Hydronic Radiant Heating And Heat Loss Calculations Flashcards
Where is a cushion/ expansion tank normally placed
Placed upstream of the circulator
Heat transfer by movement of fluid
Convection
Thin layer of reflective material placed below or above the heat transfer unit to transfer heat in the direction required
Radiant barrier
1/R = ??
U factor
This heating system heats a space from the ceiling down
Forced air system
What are the components of a finned baseboard system
Copper tube, aluminum fins , and an enclosure
This heating offers radiant heating that heats the objects in the space and have little effects on the air in the room
Radiant infloor heating
Is the temperature of the air in a room at different levels
Stratification
Where is installing radiant floor heating not recommended
Below cabinets or pantry’s that store food
Underneath refrigerators and freezers increase load on those appliances
Near water closets
Delta T is the difference between radiant floor temperature and the temperature of surrounding colder surfaces
What is the advantage of this
The greater the temperature difference between the two surfaces the faster the heat transfer
What is not recommended with setting the room temperature with radiant floor heating ?
Setting back the system at night is not recommended, due to slow response time
Most building and municipal codes require that any occupied building must have a way to exchange the air called what
Air exchangers
What’s important to consider these installing snow melt systems
Ensure proper drainage system to prevent ice build up
This piping meets or exceeds any of the stringent pressure and temperature tests required by code
Ideal for radiant flooring
Pex
Recommended maximum lengths for infloor heating
3/8” ID- 76m/250’
1/2” ID- 91m/300’
3/4” ID- 152 m/ 500’
Tubing manufacturers also make headers, but these headers are pipe specific. Connecting one manufacturers tubing to another’s header does what?
Voids the warranty
When connecting tubing to headers what must be followed
Joined per manufacturers specifications
These are installed on manifolds to ensure equal flow rate to each circuit
Balancing valves
When are balancing valves not required
Lass than 10% different between circuits
Maximum floor temperature
140 Fahrenheit
What temperature can the floor surface not exceed in areas where people stand for long periods
25 Celsius or 77 Fahrenheit
What should the Floor surface temperature not exceed in a dwelling or commercial space
31 Celsius or 88 Fahrenheit
What should Floor surface temperatures not exceed in bathrooms, indoor swimming pools and foyers
- Celsius or 91 Fahrenheit.
What temperature should floor surfaces not exceed in radiant panel perimeter areas
- Celsius or 95 Fahrenheit.
What should a radiant panel be protected with?
High limit temperature control valve
What temperatures are considered low temperature systems
Below 140 Fahrenheit
What temperatures are considered high temp systems
Over 140 Fahrenheit
What is the calculation for U factor
1/R value = ufactor
For most heat lost calculations what’s recommended with rounding of the measurements
To the nearest quarter of a foot
The difference between the indoor design and the outdoor design temperature
Design temperature difference
What is infiltration based on?
BTUH per hour per cubic foot of air within a space
Heat is lost through the ceiling by conduction and this loss is referred to as what
Transmission loss
What percent must be added to the heat loss calculation in bathrooms
20%
