Residential HERS Rating , Duct testing, Field verification and Diagnostic testing requirements.

If the job includes adding or replacing any of the following items TXV or Refrigerant Charge Method field verification may be required.

A heat pump
A coil (condensing or evap coils)
An outdoor condensing unit.

Now on to the duct testing requirements.
If the job is in climate zone 2, 9, 10, 11, 12, 13, 14, 15, or 16, duct sealing and testing may be required.
and
If 40 feet or more of the ductwork is outdoors or in unconditioned airspace, duct sealing and testing may be required.
and
If the ductwork has no asbestos (most will not have asbestos) duct sealing and testing may be required.
and
If your system has not previously been sealed, tested and certified by a HERS Rater, duct sealing and testing may be required.
and
If the job includes adding or replacing any of the following items duct sealing and testing may be required:

An air handler (a furnace is an air handler).

A coil (condensing or evap coils)

A heat exchanger (even under warranty)

An outdoor condensing unit.

A package A/C and or heating unit.

40 or more feet of ductwork. (This means that if you added or replaced 40 feet or more ductwork) . Follow the flowcharts and if you determine that duct testing and/or TXV field verification is required you will need some forms to take you to the next step.

First download these Change-out Contractors Forms.

CF-1R-ALT
Print the CF-1R-ALT form page 1 and 2. This is the form you need before you pull the building permits.
The CF-1R-ALT is the form that spells out just what work you are going to do for your customer.
It will help you determine if a HERS Rater will be required for the job and it even tells you who you need to distribute the form to.
The CF-1R-ALT should be stamped & or signed by the building department at the bottom of page two. The CF-1R-ALT is part of the building permit. You should keep a stamped copy with the permit on the job and one for your records as well.

CF-6R-ALT
This is the form that you fill out once you have installed the equipment for the job.
Page 1
Enter the project title, address, installing contractor / license number, and company name at the top. Enter the date, climate zone, phone number, and permit number as well.
Enter the system # ( 1 of 2....) on the next line.
Next you will need to enter all the information about what equipment you have installed (manufacturer, model #'s, efficiency and so on).
It is important that you enter the data for the equipment you actually installed because this is a legal document and your signature is required.
Next we go to the TXV segment. If the CF-1R-ALT requires TXV field verification (line 23 on CF-1R-ALT) and you have installed an evap coil with a TXV, check this box.
If you replaced the entire duct system (line 5 of the CF-1R-ALT) check the next box.
When finished sign and date the bottom of the page.
If the CF-1R-ALT requires a Duct Leakage Test or if this job is to be part of a sample group go to Page 2.
The HERS Rater will need information from this page in order to do the Duct Leakage Test.
You will need a Duct Blaster to test the system in order to fill this out. If you do not own a Ductblaster you may hire a HERS Rater to do the “contractors test” for you to complete the forms but we recommend that you purchase a ductblaster for yourself. It will save you lots of money in the long run.
As before fill in the top of the form and go to step 1.
If this is an alteration it is highly recommended that you test the system prior to touching the ductwork and enter the leakage measured on line 1.
Next multiply line 1 by 0.4 and enter the sum on line 2. I will get back to explaining this line later. For now lets move on to step 2.
This is where it gets tricky.
I will use a 3 ton system with a 75,000 BTU furnace as an example to help guide you through.

line 3 (cooling) enter 3 in the tons space.
Multiply that by 400 and enter the sum 1200 in the CFM blank.
Line 4 is for heating units so enter 75000 in the BTU space and multiply that by .0217 .
Enter the sum (1627) to the right in the CFM blank.
If you prefer to actually measure the fan flow and you have the equipment, enter the flow on line 5 then on line 6 check which method you used to measure the flow.
On line 7 enter the highest number from line 3, 4, or 5.
In this example enter 1627 and go on to step 3.
line 8a. Multiply line 7 (1627CFM) x 0.06 and enter the sum to the right (97.62CFM).
line 8b. Multiply line 7 (1627CFM) x 0.15 and enter the sum to the right (244.05CFM).
line 9. Multiply line 7 (1627CFM) x 0.10 and enter the sum to the right (162.7CFM). We move along to step 4.
Read lines 10, 11, and 12 and check off the appropriate boxes. Now go to step 5
Line 13. This is where you need a Ductblaster. Test the ductwork and enter the tested leakage flow in CFM. We will enter 196 CFM (for this example) and go to line 14a.
Line 14a. Since line 13 (196 CFM) is not less than line 8a (97.62 CFM) we do not check the box at line 14a. This system has failed the 6% leakage requirements. We move on to line 14b
Since line 13 (196 CFM) is less than line 8b (244 CFM) we check the box at line 14b. This system has passed the 15% leakage requirements and you can go directly to step 9, which is titled HERS VERIFICATION.
Check the box on line 26 and move on to the sampling section.
If this job is not to be part of a sample group check box 31 or box 32 which ever is appropriate.

Your system passes and you must now sign and date the CF-6R-ALT form on page 1.
You must give a copy of this form to the building department, the home owner, and the HERS Rater.
Now you need a HERS Rater to verify the test results.
Once the HERS Rater has completed the testing and provided you a completed CF-R4-ALT form then you will be ready for the building inspector.

As I stated above it is in your best interest that you test the ducts prior to starting the work.
Lets assume that you have an old system that is very leaky and possibly has broken or ripped ducts. In this scenario it may be nearly impossible to get the ducts sealed well enough to reach the required 15 % once you replace the furnace condenser and evap coil. That being the case you should pretest the system and enter the results on line 1 of the CF-6R-ALT page 2 of 2. It might go like this;

line 1 has your pretest readings of 663.
On line 2 you multiply line 1 (663) x 0.4 and enter the sum (265) in the target for 60% reduction space.
Lines 3 through 12 remain the same as above.
Now you do the work.
After replacing the system you get a reading of 500 (which if you do the math gives you a 30 %) or a fail. You go into the attic and you find a duct is detached and one is ripped. You effect repairs and test again. This time you get 255 (which if you do the math gives you a 15.67 %) or a fail on line 8b but now you go to line 15
Here you need to reduce the leakage by 60 % so lets read on.
Since line 13 (255) is less than line 2 (265) this system now passes because it is equal to or greater than 60 % reduction of leakage and you check the box on line 15 and continue.
since line 15 is checked line 16 gets checked and HERS verification is required.
since line 15 is checked but not 14a or 14b you must check line 17 and follow the instructions which include step 8.
You must smoke check the ducts and seal all accessible leaks for visual inspection but you can pass without meeting the 15% mark.
Step 7 is a level you do not want to go to because it is a last resort and we will not cover that at this time.
Do what is required in step 8 and check off the boxes #23, 24, and 25.

Unless you took a pretest reading you can not use line 1, 2, or 15 and you could spend hours finding and sealing leaks until you get it down to 15 %.
Without your own Ductblaster you have no way to do a pretest without hiring someone else to do it for you.
Good Luck.

CF-4R-ALT
This is the form you will need for the building inspector before they will sign off final inspection on your HVAC job. The HERS Rater will complete this form on the passing of the sealed duct testing or visual TXV Verification.
Only a certified HERS Rater can legally complete this document.