Why you need to include a blower door test in your energy audit?

Have you noticed that one or two rooms in your home are ALWAYS hot in the summer? Can you feel a cold draft in the winter? Heck, is your home older than 10 years old?

If you answered “yes” to any of these questions, then I’m here to tell you that you really ought to get have an home energy audit done.

Most companies that do energy audits will offer them in a few different levels. Today, I’m going to explain why step two is to include a blower door test in your energy audit.

First, what is a blower door test?

A blower door is a critical piece to an effective energy audit.

A blower door test is one of the greatest tools in a building scientist’s / energy auditor’s tool box. It depressurizes the home and (through a sophisticated tool called a manometer) is able to figure out how much air is coming into the house. Through some algorithms it then can give a number for how much air leakage there is within a home. Blower Door tests are required by LEED, ESTIDAMA and AL SA’FAT to make sure that NEW homes in UAE aren’t being built too leaky.

How does that help my home energy audit?

That’s a great question. Blower door tests aren’t just useful tools for identifying how much air is coming into the house, they are also a part of pinpointing where air is coming into the house.

While it’s great to know that the home is leaky (and honestly, most pros could probably fix 80% of the problems in the home just by going to the long list of usual places missed/rushed/ignored by builders — this is done because of steadily improving understanding of building science and good building practices, but also because not every builder makes homes of the same quality), it’s critical to pinpoint those leaks so they can be addressed.

Your energy auditor will walk through the home with one or two other tools while the blower door is running. He/she might use a smoke pen, a pressure pan, a second manometer, or a fog machine.

They can even use a thermal camera and be able to see how entire portions of your house are performing, controlling temperatures, air & moisture.

Regardless of which tool they use, they are all meant to figure out where the leaks are. Without running a blower door test during the home energy audit, you really wouldn’t be able to pinpoint air leaks. At that point you would be relying on past experience and best guesses.

What happens after an energy audit?

Once the audit is complete you should be walked through your home and have the results/findings of the audit be explained to you. If your auditor is using words you don’t understand, or doing too in-depth of an explanation, tell them to bring it down a notch. You aren’t a home builder. There shouldn’t be any expectation that you know the first thing about building science or building techniques.

You should also get a report sent to you that covers the findings and gives recommendations.

If you are a diyer, then head to your hardware store and get to work. If not, bring in some pros.

Either the way, the first step towards improving the energy efficiency of a clean & safe home is air sealing. Always.

I do want to stress that clean and safe part though. If your home has an asbestos issue, high radon, or a mold problem then you really need to get that taken care of ASAP. That poses a very real health risk, and that needs to be addressed.

Bringing it home

Ok, so you’ve identified that you need a home energy audit. You’ve found the company you want to use, and now you’re trying to pick out which level of audit to buy. Is it really worth the extra charge to have a blower door test included?

YES.

A blower door test will:

  • give you a real number for how leaky your home is…this means that every time you make some major upgrades/improvements you can compare the blower door number from before and after to make sure the problem is really being addressed
  • allow the auditor to actually find the air leaks as opposed to going off instinct & experience

The biggest loss of money, comfort, and home health comes from excessive air leakage.

Having an energy audit done with a blower door test will allow you to seal those leaks, which means your home will be more comfortable; you’ll have healthier, cleaner, less humid air in the home; and you won’t be spending as much money on energy bills.

And less spending on utility bills means more spending wherever the heck you want.

Using a Micro Fogger with a Blower Door allows auditors to localize the exact leak location.

Essentials of Air Tightness Testing

As ATTMA certified blower door testers, training providers and official suppliers of TEC, we recommend the following essential tips to carry out the air tightness tests:

Do’s – Put the hose outside

When you’re setting up the blower door, run your hose to the outdoors before you completely assemble the door. If you don’t, you’ll either have to take it apart again, go through another door, or do the “crawl of shame” to get the hose in position (see Image #2, below). After you’ve suffered one or more of those inconveniences a few times, you’ll start remembering this every time.

Image Credit: Energy Conservatory

Do’s – Put the hose in a bag, can, or shoe

When you put the hose outdoors, you need to protect the end from wind. A good way to do that is to put the end of the hose in some kind of container that’s still connected to the outdoor air. You could use your shoe. You could use a plastic container. You could even use a bag. It just so happens that the little canvas bag for The Energy Conservatory’s DG-700 is perfect for this task.

In addition to protecting the end of the hose from wind, doing this also helps protect it from water. A drop of water in the end of your hose can mess up your results, too.

