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DOE Home Energy Score Explained

April 11, 2026 · 15 min read

Last updated: April 2026

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Quick Answer

The DOE Home Energy Score gives homeowners a clear rating of their home's energy efficiency. This score helps us understand how well a house uses energy and where we can make important upgrades. A key part of figuring out this score often involves a blower door test. This test measures how airtight a home is, pointing out hidden air leaks that waste energy. For example, a proper test setup requires a 30-foot piece of clear tubing, usually supplied with Model 3 fans, to connect equipment for accurate readings [https://www.energyconservatory.com/wp-content/uploads/2025/10/Blower-Door-Fan-Field-Check.pdf?srsltid=AfmBOormL7UDkf0V3D8QFLQ0XdlPEhHYLjnNfL62J4p5BUZVbyUx4d1J]. Maintaining the calibration of blower door equipment is critical for getting reliable results. We regularly check for damaged flow sensors or leaks in the tubing to make sure our measurements are always accurate. This careful approach ensures the Home Energy Score truly reflects a home's performance and guides homeowners to effective efficiency improvements.

What is the DOE Home Energy Score?

The DOE Home Energy Score is a national rating system that tells us how energy efficient a home is. It's like a miles-per-gallon rating for a car, but for a house. This score helps homeowners understand their home's energy performance. It also shows them specific ways to make their home use less energy. The goal is to give clear information so people can save money on utility bills and live in a more comfortable home.

When we evaluate a home for its energy score, we look at many factors. These include the home's shell, its heating and cooling systems, and its water heater. The score rates a home on a scale of 1 to 10. A score of 1 means the home needs major energy improvements, while a score of 10 means it's very energy efficient. We use this score to give homeowners a roadmap for upgrades. It helps them prioritize which changes will have the biggest impact on their energy use.

Understanding the Home Energy Score means we can make smarter decisions about our homes. It's not just about the current energy use. It also looks at the potential for improvement. For example, a home might have an older furnace or poor insulation. The score will highlight these areas. It helps us see where to invest our money for the best energy savings. This makes the home more valuable and reduces its environmental footprint.

The score also provides an estimate of how much energy a home should use. This is called the asset rating. It's based on the home's structure and systems, not just how much energy the occupants actually used. This means the score is consistent from one home to another, no matter how many people live there or what their habits are. This consistency is important because it allows for fair comparisons between different homes. It also means the score remains relevant even when a home changes owners. We use standardized tools and procedures to gather the data needed for this score. This ensures that every assessment is reliable and accurate. This reliable data is what allows us to give homeowners actionable advice for improving their home's energy performance.

How do Blower Door Tests Contribute to the Score?

Blower door tests are a core part of figuring out a home's energy score because they directly measure airtightness. This test helps us find all the hidden leaks where conditioned air escapes or outside air enters. These leaks are a major source of energy waste in many homes. When we run a blower door test, we depressurize the house, making it easier to pinpoint exactly where the air is moving. This detailed information is crucial for identifying the most effective upgrades.

The process involves mounting a large fan into an exterior doorway. This fan either blows air out of the house or into it. Blowing air out creates a negative pressure inside the home. This negative pressure pulls outside air through every crack and gap in the building's shell. We can then use smoke pencils or infrared cameras to see these air leaks. Without a blower door, many of these leaks would be impossible to find. They could be behind walls, in attics, or around electrical outlets.

Finding and sealing these leaks is one of the most cost-effective ways to improve a home's energy efficiency. We know that uncontrolled air leakage can account for a significant portion of a home's heating and cooling costs. By reducing these leaks, we make the home more comfortable and cut down on energy bills. The data from the blower door test directly feeds into the Home Energy Score calculation. A tighter home will typically receive a higher, better score. This shows that the home is doing a better job of keeping conditioned air inside.

The blower door test also helps us understand the overall quality of a home's construction when it comes to air sealing. Even new homes can have significant air leakage if not built carefully. For older homes, the test often reveals decades of wear and tear, leading to numerous gaps. We use the results to recommend specific air sealing strategies. This might include sealing around windows and doors, insulating attics, or plugging gaps in crawl spaces. Every bit of air sealing we do improves the home's performance. The test provides the hard numbers we need to prove these improvements. This evidence-based approach helps homeowners feel confident in their energy efficiency investments. The Energy Conservatory makes diagnostic tools to measure building performance, and their blower door systems are widely used in this field [https://www.energyconservatory.com/wp-content/uploads/2014/07/fanfieldcheck.pdf?srsltid=AfmBOoqzOXbdLN_eAjwRiQLH2P6im4Ve5ZeT9uz_Z_PJK9dYu54Zs_Pi].

