Tag: Heat
Heat Pumps
A heat-pump cycle is a sequence of operations in which the heat of condensation of a refrigerant is used for heating. The heat required to vaporize the refrigerant is taken from ambient air at the stage where the normal refrigeration cycle (Art. 13.22) usually rejects the heat. In the summer cycle, for cooling, the liquid refrigerant is arranged to…
Radiant Heating
Radiant heating, or panel heating as it is sometimes referred to, consists of a warm pipe coil embedded in the floor, ceiling, or walls. The most common arrangement is to circulate warm water through the pipe under the floor. Some installations with warm-air ducts, steam pipes, or electric-heating elements have been installed. Warm-air ducts for radiant heating are…
Warm-Air Heating
A warm-air heating system supplies heat to a room by bringing in a quantity of air above room temperature, the amount of heat added by the air being at least equal to that required to counteract heat losses. A gravity system (without a blower) is rarely installed because it depends on the difference in density of the warm-air…
Heating-Load-Calculation Example
As an example of the method described for sizing a heating plant, let us take the building shown in Fig. 13.3. A design outdoor temperature of 0F and an indoor temperature of 70F are assumed. The wall is to be constructed of 4-in brick with 8-in cinder-block backup. Interior finish is metal lath and plaster (wall heat-transmission…
Heat Gains
These differ from heat losses only by the direction of the heat flow. Thus, the methods discussed in Art. 13.7 for heat losses can also be used for determining heat gains. In both cases, the proper inside and outside design conditions and wetbulb temperatures should be established as described in Art. 13.3. Heat gains may occur at any…
Heat Losses
Methods and principles for calculation of heat losses are presented in Art 13.3. These methods provide a rational procedure for determination of the size and capacity of a heating plant. Heat loads for buildings consist of heat losses and gains. Heat losses include those from air infiltration, ventilation air, and conduction through the building exterior caused by low…
Ventilation
Ventilation is utilized for many different purposes, the most common being control of humidity and condensation. Other well-known uses include exhaust hoods in restaurants, heat removal in industrial plants, fresh air in buildings, odor removal, and chemical and fume hood exhausts. In commercial buildings, ventilation air is used for replacement of stale, vitiated air, odor control, and smoke removal.…
Heat and Humidity
People have always struggled with the problem of being comfortable in their environment. First attempts were to use fire directly to provide heat through cold winters. It was only in recent times that interest and technology permitted development of greater understanding of heat and heating, and substantial improvements in comfort were made. Comfort heating now is a highly…
