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A guide to the “House As A System” approach to understanding comfort, IAQ, durability, and energy consumption issues caused by building air leakage and HVAC driven pressure imbalances in single-family homes.

By:
Sam Myers, Retrotec
Genry Garcia, Comfort Dynamics Inc.

How does a house operate? It seems like a silly question. Houses are stationary objects, right? What else is there to know? This may seem like the case at first glance; however, the physical activities of a home are always in motion and are constantly changing. Air is always infiltrating and exfiltrating at rates that change with the weather and when mechanical systems are powered on and off. This impacts our level of comfort, the quality of

Recent weather conditions have brought record amounts of rainfall and devastating flooding across Western Washington during the past weeks. Many homes in the area have been impacted by the flood waters and now find themselves with saturated flooring, carpets, and basements.  

Retrotec is located in Everson, Washington, where hundreds of local residents have been greatly affected, with many homes near the point of being condemned. To make matters worse, supply chains have been affected due to the ongoing COVID-19 pandemic, and residents are unable to receive adequate supplies to help remedy home problems. Retrotec recently wrote an article

Having a flood in your home is an awful situation and requires a lot of time to properly clean up. It is worth the time, however, to research and make the best choices for you and your family so that your house remains healthy and safe for years to come.

 
The Pacific Northwest has gotten more rain in the last two weeks than they normally see for the entire month of November. The recent atmospheric river of rain conditions have poured over the Pacific Northwest over the past several days and brought record amounts of rainfall and devastating flooding across Western Washington. 

Many homes in the area have been impacted by the flood waters and now find themselves with water soaked flooring, carpets, and basements.

As flooding recedes, many people will return

Duct leakage is a large contributor to comfort issues, indoor air quality and energy consumption in a home. Typical duct systems lose 25 to 40 percent of the heating or cooling energy generated by the central furnace, heat pump, or air conditioner*. Because of this, more states are adopting and enforcing duct tightness requirements for new construction and new system installations. Duct testers are the tools used to measure and expose air leaks in a duct system. It is a calibrated fan with a high-precision manometer that attaches to the duct system, usually at a return grille or at the air handler. The duct system is then sealed with a special grille mask tape or grille caps and pressurized or depressurized to 25 Pa of pressure. The high-precision manometer that comes with the duct testers kit converts the pressure reading into cubic feet per minute of air flow at 25 Pa (CFM25). This CFM25 reading is the desired leakage result.

Most codes require the duct leakage to be a percentage

If you’ve ever lived in a historic home, you’ve likely noticed the level of comfort can change throughout different parts of the house. This can typically change throughout different times of the year depending on your climate. This is primarily due to excessive air leaks in the home’s enclosure. When we think of improving the home’s comfort, the HVAC system and insulation are the items that usually come to mind. However, the air leaking through the building’s enclosure is equally important, if not more so for these older historic homes.

Let’s start with some history of construction ideologies, processes and materials. The phrase “they don’t build houses like they used to” is absolutely true. Homes that were built during and before the early 1900s were built with a different mindset than modern-day

For those looking to improve building and HVAC performance, a blower door is a must-have. This tool measures and exposes air leaks in buildings, one of the most vital contributors to high construction quality and correct HVAC equipment sizing. The blower door test removes a lot of the guesswork for builders, HVAC contractors, and insulators. It is also mandatory for HERS Raters, energy auditors, and building science consultants. If you are using a blower door, it is clear you care about the quality of your work. Therefore, you are going to want the best product available to allow you to work smarter, not harder. When shopping for a blower door system, here are some questions to consider to ensure you are getting the most bang for your buck.

Durability: Will it last? – Not all blower doors are created equally. Remember, you will be hauling

Beginning December of 2020, the Nashville Tennessee area will update its building code to the IECC 2018. This means a blower door and duct leakage test will be required for all residential new construction homes per the new code update. Are you ready to meet these new requirements?

Luckily, Retrotec’s DucTester and blower door systems come with an online training module that provides you with a Manufacturer’s Certification that will have you testing your work in no time.

A recent Retrotec webinar, “Duct Testing Best Practices,” walks through duct testing procedures relevant to those looking to begin testing in Tennessee. You can also see our latest blower door presentation: “Blower Door 101”, which covers the basics of setting up a blower door system and getting the results you need.

Article written by Sam Myers, Retrotec

When purchasing a home, the due diligence period is a dedicated amount of time where the seller takes the home off the market so the buyer can take time to have inspections completed to make sure everything is in working order. This typically starts by bringing in a home inspector, and sometimes a general contractor or engineer if structural items need a closer look. If the home has a swimming pool, a pool inspection is common as is a chimney inspection if the home has a fireplace. The same is true with HVAC and plumbing if the home inspector thinks a further look may be needed. But what about other items that will affect the new owner on a daily basis? Items such as comfort, indoor air quality, and energy consumption. Having a comfort consultation during the due diligence period is how a buyer can gain a full understanding of how the home will perform. This includes testing to determine why some rooms may be warmer

-article by Sam Myers, Retrotec

Reducing air leaks in duct systems plays an essential role to ensure efficient HVAC system operation. This keeps operating costs down and occupants comfortable. The duct tester equipment used to test for air leaks in duct work is made up of a calibrated fan, high precision manometer, tubing to connect the manometer to the fan, and flexible duct to connect the duct tester to the HVAC system. The technology applied to commercial duct testers has greatly improved over the past decade. What used to be a large blower bolted to a wheeled hand truck can now be easily carried by one worker in a case with a shoulder strap; all without sacrificing power. However, even with some of the most powerful duct testers out there, more fan power is needed for extremely large HVAC cabinets to

Yes, according to this high-performance builder, who uses it to constantly raise the quality bar

This is the 6th installment of a monthly column from Ben Walker, Co-CEO of Retrotec. Ben's column focuses on observations on the art and science of high-performance building and home testing. 

Home builders are using blower doors  
to go beyond code compliance

With codes and high-performance construction programs requiring airtightness testing, a small but growing cadre of home builders have been purchasing their own blower