How Manuals J and D Save Energy, Ensure Proper HVAC System Design

Are you looking at upgrading or replacing your HVAC system? If so, you will want to make sure your system meets a set of energy efficient standards to help keep your energy bills low. The definitive guide for HVAC contractors is a set of standards developed by the ACCA (Air Conditioning Contractors of America). Of particular importance for home heating and cooling systems are Manuals J and D.

Manual J - Load Calculations

Manual J provides a set of technical load calculations that HVAC contractors use to determine the energy efficiency of each room in your house, or rather how well each room either holds or loses heat as the seasons change. Expert contractors take into account a range of influencing points, including:

• Local seasonal temperature averages and extremes

• How the main-facing areas of your home are affected by the heat and light of the sun

• Room sizes and window positions

• Current type of home insulation

• Your preferred seasonal temperature settings in the home, and

• The impact of your home lighting and domestic equipment power needs.

Manual D – Ductwork Design

Using the Manual J load calculations, the next stage is to design the system ductwork. This is not a case of big is best, you want to have a system that is just the right size for your home heating and cooling needs. This will minimize the amount of energy needed to keep the indoor temperature at your preferred level. Manual D provides the technical guidance for designing the best ductwork system based on the results of the load calculation work.

Verify HVAC Contractor Qualifications

Check that your intended HVAC contractor has the right skill set by asking about:

• certifications

• how they perform Manuals J and D assessments, and

• what type of reports they provide on these assessments.

Further Information

For expert advice about the use of Manuals J and D to save energy, or any other matters on home heating and cooling, please feel free to contact us at Air Assurance. We have been serving the Broken Arrow area for more than 30 years.

Our goal is to help educate our customers in the Tulsa and Broken Arrow, Oklahoma area about energy and home comfort issues (specific to HVAC systems). 

Image courtesy of Shutterstock

Don't Let Those 2013 Tax Credits Get Away: Use Them on an Efficient A/C

Don't Let Those 2013 Tax Credits Get Away: Use Them on an Efficient A/C

Homeowners who install qualifying cooling systems this year can take advantage of tax credits from the federal government to help offset the cost. Those that qualify are high-efficiency central air conditioners and heat pumps. If your equipment is over 10 years old, requires frequent repairs, or uses a lot of electricity, this summer might be an advantageous time to replace it. The minimum energy efficiency for central cooling systems stands at 13 SEER (seasonal energy efficiency ratio). In order to qualify for the tax credit whose maximum amount is $300, new equipment has to have a minimum rating from 14 to 16 SEER, and depends on whether you're installing a split or package system and whether it's an air conditioner or a heat pump.You and your HVAC contractor can discuss which system would be best for your home, along with going through the other important elements when choosing a new cooling system, particularly its size. Contractors use software called Manual J to perform a load calculation to arrive at the right tonnage for your new system.Going by the size of your existing equipment could result in a system that's too large or small for your home. Oversized systems drive up energy bills and leave humidity behind. They run in short cycles more frequently, which increases the wear on all the parts. A system that's too small won't keep you as comfortable during our hottest weather.Once you've chosen the right system for your home, a thorough ductwork inspection should be made to assess your current system, its size and integrity. The leaks should be sealed with mastic or metal tape. Choosing a shady location for the outdoor condenser also helps you get the most efficiency from your new system. The hot refrigerant from your home cools faster if the condenser is out of the sun and has plenty of clearance on all sides.If you'd like more information about the 2013 tax credit and choosing a new system, contact Air Assurance. We've provided top-notch HVAC services for the Broken Arrow area for nearly 30 years.Our goal is to help educate our customers in the Tulsa and Broken Arrow, Oklahoma area about energy and home comfort issues (specific to HVAC systems).  Image courtesy of Shutterstock