High Tech Homes Construction

Performance of a Manual J Load Calculation is a critical necessity in determining the proper HVAC system size for any project whether residential, commercial or industrial.

When you, the homeowner are in the early planning stages of your project, you create a design whether it’s as basic as a sketch on a napkin, or a full-blown set of plans by a professional architect, you are establishing the design elements of your future home.

Step #1:
When performing a Manual J Load Calculation, HTH identifies the key elements of the design and evaluate their impact on the home from several perspectives. Those key elements of design are:

Shell - Defined as the exterior wall surface, this element may be 2”x4” stick built wall, 2”x6” stick built wall, ICF, SIP, etc. In each case, the R-Value must be established and plugged in to the calculation. Note: On stick built walls you must also assign the insulation being installed in the stud cavities in order to arrive at a true R-Value.

Roof system – Defined as the overall roof system, this element may be trussed, SIP, etc. and should include the trusses, decking, shingles, and any additional insulation specific to the roof type.

Foundation – Defined as the overall foundation, this element may be poured concrete, block or ICF crawl, basement, or slab-on-grade, and should reflect any additional insulation specific to the type. In this section we must also provide data with regard to exterior surfaces exposed to ambient air, so all elevations must be included.

Doors & windows – Defined as any penetration in the exterior walls where either doors or windows are to be installed. In this section we must also identify the R-Value of doors, and the U-Value of windows to be installed.

Insulation – Defined as any insulating material to be added to the overall structure such as rolled, batted, blown in or rigid insulation material where required.

Orientation – Defined as the homes orientation. We must establish which direction the home faces … North, South, East, West, etc. in order to establish solar gain.

Step #2:
When a homeowner/homebuilder submits a set of plans for load calculation HTH requires that they identify all elements above after they’ve been selected, and that they include the published R-Values and U-Values of the materials to be included in the home’s plan.

In addition to identifying the materials selected for the home, HTH also requires the homeowner/homebuilder provide us with their local utility rates i.e.: natural gas rate per therm, electric per kilowatt hour rate, and for propane the per gallon rate. These rates will later be plugged in to the program to determine operating cost estimates for the HVAC system ultimately selected for the home. This information also allows HTH to determine the HVAC system’s payback period.