• Clean Dusty Return Air Grilles

    You may notice dust building up around the Return Air grilles, the metal vents, usually located below your Central Air Conditioning system. You may be surprised to learn that these grilles may say a lot about the health of you’re A/C unit. Your Air Conditioner pulls unfiltered air through these grilles and then through your Air Conditioning Air Filter before beginning the cooling process.

    Excess dust buildup on and around your Return Air grilles may indicate that your Air Conditioning Air Filter is dirty. A dirty filter can make you’re Air Conditioning Unit work twice as hard to push the same amount of air through the system and can lead to expensive repairs in the future. So when you dust the grilles, take time to make sure you change your filter as well.

    If you can do so safely, you may want to occasionally remove the Return Air Grilles and do a thorough cleaning of the area below your Air Conditioner. If you have recently noticed a buildup of dust and changed a very dirty air filter, chances are this area is dirty as well. Cleaning it at the same time can help reduce the amount of dust you put through the new filter, which is good for your system.

    Several factors can dramatically increase the dust and debris in your home, and consequently the buildup on your Air Supply Grilles.

    • Smoking – Smoke contains particulates of the tobacco, which enter the air and are eventually pulled past your Air Supply Grilles into your system and into your Air Filters.
    • Pets – Pets that shed tend to produce dander. While some pet hair is too heavy to be pulled into your Return Air Grilles.

    • High Traffic – Opening and closing of external doors creates a steady flow of airborne particulates from outside which can make your Return Air Grilles dustier than usual, and can definitely tax your Air Filters.
    • Nearby Construction – Though it may not seem like it, construction in the neighborhood tends to fill the ambient air with dust raised by heavy equipment. This dust can enter your home and contribute to dirty Return Air Grilles and dirty Air Filters.
    • Intensive Cooking – Remember that cooking that puts a lot of smoke or grease in the air will also result in more dust and grease on your Return Air Grilles.

    Finally, dusty Return Air Grilles could also be an indication that it’s time to schedule Seasonal Air Conditioner Maintenance. Call MD Air Conditioning and Heating at (210) 569-0928 and schedule your appointment today.

  • Change Dirty AC Filters

    Air flow is critical. Air can’t flow properly through air filters when they get clogged with dust. This means your Air Conditioner has to work harder to cool the same space. An Air Conditioner that is working harder draws more electricity, which means higher energy bills. Believe-it-or-not, not changing your air filters can also lead to expensive repairs, and eventually require replacement. Replacing dirty air filters is a critical part of maintaining your Air Conditioner.

    Your MD Air Conditioning pro will check your Air Conditioning and Heating unit twice per year as weather changes, because any machine with moving parts requires maintenance to keep it from breaking down. It’s important that belts are not cracked and dry, ventilation ductwork is not gapped, cracked or rusted, and components, such as coils and fans, are clog-free and adequately lubricated for unimpeded operation. But it’s up to you to keep your filters changed!

    How often should one change the air filter on their air conditioning unit?

    How often you need to change your filter will vary depending on your make and model, the presence of pets in the house, and how often the doors are opened and closed. As a rule, most air filters should be changed once per month. The air filter is especially important if the HVAC unit is going to be on the clock year-round.

    Check your filter’s condition and change it once a month if:

    • You run your unit six months a year to year-round.
    • You have pets. Pet dander can become airborne and circulate through the home’s ventilation system just as typical household dust does.
    • You have a large family. More activity means more household dust, dirt and debris.
    • You smoke indoors.
    • You or someone in your household suffers from allergies or a respiratory condition.
    • You live in a particularly windy area or experience high winds for extended periods, especially if there are no nearby shrubs or trees to provide a natural windbreak.
    • You live in an area prone to or having recently experienced any wildfires. Airborne ash outdoors will eventually find its way indoors.
    • You have a fireplace that you occasionally use.
    • You live on a working farm or ranch. Dust and dirt that gets kicked up by outdoor work activity and/or large animals can be pulled into the home’s ventilation system, especially through open windows.
    • You have a large garden. Depending on its size and how often you work it, tilling soil, planting, pulling weeds, using herbicides and pesticides, and even watering mean that dirt, chemicals and condensation can be pulled into your home’s ventilation system.
    • There is construction taking place around or near the home. You may be installing a new roof or a pool, or perhaps a neighbor is building a home or addition. Even if the activity is only temporary, dust and debris from worksites adjacent to or near the home can be sucked into the home’s ventilation system, and this increased activity can tax your HVAC system.

    Change the filter immediately if:

    • The filter is damaged. Whether it happened inside the packaging or while being installed, a damaged filter that has bent fins, collapsed cells or holes will not work as well as an undamaged filter, so treat as it as precious cargo when taking it home from the local hardware store.
    • The filter is damp. A filter affected by moisture intrusion, system condensation, or even high indoor humidity can quickly become moldy and spread airborne mold spores throughout the home via the ventilation system. Not to mention leaving an unwanted odor.
    • There is mold on the filter. Mold spores already infiltrating the home via the HVAC system are not only bad for the unit itself, but they can pose a health hazard for the family, ranging from an irritated respiratory system to a serious allergic reaction. The musty smell produced by a moldy HVAC filter is also unpleasant and may take a while to completely eradicate from inside the home. If you discover that you have moldy air filter, it’s important to have the cause investigated further by an MD Air Conditioning pro.

