Heat Emission Units Flashcards
What is the maximum temperature for a low temperature hot water boiler?
121 C
250F
What is the maximum pressure for a low temperature hot water boiler?
1100 kpa
160 psig
If a low temperature hot water boiler is made of cast iron what is its maximum pressure?
207 kPa
30 psig
What type of low temperature hot water boiler has a lower maximum pressure rating?
Cast iron
What temperatures can high temperature hot water boilers operat at (low end)?
121c
250 f
What is the low end pressure tolerance for a high temperature hot water boiler ?
1100 kpa
160 psig
Name 3 methods of heat transfer
Conduction
Convection
Radiation
In a base board heater how is most heat transmitted to the room?
Convection
What size copper tubes are used to n a finned tube base board heater?
3/4 to 1 1/4
What size steel tubes are used ina finned base board heater?
1 “ to 2” iron pipe size
When can finned elements be installed without a protective covering?
Where there is no hazard to personnel , the elements may be installed without a protective cabinet or with minimal protective covering.
How do free standing cast iron radiators heat
Using convection currents and with radiation due to their high mass.
In a finned tube base board how many fins do they have per ft
55-65 per ft
How are the convection currents controlled on base board heaters?
Dampers
What will aluminum or bronze paint do to heat emotes by radiation ?
Reduce heat emitted by 10% or more.
What are the 2 parts of a convector?
Heating element and cabinet
Name 3 styles of convector
Surface mount unit
Fully recessed model
Semi-recessed model
Name 2 types of unit heaters
Blow through
Draw through
How many rows of fins can fin vectors have?
3
In a typical hydronic heating system when piping is fed from below up to the heat emission unit what must be installed to help with air entrapment?
Air vent
When installing baseboard heater who should be consulted to determine flow rates and supply temperatures?
Manufacturers table.
At what height should unit heaters be located?
6-12 feet above the floor
Where should unit heaters be faced?
Towards outside or exposed walls
In larger areas where should unit heaters be located?
Along exposes walls
How far from any vertical or horizontal surface must a unit heater be installed?
At least 6”
A few not heater must discharge towards a source of cold air from how far away?
15-20 feet
Air handling units are typically mounted to concrete pads and be bolted down to prevent movement
True or false?
False
Shock absorbing springs should be installed to avoid transfer of vibrations
When performing maintenance on coils what should be done.
Clean debris and straighten fins with comb .
In which direction does heat always travel?
From warmer objects to colder objects.
What is the best location for installing base board fin?
On exterior walls with or without windows.
