Topic: HVAC

Articles

Seventhwave pushes the ‘energy-efficiency envelope’ in commercial and residential buildings
07.17.17 | The U.S. Department of Energy's Better Buildings Beat Blog highlights a few of Seventhwave's recent initiatives: window-to-wall ratio, commercial plug load and rooftop units. Read the full post. MORE
ASHRAE features Seventhwave research: VRF in cold climates
03.15.17 | The January 2017 issue of ASHRAE Journal features the article "VRF Design Considerations in Cold Climates" by Seventhwave's Scott Schuetter and Scott Hackel. Variable refrigerant flow systems are not widely implemented in cold climates because they... MORE
Under a watchful eye, water-source VRF excels
10.25.16 | Seventhwave's building is highlighted in the September issue of Architectural Products Magazine. MORE
Educator promotes sustainable technologies
03.07.14 | Behind every successful HVAC installer, there is a teacher who inspired high quality work with patience and hands-on practice. Tom Niesen has been turning out some of the best residential and commercial HVAC professionals for more than 20 years at... MORE
Economic analysis in individual project selection
06.17.12 | Using net present value analysis instead of the rate of return will treat investment scale as one of the key value drivers, and will help engineers select money-making projects by Steve Kihm, CFA, Research Director and Scott Hackel, PE, LEED AP,... MORE

New technology profiles

Controls for high outside air ventilation applications
02.06.14 | Modulating ventilation in high outside air ventilation applications requires controls that can determine whether the air change rate can be lowered when a space is unoccupied or increased when contaminants are found in the air. These controls can... MORE
Variable refrigerant flow (VRF)
02.06.14 | VRF technology has been available in global markets (Europe, Asia) for some time. Until recently, there has been little interest in VRF technology in North America. Multiple forces, including reductions in the environmental impacts of refrigerant,... MORE
Single-zone variable air volume (SZVAV) roof-top units
01.13.14 | SZVAV technology has been on the market for sometime; however, until recently this technology has been limited to the largest single-zone applications. These typically included school gymnasiums and auditoriums. Because of increased interest in... MORE

Initiatives

Save energy by reducing excess ventilation
04.08.15 | Energy savings and lessons learned from observed, practical approaches to demand control ventilation Demand control ventilation (DCV) systems use sensors — generally either CO2 or occupancy sensors — to estimate the actual number of people in an... MORE
Cold climate VRF systems
02.25.15 | Application of air source variable refrigerant flow in cold climates Variable refrigerant flow (VRF) systems use variable speed, split heat pumps to provide space heating and cooling to a building's conditioned areas. Air source VRF systems perform... MORE

Publications

Commercial roof-top units in Minnesota: characteristics and energy performance
04.07.17 | RTUs are used in more than one third of U.S. commercial buildings, the highest of any cooling equipment type. Why? They are reliable and have a low capital cost, as well as established service and distribution networks. There is anecdotal evidence,... MORE
Performance of water-source variable refrigerant flow: measurement and verification of two installed systems
12.18.15 | Variable Refrigerant Flow (VRF) systems have developed into a promising emerging technology. While popular in some places in the world, these systems are quite new to the upper Midwest. The systems are an innovative version of a simple split system... MORE
Application of air source variable refrigerant flow in cold climates: a white paper
07.07.15 | This white paper outlines the optimal control strategies for designing and operating air source VRF systems in cold climates. MORE
Implement and commission demand control ventilation to capture significant energy savings
04.27.15 | Summary of findings from a field study of DCV system performance. MORE
Energy savings from implementing and commissioning demand control ventilation
04.21.15 | Demand control ventilation (DCV) systems use sensors—generally either CO2 or occupancy sensors—to estimate the actual number of people in an area and supply only as much ventilation air as is needed at a given time. DCV has the potential to save a... MORE
Promoting quality installation of central AC and heat pump systems
06.03.14 | This presentation explored quality installation and maintenance practices for residential central air conditioning and air source heat pump systems in Minnesota. It covers key technical aspects of ensuring optimal system performance from new and... MORE
Hybrid ground-source heat pump installations: experiences, improvements and tools
09.20.12 | The Energy Center of Wisconsin with assistance from the University of Wisconsin Solar Energy Laboratory studied three working hybrid system installations to compare their economic and environmental impacts with other HVAC systems. MORE
Tracking the HVAC Market for Energy Efficiency Services
09.20.12 | Study establishes a baseline of energy efficiency attitudes and practices among Wisconsin's HVAC contractors. Based on interviews with 95 HVAC contractors in five areas of Wisconsin. MORE