    Have more questions? Call MD Air Conditioning and Heating at (210) 569-0928 for fast and friendly answers to your questions.

  • Cooling BTUs

    Cooling BTUs What Size Unit Works Best for YOU!

    A well-designed home includes a “Manual J” calculation, often called “Heat Load Calculation” or “Cooling Load Calculation” which indicates how much cooling and heating a home needs to stay cool and dry in the summer and warm in the winter. Unfortunately, sometimes Manual J is neglected in the design of a home, especially an older home. Room additions can also complicate the cooling and heating loads in your home. If you are too warm in some areas of your home, and too cold in others, it may be time for another look at your Manual J calculation.

    Manual J was developed by heating and air conditioning engineers and has been used for decades to accurately size heating and air-conditioning equipment. After completing load calculations, your MD Air Conditioning and Heating technician can help you select the proper Central Air Conditioning Unit to satisfy the load.

    What does a Manual-J Load Calculation report actually provide?

    Heating Load – Heating Load is the amount of heat your home requires on the coldest day of the year, in the middle of the night (when there’s no heat from the sun). This is the number, or load, used to choose your Heating Unit.

    Sensible Cooling Load – This is the sensible heat (the amount you can feel or measure with a thermometer) that your system needs to be able to remove on the warmest day of the year, during the day (when that San Antonio sun is heating the building). This is used with Latent Cooling Load to choose your A/C system.

    Latent Cooling Load – This describes the volume of moisture your system should be able to pull out of the air under “worst-case” conditions. Worst-case for latent loads are when it’s hot and wet outside, or the Springs-like-Summers we get in San Antonio.

    The two cooling loads are used to choose Air Conditioning Units and Heat Pumps. When it comes to a Furnace or HVAC Unit, all three loads come into play. Your system should be able to supply the proper amount of latent and sensible cooling and be less than 15% over-sized. This way your system is capable of proper dehumidification, the removal of water from the air.

    Ready to learn more? Call MD Air Conditioning and Heating at (210) 569-0928 today to schedule your appointment.

  • Duct Static Pressure

    Understanding Duct Static Pressure

    Why is Duct Static Pressure important? Simply put, we all want to keep our electricity bill as low as possible. Poor installation, duct air loss and poor seasonal Air Conditioning maintenance can lead to inefficiencies in your Air Conditioner which translate to more work for your A/C System and higher electrical bills for you.

    What is Duct Static Pressure? Think of blood pressure checks. When you visit a doctor for a checkup, the first thing they check is blood pressure. It’s the same with Static Duct Pressure. If pressure is too high or too low, it is an indication of failing health of your HVAC system and various treatments are in order. Your MD Air Conditioning and Heating technician is trained in tuning your system to make sure you get the optimal air flow delivered to every room of your home, year-in and year-out.

    An ideal duct system has an air register blowing air into every room. Most homes, however, have only one or two return registers for the entire house. Air from other rooms must find its way back to these registers to be cooled or heated, depending on the season. Closed rooms without a register are a common air circulation problem, because air has no place to go in order to get reheated or re-cooled.

    Blockage of supply or return-air ducts and registers can increase or decrease pressure in a single room, which means poor performance and more air leakage through the building envelope. Airflow restrictions are hard on the return-air side of the system, so repairs should start with return ducts if necessary.

    Finally, air from every supply register must have an unobstructed path back to a return register. An MD Air Conditioning and Heating technician can install louvered grilles in walls and doors, between-room ducts, and additional return ducts and registers to improve air circulation.

    MD Air Conditioning Technicians may also increase airflow by cleaning the evaporator coil, increasing fan speed, or enlarging or adding ducts—especially return ducts. While it might seem drastic, sometimes enlarging ducts may be the only way to fix poor comfort or high energy costs.

    Remember, every home is different. Call MD Air Conditioning and Heating today at (210) 569-0928 so you can start feeling the right pressure for your comfort and cost savings.

  • Is Your Air Conditioner Obsolete?

    For Years, Air Conditioners were Part of the Problem

    Modern Air Conditioners follow strict guidelines that help protect the environment while protecting you, the consumer.

    • The government is phasing out Freon 22 as a refrigerant by 2020, because it has been identified as an environmental hazard that causes ozone depletion.
    • Environmentally-friendly refrigerants like R-410A do not contribute to ozone depletion, but operate at higher pressures which means technicians must have R-410A Certification.
    • Out-dated Air Conditioners are the biggest energy consumers in our homes.
    • Modern Air Conditioners use multiple-speed motors so you only use the electricity you need.