Cooling-load thinking

What the A/C fights

Cooling load includes solar through glass, heat through shell/thermal bridges, infiltrating air, occupants/pet,computers/cooking, compressor/condenser recirculation and stored heat in furniture.

BTU/h is a rate

A/C capacity is heat removed per hour, not electrical consumption. Electrical watts tell battery demand.COP/EER describe efficiency under stated test conditions; real performance falls with extreme outdoortemperature, bad airflow or dirty coils.

Sensible and latent

Sensible capacity lowers air/surface temperature. Latent capacity condenses moisture. Total advertisedcapacity is split between the two and varies with indoor/outdoor conditions.

Why rules of thumb fail

Van volume alone misses glass, solar orientation, insulation, color, humidity and door use. Choose with a loadestimate plus field evidence and manufacturer performance data.

System rule

Do not judge a cooling upgrade at the vent. Judge it by the hottest occupied zone, humidity, energy usedand whether the system can recover that energy safely.

CHAPTER CHECK

• I can explain which heat path this step addresses.• I measured its effect at front, middle and rear - not only by touch.• I added its power, failure mode, maintenance and safety action to the system plan.