Question

Difficulty: MediumIdentifying Unstated Assumptions

Consider the following argument: A municipal building authority plans to replace the conventional steam radiator heating systems in its historic administrative offices with low-temperature geothermal heat pumps. The authority claims that this modification will reduce total heating expenses for these buildings over the next decade because geothermal systems consume significantly less grid electricity per unit of thermal energy delivered than electric boiler steam systems.

True or False: The argument depends on the assumption that the total cost of installing and maintaining the geothermal heat pump system over the next decade will not exceed the monetary savings gained from reduced electricity consumption.

Answer: Answer

Answer

True. The argument logically depends on the unstated assumption that installation and maintenance costs will not negate the energy cost savings over the ten-year period.
The author infers a reduction in overall ten-year heating expenses solely from a premise establishing that geothermal systems use less electricity per unit of heat. For operational energy efficiency to lead to lower total financial expenditure over time, non-operational costs—specifically initial system purchase, installation, and routine maintenance—must not exceed the monetary value of the energy saved.

Step-by-Step Solution

1
Identify the argument's premise and conclusion.
Premise: Geothermal heat pumps consume less electricity per unit of heat than electric boilers. Conclusion: Replacing the system will decrease total heating expenses over the next decade.
Isolating the gap between lower energy consumption and lower overall financial expenditure reveals unstated assumptions.
2
Apply the Negation Test to the candidate assumption.
Negated claim: The total cost of installing and maintaining the geothermal system over the next decade WILL exceed the savings from reduced electricity consumption.
Negating a necessary assumption tests whether the author's conclusion can survive without it.
3
Assess the logical impact of the negated statement on the author's conclusion.
If initial installation and ongoing maintenance costs outweigh energy savings, total heating expenses over ten years will increase, falsifying the conclusion.
A statement is a required unstated assumption if its logical negation renders the conclusion untenable.

Key Concept

The Negation Test for Identifying Necessary Assumptions
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