With today’s energy efficient, airtight homes, mechanical sizing has become more important than ever before. Many people, including heating, ventilation and air conditioning (HVAC) professionals believe bigger is better when it comes to sizing the mechanical system of your home. This is simply not the case anymore: oversized and poorly designed mechanical systems cost you comfort, indoor air quality and money (both in terms of utilities and costly repairs to your home).
Priority Energy has been at the forefront of designing new home enclosures/envelopes and mechanical systems for years. What’s more, we have also been the leader when it comes to forensic analysis of comfort and building durability issues in homes and commercial buildings across the United States.
Comfort is something everyone understands, but what do we mean when we say building durability? Simply put, we mean a structure’s ability to last for generations. Time and again, we have seen durability severely impacted by poorly designed mechanical systems.
Priority Energy is an industry leader, offering Mechanical Load Sizing services to maximize comfort and indoor air quality.
ACCA Manual J (Whole Home & Room by Room Sizing)
A complete Manual J will provide the total heating and cooling load (necessary for the ACCA Manual S – Equipment Selection) along with room-by-room loads (necessary for an accurate ACCA Manual D – Duct Design), so the installed system’s heating/cooling capacity can be appropriately distributed throughout the home to maximize comfort.
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ACCA-approved software is utilized for the Manual J to ensure accuracy. (click here for a list of approved software programs). Priority Energy utilizes the latest version of Wrightsoft Right J8 for all load calculations.
ACCA Manual S (Equipment Selection)
This is the required report for permitting in the State of Illinois under IECC 2015. A total block load created with the ACCA Manual S will provide the designer with the total heat loss for heating, and the total heat gain (latent and sensible) for cooling. With the total heat load/gain, the designer will be able to select the exact furnace, AC/heat pump, and evaporator coil necessary to meet the home’s heating and cooling loads.
ACCA Manual D (Duct Design & Layout)
An ACCA Manual D is a duct diagram from the furnace/air handler to the registers, including all ductwork, connections, and fittings. A duct system designed with ACCA-approved software will ensure a quiet duct system that will extend the life of the HVAC system and decrease comfort complaints from the buyers/homeowners.
Other Resources on Mechanical Sizing
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“Strategy Guideline: Accurate Heating & Cooling Load Calculations”, US Department of Energy
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“A Complete HVAC System”, Environmental Protection Agency – Energy Star