Code Required Load Calculations, Equipment Selection and Duct Design

Cost of Course

Outline for class:

Heating/Cooling Load calculations, HVAC equipment selection and duct design: Learning basics of powerful & easy-to-use software that allows HVAC contractors and installers to build home comfort systems that meet code achieved with ACCA Manual J, Manual S and Manual D.

Course Outcomes: To get HVAC contractors comfortable performing load calcs, equipment selection and duct design as required by California Energy Code by using wright-soft software. In the program students will learn what is required by code, ACCA Manual J, Manual S and Manual D. Students will learn how current code directs designers to build high performance comfort system that deliver  By end of class, students will be able to create a simple house diagram with separate rooms each with required air CFM to maintain temperature range. Diagram will show house rooms with dimensions in feet, duct diagrams, duct sizes, furnace, windows, doors and return air grill.

Software Requirement:

upload free version of Wrightsoft software for student project.

Hardware Requirement:

Required computer and monitors windows 10 and large monitor, (two large monitors are better) internet access.

Instructor: George Matthews, Building Energy Compliance Testing

Module 1

What California building energy code requires and why. ACCA Manual J, Manual S and Manual D or ASHRAE equivalent are required by code before installing an HVAC comfort system.

Objectives:

·         Student will learn basic energy code requirements for California RE: HVAC.

·         Student will become familiar with ACCA Manual J, Manual S and Manual D.

·         Student will understand  where to use Manaul J, Manual S and Manual D.

Media

Activities

Module 2

Downloading Wrightsoft software, free student version, and installing on machine. Become familiar with palate of choices such as draw line, draw square, specify feet/inch grid, add windows and doors. Become familiar with or review system of “point and click” and “drag and drop” drafting If not already.

Objectives:

·         Student will download and install Wrightsoft software

·         Student will become familiar with palate of choices

·         Student will practice the review system

Media

Activities

Module 3

Perform home energy assessment to gain knowledge of energy loads, heating and cooling, to overcome. Students will need to document a house’s size by measuring every room and plotting on paper diagram such as large format grid paper. Every room gets measured in feet/inches and conveyed to sketch. Use digital measurement device like Bosch compact Laser Measure device.

Document crawlspace or slab and R value of insulation, repeat for walls and attics. Measure windows and note frame material and window pane number and type of coating such as low e. Document attic insulation and existing HVAC duct system if it matters to upcoming system design. Learn to make some assumptions of air leakinesss/tightness. For extra credit, do blower door test to assess air tightness of shell or envelope.

Make a clear diagram with all information as this will be translated into your digital energy model.

Module 4 Input data to program
Take sketch of house with interior room dimensions to computer and begin to transfer data into 2D digital model that is simple to create. Build one room at a time

Input insulation values into attic, walls and floors.

Module 5 Manual J – Load Calcs   
From newly created digital sketch model navigate to load calc center and look at the load numbers for heating and cooling. Input correct geographical climate data, heating degree days and cooling degree days. Find the number of BTUs and move on to finding equipment that fits those parameters.

Module 6 Equipment Selection,
Find a few different furnaces that you think will work to supply the correct amount of air flow, BTUs heating and cooling. Download the equipment’s performance numbers from the spec sheet on the manufacturer’s website. Compare and contrast the different performance levels of the machines. Compare motors and specs such as “air-tight box” and especially static pressure at X airflow. Static pressure is huge here. We must get it right as we will be adding the resistance of all the ducting, plenums, elbows and wyes in the forced air system.

Module 7 Design your ducts.
This is really the fun part of the class. Digitally drafting the duct starting at the AHU and terminating in each room exactly where you think they will both fit and work best. Drag registers to their location. Click, drag and drop lines for ducts and build your system. Click the command and watch each duct populate with CFM that duct will have to move to get the perfect amount of air and the diameter of the duct to the inch. No more guessing. You might get 4, 5 and 7 inch ducts depending on the needed airflow.

Module 8 Register Grills – How much resistance? What Model/Brand? Performance thereof.
Learn the difference in resistance in grills and how much of their surface area is actually open space air can course through or block. This is not in the California energy code but the quest for efficiency, comfort and quiet make it smart to control the air in optimal fashion.

Module 9 Feedback Testing
After fabrication of system, test airflow, leakage and static pressure numbers. Measure airflow from every register and compare to plan. Is it sufficient? Does system leak 5% or less? Does system move 350 CFM per ton? (Hopefully more!). Is the Watts/CFM less than 0.58 watts/CFM. If airflow is not close, adjust dampers installed at plenum on each duct run start coller.

Module 10  Beyond the code compliance: Productivity, efficiency, quality control tool, sales tool.
Using Wrightsoft as a money making tool that sets you apart from your competition in create value for each job. Reducing callbacks through quality control of commissioning system before handing it over to client. Develop relationship with client.

Create a detailed shopping list for complete systems and one trip to HVAC supplier. Get pricing from complete and detailed list in a format one can email to supplier. Saves time.

Create detailed sales report to make your clients confident In your professional, proposal.

Guarantee that this is state-of-the-art system performance design that is more comfortable, creates better air quality than any HVAC system they ever had while being highly economical to run.

If you want, you can figure out how much it will cost them per year to run their heating and cooling system.

Module 11 Continuous Fresh Air Ventilation systems for homes. HRVs. How to spec and design systems to bring in HEPA air to one's home.

To sign up, Contact Building Energy Compliance Testing

George Matthews

Dear Customer,
This is our approach to bringing more value to your energy compliance reports.

Doing load calculations and duct design is required by the energy code, Title 24, part 6 and CalGreen Title 24 part 11. Many building departments don't know this, but they do know they need a CF1R energy report. You are familiar with the energy report that you get from energy consultants before you can get a permit to add on, etc.

The same data-set is used for both so we do the work in Wrightsoft which does load calcs and duct (manual J, D and S) design and assists with equipment selection. We then export that dataset into EnergyPro and, after a few modifications, we generate the CF1R PRF-1. We feel that we can offer our clients a two-fer this way and get them more value for their energy compliance budget.

We started doing Wrightsoft after years of watching air conditioner installations fail (over 80%+!) because HVAC contractors don't do the math and don't know how to build energy models like in Wrightsoft. This was an attempt to follow the code and design systems that work properly and pass code mandated HERS tests.

We also use the kind of duct designs one can learn at PG&E's Pacific Energy Center in the class, "Optimizing Residential Duct Systems". Keeping the ducts inside the conditioned shell and optimizing airflow makes for better operating systems that provide more comfort at lower cost. We also design our systems to be able to run properly with restrictive MERV 13 filters which filter out pollen, pet dander, wood smoke and PM2.5 particles for our clients with respiratory concerns.

We think that pulling it all together for our clients creates better housing that is healthier, more comfortable, durable and less costly to operate. We hope you agree.

George Matthews