Heating, ventilation and air conditioning terminology can be confusing. And, how do you know everyday ways to maintain your unit and keep it at optimal comfort? To help your understanding and education, here is a list of important terms, their definitions and tips. If you ever have any questions on these terms and tips, please feel free to call us at 624-143-7110 or schedule a service call.

• How often should I change my filter?

How often should I change my filter?

You should inspect your filter monthly and change if necessary. A good time to inspect your filter is when you receive your electric bill. The motto we use is: To minimize your payment to your electric company, check/replace your filter before writing check to the electric company. Failing to change your filter regularly will result in higher utility bills, poor system cooling/heating, damage to your system and many other problems. CHECK YOUR FILTER MONTHLY!

How often should my unit(s) be serviced/have maintenance performed?

Twice a year. You should have a cooling tune-up done in the spring and a heating tune-up done in the fall. Air conditioning units are like any other piece of machinery; you must have them properly maintained to maximize their performance, efficiency and life-span. Call us at 624-143-7110 for more information on our air conditioning and heating maintenance/tune-up program.

At what temperature should I set my thermostat?

Normal cooling settings are 75 degrees – 80 degrees

Normal heating settings are 68 degrees- 72 degrees
You should always set your thermostat to the highest possible setting that is comfortable for you in the summer, and the lowest comfortable setting in the winter. Doing this will maximize your energy savings as on average every 1 degree of temperature change is equal to about 10% energy savings. For example, changing your thermostat setting from 75 degrees to 76 degrees in the summer could result in about a 10% savings on your cooling costs.

Can I turn my thermostat up in the summer (down in the winter) while I'm away at work?

Yes, the Department of Energy recommends a change of no more than 3 degrees for maximum possible energy savings. This 3 degrees is very important because if you allow your home to get warmer/colder than this, it will result in your unit having to work extra hard to return the home to the proper temperature when you get home. This period of extra hard work for the unit will completely eliminate all the cost you saved throughout the day and will actually now cost you more overall. This is especially true in the summer. For example, if you were to turn your unit off while you were at work and the house temperature rose 5 degrees , when you return home and crank down the thermostat your unit now has to work very hard to remove all the extra heat in the home, and it has to do it during the hottest time of the day. This results in huge energy usage and cost.

What should I leave my thermostat set at if I am away on vacation?

We recommend no more than 5 degrees of change from your normal setting. More than 5 degrees of change could cause damage to the contents of the home, especially in the summer when we are dealing with extremely hot temperatures. Wood floors, cabinets, pets, electronics, etc. are all items that are sensitive to large temperature changes.

Why would I need a programmable thermostat? What is the benefit of one?

A programmable thermostat can be a great tool to maximize energy savings and is recommended by your electric company. This type of thermostat can be programmed with different temperature settings for the weekends, for while you are away at work, for when you go to bed, and so on. It is not a necessary item to have, but is a very helpful tool to help you save on energy costs. You can also look into the advantages of having a NEST thermostat.

What is the most cost effective way to operate my air conditioning system?

• Find a thermostat setting that is comfortable for you and leave it alone. Only adjust the setting if you are away from the home for extended periods of time.

• Always clean/replace your filter as recommended (once a month)

• Have maintenance performed twice a year

• Read all the answers in this Advisor section of our website to fully learn how to make your air conditioning system as cost efficient and comfortable as possible. If you have further questions, feel free to call us, we are always happy to help, 624-143-7110.

Why are my utility bills so high?

There are endless reasons why your utility bills may be high, but here are some reasons why your heating and cooling is costing you a fortune.

• Your home is not properly insulated. You may have very poor windows, minimal wall and roof insulation, etc. All these things prevent your home from blocking out the heat and cold from outside. A house that is not well insulated will always be more difficult to heat in the winter and cool in the summer.

• Your system is not properly maintained. Poorly maintained units do not run efficiently and will cost you more to operate.

• Your filter is dirty and is not changed often enough. A dirty filter restricts airflow and causes your unit to run harder and therefore use more energy.

• Your system is old and inefficient. New systems are simply more efficient and use less energy to operate than old systems.

