Your Air Conditioner Installation: Why Your Tech Should Be Thoroughly Versed in Manual J and Manual D

Your Air Conditioner Installation: Why Your Tech Should Be Thoroughly Versed in Manual J and Manual D

July 24, 2013

Air conditioner installation begins with figuring out what size system is necessary to keep your home cool. Both undersized and oversized A/Cs have disadvantages. Any changes that have occurred to your home may have changed the size of air conditioner required. You don’t want to assume that your old air conditioner was correctly sized.

To size your air conditioner, your contractor will need to determine your home’s cooling load. The correct way of doing this is with the method described in Manual J from the Air Conditioning Contractors of America (ACCA). Your contractor will probably use a computer program based on Manual J to help with the calculations.

If Manual J is properly followed, it will ensure that your contractor doesn’t overlook anything. It’s important that accurate information is used for the calculations. Manual J includes a bit of overestimation, so your contractor shouldn’t do any overestimating.

Manual J offers a comprehensive and detailed evaluation of your home’s cooling load that takes into account many factors, including:

  • Home size
  • Insulation
  • Air sealing
  • Duct losses
  • Climate
  • Window area
  • Blinds and drapes
  • Number of occupants
  • Appliances and lighting

The results include a range of performance factors that your new air conditioner should have. The ACCA also has a Manual S that your contractor can use to help find an air conditioner that will provide the required performance levels in your home.

If ductwork is being installed or redesigned, it’s important that your contractor uses Manual D. This ensures that the ductwork has the proper sizing and layout to meet the cooling needs of each room without having air velocities that are too fast and noisy or that provide too little air circulation.

If you want a contractor who will use Manuals J and D during your air conditioner installation, contact JD’s A/C. We provide reliable HVAC services to residential and commercial customers in Longview.

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Split System A/C Malfunction or Damage? Make Sure Equipment Matches When You Repair

Split System A/C Malfunction or Damage? Make Sure Equipment Matches When You Repair

July 22, 2013

In the aftermath of a devastating storm or natural disaster, you may end up making extensive repairs to your A/C system. On a split-system A/C, that often means a replacement of the outdoor condensing unit or the indoor evaporator. Keeping both systems properly matched is the key to maintaining post-disaster performance and home comfort.

Both indoor and outdoor units work as a team to provide your home with the comfort you and your family enjoy. In the event of a system replacement, each unit should be evenly matched in performance, efficiency and capacity. Otherwise, you could find yourself replacing the entire system again years later, due to premature failure or dissatisfaction with reduced home comfort.

In fact, there are two very good reasons why matching your split-system A/C system is important:

  • SEER – Air conditioners and heat pumps are rated based on Seasonal Energy Efficiency Ratio (SEER). A/C systems made after 2006 are federally mandated to achieve a minimum SEER of 13. An indoor system that achieves 13 SEER won’t run as efficiently as it should when paired with an older system rated at 10 SEER.
  • Differences in refrigerant – Most new systems rely on non-ozone depleting hydrofluorocarbon (HFC) refrigerant, usually R-410A. Older systems that still use R-22 refrigerants won’t work these new units. Both indoor and outdoor units must use the same refrigerant or the system will suffer premature failure.

Any A/C replacement should be a perfect match in terms of SEER and refrigerant. If you have an older system rated at less than 13 SEER or one that still uses R-22, you might want to consider replacing both indoor and outdoor units with a newer system offering improved reliability and performance.

Contact one of our NATE-certified technicians at JD’s A/C to find out more about replacing your split-system A/C. We strive to provide quality HVAC services to our residential and commercial customers throughout Longview.

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How to Air Seal an Attic

How to Air Seal an Attic

July 8, 2013

Tiny air leaks into uninsulated or under-insulated attics are a big cause of heat loss for many Texas homes. As a result, homeowners suffer from loss of conditioned air and higher energy bills. Air sealing your attic with insulation, caulk, and spray foam is the most effective way to improve the energy efficiency of your home and its overall comfort. Here’s how to air seal an attic.

Advice for working in your attic

  • Plan – Plan your project and get together all the materials and tools you’ll need for the job.
  • Be ready to get dirty – Working with insulation in the attic is a dirty job, so wear lightweight, disposable overalls, knee pads, gloves and hat to keep the insulation off your skin and out of your hair.
  • Safety – Be safe. Only work 15 to 20 minutes at time, stay hydrated and use a government-approved particulate respirator or double strap dust mask to keep from inhaling hazardous material.

Tips on how to seal an attic

  • Create a sketch of your home’s floor plan. Highlight dropped soffits, slanted ceilings above staircases and other areas with dropped ceilings. Also, highlight the main plumbing stack, furnace flue and other ductwork.
  • Pressurize your home by placing a box fan in a window so it’s blowing air into your home. Make an airtight seal around the fan by taping cardboard around the fan. Close all windows and doors, and go into the attic closing the hatch behind you. You should be able to begin to feel the leaks.
  • Plug the large, obvious holes first and replace dirty insulation with clean insulation.
  • Seal all joists with bagged insulation.
  • To seal your furnace flue and ductwork you’ll want to contact your HVAC professional.
  • Use caulk and spray foam for the small holes.
  • Seal your hatch.
  • Check for backdrafting by installing a carbon monoxide detector on each floor. Consult with your HVAC professional about potential hazards of an airtight home.

To learn more about how to air seal an attic, contact JD’s A/C. For more than 30 years, we’ve proudly served the residents of Longview and the surrounding communities.

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