Do’s – Put newspaper over fireplace ashes

If you make the mistake of not checking the fireplace for ashes, the carpet is guaranteed to be white. I don’t know why this works, but I know from experience that it does. So, first, check the fireplace for ashes. One method I’ve found that keeps the ashes out of the house is to lay newspaper over the fireplace and then use a spray bottle filled with water to wet the newspaper. It works.

Do’s – Use Vent Caps

If you haven’t used Vent Caps yet, you’ll be amazed at the difference they can make in your setup time (see Image #3, below). They’re so much easier to use than grille mask, and if you do a fair amount of testing, they’ll pay for themselves pretty quickly with the money you save on grille mask. “Vent Caps changed my life.”

Don’t do the blower door test first

I used to go in and do the blower door test first, then set up and run the two duct leakage tests. If you’ve done any of this testing, you know that it takes much longer to set up for the duct leakage testing. If it’s a hot, humid, or cold day, when you run the blower door first, you’re making the house uncomfortable for the whole time you’re setting up the duct leakage tests.
Instead, do all your setup upfront. Then run your two duct leakage tests. Once you’ve got those results, unseal the vents and run your blower door test. Running the tests takes only a few minutes if you’re just measuring performance. If you’re doing a lot of diagnostic work, too, it’ll take a bit longer, but as soon as you’re done, you can get the air conditioner or heating system going again. Make sure your helpers know where to seal the vents.

Source: https://www.energyvanguard.com/blog/tips-tricks-for-blower-door-and-duct-leakage-testing

Essential Energy-Audit Equipment

The number-one tool on every auditor’s list is a blower door.

I thought I’d put together a list of all of the tools and equipment I use during an energy audit. Not all of these tools are used during every audit, and some aren’t essential to investigating the house. I’ve separated the lists into two categories: essential items and useful items.

I’ve listed the models of the tools I actually use, and I’ve included links to websites where these tools can be purchased. Equipment is available with more or better features; for example, high-end infrared cameras have more memory, higher resolution, and USB ports. However, this list gives you a good starting point for filling a tool kit to handle issues that come up (like moisture levels) or ones that routinely need to be covered as part of an audit (like monitoring CO levels).

Energy audit equipment: the essentials

Blower Door System. I’ve written about blower doors extensively, detailing how they help evaluations and aid diagnostic work. While the common thermal bypasses are well known, a blower door can starkly show the extent and size of air leakage problems. I use a blower door manufactured by the Energy Conservatory.

Infrared camera Surprisingly, I almost put infrared cameras in the ‘useful’ category rather than ‘essential.’ They’re very helpful for locating air leakage, moisture issues, thermal bridging, or insulation irregularities that can lead to poor thermal performance. However, they’re astonishingly useful in visually demonstrating building problems to homeowners. The model I use is the Flir B50.

Digital pressure and flow gauge. A pressure gauge is integral to blower-door testing but is also very useful on its own. Zone diagnostics (a.k.a. poking air tubes into rooms and framing cavities) can be extraordinarily informative. While almost everyone knows where the big air leaks and thermal problems are, pressure gauges can more finely detail the heat loss and air leak pathways. A pressure gauge is also used for flue gas pressure testing and worst-case depressurization testing of the combustion air zone (CAZ). I use the model DG-100 gauge from the Energy Conservatory.

Micro Fogger. A smoke creator is useful for tracking air flows when the blower door is running. It creates a pretty arresting visual when the smoke is sucked through a crack no one suspected was a problem.

Carbon monoxide detector. Carbon monoxide levels need to be monitored during an audit. The heating system is checked with the combustion analyzer and this monitor tracks atmospheric CO in the house throughout the audit. The model I use is the Fluke CO-220.

Combustion analyzer. The combustion analyzer tests the efficiency of heating and hot water systems. I use a basic model, but it does the trick. It can test flue gases for O2, CO2, heating system efficiency and carbon monoxide. It can also double as a CO detector. I use the Fyrite Tech analyzer from Bacharach.

LED flashlight. I avoid smaller (dimmer) LED lights because sometimes I need some serious light. When I’m crawling through a dark attic, I don’t want a dim little beam. The model I use isn’t an expensive, high-end flashlight, so I won’t regret it if something happens to it. I use a Neiko 40282 flashlight.

Digital camera. Like the flashlight, the digital camera is essential but I opt toward reliable but less expensive models. I use a Sony Cyber-Shot DSC-W530 camera.

25-foot tape measure. All of my energy audit equipment is either heavy-duty or easily replaceable. Like any contractor can tell you, crawling around basements and attics adds some considerable wear and tear. I use a 25-foot Fat Max tape from Stanley.

