Ventilation Air for Healthy Buildings

In the last month both ASHRAE and the director of the Healthy Buildings Program at Harvard T.H. Chan School of Public Health – Dr. Joseph Allen – have released guidance advocating the same principle; buildings need MORE ventilation air to ensure a healthy environment.

The traditional problem with increasing ventilation air in buildings has been the increase in energy costs as well as higher CO2 emissions. Addressing the increase in energy usage can help eliminate the accepted practice of minimizing the intake of fresh air. This is how the SolarWall® technology came to be developed in the late 1980s; Conserval Engineering was working with Ford Motor Company and the goal was to develop a low cost solar collector that would heat for free, large volumes of ventilation air required in manufacturing and automotive assembly lines.

Heating Ventilation

SolarWall® heating became so successful at heating ventilation air that there are now over 5 million square feet of collectors installed on thousands of buildings, generating more than 300 MW of thermal energy. This means that when you increase ventilation air, you don’t need to increase your energy costs.

Fast forward to today, and recirculating building air without adequate ventilation air is a top consideration. We must rethink the logic behind restricting fresh air to save energy.

Let’s see what the experts are advocating:

ASHRAE

HVAC systems can have a major effect on the transmission of disease, according to the “ASHRAE Position Document on Infectious Aerosols.” ASHRAE’s Environmental Health Position Document Committee provides recommendations on the design, installation and operation of HVAC systems, non-HVAC control strategies and facilities management support strategies. It also includes strategies that can reduce the risk of dissemination of infectious aerosols in buildings and transportation environments.

Once the basics are covered, such as the disinfection of frequently touched surfaces, the focus must be on those buildings that remain open.

Recommendations include:

• Increase outdoor air ventilation; with a lower population in the building, this increases the effective dilution ventilation per person.
• Disable demand-controlled ventilation (DCV).
• Further open minimum outdoor air dampers, as high as 100%, thus eliminating recirculation (in the mild weather season, this need not affect thermal comfort or humidity, but clearly becomes more difficult in extreme weather).
• Improve central air filtration to the MERV-13 or the highest compatible with the filter rack, and seal edges of the filter to limit bypass.
• Keep systems running longer hours, if possible 24/7, to enhance the two actions above.
• Bypass energy recovery ventilation systems that leak potentially contaminated exhaust air back into the outdoor air supply

SolarWall heating and ventilating systems are ideally suited for all these recommendations as the air is heated for free with zero carbon emissions. Existing controls can be easily reprogrammed to run longer and with more fresh air whenever the sun is heating the air.

Healthy Buildings Program, Harvard T.H. Chan School of Public Health – Dr. Joseph Allen

“Here’s what we should be doing. First, bringing in more outdoor air in buildings with heating and ventilation systems (or opening windows in buildings that don’t) helps dilute airborne contaminants, making infection less likely. For years, we have been doing the opposite: sealing our windows shut and recirculating air. The results are schools and office buildings that are chronically underventilated. This not only gives a boost to disease transmission, including common scourges like the norovirus or the common flu but also significantly impairs cognitive function.

A study published just last year found that ensuring even minimum levels of outdoor air ventilation reduced influenza transmission as much as having 50 percent to 60 percent of the people in a building vaccinated.

Buildings typically recirculate some air, which has been shown to lead to a higher risk of infection during outbreaks, as contaminated air in one area is circulated to other parts of the building (as it did in the school with measles). When it’s very cold or very hot, the air coming out of the vent in a school classroom or office may be completely recirculated. That’s a recipe for disaster.”

Read the rest of this article here.

 

Solar AiR Marks for the Food Industry

Crop Drying Shutterstock

Crop Drying Shutterstock

Let’s talk about the benefits of using solar heating to reduce the carbon footprint in the processing of food products. This is something that is gaining traction in both the agricultural community and with end-use consumers who ascribe a premium to such products.

Solar air heating systems are used in different configurations around the world to produce heated air that can be used for ventilation heating or process heat applications. This specific use – solar process drying – has expanded in the agricultural community as it provides a carbon reduction solution that also helps to produce high quality food products.

Many of the world’s food products need to be dried to remove moisture as part of the production process. For example; coffee beans, tea, cocoa, nuts, fruit, rice, spices, and corn all require drying to transform the raw goods into the final product. It can also be extremely carbon intensive when using mechanical drying methods that rely on propane, oil or wood.  In more traditional drying operations, it is common for produce to be passively air-dried in the sun, which lengthens the processing time and can lead to uneven  moisture levels in the final product.

Solar air heating produces a double-benefit in terms of improving both the process of drying and the final product. The solar technologies can work with a traditional mechanical dryer and heat large volumes of incoming air up to 55°C  (100°F) above ambient. This makes it ideally suited for types of crop drying  applications.  The solar heating system may provide all of the heat during a sunny day or act as a pre-heat during cloudy conditions. Typically solar air heating systems operate as a pre-heat to traditional mechanical operations where they can be easily incorporated into trough, tunnel or conveyor dryers.

