Heat Loss Calculation Flashcards
What is the primary purpose of a heating system?
To provide comfort to the individuals in the space.
Which direction does heat always travel in?
From warm objects to cooler objects.
What is not considered when calculating heat loss?
Interior walls of the building
ODT is an acronym for:
Outdoor design temperature
What does the designed temperature difference refer to?
The indoor temperature minus the outdoor temperature.
What is the recommended practise for determining room dimensions?
Measurements should be rounded up or down to the nearest 0.25 of a foot.
Which type of heat loss results in cool air flow from the outside being drawn into the building through cracks around windows, doors and loose construction?
Infiltration losses
Which of the heat loss types transfers through a ceiling?
Transmission losses
Finned baseboard heating capacity is expressed in what unit?
BTU per hour per linear foot
Which type of application are kickspace heating units ideal for?
Limited wall space due to cabinets and cupboards.
What are the three major components of a finned baseboard?
Radiant fin, housing and supply tube
What is the main function of the adjustable damper on a baseboard cabinet?
To slow or increase the convection air flow
What is the procedure for calculating the amount of finned baseboard required in a given space?
Divide the space heat loss by the output rating of the baseboard selected.
At design, which two design factors determine the output of a finned baseboard?
Supply water temperature and GPM
What causes frequent cycling of a boiler?
A boiler with excessive pressure.
What procedure should be followed to ensure proper boiler start up?
1. The plumbing code
2. The gas code
3. The boiler manufacturer
4. The general contractors recommendations
The boiler manufacturer
Flow rate, temperature drop and pressure drop are used to size what?
The size of the piping.
What must be known in order to properly size the output of a pump for a hydronic heating system?
Required GPM and the total feet of head
What is the main function of an expansion handling device?
To allow the water in the system to expand and contract as the system water heats and cools
How do diaphragm tanks differ from standard closed expansion tanks?
Diaphragm tanks have a bladder that separates the water and air.
In what section of the heating code will you find definitions?
Section 2
In which section of the heating code is quality of work referenced?
Section 3
Which section in the heating code deals with hydronic space heating?
Section 12
What is covered in section 15 of the heating code?
Auxiliary systems
What must be selected prior to installing rough in piping?
The heat transfer units
Why does ASHRAE not recommend the use of high output baseboard?
High output baseboard reduces comfort by not covering enough exposed wall.
What is the best location for installing baseboard fin?
On exterior walls with or without windows
Which reference material will best assist in the installation of baseboard fin and cabinet?
Manufacturers specifications.
Prior to making a material list, it is good practice to do which?
1. Make a detail drawing showing piping materials and parts.
2. Consult the GC.
3. check the plumbing code
Make a detail drawing showing piping materials and parts.
What is the name of the type of heat loss for the amount of heat flowing from inside to outside?
Transmission heat loss.
What unit is transmission heat loss calculated in?
BTU
What is mechanical ventilation?
A form of infiltration. Air that is removed from the building or kitchen exhaust fans must be replaced as to prevent a negetive pressure from forming within the building. This must be added to the heat loss calculation.
The I=B=R net rating is the amount of heat energy that will be transmitted to the hot water from the input fuel after losses are taken into account. True or false?
True.
What info is shown by the boiler’s manufacturer?
The input rating of the boiler, the output rating and the I=B=R net rating.
What is the “input rating” of a boiler?
The amount of fuel the boiler will consume in 1 hour.
What is the “output rating “ of a boiler?
The total BTU a boiler produces after stack and jacket losses are removed.
An oversized boiler is quite inefficient. True or false?
True, it will start and stop frequently, allowing a great deal of heat to pass up the stack and is wasted.
What is the recommended flow rate when determining friction loss, in most residential or small commercial applications?
Between 2-4 GPM to ensure laminar flow and a quiet system.
What material pump body should be utilized if the system contains high oxygen levels?
Brass or stainless.
What is the main function of the piping in a heating system?
To deliver heated water to the HTUs at a reasonable flow rate in order to maintain a set temperature drop.
What can occur in a piping system if expansion and contraction of the piping is not accounted for in the design?
Excessive pressure on the entire system, possible resulting in component damage as water is not compressible.
What are the two different types of expansion tanks?
Open and closed.
For conventional expansion tanks, what is the industry rule of thumb for the capacity of the tank?
No less than 1 US gallon for each 5000 BTU of total heat loss.
For diaphragm expansion tanks, what is the industry rule of thumb for the capacity of the tank?
No less than 1 US gallon for each 7000 BTU of total heat loss.
Where is an open expansion tank located?
The highest point in the heating system.
