In case you were wondering why we should wear a mask in public and filter the air around us, check out this demonstration of suspended micro droplets.

Micro droplets suspending in air from MixonK on Vimeo.

Our CFB HEPA Filters are currently being used by a number of hospitals to create negative pressure isolation rooms for COVID-19 patients. They are typically paired with an inline fan to exhaust the contaminated air from those areas, filter and then discharge it safely outside. Discharging the air without any filtration is considered risky since you are spreading/distributing the virus particles extracted from the patient areas. If you have questions on how to build negative pressure isolation rooms give us a call.

What is a HEPA?

HEPA stands for high-efficiency particulate arrestance. To be classified as a HEPA, the air filter must remove at least 99.97% of particles whose diameter is equal to 0.3 μm. Classification at 0.3 μm is important because this is the weakest point in the filter’s performance – typical HEPA filtration efficiency increases for particle diameters both less than and greater than 0.3 μm.

Image courtesy of the National Institute for Occupational Safety and Health (NIOSH)

Virus particles, due to their small size, typically fall in the diffusion regime of HEPA collection efficiency. Specifically, the virus that causes COVID-19 is approximately 0.125 μm in diameter. That diameter is perfectly within the particle-size range that HEPA filters capture with great efficiency: 0.01 μm and bigger (see the NIOSH diagram above).

Want to ready more about HEPA and how they filter particles the size of viruses? We found the Submicron and Nanoparticulate Matter Removal by HEPA-Rated Media Filters by NASA study is a great source of reliable technical info. Page 7 of the paper has an excellent illustration of filter efficiency as a function of particle diameter for sizes 0.01 μm and above.

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HEPA Filtration for Hospitals

On April 13, 2020, in covid, filtration, IAQ, news, by radek
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How times change…

A few weeks ago our sister company AirScape Fans (airscapefans.com) was ramping up whole house fan production for the summer season. Now they are very busy making HEPA filtration units for hospitals, and yes, observing Covid safety protocols. Masks [check], distancing [check], good ventilation [check], doors open for extra air dilution [check], hand sanitizer [check], outdoor breaks in the sun [check]. They (as did we!) spent a lot of time writing procedures on how to stay safe.

Stay safe and healthy out there!

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There’s an easier way to ventilate a house than installing separate fans for each bathroom plus a low-flow continuous ventilation system for the rest of the house. That’s a lot of installation time, several penetrations in the outside walls, and just too many systems to tie together and hope it all works. There’s good news though. There’s an easier way that not only cuts down on installation time, it also saves the homeowner money on energy bills.

American Aldes VentZone® IAQ systems are the only central ventilation systems available that provide precisely regulated whole-house Indoor Air Quality AND centralized bathroom fans in a single, highly effective and efficient ventilation kit. Each kit can provide low continuous IAQ ventilation and zone-based on-demand “boost” ventilation. Even better, they’re designed to meet ASHRAE 62.2, ENERGY STAR with IAP, LEED for Homes, and California Title 24 (CAL GREEN) standards.

Wondering how they work? The kits contain two Zone Register Terminals (ZRT-2s); these replace exhaust grilles in bathrooms and other high humidity areas like kitchens and laundry rooms. When a bathroom is in use, the ZRT damper opens for on-demand exhaust ventilation, yet the other bathrooms are not affected by the bathroom in use. Instead of the traditional exhaust fan, the kit has a centralized multi-port fan, so one fan can support 2-4 bathrooms. When the on-demand boost isn’t in use, the ZRTs still provide low-continuous airflow to keep the whole house ventilated.

Checkout the kits and pricing in our Zoned Exhaust Systems area:

http://www.hvacquick.com/products/residential/Bathroom-Ventilation/Zoned-Exhaust-Systems/Aldes-VentZone-IAQ-Continuous-Exhaust-Ventilation-Kits

Aldes VentZone System

Also, get more info from the American Aldes site:  VentZone® IAQ System

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Decorative Grilles and Registers

On July 23, 2015, in cool products, news, by radek
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Exciting news!  We added SteelCrest decorative grilles and registers to our product lineup.  With their unmatched selection of designs, finishes, and custom features your sure to find the perfect compliment to any home.

The SteelCrest product line is divided into 5 main series:

  • Bronze Series: Least expensive. Punched steel and available in 3 patterns and 4 colors. Manufactured using 18 gauge steel.
  • Silver Series:  Laser-cut and available in 6 patterns and 5 colors. Manufactured using 11 gauge steel.
  • Gold Series:  Most expensive. Laser-cut and available in all 16 patterns and all 15 colors. Manufactured using 11 gauge steel.
  • Pro-Linear Series and Pro-Vertical Series:  Bar linear style grilles.  Approved for floor use.

steelcrest_1

 

steelcrest_3

 

 

California has begun mandating Whole House Fans in certain climate zones.  July 1st, 2014 brings us the latest edition (labelled 2013) of the Title 24 standard that mandates the installation of Whole House Fans in climate zones 8-14.  This applies to designers using the “Prescriptive Standards/Components Package” design method (vs. the Performance Standards method).

All AirScape Whole House Fans are Title 24 compliant.

You can find the standard for download on the energy.ca.gov website or via the link below.  Of particular interest is Section 150.1.

