Manual J versus Manual S

Manual J versus Manual S

Today on the the Reschexpert blog we want to look at two energy reports that have nothing to do with online Rescheck reporting. The first energy report is Manual J and we are going to create an in depth comparison to Manual S. These reports are essential in many jurisdictions and help homeowners, architects, contractors, subcontractors, engineers, and HVAC professionals choose how they will manage the indoor comfort. Take a journey with us as we look at the ever popular Manual J vs Manual S.

Manual J has the following characteristics on every report report.

Shows a Sensible Heat Gain

Calculates a Latent Heat Gain

Calculates a Total Heat Loss

Takes into account the Summer Outdoor climate data from a local temperature collection area

Uses the Winter Outdoor climate data from a nearby station that monitors local temperatures

Altitude is used when calculating both the heat loss and heat gain

Uses all portions of a homes insulation envelope including roofs, walls, windows, doors, and foundation insulation values

Bases calculations on the assumed number of occupants in a home

Most commonly used for Residential additions, new construction, and home renovations. Sometimes for smaller commercial applications.

Methods for calculations are varied and range from software, to spreadsheets, custom calculators, or by hand

Measures the appliances within a home and the loads they create

Data is compiled into a concise report that’s main features include a minimum information output of jobsite location, local climate data, elevation, sensible heat gain, latent heat gain, and total heat loss.

Can be referred to as Manual J heat loss and heat gain

Now let’s take a look at Manual S. The Manual S has the following characteristics on each report

The Manual S is a derivative of the Manual J. Meaning the sensible heat gain, latent heat gain, and total heat loss are used in calculating the Manual S.

You cannot create a Manual S without first creating a Manual J

The Manual S uses Summer Outdoor climate data from a local temperature collection area to size HVAC equipment

A Manual S considers the Winter Outdoor climate data from a nearby station that monitors local temperatures to size your HVAC equipment

Altitude is considered when calculating Manual S equipment sizing

Manual S looks at the sizing of a furnace based on the structure’s total heat loss

Manual S creates the sizing of an air conditioning unit based on the structure’s sensible heat gain and latent heat gain

Manual S looks at the HVAC equipment manufacturers data to calculate if the proposed unit is sized correctly for the structure, climate zone, and customer needs.

Manual S can also be referred to as Manual S Equipment sizing

Overall Manual J and Manual S are two of the most required and important energy reports on any construction project. The Manual J is the first step in the process and then comes the Manual S. The essential data created in the Manual J heat loss report is the sensible heat gain, latent heat gain, and total heat loss. These outputs from the Manual J are then transferred into the Manual S and compared against the chose HVAC equipment manufacturer’s output data. The Manual S will then offer you a sizing report that tells you whether the suggested equipment is sized correctly for the proposed structure.

As to which report wins in the Manual J vs Manual S face off, we would have to choose the Manual J. This is because the Manual S is reliant so much on the Manual J. Manual J and Manual S share a commensalism. The Manual S benefits from the Manual J, but does not harm or alter the Manual J. The Manual J is not necessarily harmed by the calculation of the Manual S, but the existence of the Manual J heat loss and gain is essential to the creation of the Manual S equipment sizing.

We thank you for reading our in depth study of Manual J heat loss versus the Manual S equipment sizing. We hope we have provided you some in depth insight into the ever changing world of home energy auditing. If you need a Rescheck, Manual J, or Manual S created for you then simply email us a PDF of your plans, jobsite address, and square footage and we can get your reports taken care of. The email address is service@rescheck.info