• You have an oversized unit. Having a unit that is too big for your home will cause short cycling of the unit. The unit will come on and cool the house rapidly while drawing a lot of power. It will then shut off for a short while, turn on for a short while, shut off for a short while and so on. This short cycling process draws more energy than would be drawn under normal operation of a properly sized unit. The system on start-up takes about 5 minutes, of operation, to achieve full capacity and efficiency. Short cycling also does not allow the system to dehumidify properly.

• You have undersized ductwork. Undersized ductwork chokes the system and causes the unit to work harder to move air. Try blowing through a large diameter straw; now try to blow through a small diameter straw. It takes much more effort to blow through the small diameter straw than the large one. This extra work again results in more energy consumption.

• You adjust your thermostat too often throughout the day. Yo-yoing with your thermostat (bumping it up a few degrees, then down, then up) while you are home causes a great loss in energy efficiency. Your air conditioning unit functions best when it is left at one setting. This allows it to cycle properly and run at maximum efficiency.

• You turn your unit off while you are away at work or adjust the set point too much. (See “Can I turn my thermostat up in the summer (down in the winter) while I'm away at work?")

When should I run just the unit's fan? When shouldn't I?

rooms more evenly tempered throughout the day and will keep the indoor air better filtered, when humidity levels are LOW.

Can I close off registers to rooms not in use?

You should never close more than one register in your home if the air conditioning system was installed by ISI Air Conditioning Company. If your duct system was not installed by ISI Air Conditioning Company, you should not close any registers. CLOSING OFF REGISTERS DOES NOT SAVE ENERGY! Find out about a temperature zoning system. If you close off air to rooms they still will have heat gain from the outside. This heat gain is transferred to the rest of the house through doors, walls, ceilings, etc. This heat gain will cause your unit to work just as hard as if the all the registers were open. There is no energy savings to be gained from closing off registers.

Can I put coverings/covers over registers or return grills?

Absolutely not. Never cover registers or return grills with any material what-so-ever. Doing this adds resistance to the system, causing your unit to work harder and your energy bills to rise. Your system was designed to operate with all registers fully open and unblocked.

Why are rooms on the west side of my house always hot in the afternoon?

Rooms in your home that have western exposure (walls and windows) will be warmer in the afternoon than other rooms due to solar gain from the sun through windows and walls. Window coverings must be drawn on in the afternoon on west facing windows to avoid these increased indoor temperatures. Your air conditioning system cannot adjust airflow throughout the day based on the movement of the sun. If you fail to draw window coverings, your rooms will get hot and your energy usage will rise. It is also a good idea to install awnings over west facing windows if possible or plant trees to shade these windows in the afternoon.

Why are my upstairs rooms always hot and downstairs ones always cold?

Physics. Hot air rises, cold air falls. This is why ISI Air Conditioning Company recommends separate systems for upstairs and downstairs or zone controls. It is impossible to have a balanced, comfortable system in a two story house with one unit and no zone control. Many HVAC contractors wrongly install one unit on a two story house as a way to save money. While this does indeed save on the initial cost, it will lead to an uncomfortable home that is impossible to balance. We are only interested in happy and comfortable customers. This is why we will not install a single unit on a two story application unless it is equipped with a temperature zoning system.

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Why is my home office always hot?

In a typical home, a bedroom is converted into a home office. Chances are that the air conditioning system was not designed to account for the added heat loads that are associated with home offices, such as: computers, monitors, additional lighting, printers, copiers, scanners, TV's, etc. All of these items add a great deal of heat to your office. Since your system was not designed to account for these items, the room will always be hotter than the rest of the home. You can have an air balance done to slightly help this problem, but it will not completely remedy it. The only solution that will completely fix the problem is to have duct modifications made and possibly a new unit installed.

What is SEER?

SEER stands for Seasonal Energy Efficiency Ratio. It is an energy efficiency rating for air conditioning units. The higher the SEER rating, the more efficient a unit is.

• For example, older units used to have a SEER rating of 6-10.

• New units today must have a minimum SEER rating of 13.

• The most efficient systems available today are about 19 SEER.

What is BTUh?

BTUh stands for British Thermal Unit Hours. It is a simple measurement of heat. One BTU represents the quantity of heat necessary to raise one pound of water 1 degree F.