2013 Building Energy Efficiency Standards – Title 24

Title 24 position on whole house fans:

12. Ventilation Cooling. Single family homes shall comply with the Whole House Fan (WHF) requirements shown in TABLE 150.1-A. When a WHF is required, comply with Subsections A through C below:
A. Have installed one or more WHFs whose total Air Flow CFM as listed in the CEC Directory is at least 2 CFM/ft2 of conditioned floor area; and
B. Have at least 1 square foot of attic vent free area for each 375 CFM of rated whole house fan Air Flow CFM; and
C. Provide homeowners who have WHFs with a one page “How to operate your whole house fan” informational sheet.

Table 150.1-A in the standard breaks down which zones are required to install the whole house fan.  If you are not sure what climate zone you are in, have a look at the map below or click here for a city by city breakdown.

building_climate_zones

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Pressure Balancing Rooms

On November 5, 2013, in news, by radek
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Central forced air heating (furnace) and air conditioning systems operate by pushing conditioned air to each room in a house.  To return the “stale” house air back to the furnace return registers have to be installed throughout the house, pressure balancing each room.

In a typical house these return registers exist only in common areas (1 or 2 per level) and not in individual bedrooms. To help the stale air get back to these central returns, builders will often undercut doors. These undercuts can be inadequate for providing enough air flow, especially when plush carpet and under-padding are installed or for large bedrooms with multiple supply grilles. Inadequate return air pathways can result in pressure imbalances, which can cause drafts and temperature differences between rooms or floors, leading to comfort complaints.

The typical recommendation is to provide 1 square inch of free area opening per 1 CFM of conditioned air being pushed into the room.

If building return air ducts into each room is not possible, one common option is installing jump ducts or transfer grilles in the rooms that are often closed. A jumper duct is a short piece of insulated flex duct installed in the attic and attached to ceiling grilles in the closed room and a common space.  This provides a return air pathway between the two areas.

Jump duct

Typical jump duct.  Note the sealant around the grilles.

 

Jump Duct installed in new construction.
Jump duct installed in new construction.

 Images courtesy of DOE’s Office of Energy Efficiency and Renewable Energy.

 

 

 

Take the stress off, your plants!

On August 3, 2010, in solutions, by radek
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Another great addition to our lineup:  The Ostberg CK series inline hydroponics fans.

ostberg inline fans

Keep the temperature down and prevent stress on your plants through proper ventilation.  These puppies are designed for tough high static pressure applications such as carbon filters and humid grow room environments.  The tough baked epoxy coating and a 10 year warranty are icing on the cake.

http://www.hvacquick.com/products/residential/Fans/Hydroponics-Fans/Ostberg-Inline-Hydroponics-Fans

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Recommendations for bathroom ventilation sizing can vary considerably between manufacturers and competing standards.  Some of the newer recommendations allow for low ventilation rates over long periods of time as opposed to the typical 8 air changes per hour. 

We prefer 8 air changes per hour as A MINUMUM and here is why:
When moisture is introduced into the bathroom it has an annoying tendency to get diluted into the entire air content of the space.  With low CFM (background) ventilation that moisture will eventually be exhausted, but in the meantime it will linger in the air and potentially condense on colder objects such as walls and fixtures.  Once it’s in liquid form on your walls it takes A LONG TIME to evaporate it again, not to mention the potential long term damage to the bathroom.

So what do WE recommend?
– minimum of 8 air changes per hour (more is better since the extra CFM typically comes at very little cost; nothing wrong with 10 or 12 air changes per hour)
– 100 CFM minimum per bathroom, no matter how small it is
– multiple grilles in larger bathrooms to pickup the moisture/smells close to the source
– keep the system quiet (inline fans!!) so that you will use it
– install a timer and leave the fan running for at least 20 minutes after leaving the bathroom

And remember, the standards are there for the builders and not necessarily for you.  Keep the moisture off your walls with adequate CFM and you will avoid mold issues.

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Hole in one.

On July 1, 2010, in technical-support, by radek
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One of the most frequent calls we get is how to size/select our Dayus custom grilles.  The answer is simple:  The HOLE size.

The measurement we need to build a grille is the size of the hole/opening (we call it LIST SIZE).  The hole size is the information entered into our website for pricing and ordering.  Dayus will build the grille slightly undercut to make sure the recessed portion of the frame slides nicely into the hole. 

The grille flange is roughly 1″ all around, giving you a finished flange to flange dimension 1-11/16″ bigger than the hole size (list size) you gave us.

Dayus Bar Linear Grille

Dayus grilles:
http://www.hvacquick.com/products/residential/Grilles-Registers/Grilles

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ECM motors on whole house fan…

On June 30, 2010, in cool products, by radek
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The latest trend we see in whole house fan design is the inclusion of ECM motors (electronically commutated motor).  Match that with an efficient blade and you get a great power profile and low noise.

Lets look at the AirScape 4.4e WHF whole house fan as an example.  The graph below shows the energy use profile of the 4.4e as compared to the theoretical efficiency of a fan system.  102 watts on low speed!!

AirScape ECM Fans

This tickles my engineering senses to the point I will probably upgrade my trusty AirScape 1.7 WHF with this new unit.  Smile

More on AirScape Whole House fans including the 4.4e WHF:
http://www.hvacquick.com/products/residential/Whole-House-Fans/Whole-House-Fans

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