Heat rises, right? We all know that to be true for the most part.
The implications are important to homeowners when we find both hot and cold spots make parts of the home uncomfortable.
How do we manage hot and cool air distribution at home?
Uneven temperatures can make your home or office uncomfortable places to be and even make it difficult to manage your wardrobe. When air forms layers (or stratifies, as some say), the upper floors can be too hot, while the basement is too cold.
Spending any great lengths of time in the basement can make you want to turn off the AC or crank up the heat. But the heat migrates upward through any open areas, and anyone upstairs will soon complain that it’s too hot. A professional can diagnose the location of any air seepage and help come up with a plan to keep everybody all floors at a comfortable even temperature.
We call it “stacking”
Heated air is not as dense as cold air, which is why it travels upward. For the same reason dense, cold air sinks to the bottom of a room. Areas divided by floors tend to stratify, holding on to air pockets according to density. This is the simplest explanation of why most basements are colder than the upper-floors, even in well vented houses.
This is called “stacking,” or “the stack effect,” in HVAC industry-speak.
Your home acts as a giant chimney (or stack), the upward-moving air has to go somewhere. The hot air finds small gaps and openings in your attic, and all of a sudden you are paying to heat the air outside of your home.
What causes multi-level heat discrepancies?
Multi-level heat discrepancies in homes and other buildings is typically the result of poor HVAC design and installation. The problems can include:
- Poor Duct Design – Lots of structural factors impact the size, style and routing of ducts, the placement of your furnace, and the placement of registers or vents. Specialized training helps our HVAC technicians to predict and design solutions to problems such as frictional loss, ensuring that both quantity and velocity of treated air is adequate to every area of the home or building.
- Improperly sized equipment – Both too-large and too-small furnaces and air conditioners can cause air distribution discrepancies. A unit that’s too large may cycle on and off too quickly for the building to even out, and a unit that’s too small may struggle to heat or cool the space enough (that struggle often causes premature component failure).
With modern insulation, old industry formulas for sizing equipment are outdated and irrelevant.
In the U.S., ducting must be installed according to Air Conditioning Contractors of America (ACCA) Manual D standards and equipment sizing to ACCA Manual J standards. In Canada, the largest organization serving HVAC contractors is the Heating, Refrigeration and Air Conditioning Institute of Canada, or HRAI. HRAI’s equivalent to Manual D is the Load and Duct Manual; HRAI’s equivalent to Manual J is CSA F280.
The proper sizing of equipment can be carried out in Canada using either set of guidelines, and all Air Treatment ClimateCare technicians are fully trained and familiar with these guidelines. Without these skills, supported by regular education and testing, the homeowner has no guarantee their system will provide the air movement needed to ensure your home comfort systems work as intended.