Stellar Building Performance recently completed blower door testing in Vero Beach for a new construction single family residence at The Strand, a gated community of 47 homesites on Orchid Island between the Indian River Lagoon and the Atlantic. The home was built by GHO Homes. I was onsite performing the test as part of our ongoing work in partnership with Energy Code Compliance Specialists.
The house measured 1,929 CFM50 against a building volume of 40,304 cubic feet, which works out to 2.87 ACH50.
Building on the Vero Beach barrier island and need envelope testing scheduled around your closeout? Request blower door testing in Vero Beach and we will work to your construction calendar.
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A 2.87 ACH50 Result at The Strand in Vero Beach
ACH50 expresses the measured air leakage relative to the volume of the home, allowing the blower door result to account for differences in building size. The fan pulls the house to 50 pascals of negative pressure and measures how much airflow it takes to hold it there, reported in cubic feet per minute. Multiply that airflow by 60, divide by the conditioned volume, and you have the number of times the air inside the house turns over in an hour at that test pressure.
On this home the arithmetic runs 1,929 times 60, divided by 40,304, which returns 2.87.
The energy documentation for this residence followed the R405 performance path, and the air leakage rate carried on that form was 7.0 ACH50. The measured result landed at well under half of the figure the calculation was built around. Worth saying plainly though: 7 ACH50 is the prescriptive ceiling in Climate Zones 1 and 2 under the 2023 Florida Building Code, Energy Conservation, Eighth Edition. It is not a universal requirement. On a performance or ERI path the target is whatever the energy calculation for that specific house says it is.
If you want to understand how the leakage target on your energy calculation gets set in the first place, we walk through it in our guide to the R405 performance path.
Why 1,929 CFM50 Is Not a Large Number on a House This Size
This is probably my favorite part of this particular Project Update, because the raw airflow number looks alarming right up until you put it next to the volume.
1,929 CFM50 would be a poor result on a modest home. Drop that same airflow into a 15,000 cubic foot house and it comes out around 7.7 ACH50, which does not pass. Spread across 40,304 cubic feet, the identical airflow is 2.87 ACH50.
A larger house has more surface area, more window and door perimeter, more penetrations and more roof to wall transitions. It is expected to move more air in absolute terms. What ACH50 does is ask how leaky the enclosure is relative to what it contains, which is the only fair way to compare an 1,800 square foot home against something like this one.
I bring it up because superintendents sometimes see the CFM reading on the gauge before they see the ACH50 and assume the worst. The number on the screen is not the number that goes on the form.
Questions about where your home is likely to land before test day? That is a conversation we are always glad to have. Reach out about blower door testing anywhere on the Space Coast and Treasure Coast.
What a Result Below 3 ACH50 Triggers in the Florida Energy Code
Testing below 3 ACH50 is not a bonus and it is not a penalty, but it does change one thing. Under Section R402.4.1.2 of the Florida Building Code, Energy Conservation, a dwelling unit with a tested air leakage rate below three air changes per hour must be provided with whole house mechanical ventilation, installed in accordance with Section R403.6.1 of the Energy Code and Section M1507.3 of the Florida Building Code, Residential.
The envelope leakage report carries a check box for exactly this, and the ventilation installation is verified by the building department. At 2.87 ACH50 this home sits on the requiring side of that line.
The logic behind it is straightforward. A house tight enough to hold onto its conditioned air is also tight enough that it will not reliably exchange stale indoor air on its own, so the code asks for a designed path in rather than an accidental one. Testing is done in accordance with ANSI/RESNET/ICC 380, reported at 0.2 inches of water gauge.
We also perform mechanical ventilation testing, so the ventilation side of a tight house can be verified on the same visit instead of becoming a second trip.
Working With GHO Homes on the Vero Beach Barrier Island
GHO Homes has been building on the Treasure Coast since 1983, when Dan Handler moved the family construction business out of commercial work and into residential. The company has been a subsidiary of Green Brick Partners since 2018 and builds across Indian River and St. Lucie counties.
We have now tested in several of their communities. Over the past couple of months we were at HighPointe in Vero Beach and at Lucaya Pointe, and down in St. Lucie County we worked at Belterra in Tradition. The Strand is a different sort of project from any of those, a small barrier island community of larger homes near the historic Jungle Trail with direct beach access.
Every one of those visits came through our partnership with Energy Code Compliance Specialists, who coordinate the energy code work across these builds. That arrangement is what lets testing land on the schedule the builder is actually running rather than the other way around.
If you build in Indian River County and want energy code testing that keeps pace with your production schedule, here is how we work with builders and developers.
A First Training Day on the Blower Door at The Strand
There was a first on this job that has nothing to do with the number. I started training my wife on blower door testing.
Stellar is a family company, and as it keeps growing she is going to be taking on testing work alongside me. This was day one of that.
There is more to this than switching on a fan. The frame and panel have to seal properly in the opening, the gauge and pressure tubing have to be set up right, and the house has to be configured to the standard before a single reading counts for anything. Then somebody has to know what the number means once it lands, and what to do when it does not land where it should. That is the part that takes time, and it is learned on real houses rather than in a classroom, which is why it started on a job site.
More of that ahead. For now it is worth writing down that it started here, at The Strand.
Growing the bench is how we keep coverage tight across five counties without stretching the schedule. A little more about who we are and how we work is on the about page.
Blower Door Testing Across Vero Beach and Indian River County
Orchid Island projects sit in a particular environment. Salt air, high humidity, a lot of glass facing the water and homes designed to open up to the outside. None of that changes how a blower door test is run, but it does mean the envelope details are worth looking at closely rather than filing the report and forgetting it.
We cover Vero Beach and the rest of Indian River County regularly, including Sebastian, Fellsmere, Orchid and Indian River Shores, and we are on the island often enough that adding a home to an existing trip is usually straightforward.
Stellar Building Performance provides blower door testing, duct leakage testing, infrared thermography, duct smoke testing, mechanical ventilation testing, energy and load calculations, HERS Ratings and third party quality assurance across Brevard, Indian River, St. Lucie, Martin and Okeechobee counties.
Ready to get a test on the calendar in Vero Beach? Request services and tell us what you have coming up.
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