HVAC/ACR International Mechanical Code
Venting Systems for Mid-Efficiency Furnaces
A vent is defined as a pipe or conduit that contains a passageway for conveying combustion products and air to the atmosphere. Products of combustion contain carbon dioxide, water, and sometimes carbon monoxide. Therefore, it is important to safely vent a gas furnace.
Modern gas furnaces are available with efficiencies that range from 80% to 98% Annual Fuel Utilization Efficiency (AFUE) ratio. Furnaces that are 90 to 98% AFUE are considered very efficient and utilize a category 4 vent system. This means that the flue gases operate under a positive vent stack pressure with a low vent gas temperature, causing the gases to condense before discharging from the vent. Venting materials used for category 4 furnaces are those recognized by the furnace’s installation instructions such as stainless steel, PVC, and ABS. Furnaces one tier lower in efficiency use more traditional venting methods than the 90+% units. Even though these systems are associated with conventional chimneys and vents, special attention must be given to their installation.
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Duct Leakage Tests
The International Code Commission (ICC) mandated HVAC duct leakage testing for the first time in the 2009 International Energy Conservation Code (IECC). Since the first leakage test requirement was rolled out, extensive testing procedures and equipment have remained in the Code. Obviously, the scope of the IECC is to conserve energy. Leaking conditioned air to unconditioned spaces is wasteful and unnecessary. There are many duct sealing systems available that will fill most of the small openings around duct fittings. To seal ducts and conduct a leakage test, a HVAC contractor, engineer, or HERS rater use these specialized tools and metho
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Smart Thermostats: Benefits and Advantages for Homeowners | JADE Learning
Thermostats have changed a whole lot in the last 20 years. Gone are the mercury bulbs and long levers. Even first-generation programmable thermostats are second class to the newest variety. Thermostats such as Google Nest, Honeywell T9, and Ecobee lead the way with the latest features for home comfort and energy savings.
Smart thermostats make it easy to get comfortable. These devices can be controlled remotely with a phone, tablet, or computer, and even utilize their own intelligence to keep a home’s temperature right where the owner wants it. How about a thermostat that you can talk to? It’s available with some of the smart thermostats. Because these thermostats are WIFI enabled, programming them to work with the different “talking” services can be easy. You can tell the thermostat you are leaving, which would reduce the system run time while you were away. You could tell the thermostat you were going on a vacation. This command indicates the home is unoccupied and will not need the same comfort conditions, thereby saving energy. Or, you could just say “Alexa, set the temperature to 77 degrees.”
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HVAC Systems Using Sustainable Energy
The world continues to move in the direction of sustainable energy, and HVAC systems are no exception. Three types of systems in particular — DeVap, Solar, and Geothermal — are serving on the front lines of the HVAC fight against nonrenewable energy.
Learn the basics of each type of system and how they promote a more comfortable environment inside and a more sustainable one outside.
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Ventilation Systems in a Post-COVID World
Sometimes it takes a dramatic event to institute real change. In the case of the COVID-19 pandemic, building ventilation systems could potentially be forever changed. Here, we attempt to predict how ventilation systems might evolve in the aftermath of the coronavirus and what those changes will mean for HVAC professionals. […]