Cordless drill. Drills are a less obvious but necessary piece of energy audit equipment. Many times the heating system exhaust pipe doesn’t have an access hole drilled yet for the combustion analyzer probe. (Warning: For bleep’s sake, make sure it’s not a concentric vent before drilling.) A drill is also handy if you need to check inside a wall cavity (with the homeowner’s permission, of course). I use a an 18-volt DeWalt DC970K-2 cordless drill

Telescoping ladder. Attic access hatches are often tucked away and hard to reach. A full ladder might not fit in an awkward closet. A heavy-duty telescoping ladder (I’m around 250 pounds, so I mean heavy) will make snaking through a clothes closet to the attic hatch that much easier. I use a Telesteps 1800EP Pro aluminum ladder.

Energy audit equipment: useful tools

Moisture meter. Technically called a “hygro psychrometer,” this meter allows you to quickly read several moisture measures, including relative humidity. While no substitute for year round metered data and observation, it is incredibly useful for gaining a sense of the moisture levels in a building. The model I use is the Extech RH390. (Tip: a less sexy but less expensive piece of energy audit equipment would be a few $10 humidistats from Lowes. Place a few around the house at the start of the audit and get the final readings when you collect them.)

Fiber-optic borescope. Borescopes are a perfect example of a great but maybe not essential piece of energy audit equipment. Borescopes allow you to look inside wall cavities, sealed crawlspaces, duct work. They’re incredibly useful for figuring out what’s happening in the building shell. The one I use is the Dewalt DCT410S1 inspection camera kit

Non-contact voltage detector. Very often you need to test for live wires. Knob and tube wiring also comes up with all the time in audits (at least in Maine). Testing whether they are live is important as insulating near or over live knob and tube is a potential fire hazard. The one I use is a Greenlee GT-16.

Laser tape measure. Sometimes it is easier to use a laser than it is to roll out the ol’ tape measure. I use a Fluke 411D laser distance meter

Distance measuring wheel I wouldn’t use this for precise measurements, but it’s fine for measuring a building perimeter. Mine is a CST/Berger Measure Mark 31-10M

Hat with LED light. You’ll never appreciate this hat more than when you’re trying to write something down while jammed between some attic trusses

Whew — that took a while. I also use a few other less exciting items (like a plastic darning needle to poke around behind outlets), but that covers all the major energy audit equipment.

Airtightness Enhances Energy Efficiency

In the modern fast-paced construction industry, the quality of the materials and the construction methodologies are given prime importance to achieve higher energy efficiency standards. However, the Airtightness of the building envelope is often ignored due to the lack of awareness on the relationship between the Airtightness and the Energy Efficiency.

In the recent days, the buildings are provided with energy efficient insulation systems. However, because of the absence of airtight envelope, the air leakage nullifies the impact of the efficient envelope on the overall operation costs of the building.

So, in this article we talk about the importance of ‘Airtightness’ in the building envelope.

Let’s understand about the ‘Air Leakage’

In general, Air Leakage is assumed as wind blowing into our houses. While this is partly true, in reality the situation is more complex.

Wind creates zones of positive and negative pressure around our homes, which both pushes air in and sucks air out. In addition, as we all know, heat rises, and this can also generate positive and negative pressure zones within a building.

Air leakage occurs mainly at the junctions between different elements of the building and particularly between materials. Some components are naturally airtight, while others need to have an additional layer applied to achieve the desired performance. Leakage also occurs through penetrations – a typical example would be from services, such as drainage pipes and cables – and even from light fittings if the airtight layer is on the inside of the structure.

Air Barrier – the solution to achieve airtight envelope

The basic principle to optimize the Airtightness is to establish an air barrier line all the way around the building, including its walls, floors and roof. This is similar to the thermal envelope that is used to establish the boundary for insulation. ATTMA guidelines recommends drawing a red line on the detailed plans to show where the air barrier will lie.

This barrier line can be drawn either inside the structural members of the building or outside of it, but cannot be a mixture of both, as this introduces great complexity and is a recipe for failure.

In the UK, internal air barriers are more common, but these require specialist components and have multiple penetrations for services. In North America, external air barriers are generally preferred, as they are considered simpler to install correctly, with fewer components and fewer penetrations to worry about.

The barrier may require an additional layer to be added to the construction in some places, but in other areas the existing material may be sufficient. For example, oriented strand board (OSB) is relatively airtight so it may only be strictly necessary to provide an effective seal at the joints between the boards.

