Question 1

With a centralized hydronic heating system, cost allocation is handled by measuring the total thermal energy transferred to each space on a periodic (usually monthly) basis.This approach is called heat metering, or, more commonly in North America "____."

Accepted Answer

The approach described in the statement is known as "heat metering" or "BTU metering." It involves measuring the thermal energy transferred to each space on a periodic basis and allocating costs accordingly. The other options provided (climate control, shared metering, central bookkeeping) do not accurately describe this process.

Question 2

One way of initiating several short on/off cycles is by adding thermal mass to the distribution system using an insulated buffer tank.

Accepted Answer

Adding thermal mass to the distribution system using an insulated buffer tank actually helps to reduce short on/off cycling by storing excess heat and releasing it slowly, leading to more stable and efficient operation.

Question 3

As a rule, the piping and circulator, as well as the thermal rating of the tank's heat exchanger should be able to ____ heat as fast as the boiler, or other heat source, can produce it.

Accepted Answer

The piping and circulator, as well as the thermal rating of the tank's heat exchanger, should be designed to transfer the heat as fast as the boiler or other heat source can produce it. This ensures that the heat is effectively and efficiently distributed throughout the system without any loss or waste.

Question 4

For garage heating, radiant slab heating is the least efficient in situations where a relatively constant temperature will be maintained.

Accepted Answer

Radiant slab heating is actually very efficient for maintaining a constant temperature in a garage because it allows for more even heat distribution and does not constantly cycle on and off like a forced-air system.

Question 5

It is often necessary to adjust valves within each branch to achieve flow rates equal or close to those necessary for proper heat delivery.This process is called "____" the system.

Accepted Answer

The process of adjusting valves within each branch to achieve flow rates equal or close to those necessary for proper heat delivery is called "balancing" the system. This ensures that each area or zone of the building is receiving the appropriate amount of heat, and is a key aspect of properly operating a hydronic heating system.

Question 6

An indirect water heater is an insulated storage tank that produces its own heat, as does a typical direct-fired water heater.

Accepted Answer

An indirect water heater does not produce its own heat. It relies on an external source such as a boiler to heat the water in the tank.

Question 7

Buffer tanks are always needed when the system contains several small individually controlled loads that have low thermal mass.

Accepted Answer

Buffer tanks are not always needed in systems with several small individually controlled loads that have low thermal mass. Their necessity depends on the specific system design, the ability of the heating or cooling source to modulate output effectively, and the dynamics of the load variations. Buffer tanks are used to improve system efficiency and stability, but alternative design strategies can sometimes achieve these goals without them.

Question 8

The dominant heat loss from pools is caused by evaporation of water.

Accepted Answer

Evaporation is the most significant cause of heat loss from swimming pools, accounting for about 70% of total heat loss.

Question 9

Domestic hot water (DHW) is by far the most common auxiliary load to be combined with hydronic space heating.

Accepted Answer

Domestic hot water (DHW) is indeed the most common auxiliary load combined with hydronic space heating.

Question 10

When low mass on/off heat sources are combined with extensively zoned distribution systems, it is possible for the heat source to ____ when only one or two zones operate.

Accepted Answer

When low mass heat sources are combined with extensively zoned distribution systems, if only one or two zones operate, the low mass heat source can short-cycle. This means that the heat source will turn on and off frequently, leading to inefficient and potentially damaging operation.

Question 11

One method of providing domestic hot water using a boiler, which was widely used in older North American hydronic systems, was to insert a copper heat exchanger called a ____ into the upper portion of the boiler.

Accepted Answer

A tankless coil is a copper heat exchanger that is inserted into the upper portion of the boiler to provide domestic hot water.

Question 12

The author's position is that antifreeze must be used in all hydronic garage heating applications.

Accepted Answer

The author states in the passage that "antifreeze must be used in all systems" and provides reasons why it is important for hydronic garage heating applications.

Question 13

An advantage of snow and ice melting systems (also know as SIM systems) is the ability to use almost any fuel or heat source to provide the energy needed to operate the SIM system.

Accepted Answer

Snow and ice melting systems can be powered by a variety of energy sources, including natural gas, electricity, propane, and even solar power.

Question 14

A pool heat exchanger is piped into the system as a(n) ____ branch circuit.

Accepted Answer

A pool heat exchanger is typically piped into the system as a parallel branch circuit. This allows for the efficient transfer of heat to the pool water without interfering with the primary heating system's operation.

Question 15

Many auxiliary loads require a transfer of heat from the hot water released by a boiler or other heat source to some other liquid operating at a lower temperature.Such situations require the use of a ____.

Accepted Answer

Heat exchangers are specifically designed to transfer heat from one fluid to another. In this situation, a heat exchanger would transfer heat from the hot water released by the boiler to the other liquid operating at a lower temperature, allowing for efficient heating of the auxiliary loads.

Question 16

Most manufacturers of indirect water heaters provide two types of rating information.One is called the first hour rating; the other is called the ____ rating.

Accepted Answer

The first hour rating of an indirect water heater refers to the amount of hot water it can produce in the first hour of use. The continuous flow rating refers to the amount of hot water the unit can consistently produce over an extended period of time.

Question 17

One benefit of an indirect water heater is that the stored water provides ____ that allows the boiler to operate for longer cycles, and thus at higher efficiencies.

Accepted Answer

Indirect water heaters have a large thermal mass, allowing them to store a significant amount of heat energy. This thermal mass provides the boiler with a buffer, allowing it to operate at higher efficiencies and for longer periods. This also means that the boiler doesn't have to cycle on and off as frequently, reducing wear and tear on the system and extending its lifespan.

Question 18

Hydronic snow and ice melting systems (also know as SIM systems) use ____ tubing embedded in pavements to melt snow and ice.

Accepted Answer

PEX (cross-linked polyethylene) or PEX-AL-PEX (a composite pipe consisting of aluminum layer sandwiched between two layers of PEX) are the best choices for hydronic snow and ice melting systems due to their flexibility, durability, and resistance to corrosion and freeze damage. Copper and stainless steel are more expensive and can be prone to corrosion, while aluminum is not as strong and may crack under stress.

Question 19

A minitube distribution system designed to take advantage of the large temperature difference available between hot boiler water and the relatively cool water returning from a heated slab-on-grade floor.

Accepted Answer

A minitube distribution system can be designed to take advantage of the large temperature difference available between the hot boiler water and the cool water returning from a heated slab-on-grade floor. This system can improve the efficiency of the overall heating system.

Question 20

Although space heating is the primary load, hydronic systems can also provide heat to other auxiliary loads.Examples include domestic water heating, garage heating, pool or spa heating, and snow melting.

Accepted Answer

Hydronic systems can indeed provide heat to other auxiliary loads in addition to space heating. Some examples include domestic water heating, garage heating, pool or spa heating, and snow melting.

Quiz 14: Auxiliary Loads and Specialized Topics