• 12,000 BTU's of total capacity per ton of air conditioning (example: A four ton air conditioning machine has a capacity of 48,000 BTU's)

• 8,000 BTU's of sensible cooling per ton of air conditioning (approximately)

What is AFUE?

AFUE stands for Annual Fuel Utilization Efficiency. It is an efficiency rating for gas furnaces. AFUE ratings are given in percentages. This percentage represents the amount of energy input to the furnace that is actually converted into heat for the home. The remaining energy input is lost up the flue pipe. Gas furnaces of the past had AFUE ratings of about 60-75%. Today's furnaces have ratings of 80-95%.

What is HSPF?

HSPF stands for Heating Seasonal Performance Factor. It is a heating efficiency rating for heat pumps. The HSPF scale goes from 7.5-9.0 with 9 being the best possible rating.

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Should/Can I open my windows and doors after a storm?

I know we all love the feeling of that cool air after a storm, but this is the absolute worst time to open up your doors and windows. Doing so will introduce extremely high levels of humidity into the home. This humidity gets absorbed into carpets, draperies, bedding, clothes, etc. When you fire your air conditioning back up later it is going to work extra hard for the next 24-48 hours to remove all the added humidity in the house. Yes, it takes that long to return your homes humidity back to normal. This extra work will greatly increase you energy bills. So if you want to enjoy that cool monsoon air, go outside and have dinner on the patio, don't completely open up your house.

Why does my furnace smell when started up for the first time every heating season?

Your furnace smells because dust has accumulated on the heat exchanger inside the furnace. The smell is the dust being burnt off. Under normal conditions, this smell should stop coming from the furnace within 24-48 hours.

Should I cover my outside unit when it is not in use?

Absolutely not. You should never do this. Covering the outdoor unit will trap moisture around the unit and eventually cause it to rust.

Should I shade my outdoor condensing unit or package unit with a cover of some sort?

No, never. Any covering that is close to the unit will cause recirculation of hot air around the unit. This recirculation will greatly reduce the unit's efficiency and capacity. Most units already have a metal coil guard that shades the condenser coil from the sun. We have measured 120 degree inlet temperatures on 105 degree days on units that have been covered by the homeowner. Having any covering or object close to your outdoor unit can cause recirculation which leads to poor system performance.

Do pets have an effect on my air conditioning system?

Yes. Pet hair and dander causes blockage of the filter and can also cause blockage of the indoor coil. Any blockage in the system will lower the systems performance and efficiency.

Doggie doors create more heat gain for the home because they have no insulation. A great deal of heat and hot air infiltration can be gained through these small doors.

Large fish tanks have been seen to increase humidity in homes therefore making the unit run longer and harder to reduce humidity levels. This leads to increased energy consumption and higher energy bills.

How often should I clean my condensate drain?

At least yearly with proper filter maintenance. If you do not change you filter at regular intervals your indoor coil could become clogged which could then cause your condensate drain to clog and flood your mechanical room. ISI Air Conditioning Company performs this cleaning during our spring tune-up.

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How do supply and return duct affect my air conditioning system?

Undersized ductwork (which is what most homes have) can greatly reduce airflow and can damage the compressor in the outdoor unit.Undersized duct will also increase noise due the increased air velocities inside the duct. Undersized ductwork will decrease the volume of air that can be delivered to each room, therefore decreasing comfort of the home.

Think of it this way: Undersized ductwork is like a small cocktail straw. Try to blow through that straw as hard as you can and feel the amount of resistance there is. This is the same resistance a unit has to deal with when the ductwork is too small.

Undersized duct creates poor airflow. If there is not enough air flow over the indoor coil, it will ice up and could potentially flood the mechanical room and damage the home.

There are endless problems associated with wrongly sized duct. Please feel free to call our office with any more questions you have on this subject. 624-143-7110.

How often does my systems refrigerant need to be changed?

The refrigerant in your system should never have to be changed. Refrigerant is not like oil in a car. It only has to be changed if it becomes contaminated from an outside source. Even if this happens, your refrigerant can often be filtered to remove contaminants.

What type of filter should I use? What are the differences?

