For many years, both residential homes and commercial buildings have used heating, ventilation, and air conditioning (HVAC) and water heating systems independently. This leads to two separate bills: one for electricity, and one for gas (assuming the water heater is gas-fired).
As opposed to using these systems separately, the introduction of heat pump water heaters has proven to be very cost effective in a variety of projects for several reasons:
- Reduces two energy bills into one. Heat pump water heaters have the ability to move heat away from a room to the water, thereby providing simultaneous cooling of the room while displacing the excess heat for a useful purpose such as water heating.
- Generous storage space savings. Traditional tank storage central based water heaters require a large amount of space to be stored. The same can be said if each dwelling unit in a multifamily building has their own separate water heater.
- Initial cost savings. Purchasing a central water heating system or individual water heaters per unit can be very costly, especially for large high rise apartments. Instead of purchasing two systems, only one is needed for each unit.
- Can be used for LEED credits. It may be possible to use ASHRAE prescriptive SEER and EER values for the heat pump as opposed to Title 24 standards and still obtain lots of points due to energy savings. This allows customers to save on purchasing expensive high SEER heat pumps for LEED credits.
Heat pump water heaters, like a vast amount of HVAC systems, have their limitations when it comes to performance and/or installation. Some of these limitations include but are not limited to:
- Noisy operation. This depends on the type of heat pump water heater that is being used. The ready-made combined water-heating/air cooling heat pump water heaters tend to produce lots of noise and need to be stored in a sound insulated compartment.
- Installation may delay existing projects. If the customer chooses not to purchase ready-made available heat pump water heaters, then installing the components necessary to make the heat pump work in combination with water heating could be time-consuming.
- Performs less efficiently in colder climates. Because heat pumps move heat from one space to another, more water will be heated if there is more heat available to move. Therefore heat pump water heaters perform better in hotter climates.
Even though there are some limitations to heat pump water heaters, the pros outweigh the cons. In addition to the benefits mentioned above, this technology can also provide owners higher property values for their projects.
For more information on how to save energy for your building, contact VCA Green below:
Moe Fakih, Principal
Contributing Writer: Georgio Mahmood, PE