Concrete is another product that’s effectively airtight, so solid floors should not need an additional layer. Glass is also airtight, so in most cases it’s the junctions between dissimilar materials that need to be focused on.

Buildings are complex and have all kinds of necessary structural connections between elements, such as at wall/floor junctions or wall/roof junctions. Careful detailing is required to achieve good performance at these points but, increasingly, products are becoming available that help designers and installers deal with these challenges.

For example, where a soil pipe exits the airtightness layer, a purpose-made flange is fitted to the pipe and the horizontal section is then sealed to the barrier through which it penetrates to attain the required result.

Challenges faced during the execution stage

The most important thing in achieving good airtightness is to plan the barrier line fully at design stage, then to have a process in place to ensure that every detail of the design is carried through during the construction phase.

Getting this right requires cooperation between the design team and the main contractor. It is much cheaper and less stressful to do this at the early stages than to have to take sections of a building apart and retrofit a barrier where air leakage has been identified by post-construction testing.

A particular challenge is to think ahead and get the sequencing correct. Some project teams may not have worked to these standards before, so will need to go through training to fully understand their role in the process and learn the sequencing of applying the requirements.

This is best addressed by appointing an airtightness champion – someone who will understand exactly where the barrier lies and communicate this to all participants on site, supervise all relevant work and make sure that later participants do not damage the layer as they work. It is preferred that the airtightness champion shall be ATTMA certified building envelope professional or equivalent.

Airtightness Testing

Let this be the final stage in ensuring the building achieves the desired Airtight Envelope. This isn’t the final pass/fail test. Instead it is undertaken when the airtightness barrier is in place, but the finishing layers (plasterboard etc) have not been completed. This means that the barrier is accessible and remedial action can be taken if required.

This process the identification of leakage routes using smoke pens and thermal imaging cameras. The result should be a detailed report that shows the builder where there are issues in the fabric to resolve.

The below image shows the airtightness testing undertaken by our specialists: the front door is replaced by a temporary unit, with a fan that pumps air into the house to increase the pressure.

Image: Blower Door System used for airtightness testing

Source: https://www.self-build.co.uk/eco-design-guide-make-house-airtight/

Does Your Home Make You Sick? Check The ‘Air Quality’

‘More than half of the air you’ll breathe in your lifetime is inhaled inside your home’

An article from World Green Building Council states that ‘An estimated 5.5 million lives were lost in 2013 to diseases associated with outdoor and household air pollution. These deaths cost the global economy about US$225 billion in lost workforce productivity and over US$5 trillion in welfare losses. China has lost substantial chunks of national GDP due to lower productivity from pollution – 6.5% in 2016. The annual cost of asthma and pulmonary disease is 82 billion Euros across Europe and CAN$8 billion in Canada, which we know is being worsened by air pollution’.

The major indoor air pollutants that affects the health of the occupants are pollutants released from cooking and heating with traditional biomass coal stoves, as well as toxic chemicals, such as Volatile Organic Compounds (VOCs), emitted from cleaning products, furnishings, and paints in your home.

Know the Basics: ‘Air Quality and Ventilation’

Indoor air quality is governed, to a large extent, by the materials and finishes that go into a building, as well as the activities of its occupants (cooking etc). The idea to minimise or eliminate the presence of toxins in the internal atmosphere through a combination of good ventilation and well-informed product selection.

A report by the Royal College of Physicians and the Royal College of Paediatrics and Child Health suggests that those susceptible to indoor air pollutants are at risk of major health conditions, such as cancer, heart disease and respiratory related illnesses.

With modern construction, some of the key culprits are the goods containing VOCs (volatile organic compounds) such as formaldehyde, which can off-gas low levels of toxins over the long term. VOCs are present in many conventional paints and adhesives, in addition to a range of common building materials such as treated timber, OSB (oriented strand board), MDF (medium density fiberboard) and plasterboard. Other common air quality issues include condensation and mold. This can be arrested by ensuring the building envelope is airtight.

The air quality issues can be mitigated by selecting robust yet chemical-free structural materials and finishes, as far as is practicable, and to ensure that adequate ventilation is provided in the design and best indoor air quality management practices are followed during the construction.

Ventilation

Adequate ventilation shall be provided by following the local regulatory requirements and the international standards. But it should be noted that if effective ventilation is not in place to remove harmful contaminants, it may create adverse effects on the overall Air Quality of the living space.

It is recommended to design a proper mechanical ventilation system to deal with the outdoor / fresh air supply. Nowadays, most of the international design standards recommends a high-quality filter in the ventilation systems to ensure a fresh, filtered and safe incoming air supplied into the space.

