As kids, we were always told that heat rises, right? In large part, the old physics class credo does hold true. It may not have been too interesting at age 11, but its implications become far more important when we grow up, buy a home and find both hot and cold spots make parts of the house frustratingly uncomfortable.
Isn’t there a happy medium?
Uneven temperatures can make your home or office a brutal place to spend the day. When air forms layers (or stratifies, as some say) on a floor-by-floor basis, the upper floors can be sweltering, while a visit to the basement require slippers and a blanket.
Occupants of the lower floors crank up the heat, the furnace warms up the occupied spaces, which immediately migrates upward through any open areas. Those upstairs get even hotter, while the basement becomes frigid again. Spending money on making things worse for everyone isn’t good, so understanding and dealing with the issue is important.
“Stacking” is the industry term
Heated air is less dense than cold air, which is why it travels upward. For the same reason, more dense colder air sinks. 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 most upper-floor bedrooms, even in well heated houses.
The phenomena is called “stacking,” or “the stack effect,” in industry-speak.
Aside from the scenario suggested above, this is bad for budget and environmental impact. In this scenario, your home is acting as a giant chimney (or stack, coincidentally). The upward-moving air has to go somewhere. It will find the small, unintentional gaps and deliberate openings in your attic. All of a sudden you are, in a very real sense, paying to heat the outside air.
Your best (and easiest) solutions
Multi-level heat disparity, in both homes and commercial buildings, is typically the result of poor HVAC design or installation. The problems include, but are not limited to:
- Duct Design. Numerous structural factors impact the size, style and routing of ducts, and the placement of registers, or vents. Specialist training helps our technicians to predict and design answers to impediments such as frictional losses, ensuring that both quantity and velocity of treated air is adequate to all areas.
- Inadequately sized equipment. Both too-large and too-small furnaces and air conditioners can cause problems; the former cycle on and off too rapidly for the building to even out, and the latter struggle to do any good at all (that struggle often causes premature component failure).
With modern insulation, old rule-of-thumb formulas for sizing equipment are outdated and irrelevant.
The Air Conditioning Contractors of America (ACCA) is the largest organization serving HVAC contractors in North America. In the U.S., ducting must be installed according to ACCA Manual D standards; 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 parameters, and all Guelph ClimateCare technicians are fully trained in their use. 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.