What Equipment is Used for Blower Door Testing?

Blower door testing relies on specialized equipment to accurately measure a home's airtightness. The core of this system is a powerful fan mounted in a temporary door frame. The Model 3 Minneapolis Blower Door fan is a very common tool we use in the field. This fan is designed to create a specific pressure difference between the inside and outside of a house. For more details, see Energy Conservatory Blower Door Fan Field Check procedure.

Beyond the fan itself, several other pieces of equipment are essential for a complete blower door test. We need a 30-foot piece of clear tubing. This is the longer, clear tubing that comes with all Model 3 fans. The red and green tubes are too short for some tests [https://www.energyconservatory.com/wp-content/uploads/2025/10/Blower-Door-Fan-Field-Check.pdf?srsltid=AfmBOormL7UDkf0V3D8QFLQ0XdlPEhHYLjnNfL62J4p5BUZVbyUx4d1J]. This tubing connects different parts of the system to measure pressure accurately. We also use a 1 ml syringe, which is usually 1.2 to 1.3 ml in size, available from The Energy Conservatory. This syringe is key for performing leak checks on the equipment itself.

To connect the tubing, we use two tubing T's for standard ¼” OD tubing. These T-connectors help us create the right setup for pressure measurements and leak tests. The data from these measurements is read by a DG-1000 or DG-700 manometer. This device measures air pressure differences with high precision. We also need a straightedge, like a carpenter’s level or a heavy yardstick, and a ruler that measures in 16ths of an inch or millimeters. These tools help with setting up and confirming the correct positioning of equipment components. While it's optional, a workbench or table can make these checks easier to perform, though they can be done on the floor [https://www.energyconservatory.com/wp-content/uploads/2025/10/Blower-Door-Fan-Field-Check.pdf?srsltid=AfmBOormL7UDkf0V3D8QFLQ0XdlPEhHYLjnNfL62J4p5BUZVbyUx4d1J].

It's important to remember that The Energy Conservatory is not the only manufacturer of blower door systems. Retrotec also manufactures a range of blower door systems. They offer options for residential energy audits, large building testing, and even enclosure integrity testing for specialized applications like fire suppression systems [https://retrotec.com/product/blower-doors.html?srsltid=AfmBOoob4nT4DNxaqPYvFzIZYtxRPEVv1mgsGjXzthvVhrV_QGPEuuJL]. Their residential blower door systems are specifically designed for home energy assessments [https://retrotec.com/product/blower-doors/residential-energy.html?srsltid=AfmBOorTr_V0fdZtKO4X41lApm7MAX7GnNDO3qE5w5Y1DX01Gy64tGf]. Regardless of the brand, the principles of blower door testing remain the same: depressurize the house and measure the airflow to determine its airtightness. Maintaining all this equipment in good working order is essential for accurate and reliable results every time we perform a test.

Key Components of a Blower Door System

How Do You Check a Blower Door Fan's Calibration?

Checking a blower door fan's calibration is critical for ensuring accurate energy audit results. Model 3 Minneapolis Blower Door fans generally hold their calibration well. However, physical damage to the fan can change this. This includes damaged flow sensors, leaks in the flow sensor or its tubing, or incorrect positioning of the flow sensor relative to the fan housing. We must test for these conditions regularly to maintain accuracy.

Before we start any checks, we make sure everything is at room temperature for at least 30 minutes. If the tubing, gauge, or fan are warming up or cooling down during the test, the results might not be accurate [https://www.energyconservatory.com/wp-content/uploads/2025/10/Blower-Door-Fan-Field-Check.pdf?srsltid=AfmBOormL7UDkf0V3D8QFLQ0XdlPEhHYLjnNfL62J4p5BUZVbyUx4d1J]. This simple step prevents temperature-related pressure changes from affecting our readings.

One of the first things we check is for leaks in the syringe, tubing, and manometer. We attach a loop of tubing and a "T" to the end of the 30 ft tube. Then we depress the syringe plunger most of the way down until it reads about 1000 Pa on the manometer. After 15 seconds, it should still read at least 900 Pa. If the reading drops lower than 900 Pa, it means the syringe or the tubing has a leak and needs to be replaced. This leak test confirms the integrity of our measurement tools before we even touch the blower door fan itself [https://www.energyconservatory.com/wp-content/uploads/2025/10/Blower-Door-Fan-Field-Check.pdf?srsltid=AfmBOormL7UDkf0V3D8QFLQ0XdlPEhHYLjnNfL62J4p5BUZVbyUx4d1J].

