One by-product of having a heat pump water heater in addition to dehumidification is a slight cooling affect. While this will be beneficial in the summer, it may not be welcome in the winter. Some manufacturers have incorporated a "stop cold air" control that can allow the user to switch off the heat pump for a prescribed period of time during the winter. The water heater would then automatically switch back into the hybrid mode at the end of the setting, up to 99 days. For water heaters installed in a basement or garage, the cooling affect may not present a concern.

Utilities often charge their customers based on the peak load. These are the times when more consumers require electricity from the utility. On a very hot day air conditioning loads can mean an increased power requirement for the utility. The smart controls on some hybrid water heaters can respond to utility smart meters to help shed some of this load during critical times while still maintaining the hot water needs of the home.

Incentives - National and State

The American Recovery and Reinvestment Act of 2009 extended many consumer tax incentives originally introduced in the Energy Policy Act of 2005 (EPACT). Federal Income Tax credits were eligible to  be applied dollar for dollar and deducted to taxes paid or owed. For 2012, most of those credits have expired, although the possibility remains for new tax credits to emerge. It is more likely, however, that new regulations will simply mandate higher performance for all water heaters. For example, a proposed 2015 energy mandate will essentially outlaw resistance water heaters below a .95 EF and require all water heaters 55 gallons and above to have a minimum EF of 1.964 just to be manufactured (i.e. Energy Star qualified product).

Despite the loss of tax credits, Energy Star qualified heat pump water heaters are commonly eligible for rebates from local electrical utility companies. The initial cost and installation of a heat pump water heater ranges between $1500 and $2,000. Professionals can search The Database of State Incentives for Renewables & Efficiency (DSIRE) to find dollar saving programs. DSIRE is "a comprehensive source of information on state, local, utility, and federal incentives and policies that promote renewable energy and energy efficiency. Established in 1995 and funded by the U.S. Department of Energy, DSIRE is an ongoing project of the N.C. Solar Center and the Interstate Renewable Energy Council." By choosing the energy efficient database and their state, the professional will receive up to date information on numerous financial incentives. Many of the utility rebates benefit both the builder as well as the owner for new construction and replacement in an existing home. For example DSIRE currently shows $1,000 rebate for residents of Massachusetts and Rhode Island who are customers of National Grid, NStar, Western Massachusetts Electric, Unitil, and Cape Light Compact. Similarly, a $650 credit on the energy bill is available for customers of the Orlando Utility Commission (OUC) and $700 for Gulf Power customers.

In many cases, the operating cost savings alone will eventually pay for the heat pump water heater in a few years. . Obviously, the use of rebates and other incentives not only offset the initial cost of the units, they also dramatically shorten the payback period. Given an estimated energy savings of $320 per year, the payback  could be as little as 1 -2  years, providing pure additional household savings in the following years.