton California

TM Mechanical Company, Inc provides ac repair and air conditioning service in Pleasanton, California with a focus on the following
neighborhoods: Pleasanton, Dublin, Livermore, San Ramon, Danville, Alamo and Walnut Creek California

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