The flow sensor itself is a common point of potential issues. "Model 3 Blower Door and Series B Duct Blaster fans maintain their calibration unless physical damage occurs to the fan. Conditions which could cause the fan calibration to change are primarily damaged flow sensors, leaks in the flow sensor or tubing running from the flow sensor to the fan pressure tap, or improper positioning of the flow sensor relative to the fan housing. These conditions are easily detected and should be tested for on a regular basis," according to The Energy Conservatory. This highlights why our regular visual and physical checks are so important. We always look for any signs of impact or deformation on the flow sensor. We also confirm it is firmly attached to the motor with its three metal clips.

Steps for Checking Calibration:

These steps help us ensure that our blower door equipment is always in top working order, providing reliable data for every home energy audit.

What are the Steps for a Flow Sensor Leak Test?

Performing a flow sensor leak test is a crucial part of maintaining the accuracy of your Model 3 Blower Door fan. This test specifically checks the integrity of the round white plastic flow sensor mounted on the end of the fan motor. It ensures that the sensor itself and its connections are not leaking, which could skew your readings during an actual blower door test.

First, we visually confirm the flow sensor is not broken or deformed from any impact. We also check that it is firmly attached to the motor using the three metal attachment clips. This initial visual inspection can catch obvious problems before we even begin the pressure test [https://www.energyconservatory.com/wp-content/uploads/2014/07/fanfieldcheck.pdf?srsltid=AfmBOoqzOXbdLN_eAjwRiQLH2P6im4Ve5ZeT9uz_Z_PJK9dYu54Zs_Pi]. A damaged or loose sensor will never give accurate results.

Next, we prepare the flow sensor for the leak test. We find the four intentional sensing holes located on the outside rim of the flow sensor. These holes are positioned at 2, 4, 8, and 10 o’clock. We temporarily seal these four sensing holes by carefully covering them with tape. Using dark-colored painter's tape is a good tip because it makes it obvious that the sensor has been taped. This prevents us from forgetting the tape is there, which would make it impossible for the fan to measure flow later on [https://www.energyconservatory.com/wp-content/uploads/2025/10/Blower-Door-Fan-Field-Check.pdf?srsltid=AfmBOormL7UDkf0V3D8QFLQ0XdlPEhHYLjnNfL62J4p5BUZVbyUx4d1J]. For more details, see The Energy Conservatory Model 3 Blower Door User Manual.

Once the sensing holes are sealed, we set up the tubing and manometer. We attach one end of the 30-foot tube to the pressure tap on the blower door. The other end of this tube connects to a tubing "T". From this "T", we attach two shorter lengths of tubing. One of these short tubes connects to Channel A of the manometer, and the other connects to the 1 ml syringe. This setup creates a closed system where we can control and measure pressure changes [https://www.energyconservatory.com/wp-content/uploads/2025/10/Blower-Door-Fan-Field-Check.pdf?srsltid=AfmBOormL7UDkf0V3D8QFLQ0XdlPEhHYLjnNfL62J4p5BUZVbyUx4d1J].

We then remove the plunger from the syringe and make sure the manometer reads 0 Pa. This confirms our baseline. After that, we depress the plunger all the way in and immediately start a stopwatch. It's important not to hold the syringe with your hand during this step, as the warmth from your hand can raise the pressure and affect the reading. The manometer pressure should spike up to 800 Pa or higher, then slowly begin to drop. We record the pressure reading exactly when the stopwatch reaches 15 seconds. This recorded pressure helps us determine if there's a leak in the flow sensor system [https://www.energyconservatory.com/wp-content/uploads/2025/10/Blower-Door-Fan-Field-Check.pdf?srsltid=AfmBOormL7UDkf0V3D8QFLQ0XdlPEhHYLjnNfL62J4p5BUZVbyUx4d1J]. Consistent adherence to these steps ensures that our blower door equipment provides precise measurements for every energy audit.

