Whole House Load Calculation (Manual J)

Manual J Whole House Load Calculation

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What is a Manual J?

A Manual J is complete residential calculation used to determine how much heating/cooling a home needs to stay cool and dry during the summer or warm during the winter. This load calculation process was developed by engineers in the heating and air conditioning industry and has been used for decades to accurately size heating and air-conditioning equipment.

Once you have this complete  load calculation, you will have the certainty of selecting a properly sized system to satisfy the load of your property.

When acquiring our Manual J Calculator Service, Our Team of Professionals will provide the complete residential whole house heating and cooling load calculation expressed in BTUH.  Calculations can be performed in either 7th or 8th edition.  You will also have the option of getting a Whole House Summary or room by room Manual.


Electronic Request Form   Download Manual J Sample


Here is How it Works:

  1. You purchase the  Whole House Load Calculation (Manual J) Service
  2. You email us a file with the .pdf plans of the property either Residential or Commercial.
  3. Our licensed HVAC professionals produce your complete Whole House Load Calculation (Manual J)
  4. We email you back the comprehensive Manual J based the information you provided us.

Call Us Today & Lets Get Started!

800-810-3280 Ext. 102

  Fill our Electronic Request Form


What a Manual J Will Provide for You:

A Manual J will provide for you three important pieces of information about the heating and cooling load of your property:

  1. Heating Load: How much heat your property will require on the almost-coldest day of the year, in the middle of the night (when the sun is not present). With this number or load you will be able to select the right piece of heating equipment.
  2. Sensible Cooling Load: The amount of sensible heat (what you can usually measure with a house thermometer) that your system should be able to remove on the almost-warmest day of the year, during the daytime (when the sun is at its strongest point). In conjunction with the “Latent Cooling Load”, this load will help you to select the right cooling equipment.
  3. Latent Cooling Load: How much moisture your system should be able to remove under “worst-case” conditions. Worst-case for latent loads is typically when it’s hot and wet outside (i.e.daytime in the summer).

With these three loads you will be able to select the right equipment to fit the loads (heat losses or gains) of your property.

Manual J: Whole House Summary or  Room by Room?

When buying a Manual J Calculation, selecting a Whole House summary or a Room by Room analysis is determined by whether you are going to size the duct system or just the equipment needed. A Whole House Summary looks at the structure as a whole and gives you the total for whole structure. A Room by Room report looks at each individual room and gives you an individual room requirement, this is only necessary if you are sizing the duct system.

  • Whole House Summary Report: Provides a Manual J Calculation for the entire house. It will give you a total heating and cooling BTUH requirement for the entire envelope so You may choose the properly sized equipment .
  • Room by Room Report: Provides a Manual J Calculation for each individual room. It will give you a heating and cooling BTUH requirement for each individual room so a properly sized duct system may be designed.

Take a Peek at Our Manual J Sample!



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