Quiz 3 Flashcards
How many BTUs per pound is recovered and a 90+ gas system
970
Is a chimney required preventing 90+ systems
no
How are 90+ systems vented
side wall vented 1’ above anticipated snow level (NH 18”)
So about 30” above grade
What do we use for venting
PVC, CPVC, polypropelene, stainless steel
What are the proper ways to drain condensate if we cant drain staight to the outside w/o freezing
Floor drain, utility sink, washer machine standpipe (with properly vented trap)
What extra precaution must we take if we install in an attic
Secondary drain pan with alarm
Air handler (Primary Equipment)
Large insulated cabinet which does not include a direct heat producer. Includes blower, filter, Control system, and A/C and heat coils
Where are perimeter systems used
cold climates, definately on slab (no heat below)
Where is the most heat available on a perimeter system and how was it directed
At the floor
Where are ceiling supply systems used and How are the supplies directed
Warm air climates or second floors and are directed to the walls
What is the most common supply duck configuration
Truck and branch reducing Plenum
Where are High inside wall systems used and how is supply air yeah directed
Warm air climates or second floor applications, discharge air extended to opposite wall (outside wall)
Pros of perimeter loop system
Comfort at floor level (slab construction)
Easy to balance
Good for a high velocity Applications
Cons of the perimeter loop system
Most expensive
Most difficult to configure (design and install)
Central furnace location recommended
Increased lab loss
radial system pros
Inexpensive (no trunks)
easy to install
Good for high velocity applications
Trunking branch (extended Plenum) pros
Inexpensive, straight duct, one size
Can be located in basements, crawls, attics
Can take off anyway from the appliance
Trucking branch (extended Plenum) cons
Max trunk length 25’
No take off within first 18” or last 12”
Centrally located
Trunk and branch (reducing Plenum) pros
Most versatile, most common residential
Easy design and install
Can be located in attics, basements, and crawls
Not restricted to 25’ length
Take off anyway
balances airflow to take off with reduction at 50% velocity
No central location necessary