Airtightness

In addition to the ventilation and materials, it is important to build your home airtight because through the gaps in the envelope, the hot outdoor air can enter the building making mechanical systems inefficient and supports mold growth inside the living space.

It is to be noted that ‘Over five million people in the UK are thought to suffer from asthma, and this can be triggered by poor internal environment’. Mold growth is one of the major indoor environment pollutants, and it is one of the most complicated processes to remove or stop mold growth in a space once it is established or developed.

‘Envelope Airtightness’ is currently a major requirement that has to be addressed from design to construction of any building, mainly in the very hot and cold climates. Envelope airtightness can be ensured by conducting air leakage tests as per the ASTM or ISO standards. However, to ensure the integrity of the leakage tests; the tests shall be conducted by certified professionals from organisations like ATTMA, ABAA…etc. Also, to ensure the continuity of envelope insulation, thermographic tests can be carried out.

How a healthy home can be defined?

A healthy home can be defined as an airtight, highly insulated, energy efficient home that costs very little to operate and supports the occupant’s health and lifestyle.

Source:

https://www.worldgbc.org/sites/default/files/20181204_WGBC_Homes-Research-Note_FINAL_spreads.pdf

https://www.self-build.co.uk/how-build-healthy-home/

Air Leakage Test for Solving Moisture-Related Problems in Your Building

As ATTMA certified blower door testers, training providers and official suppliers of TEC blower door systems, we recommend ‘Air Leakage Test’ as a diagnostic tool to find air leakages that make your building inefficient and are often the cause of moisture-related problems.

Air Leakage Leads to Building Durability Problems

In an air-conditioned space, it is important to limit the ‘Air Leakage’ that negatively impacts comfort, indoor air quality, and energy use in buildings. In addition to carrying heat, air leakage often carries moisture with it, which means that air leaks can lead to a variety of building durability problems.

Examples of air leakage that leads to durability problems include growing mold on roof or wall sheathing due to outward air leakage in cold climates, or condensation on cold ducts or pipes due to inward air leakage in hot-humid climates. In addition, indoor humidity problems are more prominent in Middle East and air leaks are part of them.

This article is about the devices that measure air leakage (such as blower doors and duct blasters), differential pressures, and airflow.

Air Leakage Testing – Blower Doors and Duct Blasters

A blower door (Minneapolis Blower Door) is a calibrated fan used to measure air leakage in buildings; it is typically installed in a fabric shroud mounted in a doorway (Figure 1). The fan is used to depressurize the building to a known test pressure (typically 50 Pascals), and the airflow (cubic feet per minute or CFM) required to reach that pressure is a measurement of the building’s total air leakage (reported as “CFM at 50 Pascals” or “CFM 50”). Blower doors are used for both houses and large commercial buildings (although more fans are needed for the latter).

Duct testing equipment (for example, Duct Blaster) is used in a similar manner to test duct airtightness. The calibrated fan is connected to a ductwork system, the intentional holes in the system (i.e., registers and grilles) are sealed, and the airflow required to reach a test pressure provides a measurement of leakiness.

Incidentally, Duct Blasters are useful for more than ductwork testing. They can also be used to test airtightness of small buildings (such as the cottage in Figure 1), very airtight buildings, or individual dwelling units in multifamily buildings.  Figure 2: Testing a house with a blower door.

Figure 1: Testing a cottage with a Duct Blaster.
Figure 2: Testing a house with a blower door

Differential Air Pressure – Manometers

Air pressures define which way the air moves, and how quickly. Therefore, measuring air pressures during normal building operation can also provide clues to problem conditions. For instance, in southern climates, “buildings that suck” can lead to huge moisture problems from pulling in hot, humid outdoor air.

It’s also useful to have a bit more of an intuitive understanding of the pressure measurement of Pascals/Pa that we use. It is a very small unit—one Pascal is about the weight of a fly on the area of a penny. Also, 1 psi is 6895 Pa. Correctly-operating houses normally operate in the 3-5 Pa range, the blower door and duct blaster tests are run at 50 Pa and 25 Pa respectively, and when buildings are pressurized to exclude contaminants, 10-12 Pa is a typical range.

When we deal with commercial building facility managers and ask them whether their building is running at a positive or negative pressure, they sometimes respond, “they added up the airflows and it should be positive”. Our response always been: let’s measure it directly to figure it out—and plenty of times, adding up the airflows gives the wrong answer. Indoor-outdoor pressure measurements are simple if you can find an operable window or doorway.

