Chapter 2 - Heating Load Estimates

The design heating load of a building is an estimate of the rate at which a building loses heat during the near minimum outdoor temperature.

One can assume that individual room heating loads are proportional to room floor area.

The R-value of a material is not directly proportional to its thickness.

Many residential and commercial buildings have concrete floor slabs rather than crawl spaces or full basements. Downward heat losses are relatively small from interior areas of the floor slab.

The U-value of any material or assembly is simply the reciprocal of the R-value of that material or assembly.

Heat is lost through all building surfaces that separate heated space from unheated space.

It is relatively easy to assess the location and magnitude of all the air leakage paths in a typical building.

The number of heating degree days that accumulate in a 24-hour period is the difference between 72 F and the average outdoor air temperature during that period.

Knowing how many MMBtu a building requires over a typical heating season is not of much use to most owners.

A boiler, furnace, or small space heater operating on the same fuel, at the same assumed conversion efficiency, would produce the same estimated annual heating cost.

The heating load is __________ of heat flow from the building to the outside air.

The proper approach is to perform a heat load calculation __________.

An object's thermal __________ can be defined as its thickness in the direction of heat flow divided by its thermal conductivity.

Heat flow from a basement or slab-on-grade foundation is determined by complex interactions between the building, the surrounding soil, insulation materials (if present), and the __________.

All building surfaces that separate heated space from unheated space (walls, windows, ceilings, doors, foundation, etc.) are called the __________ of the building.

The U-value of any material or assembly is simply the reciprocal of the __________ of that material or assembly.

In addition to conduction losses, heat is also carried out of buildings by uncontrolled air leakage. This is called __________ heat loss.

One common method of factoring local weather conditions into estimates of heating energy use is based on heating _________.

Once the __________ price of the fuel options has been calculated, a simple multiplication determines the estimated seasonal heating cost in dollars.

To estimate the annual space heating cost provided by an electrically operated heat pump, its average COP must be factored in. What does COP stand for?