According to the US Department of Energy the ideal temperature to keep your AC at in the summer is 76 degrees. When your going away from home you can even push it upto 80 degrees. If 76 still feels too warm you can experiment and bring it down a few degrees but don’t drop the temperature more than a few degrees or your electric bill will shoot up.
A smart thermostat would connect to your homes wifi and can be programmed to readjust the temperature based on outside weather and the time of the day.

Regular maintenance check-ups, keeping the air filters clean and replaced, reducing usage as much as possible, taking care of the condenser, upgrading to a smart thermostat, and making use to the auto setting are all common ways to extend the life of your HVAC system.

HVAC Tune Up Checklist : –

An HVAC tune up list includes but is not limited to; inspecting the indoor unit coil for dirt, changing air filters, checking the blower motor and belts, testing the thermostat to make sure it works, making sure electric connections are tightened and working, cleaning the coil and condensate drain, measuring refrigerant levels, checking the duct work, looking at the heat exchanger for leaks and cracks, and inspecting safety controls.

• The biggest reason is a dirty air filter. Over time your air filter catches pollutants and others dust particles, once this builds up it restricts the overall air flow, as a result condensation from the air’s humidity will start freezing over the AC coils instead of dripping into the drip pan.
• Arefrigerant leak — If the refrigerant level is too low it will cause your evaporator coils to become too cold. Air that comes in contact with your evaporator coil will then end up freezing.
• Problems with your AC’s fans cause cause the AC unit to freeze up.
• Dirty air ducts will block airflow and also cause part of your AC unit to freeze up.

• Avoid any sort of lint and dust build up by keeping the furnace vacuumed.
• Test and make sure the carbon monoxide and smoke alarms are working so incase there is an accident you are prepared.
• Replace any damaged or unclean filters regularly.
• Keep away any inflammable items such as paper, wood, gas, etc.
• Get your furnace inspected atleast once a year to make sure everything is in working order.

If your leaving home just for the day its more efficient to keep your AC unit on but turn it a few degrees higher then what you would normally keep it on at home. However if you are leaving your place for more than a few days it would save you more money and be more efficient to just shut the system off.

Keeping your windows and door shut when the AC on is important so the house can retain the cool air coming from the AC system. Even a small crack will let the cool air flow outside. When cool air is going outside it will need to be kept on longer to keep the house cool thus putting more pressure on the system and increasing your electricity bills.

Ideally you want to replace both units at the same time; AC unit and outdoor heat pumps are built to work with a matching indoor unit, when you mix different kinds of units between the outside and inside this will lead to inefficient performance and overall output. By getting a new outdoor and indoor unit at the same time you will get a warranty covering the whole system so you will not need to cover any repair costs during this warranty period.

• Change your air filters often.
• Schedule regular maintenance for your HVAC System.
• Buy indoor plants to keep the air fresh and clean.
• Use Good quality Air purifiers throughout the house.
• Check your air ducts and make sure they are clean.
• Reduce humidity using dehumidifiers.
• Use chemical free/non-toxic cleaning products in your home.

You should change your air filters generally every 90 days (3 months).

A gas furnace should be serviced atleast once a year however ideally twice – one in the spring before it gets warm and one in the fall before it gets cold. These maintenance check ups can include looking at various parts such as the air filter, heat exchanger, fan and pilot light to prevent issues from coming up later.

It is ideal to have your HVAC Unit serviced twice a year, once in the spring before it gets hot, and once in the fall before it gets cold. This will make sure that the parts are clean and everything is functioning well so when it gets too hot or too cold your unit wont give you any issues and can perform optimally.

How many watts an AC unit uses will depend on multiple factors such as the type of unit. For example a minisplit AC and ductless system will use anywhere from 700 to 2000 watts per hour of power whereas central AC systems will use about 1000 watts for every ton. So a 3.5 ton central AC unit would use somewhere around 3500 watts. Window AC units are much smaller and require less usage so they would average around 900 watts.
It is important to not choose an AC unit based on watts but instead using a unit that is appropriate for the space in which you live that way your home is not cooled down too quickly or too slowly which would lead to other issues.