These ΔP measurements are also important for residential work—for instance, if they installed an oversized kitchen range hood in a custom house without a makeup air system, we can measure the net effect. Also, very airtight construction with unbalanced fans (e.g., exhaust-only ventilation) can cause problems. Figure 3 and Figure 4 show measurements of indoor-outdoor ΔP at a door or window.

Figure 3: Indoor-outdoor ΔP at a doorway.
Figure 4: Indoor-outdoor ΔP at a window.

But there are times when a one-time measurement isn’t enough to fully understand what is going on. For instance, on a windy day, it can be next to impossible to tease out the effect of operating fans on house pressures. Also, it can be useful to get a log of operating many mechanical systems (kitchen exhaust, bath exhaust, dryer) in various combinations to determine their effect. In those cases, you can connect Energy Conservatory manometers (pressure meters) to a computer (Figure 5) and use free TECLOG software to graph the pressures in real time, and to observe the effect of changes visually (Figure 6). This creates a computer file that you can refer to and run calculations on later.

Figure 5: Using TECLOG to log pressures. Figure 11: TECLOG real-time pressure graph.
Figure 6: TECLOG real-time pressure graph.

Air Flow Indicators – Smoke Pencil, Air Velocity Meter

In addition to putting a number on pressure differences, it’s often useful to demonstrate where air leaks are, and which way airflow is going. The typical go-to solution is a smoke generator or a smoke pencil (Figure 7).

Figure 7: Smoke pencil from a vaping pen.

To get more precise, wind or air velocity meters can measure these flows—typically in feet per minute/FPM. You can estimate flows out of HVAC registers by measuring airspeeds and the opening area (called a “traverse”) with these meters.

However, based on our experience, we prefer a hot wire anemometer which has a fine wire that is heated above air temperature, and the rate of heat loss/cooling measures the airspeed. This tool is exceptionally useful because it has an extension probe that lets us “feel” for air leaks out of arm’s reach. A typical use is to depressurize the building and put the probe on suspected air leakage locations.

Figure 8 is the inside of a metal panel building—this panel seam was leaking despite the double-gasket design. Figure 9 shows measurements of air leaks around a windowsill with the trim removed: hot, humid air was getting pulled from the masonry cavity at these openings under the window trim, condensing, and dripping.

Figure 8: Hot-wire anemometer air velocity meter.
Figure 9: Hot-wire anemometer air velocity meter.

Air Flow Measurement Devices – Flow Capture Hood, Exhaust Fan Flow Meter

The equipment that an HVAC technician would use is a flow capture hood (Figure 10)—it can be used for either supplies or returns (up to a limited size).

A useful tool for exhaust fans is a “flow box” (Energy Conservatory Exhaust Fan Flow Meter, Figure 11) It’s a box with a variable opening and measuring the pressure inside the box provides the exhaust flow. It is light, quick, reliable, and works well. Lastly, if you’re looking at exhausts, the “toilet paper test”—despite its simplicity—gives some useful information. If the toilet paper sticks to the fan face, you’re probably getting a decent airflow.

Figure 10: Flow capture hood.
Figure 11: Exhaust fan flow meter.

Sources:

https://www.greenbuildingadvisor.com/article/how-to-look-at-a-house-like-a-building-scientist-part-1-air

https://www.buildingscience.com/documents/published-articles/pa-1901-how-look-house-building-scientist-part-1-air

Net Zero Energy and Green Buildings

The WorldGBC definition of a net zero carbon building is a “building that is highly energy efficient and fully powered from on-site and/or off-site renewable energy sources”.

It is considered that going forward, all the buildings should target ‘Net Zero Energy / Carbon’ to achieve Paris Agreement levels of global emission reductions. So, the World Green Building Council (WGBC) has created a project called “Advancing Net Zero project” that is dedicated to supporting market transformation towards 100% net zero carbon buildings by 2050, and other Green Building Councils across the world are participating in the program.

The below infographic from WGBC highlights the Advancing Net Zero project’s key target dates, definition for net zero carbon buildings, the action pathways being taken by GBCs, and the key principles that are guiding their actions.

As part of the action from the participating Green Building Councils, several Net Zero Building Certification programs are being developed to encourage the building developers/operators to participate in achieving the goal of WGBC ‘100% of buildings must operate at net zero carbon by 2050’. Here are the Net Zero Certification programs developed by the Green Building Councils:

  • Green Building Council in France: “E+C- Bâtiment à Énergie Positive et Réduction Carbone”.
  • Canada Green Building Council (CaGBC): “Zero Carbon Building Standard”.
  • GBC Brasil: “Zero Energy Standard”. 
  • Australian Federal Government: “National Carbon Offset Standard for Buildings”.
  • Green Building Council of South Africa: “Net Zero Certification Programme”.
  • USGBC: “LEED Zero”.
  • DGNB: “Framework for Carbon Neutral Buildings”.
  • UKGBC: launched a framework definition for net zero carbon buildings in the UK.

