Final answer:
Safety concerns with directly fired water heaters include combustion safety and ventilation. Heat pump water heaters offer advantages such as efficiency and reduced emissions, making them eco-friendly and potentially cost-effective over time. (option a)
Step-by-step explanation:
When using directly fired water heaters to heat indoor swimming pools, certain safety concerns must be addressed. The primary concerns are related to combustion safety and ventilation. It is vital to ensure that combustion byproducts are adequately vented to prevent the buildup of harmful gases like carbon monoxide and to make sure that the system components are safely managed to prevent accidents.
On the other hand, heat pump water heaters offer several advantages in this setting. One significant advantage is efficiency, as heat pumps can transfer more energy to the heated space than the electrical energy they consume. Another benefit of heat pumps is reduced emissions since they do not burn fuels directly and thus produce fewer greenhouse gases. Also, heat pumps can operate at lower costs where electricity is cheaper than fossil fuels, and they are beneficial in climates where both heating and cooling are desired. However, the initial cost and the cost of electricity should be considered when evaluating their overall cost-effectiveness.