Today’s cutting edge HVAC technologies take performance, energy efficiency and cost savings into account. Through the use of Dedicated Outdoor Air Systems, radiant heating and cooling and natural ventilation, indoor spaces are made comfortable with more energy efficiency than in the past.
CUTTING EDGE TECHNOLOGIES IN HVAC
Dedicated Outdoor Air Systems (DOAS) is the traditional HVAC system reconfigured to separate the fresh outdoor air from that which has been recirculating inside the space. As a result, humidity and fresh air are controlled within the designated space, creating less of a need for heating or air conditioning. The benefits of this system aren’t limited to energy conservation and cost efficiency. “DOASs are becoming increasingly popular, primarily because it separates the ventilation loads from the rest of the heating and cooling loads,” said Lynn Bellenger, President of ASHRAE.
According to Bellenger, DOASs provide a more efficient way to heat or cool a space and meet the requirements of the occupants. Additionally, DOASs help control mold, humidity and water penetration.
Radiant heating and cooling has been popular in Europe and is gaining traction in the United States. The concept relies on adjusting the temperature of the floor, ceiling and/or walls. While radiant heating relies on heat transfer to create warmth in a space, radiant cooling absorbs the heat generated by the rest of the room, creating an overall cooling effect.
According to the US Department of Energy, radiant heating is seen as more efficient than baseboard or forced air heating systems because less energy is lost. Further radiant heating systems located on the floor rely on convection for effective heating.
Radiant cooling proves trickier, requiring precise temperature control and a dry climate. The slightest exposure to humidity can create condensation. Additionally, these systems require more initial capital to install.
THE RETURN OF OLD TECHNOLOGIES
Natural ventilation is a climate driven technology that is becoming popular in Europe and in parts of California. “Natural ventilation or a hybrid system that mixes mechanical and natural ventilation, depending on conditions, is becoming more prevalent,” said Bellenger. The natural flows of air through the building and basic physics work together to heat or cool the space. In areas where the climate is favorable, natural ventilation is a low energy way to create a comfortable indoor environment.
WHAT’S DRIVING THE CHANGE?
“Affordability and value for money will drive all low carbon technology choices in the UK from now on, says Martin Burton, President of HVCA. “We must also demonstrate efficiency in the procurement process and in the lifetime operation of the building and that can only be done through the early involvement of building services specialists.”
Additionally, energy standards drive HVAC technology to improve efficiency. According to the ASHRAE website, “Standard 189.1 provides a ‘total building sustainability package’ for those who strive to design, build and operate green buildings.” The standard is comprised of six different categories, which include mandatory provisions, a prescriptive path and an alternate performance path. The regulation is designed as a compliance option for high performance green buildings to adhere to the Public Version 1.0 of the International Green Construction Code (IgCC). Created in partnership between ASHRAE, the US Green Building Council (USGBC) and the Illuminating Engineering Society (IES), the standard is the first green building standard to be published and has been well received by the industry. In fact, the International Code Council (ICC) has chosen and made standard 189.1 a compliance path in the international green construction code.
“The more ‘alternative’ solutions are delivered, the cheaper they will become so creating the capital and running cost benefits that will be demanded by all specifiers” says Burton. “The most successful products will be those that give building users the comfort conditions they need without disrupting their day-to-day home and working lives.”
THE FUTURE OF HVAC TECHNOLOGY
“We’re doing much better in the building industry using integrated design,” said Bellenger. “This means having the architect involve the entire design team, construction and the owner very early in the design stage, so you can use energy modeling or computer modeling to investigate a host of alternatives to lock down the information about the loads that you won’t be able to change in the future.”
According to Bellenger, this information gives the team the opportunity to decide on a building design shape, orientation and direction. “That’s what will make the biggest difference in our industry because we’ll be able to minimize the loads,” Bellenger said.
The creation of truly low energy use buildings that the industry strives for depends on integrated design and making the essential decisions that affect the energy use of the building long after the ribbon-cutting ceremony. “We must focus on good engineering principles and apply our ‘energy hierarchy’,” says Burton. “This means improving the building ‘fabric’ as a first step to reduce heat losses; installing and commissioning good control systems to manage the energy performance and balance of the services; before finally considering the use of replacement low and zero carbon technologies. This step-by-step approach will deliver excellent value for money every time.”