LEED Zero is one of the widely recognised Net Zero Certification programs across the globe which is developed by USGBC and certified by the Green Building Certification Institute (GBCI). USGBC has developed LEED Zero, a complement to LEED that verifies the achievement of net zero goals:

  • LEED Zero Carbon recognizes buildings or spaces operating with net zero carbon emissions from energy consumption and occupant transportation to carbon emissions avoided or offset over a period of 12 months.
  • LEED Zero Resources
    • Energy recognizes buildings or spaces that achieve a source energy use balance of zero over a period of 12 months.
    • Water recognizes buildings that achieve a potable water use balance of zero over a period of 12 months.

Waste recognizes buildings that achieve GBCI’s TRUE Zero Waste certification at the Platinum level

Our Experience with Net Zero Energy Projects

Salimus Consultancy has been fortunate enough to assist with Net Zero Energy projects in MENA region. We are currently working in an upcoming project in UAE, Saint-Gobain Multi-Comfort House which is a model NZEB developed by Saint-Gobain to promote their Energy Efficient and Environment-Friendly products. We facilitate the Integrative Design Process and assist the Client and Designer to select appropriate systems and design elements to achieve the Net-Zero target.

Does Net Zero Energy Have Cost Impact? 

US Department of Energy demonstrates that high-performance NZE design is possible on budgets similar to those of traditionally constructed buildings. What are some of the strategies that can lower costs and ensure NZE?

  • Assemble a qualified project team including the contractor. Use of experienced subcontractors early in the design process can help to ensure that your cost guidelines are being met. 
  • Utilize performance-based procurement to strike a balance between budget, energy savings and other benefits.
  • Consider cost shifting. Money spent on energy efficiency measures can be saved in the reduced size and capacity of the mechanical systems.
  • Consider life cycle cost impacts when designing. 
  • Maximize the usage of repeatable, modular design strategies during the design phase. 
  • Investigate local incentives (utility and tax rebates) and alternative financing options for higher-cost construction projects. 

Sources:

https://www.usgbc.org/programs/leed-zero

https://www.worldgbc.org/advancing-net-zero

The Energy Conservatory’s New Blower Door Kit

TEC did its homework: its new blower door package is a truly engineered and integrated equipment system

As an expert in Airtightness Testing, we did enough of blower door works to appreciate the attention to detail that The Energy Conservatory (TEC) built into its new blower door kit. The kit features a digital pressure and air flow gauge, the DG1000.

I have used both TEC and Retrotec blower door kits and found them trustworthy and rugged. But recently I got to work with a brand spanking new TEC blower door kit that included the DG1000, and here are the features that sold me:

(1) All the equipment fits together physically. What I mean by this is:

  • The blower door frame no longer has a clunky “gun” case; it has a soft but rugged fabric case with a slot for each frame member. The new case is much easier to deal with in terms of transporting and storing.
  • There is a single sturdy mounting plate for both the digital gauge and the rheostat or fan speed controller, with a screw jack that makes it really easy to secure to a door frame or other trim, at any height.
  • The DG1000 has four corner backside magnets that correspond to the same configuration on the metal of the mounting plate, so it’s easy to mount and release the gauge, even while it is held firmly in place.
  • The fan speed controller has a built-in cooling fan so it never overheats, no matter how long you may run the blower door, at any speed.
  • The DG1000 is essentially now a gauge and computer, but it is still rugged and comes with a very robust case — so no worries for the rough-and-ready aspect of work on job sites.

(2) The DG1000 is sophisticated and intuitive.

  • All of the DG1000 screens are uncluttered, well-organized, and sequential.
  • You can back out of any place within the functions and options.
  • Images or icons make it easy to navigate.
  • The DG1000 can be connected to your computer in three different ways: with a USB port, ethernet port, Wi-Fi, or via an app (TEC AutoTest) on your iPhone or iPad.
  • The DG-1000 can be a Wi-Fi hub.

(3) The TEC help system is really unparalleled; the company offers:

  • A whole library of pdf guides
  • A whole library of how-to TEC website and YouTube videos.
  • Quick-response human tech support.

