Mech/Elec ALS Lesson Three - Mechanical Equipment and Energy Codes: System Distribution Types - Electrical & Hydronic Systems

System Distribution Types - Electrical

Simplest, lowest first cost, most expensife life cycle cost

only justified in mild climates where system is off most of the time

two electrical system categories:

radiant systems = radiant panels or wires embeded in ceiling, also baseboard heaters that heat up and cause convective air circulation

pros: turn on per location, objects heated not air, 

cons: electrical generation from combustion, therefore low efficiency, wasteful and expensive

System Distribution Types - Hydronic Systems

Hydronic systems = also radiant, hot water or steam circulates through registers or pipes embedded in floors, heat then radiates into space.

Baseboard heaters can use hot water and steam too.

Forced air can be added, which blows air past the heated coils, pipes or radiators

Different loop patterns:

Single pipe = single supply and return pipe, runs in series or partly parallel.

hot water circulates through each register(coil), first one is hottest with decreases down the line.

Low first cost, limited service distance since water would be quite cold at last register, more than five is not good

Two pipe (parallel) = separate supply and return pipes, water not mixed back into supply pipe after through register, keeps same high temp. at all registers

Three pipe = for heating and cooling one supply to cold coil(register), one supply to hot coil & one mixed return pipe

more expensive to operate since water must be re-heated or re-cooled since mixing changes the temp's instead of having relatively hot and cold water in separate return pipes, see next system

Four pipe = Separate two pipe system for cooling and heating resulting in four pipes. Separate supply and return pipes.

fairly constant temp's, more cost efficient