Detailed Procedure for Flow Sensor Leak Test:

  1. Visual Inspection: Check the round white plastic flow sensor for any damage or deformation. Confirm it is securely attached to the fan motor with its 3 metal clips [https://www.energyconservatory.com/wp-content/uploads/2014/07/fanfieldcheck.pdf?srsltid=AfmBOoqzOXbdLN_eAjwRiQLH2P6im4Ve5ZeT9uz_Z_PJK9dYu54Zs_Pi].
  2. Seal Sensing Holes: Locate the 4 intentional sensing holes on the flow sensor's rim (at 2, 4, 8, and 10 o'clock). Cover each hole carefully with dark-colored painter's tape [https://www.energyconservatory.com/wp-content/uploads/2025/10/Blower-Door-Fan-Field-Check.pdf?srsltid=AfmBOormL7UDkf0V3D8QFLQ0XdlPEhHYLjnNfL62J4p5BUZVbyUx4d1J].
  3. Connect Tubing: Attach one end of the 30-foot tube to the pressure tap on the blower door. Connect the other end of this tube to a tubing "T". From the "T", connect two short tubes: one to Channel A of the manometer and the other to the 1 ml syringe [https://www.energyconservatory.com/wp-content/uploads/2025/10/Blower-Door-Fan-Field-Check.pdf?srsltid=AfmBOormL7UDkf0V3D8QFLQ0XdlPEhHYLjnNfL62J4p5BUZVbyUx4d1J].
  4. Zero Manometer: Remove the plunger from the syringe and verify that the manometer reads 0 Pa.
  5. Initiate Pressure Test: Depress the syringe plunger all the way in and immediately start a stopwatch. Avoid holding the syringe to prevent heat transfer from your hand [https://www.energyconservatory.com/wp-content/uploads/2025/10/Blower-Door-Fan-Field-Check.pdf?srsltid=AfmBOormL7UDkf0V3D8QFLQ0XdlPEhHYLjnNfL62J4p5BUZVbyUx4d1J].
  6. Record Reading: The manometer pressure should initially spike to 800 Pa or higher and then slowly drop. Record the pressure reading precisely at the 15-second mark on the stopwatch [https://www.energyconservatory.com/wp-content/uploads/2025/10/Blower-Door-Fan-Field-Check.pdf?srsltid=AfmBOormL7UDkf0V3D8QFLQ0XdlPEhHYLjnNfL62J4p5BUZVbyUx4d1J].

Does The Energy Conservatory Offer a Warranty?

Yes, The Energy Conservatory provides an express limited warranty for its products, including the Model 3 Minneapolis Blower Door System. This warranty ensures that their products are free from defects in workmanship and material under normal use and service. The standard warranty period for new products is 24 months from the date of shipment to the customer [https://nascsp.org/wp-content/uploads/2018/02/the-energy-conservatory-mn-blower-door-operations-manual-for-model-3-and-4.pdf]. This gives customers peace of mind, knowing their diagnostic tools are covered for a significant period after purchase.

The warranty terms are clearly outlined in the operator's manual. "Seller warrants that this product, under normal use and service as described in the operator’s manual, shall be free from defects in workmanship and material for a period of 24 months, or such shorter length of time as may be specified in the operator’s manual, from the date of shipment to the Customer," states The Energy Conservatory. This commitment reflects their confidence in the quality and durability of their equipment. It also emphasizes the importance of using the product as described in the manual to ensure warranty validity. For more details, see Retrotec Blower Door Systems for Residential use.

This limited warranty does come with certain exclusions and limitations. For example, if repair services are rendered, The Energy Conservatory warrants that the parts repaired or replaced will be free from defects in workmanship and material for a shorter period of 90 days from the date of shipment to the purchaser [https://www.energyconservatory.com/wp-content/uploads/2023/11/Blower-Door-Manual-Current-Version.pdf?srsltid=AfmBOoq_1Naf_C7vlNDweROL5iyiB47b7gEhCXysMNyf9dsP9rDZ5CtT]. This distinct warranty period for repairs helps clarify expectations for customers receiving service. It's also important to note that The Energy Conservatory does not provide a warranty on finished goods manufactured by others; in such cases, only the original manufacturer’s warranty applies. This means if a system includes components from different brands, the warranty for those specific parts would fall under their respective manufacturers.

When returning a product under warranty, the purchaser is responsible for all shipping charges to send the product back to The Energy Conservatory. However, The Energy Conservatory covers the cost of return standard ground shipping. If a customer needs expedited return shipping, they can request it and pay for the added cost. This division of shipping responsibilities is a standard practice and helps manage the logistics of warranty claims. Understanding these terms helps us manage our equipment effectively and plan for any necessary servicing or replacements.