• Schedule regular maintenance check ups for your unit
• Change & clean the air filters frequently
• Check your homes insulation – sufficient insulation will keep your HVAC unit from running constantly
• Upgrading to a smart thermostat will allow you to adjust the temperatures for specific timeframes.
• Keep the condenser clean and free from debris, vegetation.

Indoor air quality is effected mostly by pollutants that come from materials such as wood, walls, insulation, and other household materials. Other particles can come form humans, pets, or outdoor substances like pollen. The most dangerous would be chemical substances like carbon monoxide, lead particles, and asbestos. The inhalation of mold can cause damage to ones health as well. One of the most impactful things you can do to keep the air as clean as possible is have a reliable air filtration system. HEPA, ionizers, and UV filters are some common examples of filters that will help keep the air in your home clean. In regards to how often they should be changed will depend on various factors such as the size of your home, whether you have pets, and the quality of your filters.

Advantages –
Much more efficient; about 300-500% more efficient. You can save 35-60% on heating costs, and 25-50% on cooling costs. They are also extremely environmentally friendly, and nearly emission free. Highly reliable and low maintenance and are overall much less noisy.

Disadvantages – Much higher upfront cost, however this can pay off in 5-10 years because of the efficiency. These are much more suitable for newly built homes. Since it’s a new technology much less HVAC technicians know how to install and repair geothermal units.

Why Is My Air Conditioner Not Cooling the House can be due to several different reasons but most common reasons are the 12 Common AC Problems are 

1. Clogged air filters

2. Air conditioner low on Freon – Refrigerant. 

4. Duct dampers closed.

3. Ice on indoor coil. 

4. Air leaking from ducts. 

5. Outdoor compressor is not running. 

6. Bad capacitor.

7. AC thermostat going bad. 

8. Fan motor issue.

9. Direct sun coming in the house.

10. Lack of insulation in attic or walls. 

11. Windows / doors seal bad. 

12. Outdoor coil dirty. 

Most common reasons of AC unit freezing up is –

1. Dirty Air Filter.

2. Closed dampers.

3. Bad blower motor or capacitor. 

4. Restriction in air flow. 

5. Restricted Evaporator Coil. 

The reason to cover you a/c after summer ends is to keep unit clean from debris, leafs, dust mulch and snow. So it’s a good idea to cover it with tarp or plastic during the off season. Home owner can either buy or make some kind of cover the top and sides. 

Most AC units run for about 10 – 12 years without any major issues. After this in some systems leaks develop or problems related in metering device or compressor occurs which can be a major expense. 

After removing old existing ac, level the ground if required.

Setup outdoor AC condenser unit.

Connect to the existing copper pipes.

Charge with nitrogen for leak test.

Check for refrigerant leaks.

Connect the low voltage thermostat wires.

Connect to the high voltage 230 volts wire coming from the circuit breaker.

Vacuum the lines and complete system.

Open the service valves on the new unit and check the Sub Cooling / Super Heat.

Add refrigerant if required.

Check amps at the compressor and outdoor air conditioner.

A broken HVAC, Heat Pump or air conditioner can be considered as an emergency repair when your AC has broken down on an extremely hot day (above 85 degrees) You have young children, elderly adults or medical condition people in your home that may be sensitive to excessive Humidity or heat.

New high efficiany compressors change the speed of the compressor in certain models from 30% to 100% depending on the demand. This helps to reduce the electric bill e to control the humidity. 

A replacement of new HVAC unit can be a big investment. Depending on the size and efficiency, so unless the existing unit is not working right or not cooling well and it requires a major repair then it makes more sense to have it replaced.

AC leak repair cost – AC leak repair costs $300 to $1,550 in most cases this is on average to find and fix the leak and refill the Freon. Air conditioner Freon leak repair costs depend on the kind of HVAC, location, leak test method, refrigerant kind and prices, and replacement parts if required. An AC leak test costs $299 to $649. for detection only.

