How to install HPWH?
Given these issues, EPA recommends the following for colder climates: 1 Avoid placing HPWHs in conditioned space if possible. If you must place the unit in conditioned space, do not install it near a thermostat or living spaces sensitive to colder temperatures. 2 Avoid placing HPWHs in garages 4 or outdoors where the temperature can be consistently in the freezing range. 3 Install HPWHs in unconditioned or semi-conditioned interior spaces, such as a basement, where temperatures remain above 50 degrees F most of the year. An ideal situation would be near a furnace in a basement that is relatively warm all winter. 4 Consider HPWHs that meet Northern Climate Efficiency Specification developed by the Northwest Energy Efficiency Alliance (NEEA). NEEA has identified HPWHs that are efficient in colder climates by using a test procedure that uses lower temperature ambient air and inlet water to reflect conditions in colder climates. A prerequisite to qualify for the Northern Climate HPWH Specification is that the units must be ENERGY STAR certified. These HPWH units generally have larger compressors that cut off at lower temperatures to work more efficiently in colder climates. Click here to learn more#N#(link is external)#N#.
Can HPWHs be installed in a conditioned room?
Avoid placing HPWHs in conditioned space if possible. If you must place the unit in conditioned space, do not install it near a thermostat or living spaces sensitive to colder temperatures.
Can HPWHs be placed in a basement?
In colder climates, most HPWHs are placed in unconditioned or semi-conditioned basements. However, if placed in conditioned space, HPWHs will produce cool and dry air that is a benefit in the summer months but will lead to higher heating bills in the winter months. 2.
How many square feet does a water heater need?
While it’s possible to install other water-heating technologies in areas as small as a closet, HPWHs usually need at least 750 or 1,000 square feet. Any location big enough must also be stable in temperature (ideally never going below 40 degrees or above 90 degrees).
How much does an energy star save?
According to the EPA, an ENERGY STAR certified HPWH can save the average family as much as $3,500 over the full duration of its useful lifespan. Advertisement. As an added benefit, ENERGY STAR HPWHs also help save the planet.
How much does an HPWH save?
Those incremental savings really add up over time. According to the EPA, an ENERGY STAR certified HPWH can save the average family as much as $3,500 over the full duration of its useful lifespan.
Why don't homeowners consider HPWHs?
Some homeowners don’t even consider HPWHs because the technology requires a relatively large up-front investment. The purchase price of a HPWH typically runs three or four times higher than a conventional model. To fairly judge the cost-effectiveness of a water heater, however, you must consider the cost of running it as well as the cost of the equipment itself. By virtue of their unparalleled efficiency, HPWHs often cover their extra cost within a few years, and from then on any savings go right into your pocket.
How does a refrigerator work?
While a refrigerator expels hot air from inside its storage compartment , HPWHs accomplish the reverse, pulling heat in from the surrounding air.
How does a water heater work?
Conventional water heaters use energy—usually either gas or electricity—to generate heat. Heat pump water heaters (HPWHs) operate in an entirely different way. They, too, use energy, but not to generate heat, rather to move it from one place to another—from the air surrounding the appliance to the water held in the unit’s storage tank.
Do HPWHs cover extra cost?
By virtue of their unparalleled efficiency, HPWHs often cover their extra cost within a few years, and from then on any savings go right into your pocket. Advertisement. Another important factor to weigh in your decision: There are a number of rebates available to help mitigate some of the purchase price.
What is a heat pump water heater?
Heat pump water heaters (HPWHs) are an energy-efficient alternative to electric-resistance water heaters. Instead of heating water stored in a tank by running electrical current through resistors (i.e., the electric water heater elements), HPWHs use a vapor-compression refrigerant cycle (the same basic mechanism used by standard heat pumps, air conditioners, and refrigerators) to transfer heat from the surrounding air to the water.
Why are HPWHs good for garages?
For this reason, warm climates with lengthy cooling seasons are a very good fit for HPWHs. The efficiency and capacity of heat pumps decrease with decreasing air temperature, so an HPWH located in a garage in a cold climate would have more difficulty producing hot water to meet load when operating in heat-pump-only mode. Nearly all HPWH models in the market come with backup electric-resistance heating elements, which allows them to operate in full electric-resistance mode or “hybrid” mode (i.e., the unit switches between heat-pump and electric-resistance modes as determined by the water temperature). The hybrid or full electric-resistance modes can be used to keep up with high hot water loads (e.g., periods of high hot water draw and/or during the winter for units located in the garage of a cold-climate home).
How does an HPWH condensate?
As the surrounding air is drawn across an HPWH’s evaporator coil and cooled, moisture in the air will condense on the coil. This condensed water must be routed to a drain. If a gravity drain (i.e., floor drain) isn’t possible, then a condensate pump may be needed to move condensate to the appropriate drainage piping (e.g., clothes washer drain). While condensate from gas-fired equipment calls for the installation of a neutralizer, the condensate produced by a HPWH doesn’t need neutralization since it’s non-acidic (i.e., distilled water). An HPWH’s fan and compressor will make noise while operating, [2] so the unit should ideally be located in a place where this noise would not disturb occupants.