Warranty Details:

Frequently Asked Questions

What is the main purpose of a blower door test?

The main purpose of a blower door test is to measure a home's airtightness. This helps us find uncontrolled air leaks that contribute to energy loss and discomfort. The test is crucial for pinpointing where a home needs air sealing improvements, which directly impacts its energy efficiency and can significantly affect its Home Energy Score.

How often should I check my blower door fan's calibration?

You should check your blower door fan's calibration on a regular basis. Model 3 Blower Door fans generally maintain calibration unless physical damage occurs to the fan, flow sensors, or tubing [https://www.energyconservatory.com/wp-content/uploads/2025/10/Blower-Door-Fan-Field-Check.pdf?srsltid=AfmBOormL7UDkf0V3D8QFLQ0XdlPEhHYLjnNfL62J4p5BUZVbyUx4d1J]. Regular checks, including visual inspections and leak tests, help detect these issues early and ensure accurate measurements.

What are the signs of a damaged flow sensor?

Signs of a damaged flow sensor include visible breaks or deformation due to impact, or if it is not firmly attached by its three metal clips [https://www.energyconservatory.com/wp-content/uploads/2014/07/fanfieldcheck.pdf?srsltid=AfmBOoqzOXbdLN_eAjwRiQLH2P6im4Ve5ZeT9uz_Z_PJK9dYu54Zs_Pi]. During a leak test, if the manometer pressure doesn't spike to 800 Pa or higher, or drops too quickly, it could indicate a problem with the sensor or its connections.

Can I use any tubing for the blower door field check?

No, you cannot use any tubing. For the Model 3 Minneapolis Blower Door fan field check, you need a 30-foot piece of clear tubing, which is the longer tubing supplied with the fans. The shorter red and green tubes are not long enough for this specific test [https://www.energyconservatory.com/wp-content/uploads/2025/10/Blower-Door-Fan-Field-Check.pdf?srsltid=AfmBOormL7UDkf0V3D8QFLQ0XdlPEhHYLjnNfL62J4p5BUZVbyUx4d1J]. Using the correct length and type of tubing is essential for accurate pressure measurements.

What is the warranty period for a new Model 3 Minneapolis Blower Door System?

A new Model 3 Minneapolis Blower Door System comes with an express limited warranty for 24 months from the date of shipment to the customer [https://nascsp.org/wp-content/uploads/2018/02/the-energy-conservatory-mn-blower-door-operations-manual-for-model-3-and-4.pdf]. This warranty covers defects in workmanship and material under normal use. Repaired or replaced parts, however, have a separate 90-day warranty period from their shipment date [https://www.energyconservatory.com/wp-content/uploads/2023/11/Blower-Door-Manual-Current-Version.pdf?srsltid=AfmBOoq_1Naf_C7vlNDweROL5iyiB47b7gEhCXysMNyf9dsP9rDZ5CtT].

— The Efficiency Team

Related Reading

Sources

  1. https://www.energyconservatory.com/wp-content/uploads/2025/10/Blower-Door-Fan-Field-Check.pdf?srsltid=AfmBOormL7UDkf0V3D8QFLQ0XdlPEhHYLjnNfL62J4p5BUZVbyUx4d1J
  2. https://www.energyconservatory.com/wp-content/uploads/2014/07/fanfieldcheck.pdf?srsltid=AfmBOoqzOXbdLN_eAjwRiQLH2P6im4Ve5ZeT9uz_Z_PJK9dYu54Zs_Pi
  3. https://www.energyconservatory.com/wp-content/uploads/2023/11/Blower-Door-Manual-Current-Version.pdf?srsltid=AfmBOoq_1Naf_C7vlNDweROL5iyiB47b7gEhCXysMNyf9dsP9rDZ5CtT
  4. https://nascsp.org/wp-content/uploads/2018/02/the-energy-conservatory-mn-blower-door-operations-manual-for-model-3-and-4.pdf
  5. https://retrotec.com/product/blower-doors.html?srsltid=AfmBOoob4nT4DNxaqPYvFzIZYtxRPEVv1mgsGjXzthvVhrV_QGPEuuJL
  6. https://retrotec.com/product/blower-doors/residential-energy.html?srsltid=AfmBOorTr_V0fdZtKO4X41lApm7MAX7GnNDO3qE5w5Y1DX01Gy64tGf

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