Also Leaks in the refrigerant line cost the least to repair. Leaks in the evaporator coil or compressor are the most expensive to repair. AC Condensation pipe water leak repairs cost $175. to $400 to fix.

Air conditioning units in most cases needs to be replaced every 15 – 20 years. It can last a long time if it’s been maintained properly by professional HVAC guys, but they can also break unexpectedly during the summer. You can expect to replace an AC unit every 15 to 20 years.

The average cost the repair an AC Unit in Fairfax, Arlington, Alexandria Virginia Bethesda, Gaithersburg, Silver Spring and Fort Washington in Maryland is $389. The typical range is between $175-$639. While the high end of repairs can be as high as $1400. Certain types of repairs will also cost more than expected. 

New air conditioning units can last between 15-20 years, and older air conditioners last around 10-20 years on average, though the life of the unit also depends on the maintenance and regular cleaning of the unit been done in the past. An Amana high efficiency unit installed by AVS Heating and air comes with 10 years on all HVAC parts and limited life time warranty on the compressor.

Compressor works like a pump with moves hot refrigerant constantly while its running. 

Refrigerant pumped into the outdoor condenser coil first is converted into the liquid when it leaves the outdoor unit. 

Refrigerant passes through a metering device and coverts into vapor. 

 When fan blows air through the indoor coil (called evaporator) and during this process the air temperature normally drop around 20 degrees. 

Now the warm air becomes cold air and distributes throughout the home.

This process repeats until the house temperature reaches the desired temperature set at the thermostat. 

In most cases homeowners can’t repair their own air conditioners? There is 230 volts and 440 volts at certain places in the AC unit. So it’s required to be done by licensed HVAC contractor only. Also the repair can require advanced technology tools to measure Super heat and sub cooling etc. 

Breaker tripped off. Bad fuse. bad wire. Loose connections, burned wires, and aged electrical wires all can cause your thermostat to eventually lose its connection to your A/C and heating system. Inspect your wiring thoroughly, making sure the connections are tight, and replace any wires as deemed necessary by you or an HVAC professional.

This can be due to several issues like 
1. Thermostat related problem
2. Filter dirty Issues
3. Issues with the flame roll out or High Limit Switch 
4. Condensate Line blocked in high efficiency furnaces.
5. Problems at the control board.
6. bad inducer draft motor.
7. Pilot Light don’t stay on.
8. Gas Valve Issues
9. Burner dirty
10. Flame Sensor needs to be cleaned. 

A high-pitched squeal coming from your furnace is usually the result of an issue with the blower or belt for the blower. The blower in your furnace is powered by a motor, which has bearings that can wear out because of age or overheating. Overheating is usually caused by dirt buildup or a bad capacitor in the furnace.

It varies in different homes. in some houses it last one month and in some houses same filter last 5-6 months. In general, Most commonly these filters replaced are for 1- to 2-inch filters, replace them every 2 to 3 months. For 3- to 4-inch filters, replace them every 6 months.

Two-stage heating means the furnace has two levels of heat output: first it runs on lower Btu flame and if temperature does not satisfy the thermostat in certain time period then flame btu increases. ( high for very cold winter days and low for other days. Since the low setting is adequate to meet household heating demands most of the time, a two-stage unit runs for longer periods and provides more even heat distribution. 

There are several factors involved in calculating the size of the furnace.
Calculate the square footage of your home along with all windows and doors. also the direction of the house. Normally west facing houses get more sun. 
Find out Climate Zone for your Home is another factor that helps determine how many BTUs you need to heat your home.

Standard-efficiency furnaces use to be 68% and now days they convert roughly 80% of the energy from gas into heat and 20% goes in waste. High-efficiency furnaces convert 90-97% (depending on the model you select) of the energy from gas into heat.

A heat pump absorb heat from outdoor air in the winter and release it inside the house and it absorb heat from inside the home during the summer and release it outdoor. 