Videos

Vision and sustainable strategies: our new building
12.19.13 | Frank Greb and Scott Hackel share the vision for our new space and give a brief technical overview of the HVAC system (including variable refrigerant flow geothermal) and lighting/daylighting strategies. MORE

Webinars

Optimal cleanroom ventilation
05.22.17 | Due to circumstances outside of our control, we have to cancel the upcoming webinar Optimal cleanroom ventilation with Craig Bahr on June 22 at noon Central. Thank you for your interest and please stayed tuned for future opportunities. Check out our... MORE
RTUs: characterization and energy performance
01.26.17 | RTUs are used in more than one third of U.S. commercial buildings, the highest of any cooling equipment type. Why? They are reliable and have a low capital cost, as well as established service and distribution networks. There is anecdotal evidence... MORE
Boilers: thermodynamics and combustion (video series)
08.26.16 | As a result of this video series, you will be able to: Explain what goes on in a boiler when heat energy is applied. Describe how boiler heat is transferred, as well as the importance of the respective (heat transfer) surfaces and their operational... MORE
Better homes video series
01.21.16 | Learn how to add value to one of the largest purchases of your life, your home, through energy upgrades that also enhance comfort. In addition, take a look at various green certifications and how they provide a roadmap toward the pursuit of a... MORE
VRF system optimization: going with the flow
10.14.15 | As a result of this webinar, you will be able to: Discuss various types of VRF systems. Identify VRF energy improvement opportunities. Analyze and identify the proper applications for VRF systems. Describe real-world examples of VRF systems in... MORE
The fundamentals of operating and maintaining chillers: cooling towers
09.17.15 | As a result of this webinar, you will be able to: Explain the function of a cooling tower Describe the components of a cooling tower Specify the critical steps for maintaining a cooling tower Understand the operational importance of properly... MORE
Subslab ventilation systems for moisture control
08.20.15 | From rotten walls to mildew, extreme moisture problems can wreak havoc on a home and the health of its occupants. During the design phase, consider moisture control solutions and make subslab ventilation systems part of the conversation. It is true... MORE
Demand control ventilation: maximize savings with practical approaches
03.12.15 | Ventilation systems in commercial buildings deliver a constant flow of fresh air to occupants. These systems assume full occupancy, all the time—but buildings are rarely full. Demand control ventilation (DCV) adjusts the amount of fresh air... MORE
Optimization of commercial building systems: technologies, practices and strategies
03.31.14 | AS A RESULT OF THIS WEBINAR YOU WILL BE ABLE TO: Understand the resources available for tracking building performance. Describe examples of HVAC and lighting operational practices that can lead to improved performance. Discuss methods for testing... MORE
Advanced RTU control strategies
03.31.14 | As a result of this training you will be able to: Explain the RTU related requirements of the IECC. Select the appropriate RTU accessories to maximize performance and efficiency. Describe the newest energy savings RTU option of multi-speed fan... MORE
Dynamic ventilation reset strategies
12.17.13 | Ventilation is an important part of making a building safe and comfortable, but it can require a significant amount of energy to properly condition that air. In this webinar, we will discuss dynamic ventilation control strategies to vary the amount... MORE
Drain water heat recovery systems: Energy savings and practical applications
09.24.13 | Drain water heat recovery systems can save a significant amount of energy in the right setting. In commercial building retrofits the technology can be a challenge, but new construction applications show promise for easier installation. Join us to... MORE
Enhancements for new and existing RTUs
12.13.12 | As a result of this webinar, you will be able to: Explain standard Air-Conditioning, Heating and Refrigeration Institute (AHRI) efficiency ratings for packaged RTUs. Identify International Energy Conservation Code (IECC) RTU related requirements.... MORE
Basic building science—a study of air, heat and moisture movement
12.12.12 | As a result of this presentation, you will be able to: Explain the driving forces behind air, heat and moisture movement Identify heat and moisture transfer mechanisms Describe what creates an effective thermal boundary Specify building details... MORE
Ventilation systems and the ASHRAE 62.2 standard
10.10.12 | As a result of this webinar, you will be able to: Describe the importance of residential ventilation and promote its benefits. Select appropriate ventilation equipment. Apply various control strategies including intermittent operation. Explain the... MORE
Hybrid geothermal systems: less is more
09.28.11 | Geothermal heat pump systems are an excellent choice for high performance heating, cooling and air conditioning, but cost is often a barrier. The solution? Go hybrid! Scott discusses the hybrid geothermal approach and reveals the results of an... MORE