We recommend at minimum a 1" pleated filter. Do not use 3M Filtrete or Angelhair filters. These filter types are much too restrictive and will cause damage to your system (from our experiences with them).

Washable filters are okay if they are properly maintained. However, most people fail to properly maintain them and this causes problems with the system. To properly clean your washable filter you should first vacuum it completely from the incoming air side. Once it is completely clean, flush with water in the opposite direction of airflow. If you flush the filter from the wrong direction or fail to vacuum it, you will just further imbed dirt and debris into the filter. The cleaning process must be done monthly without exception.

5" high efficiency filter are a good upgrade to the standard 1". They are about 20 times more effective at filtering the air inside your home.

The new Accuclean/Clean Effects filtration system from American Standard/Trane and the April Aire 5000 electronic filtration system from April Aire are 100 times better at filtering the indoor air than the standard 1" filter. These systems are great upgrades for those with allergies and sensitivity to other indoor pollutants. For further information on Indoor Air Quality products, see our Indoor Air Quality section of this website or call us directly 624-143-7110.

Is it a good idea to keep spare fuses at my home?

Yes, it is a good idea to keep some extra fuses in case of storms or power surges.

HOWEVER, READ THE FOLLOWING CAREFULLY BEFORE YOU CHANGE OUT A FUSE ON YOUR OWN!!!! You MUST always turn off the breaker (make sure it is the correct breaker also) before you change the fuse. If you fail to do so you can and will suffer major injuries. There is a lot of voltage going through your unit's disconnect box. If you touch the wrong thing without having the breaker off you will get hurt. ALWAYS TURN OFF THE BREAKER BEFORE CHANGING A FUSE, NO EXCEPTIONS!!!

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How often should I oil the motors in my air conditioning units?

If you have a newer unit, you don't have to oil the motor because they are sealed bearing and can't be oiled. If your unit is older and does not have sealed bearing motors, you should oil them or have them oiled with a drop or two of oil once yearly.

What makes one unit better than another? Example, American Standard v. Goodman.

There are many factors that make one brand of air conditioning equipment better or worse than another. Here is a short list of the main factors:

• Technical support on the backend

• Availability of parts

• The quality and reliability of the internal components

• Capacity of the equipment. This varies from brand to brand.

• Available SEER ratings

• Build quality

• Engineering of the product

• And so on, and so on…Call our office if you would like to discuss this topic further 624-143-7110

What is 2-stage cooling?

2-stage cooling is a method of cooling that can better manage the cooling of your home while outdoor temperatures are changing. It can also better maximize indoor comfort and energy efficiency. 2-stage cooling systems are typically the most energy efficient systems out there.

2-stage cooling can be done by having one unit with two compressors, one small and one large. The small one is typically capable of putting out about 50% the capacity of the larger one. The second way to have 2-stage cooling is to have a single scroll unloading compressor. This compressor can unload its capacity down to about 66% of maximum capacity. Both these methods of getting 2-stage cooling allow the unit to run at a lower stage when the high stage is not needed. By doing this, energy is saved. It is the same principle that is used in car engines that have the ability to drop out cylinders when they are not needed.

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What is 2-stage heating?

2-stage heating has the same principle as 2-stage cooling. It allows the unit to adjust itself based on the amount of heating that is necessary. 2-stage heating is a good way to save on heating costs.

A heat pump system would have two different sized compressors, a small and a large one. The compressor that is used at a given time would depend upon the need. If only a small amount of heating is necessary, the smaller compressor would be used to save energy. The large compressor would only be used when a large amount of heating was needed.

A gas furnace that is 2-stage has a modulating gas valve that regulates gas flow depending upon the need.

What is “variable speed"?

Variable speed refers to an indoor motor that changes speed. This type of motor increases speed and airflow from start up to full capacity over a span of 8 minutes. This results in quieter start-up and shut down of the system. This motor is also about 5 times more efficient than a conventional indoor fan motor.

What does “ton" mean when referring to air conditioning? Example: I have a 4-ton air conditioning unit on my home.

Air conditioning units are sized in tons. One ton is equal to 12,000 BTU's of total capacity. So, for example, a 4-ton air conditioning unit has a total capacity of 48,000 BTU's while a 2-ton machine only has a total capacity of 24,000 BTU's.