Top Most Common Heating Repair Problems are 
Dirty / Clogged Air Filters. 
Bad belt. Wear & Tear From Daily Use. 
Noise furnace.
Broken Thermostat.
Faulty Ignition Control or thermo couple.
No Heat in certain part of the house.
unit running all the time.
Cycles Frequently.

Signs That You Need to Schedule a Heating Repair
Cold Spots Throughout Your Home.
Grinding, squeaking, Banging, Clanking and Screeching Sounds.
All of a sudden Unusual Odors.
Short-Cycling or Constantly running for long period of time.
Flame is burning Red or orange instead of blue Color.
Cold Air Coming From Registers and Vents.

As the technology advances the Annual Fuel Utilization Efficiency (AFUE) rates furnaces: the percent of heat produced for every dollar you spent. higher the AFUE rating, the lower your fuel costs. All furnaces manufactured must now meet at least 80% AFUE.

If your fireplace has glass panels, leaving your pilot light on for long periods of time during the summer can cause sulfur buildup and build a misty film on the glass and permanently damage the glass. Also an active burning pilot light all year can create moisture, which may collect inside the pipes and may cause corrosion.

Its a good idea to schedule service once a year before winter start. If you only use your gas fireplace occasionally, you can probably get by with a fireplace service check every other year.

Even if you don’t notice extra cycling or the need for constant adjustments, you will probably notice a rise in your power bills. If you think your bills are increasing when you compare energy costs for the last few years. If the expenses seem to constantly climb, you may need a heating system upgrade.

1. Schedule HVAC Yearly Tune-ups Every Spring and Fall
2. Change Air Filters Every Month
Dirty filters harm or overheat your HVAC equipment and create serious problems by overheating that may require expensive repairs. Changing the filters regularly protects your heating and cooling systems from this potential damage.
3. Keep an Eye on the Condensate Line to prevent water leak and may cause mold.
Your heating and cooling system condensate lines won’t usually develop clogs if your equipment is getting regular spring and fall tune-ups. Condensation should be draining through the PVC condensate pipe and dripping on the ground or into the pump. If you notice water puddles around your furnace, you may have a clogged drain line that should be checked by an HVAC professional.
4. Make Sure the Area Around the Outdoor Unit Stays Clean from dust and debris.

5 signs you need a new furnace
If your energy bills ( electric, gas) higher than usual then It might be time for a new heating system.
The typical lifespan of a furnace can be anywhere from 15 to 20 years. If you’ve had your furnace for less than 12 years, you likely don’t have to worry about replacing it any time soon. But if it’s older than 12 years and you’ve started noticing issues, it may be on its last leg. And if your furnace is nearing 20 – 30 years old, then it’s probably time to replace it in the near future.
Your furnace is making different noises: If you’ve noticed that your furnace is suddenly making strange noises, pay attention. Noises such as grinding, squeaking, rattling, humming, clicking and more could be a sign that your furnace is no longer working properly.
Your energy bill has increased: When a furnace is nearing the end of its life, it doesn’t heat your home as efficiently. As a result, it takes more energy — and therefore, more money — to heat your home. 
Your home is being heated unevenly: Have you noticed that certain areas of your house are colder than others? If your furnace is heating your home unevenly, it could be a sign that it’s on its last leg and its time to replace it.
You’re having to make frequent repairs every so often or If your furnace has needed quite a few repairs lately and it’s more than 12 – 15 years old, then it may be time to replace it. Extending the life of your furnace past its useful life may do more harm than good.

There can be several reasons for furnace-chimney incompatibility. Chimney has to match the size of the flue coming out from the furnace flue pipe. High efficiency furnaces generate  more heat into your home and discharge less heat up the chimney than older style low efficiency furnaces (less-efficient units). So this also means that the existing chimney might be too large for the new furnace. The result could be improper ventilation of flue products, which can cause condensation problems inside the chimney causing bricks or exterior material to get damage.