In both cases, solar crop drying  reduces the dependency on traditional fuels and creates the following benefits:

  • 1) Reduced operating costs;
  • 2) Lower reliance on fuels that need to be transported to remote sites;
  • 3) Reducing deforestation by lowering the quantity of trees that are harvested for fuel;
  • 4) Lower humidity in the incoming air (because it is heated before entering the building or drying chamber) which means that the air has been preconditioned to absorb more moisture;
  • 5) Reducing carbon emissions, and
  • 6) Producing a high quality finished product that is eco-friendly and was processed using “clean & green” energy.

 

SolarWall® heating  helps agricultural producers promote their products as being “solar-dried” with the Solar AiR logos. This allows companies that produce solar dried fruit, coffee, tea, nuts, herbs, and other food products to proudly display their commitment to sustainability and carbon reduction on their product packaging and in their promotional material.  It will also provide consumers with a choice to favor those foods and products that are dried and processed using solar heating.

Examples in Food Industry

Carriere & Sons; Walnut Drying California

Carriere & Sons owns and operates hundreds of acres of walnut trees, in addition to their walnut drying facility. They are also in partnership with Borges of California, which is owned by Borges of Spain. Borges is the world’s leading walnut operator and has forty-eight companies in its group devoted to the production and marketing of oils, dried fruits and nuts. Walnuts are dried at a relatively low temperature with a minimum temperature of 110°F (43°C) leaving the dryer. This low temperature requirement is ideally suited for the use of solar air heating technology.

A normal drying season consists of two months of drying from September 1st to October 31st. The walnuts are dried from 35% moisture content to 10% moisture content.

The SolarWall solar heater was installed on the roof of a drying building at Carriere. The 3,200 ft2 (300 m2) solar system spans the entire roof area and will displace around 308 million BTU of natural gas for the two month drying season. The system heats approximately 25,000 cfm of air, which is then ducted into the 70,000 cfm blower.

Coopeldos Coffee Drying; Costa Rica

The coffee drying cooperative Coopeldos R.L., located in the province of Guanacaste in Costa Rica, installed a solar drying system on the entire roof of their building. Coopeldos, an ISO 9000 and ISO 14000 registered company, was the perfect candidate to demonstrate state-of-the-art solar air heating crop drying technology, since maintaining the ISO 14000 designation necessitates meeting certain energy conservation standards.

A 860 m2 (9,250 ft2) black solar air heating system was installed on the roof at the Coopeldos facility. The warmed air that is collected from the system is used for two purposes:  It heats the vertical pre-drying silo, which dries the coffee beans from 60% moisture content, to 35%.  It also heats the guardiolas, which are the rotating drums that carry out the final drying stage. Here, the beans are further dried to a 12% moisture content. Following this second drying stage, the beans are packaged in bags.

Municipalities and their Carbon-Free Buildings

Offices and Warehouse Cropped

One of the best endorsements you can receive is to have repeat demand. The SolarWall technology is amenable to a wide variety of municipal and government buildings. As municipalities either expand their building stock or make improvements to their existing buildings, we are always proud when SolarWall systems are chosen over and over again to be part of their carbon-free future.

At the end of September the Region of Peel had a ceremony to officially open one of their brand new Paramedics Station in Mississauga, a rapidly expanding city adjacent to the City of Toronto. The Streetsville Paramedic Station is a reporting station that will house 20 ambulances and work with smaller satellite stations in the community.

SolarWall systems were incorporated into three walls of the facility, totaling around 8,700 ft2 of collector space. The metal SolarWall cladding system works in harmony with the aesthetics of the building while also helping the Region of Peel to reduce their carbon footprint. The SolarWall technology was also used on the last paramedics station that was constructed in Peel and opened in 2016.

SolarWall Cladding for Condos & Apartments

Building

Condo buildings are on the rise across all urban areas, and so is the use of the SolarWall air heating technology for high-rises. The SolarWall system becomes the exterior facade for the building and offers maximum architectural flexibility. We love working with architects to help create these buildings that are not only beautiful but are dramatically reducing their carbon footprint with SolarWall air heating.

Read more here about the use of SolarWall heating by condo developers to reduce their carbon footprint and help facilitate Net Zero Building Standards; and also the use in older multi-residential buildings for recladding / over-cladding purposes.

https://www.solarwall.com/industries/multi-residential/

 

 

 

 

Is Zero Carbon the new LEED?

Evolv1 Building

This exciting new standard is the only one in North America that uses carbon as the key performance metric. The Evolv1 Urban Office in Waterloo, Ontario is the first building in Canada to be certified to this Zero Carbon Building Standard. A SolarWall air heating system was included as a key on-site renewable energy generation technology to help reduce their carbon footprint and provide carbon-free heating. The SolarWall system is also a key part of the front facade, showing that aesthetics and functionality can go hand-in-hand. Read more about this landmark project here:
https://www.solarwall.com/cas…/evolv1-urban-office-building/