But enough of what I think about the new TEC blower door kit; I decided to check in with one of the most seasoned building performance specialists in our industry, Vladimir Limin of Salimus Consultancy, Dubai. Vladimir has conducted many of building audits; Vladimir is also the representative of TEC in the Middle East.

“I really like the new screen; it’s much easier to see and read,” begins Vladimir Limin. “I also like the rechargeable user replaceable batteries. But there are two functional aspects of the new system that are important to my work:

  • Long averaging of building depressurization when investigating combustion appliance performance; other systems have a 2-minute limit on averaging.
  • Being able to see the blower door numbers on my phone while reading the digital pressure gauge in my hand (when doing series leakage work).”

Vladimir also thought that the ability to update the DG1000 is a huge advantage. “There are all kinds of capabilities that we talked about as the DG1000 was being developed that we might not necessarily see yet, but these will be easily added over time,” says Vladimir. One example dear to Vladimir’s heart is setting up the DG1000 with a checklist system so that any user can be literally walked through the steps it takes to do any manner of blower door work.

“We have to be careful, though; we don’t want a tool like the DG1000 to get so easy that we don’t need trainers like me anymore,” joked             Vladimir.

The equipment is always improving

Let’s see what TEC can do next: maybe a powerful calibrated fan that does not weigh 33 pounds…

Source: https://www.greenbuildingadvisor.com/article/the-energy-conservatorys-new-blower-door-kit

Keep Your Building Cool

‘Airtight Envelope’ is one of the solutions to keep your building cool in hot climates

Our perception of comfort mostly depends on our activity, clothing and the properties of our thermal environment according to the scientist P.O. Fanger. The following are the main ways to achieve indoor comfort when it’s warm and possibly humid outside:

1. Encourage internal air circulation by keeping your building open

Image 1: Traditional Building in UAE.
Source: building a zero-energy house for UAE: traditional Architecture revisited.

The commonly seen traditional design solution in hot and humid climate is to keep your building open to ensure that high volumes of air can flow throughout. These draughts help to keep your body cooler through the process of evaporative cooling on the skin. It is also suggested to use stack ventilation design for achieving better results.

In the recent times people are used to air-conditioned cars, shops and indoor public spaces. So, they are not willing to accept the thermal comfort conditions achieved by the traditional design approach because the traditional approach is highly dependent on the outdoor temperatures, humidity and wind speed. To address this, majority of the traditional buildings in hot climates are installed with air conditioning units, which is neither energy efficient nor particularly comfortable.

2. Isolate the interior space from the exterior space

The Passive House Standard suggests this approach to isolate the interior space from the exterior space when the exterior space is warmer and more humid than the acceptable indoor conditions. Isolating the interior from the exterior will help reduce the heat gains in the interior as well reducing the energy demand of the building. But, how is this possible?

Reducing / Limiting the heat gains

Any building requires to cool the unwanted heat gains in the space. In general, the heat gains are through the internal and external sources. The internal heat gain sources can be limited by selecting energy efficient appliances and electronic devices. In addition, highly efficient ventilation systems shall be selected and the utility systems like hot water systems and pipes shall be insulated properly to limit the unwanted heat from these systems to the interior space.

Image 2:

The external heat gains are the major contributor to the unwanted heat in the building. The external heat gains can be reduced by selecting sufficient insulation systems for the building envelope. The other primary source for the unwanted heat to enter the building is through the leakages in the building envelope.

‘Envelope Airtightness’

is currently a major requirement that has to be addressed from design to construction of any building, mainly in the very hot and cold climates. Envelope airtightness can be ensured by conducting air leakage tests as per the ASTM or ISO standards. However, to ensure the integrity of the leakage tests; the tests shall be conducted by certified professionals from organisations like ATTMA, ABAA…etc. Also, to ensure the continuity of envelope insulation, thermographic tests can be carried out.

Passive Cooling Strategies

Based on the local climate profile, passive cooling strategies like window ventilation can be selected if the outdoor conditions are similar to the desired indoor conditions. Also, the designers can explore the feasibility of installing a geothermal heat exchanger system.

If Active Cooling is Needed

By deploying the above-mentioned strategies, the buildings can reduce the cooling load to become smaller than in conventional buildings. To address the remaining cooling demand, the designers can opt for energy efficient ventilation systems and other options like concrete core activation, which is especially good for bigger buildings and dry climates. All these options are currently being tested in the first Passive House in Dubai. In humid climates, additional dehumidification may be required.

Image 3: First certified Passive House building in Dubai, UAE. Photo: MBRSC/Dubai.

Sources:
https://blog.passivehouse-international.org/keep-building-cool-hot-climates

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