Can you do a Manual J HVAC calculation in less than 60 seconds?

Can you do a Manual J HVAC calculation in less than 60 seconds?

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HVAC contractors use a Manual J calculation to determine the heating and cooling loads of a home or building, and recommend the capacity of HVAC equipment needed. It's one of the tools published by the Air Conditioning Contractors of America to help HVAC contractors design a heating and air conditioning system. A new online tool lets contracts complete the complex task in about a minute.

By using Manual J methodology, HVAC designers are able to accurately determine the total amount of heat that is lost through the exterior of a home during the cooler months, and the total amount of heat that is gained through the exterior of a home during the warmer months. Through a complex series of calculations and inputs, the HVAC designer is able to analyze all aspects of the thermal characteristics of every wall, floor, ceiling, door and window. In addition, an HVAC load calculation also takes into consideration other factors such as the home's geographic location, orientation to the sun, envelope tightness, duct leakage, lights and appliances. ACCA's Manual J even calculates the amount of heat and humidity that each occupant of the house will add to the interior of the home.

Understandably, properly performing a Manual J calculation can take some time.

A new tool developed by Distributor Corporation of New England (DCNE) promises to streamline the process of calculating home energy performance. The Cool Calc Manual J tool enables contractors to leverage the power of big data to measure a home’s HVAC needs before making a house call.

The tool is the result of two years of development by a team at DCNE. Launched earlier this year, Cool Calc is one of only seven products to earn the coveted "Powered by ACCA Manual J" approval for full residential load calculation from the Air Conditioning Contractors of America, and is the only ACCA-approved Manual J calculator available free online.

It is fully compliant with ANSI/ACCA 8th Edition Version 2 and was featured at the ComfortTech trade show in St. Louis in September 2015.

Cool Calc uses advanced geospatial algorithms to process publicly-available Lidar data and Ortho imagery, allowing it to automatically detect a building’s footprint, wall area, ceiling area, floor area and exposures.

The software uses a home's property tax records and location to automatically select the building materials required to meet local building codes during construction. By combining the dimensional data with the material selection, a contractor can perform an ACCA-approved manual J in less than one minute.  

“This tool is designed to help contractors serve customers more efficiently,” said Nancy Kolligian, DCNE President and Chief Executive Officer. “By leveraging technology, this product can lower the cost of new customer acquisitions. It’s not designed to replace site visits, but aims to create a more efficient home visit.”

A contractor or office administrator can use Cool Calc to perform a preliminary Manual J calculation prior to going out to a job site. They can then refine the results from a mobile phone or tablet right from the home, rather than starting from scratch.

Cool Calc is designed for technicians with varying levels of technical proficiency. The software is Web-based and uses a responsive design. It can be used on any Internet connected device. “Our goal from day one was to develop a product that requires no formal training,” said Kolligian.

For more details visit

Read more about energy efficient heating and air conditioning.

Topics: Building Green, Energy Recovery & Heat Recovery, Energy Star, Geothermal Heating & Cooling, Heating & Cooling, Remodeling

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