Your blower door test is done and the report hands you two numbers: an ACH50 and a CFM50. Nobody told you what counts as good, or whether your house just failed something. Novus Mechanical, serving Monmouth County, NJ, runs the test and then walks you through the result, because a number with no plain explanation is useless. The short version: a lower number means a tighter house, and a tighter house is cheaper to heat and cool.
There is no single grade you pass or fail. A good blower door score is a relative thing, judged against how the house was built and what the goal is. New construction is built far tighter than older homes, so the targets differ. Air sealing saves about 15% on heating and cooling, according to ENERGY STAR, and a blower door test from Novus starts at $350.
A blower door score is a measurement of how much air leaks out of a house, reported two ways: CFM50 and ACH50. The blower door fan pulls the home to 50 pascals of pressure, then the Retrotec gauge reads the leakage. First, CFM50 is the raw airflow, the cubic feet of air per minute escaping at that pressure. Second, ACH50 takes the same leak and divides by house volume, giving air changes per hour. Third, ACH50 lets you compare a small ranch to a big colonial fairly, because the number is scaled to size. A lower number means a tighter house. We measure the leak using Retrotec equipment, then explain both numbers in plain words. Sealing the worst leaks saves about 15% on heating and cooling, according to ENERGY STAR. A blower door test from Novus Mechanical starts at $350.
A lower blower door score is better, because a lower number means less air leaking and a tighter, more comfortable house. Picture two homes in Monmouth County. The leaky house posts a high CFM50, so heated air pours out the rim joist and cold air pours in. The sealed house posts a low CFM50, holds the warm air, and costs less every month. First, a high number signals lots of leaks to chase. Second, a low number signals a tight shell already doing the work. Third, the goal is to push the number down without starving the house of fresh air. A leaky house and a tight house carry different heating and cooling loads, so this score feeds the Manual J load calculation that right-sizes new equipment. We run the test using Retrotec gauges, then rank the leaks worst to smallest. Air sealing and insulation save about 15% on heating and cooling, according to ENERGY STAR. A blower door test from Novus starts at $350.
An older home is leakier than a new build because older homes were not built to today's airtight standards, and a higher leakage number is normal for the age. A 1980s colonial like the ones around Freehold was framed before tight building was the rule, so air sneaks through the attic hatch, the rim joist, recessed lights, and old windows. New construction is built far tighter, with targets set by programs like ENERGY STAR. First, age explains most of the gap, not bad upkeep. Second, a high number on an older house is fixable, not a failure. Third, sealing the leaks closes much of the distance to a new build. We measure the leakage using Retrotec equipment, then show you where the air moves. Air sealing saves about 15% on heating and cooling, according to ENERGY STAR. A blower door test from Novus starts at $350.
Novus turns the blower door score into a punch list, because a number alone fixes nothing. The CFM50 reading is the starting line, not the finish, and it guides the sealing work before a central AC replacement so the new system fits the tightened house. Here is how Novus uses your result across Monmouth County.
Chasing the biggest leaks first is the whole strategy. Air sealing and insulation save about 15% on heating and cooling, according to ENERGY STAR. A blower door test from Novus Mechanical starts at $350.
A blower door score is one measurement inside a larger home energy audit, the single biggest clue to where a house wastes energy. The blower door test finds the leaks, and the audit puts the leaks in context with insulation, ducts, and equipment. First, the blower door number shows how much air escapes. Second, the audit shows where the air escapes and what the fix is worth. Third, the plan seals the worst leaks before spending on anything fancy. Monmouth County sits in Climate Zone 4A, where winter design cold hits 13 degrees, so a leaky shell stings on the heating bill. We measure the whole picture using MeasureQuick and Retrotec gauges. Air sealing saves about 15% on heating and cooling, according to ENERGY STAR. A blower door test from Novus starts at $350.
A good blower door number is a low one, because lower CFM50 and lower ACH50 both mean less air leaking and a tighter house. There is no single pass-or-fail grade for an existing home, since a fair target depends on how the house was built and how old the house is. New construction is built far tighter, with goals set by programs like ENERGY STAR. An older house in Monmouth County will read higher, and a higher number is normal for the age. First, we run the test using Retrotec gauges. Second, we compare your number to a realistic goal for the home. Third, we seal the worst leaks to push the number down. Air sealing saves about 15% on heating and cooling, according to ENERGY STAR. A blower door test from Novus Mechanical starts at $350.
No, a high blower door score does not mean your house failed, because a blower door test is a measurement, not a pass-or-fail exam. A high CFM50 simply means more air is leaking, which is common and expected in older Monmouth County homes. A 1980s colonial like the ones around Freehold will almost always read leakier than a new build, and a leaky shell is fixable. First, we run the test using Retrotec gauges to get the real number. Second, we rank the leaks from worst to smallest. Third, we seal the biggest leaks first to bring the number down. Air sealing and insulation save about 15% on heating and cooling, according to ENERGY STAR. A blower door test from Novus starts at $350, and the result becomes a clear plan.
New construction is tighter than an older home because new homes are built to today's airtight standards, with leakage targets set by programs like ENERGY STAR. Older homes were framed before tight building was the rule, so air escapes through the attic hatch, rim joist, and old windows. A higher number on an older house is normal for the age and is not a sign of neglect. First, we measure the leakage using Retrotec gauges. Second, we find where the air moves through the shell. Third, we seal the worst leaks to close much of the gap to a new build, the same fixes the Department of Energy recommends for older homes. Air sealing saves about 15% on heating and cooling, according to ENERGY STAR. A blower door test from Novus Mechanical starts at $350, and sealing the leaks is the payoff.
Novus turns the blower door result into a ranked fix-it plan, because the number is only useful when the number leads to action. The CFM50 reading shows how much air leaks, and the worst leaks get sealed first. First, we run the test using Retrotec gauges to get the CFM50 and ACH50. Second, we rank the leaks from worst to smallest across the house. Third, we seal the biggest air movers, where each dollar buys the most tightness. Finally, we retest and verify the system using MeasureQuick. A blower door test from Novus starts at $350. Air sealing and insulation save about 15% on heating and cooling, according to ENERGY STAR, which is why sealing the worst leaks first is the smart order. For more, see our blower door test guide.
We measure your home, explain what we find, and hand you one clear price. Book a consultation in Freehold or Monmouth County.