What is the efficiency of an electric water heater?
Because electric-resistance water heaters convert electrical energy into heat, their maximum theoretical efficiency is 100% (corresponding to an energy factor (EF) of 1 , or one unit of energy supplied to the water per unit of energy input to the water heater). [1] HPWHs can achieve EFs of greater than 1 because more than one unit of heat energy can be moved from the surrounding air to the water per unit of electrical energy used by the heat pump’s compressor (ENERGY STAR certified HPWHs have rated EFs of 2.21-3.39). [2]
How does an HPWH affect the heat?
During the summer, an HPWH will provide a minor reduction in the home’s cooling load. During the winter, the HPWH will cause a minor increase in the heating load. For a given home, the specific impact on space conditioning energy use depends on the climate, the home’s size and configuration, the location of the HPWH, and the space conditioning systems used. Care should be taken during site selection to ensure that cooled air from an HPWH does not cause comfort issues for occupants, although this issue is generally mitigated by common water heater locations (e.g., basements, storage areas, laundry rooms, etc.) that are not frequently visited by occupants. For HPWHs installed in unconditioned “buffer” spaces (e.g., garages), there is little to no impact (because those spaces exchange heat with conditioned spaces). Garages or basements that are infrequently occupied are good locations for an HPWH since the fan/compressor noise is isolated from occupants.
What is technical validation reference material?
The Technical Validation/Reference Materials section below characterizes Federal appliance standards for residential water heaters to assist in model selection and utility measurement and verification planning and additional resources applicable to HPWHs.
What is the purpose of a heat pump brief?
The intent of this brief is to provide code-related information about heat pump water heaters to help ensure that upon inspection, the water heating system will be accepted as being in compliance with the code. This code-related information is expected to result in increased compliance and timely, less challenging, and more uniform plan review and field inspections for all relevant parties verifying compliance (e.g., code officials, builders, contractors, designers, etc.).
Why are HPWHs taller than conventional water heaters?
HPWHs are taller than conventional water heaters because of the heat pump located on top of the tank. Check manufacturers’ specs before buying; it’s likely that some units won’t fit in a low-ceiling crawlspace.
How does a heat pump water heater work?
To understand how a heat-pump water heater turns 68-degree-or-cooler room air into 120-degree water, there are two facts you have to grasp: First, heat is a measurable unit of energy, and secondly, heat energy always moves from hot to cold.
What happens if my water heater quits?
But when your water heater quits at the end of its 10-15 year lifespan, you might just find yourself standing in a cold shower. Or worse, the heater’s tank has corroded through, turning your basement, garage, or utility room into a soggy mess and running up additional bills for drywall repair and carpet cleaning.
How does a compressor work?
The refrigerant has a low boiling point, and the air’s heat raises the liquid’s temperature enough to turn it to a gas. A compressor then increases the pressure of the gas, further raising its temperature. A pump circulates the tubes filled with hot compressed gas down and around the cool water in the heater’s tank.
What is a heat pump?
A heat-pump byproduct is cooled, dehumidified air. Some models allow you to vent that conditioned air to another room in the house, which can be a boon during summer months, but most models just blow that cooled air into the room where the unit it located. Similar to an air conditioner, an HPWH also produces a small amount of distilled water that has to be directed outdoors or into a drain, a consideration when you’re choosing a location for the heater.
How many calories does a BTU have?
One Btu equals the amount of energy it takes to raise the temperature of a pound of water by one degree Fahrenheit or almost 252 calories. (Burning off the calories from eating a frosted donut is not really related to this discussion.) ...
Why does my hand feel cold?
Your hand may feel cold but only because it has less heat energy in it , and, in fact, the steel has gotten warmer from your touch.
What Are Heat Pump Water Heaters?
A heat pump water heater essentially pulls heat from the air and moves it to warm up water in a storage tank that's accessed every time you take a shower, a bath, or do the dishes. Heat pump technology isn't unusual or difficult to understand because it's the same technology employed in refrigeration systems.
Comparing Purchase and Operating Costs
Every new water heater has a yellow Energy Guide label that displays two important pieces of information.
Heat Pump Water Heater Electrical Requirements
The compressor that powers a heat pump system is basically the same type of compressor that a refrigerator uses, although it's more powerful and consumes slightly more electricity.
Pros and Cons of Heat Pump Water Heaters
Heat pump water heaters offer many benefits to homeowners as well as to the environment, but they aren't without their drawbacks. Whether you're considering one as a replacement for an existing water heater or you're installing one in a newly constructed home, you have a few pluses and minuses to weigh.
Shopping for a Heat Pump Water Heater
If you're considering a new heat pump water heater, you want to take advantage of all possible financial incentives, including a federal tax credit of $300 and other incentives offered at the local level. The best way to guarantee this as well as to maximize your energy savings is to purchase a unit with the ENERGY STAR label.
