Electric Consumption of Water Heater With Heat Pump

[frankge]

In Florida, my heat pump WH keeps me below my consumption limits. Its also cools my garage so I can "add" the cost savings of buying and running a minisplit. My garage is considered another room in my house. What's even better is I found an 80 gallon AO Smith for $150.00 and its been running for 4 years! If it went I'd get another. During our "Winter" I'll run it in resistance only mode if it gets cold in the garage.

BTW - according to my Sense monitor its using 816 watts right now.

[jovenac]

We will install solar this year. We have a gas water heater and I am thinking of replacing it with an electric water heater with integrated heat pump within the next couple of year. In order to size the solar installation with Dependable Hot Water in mind, I need to know about how much kWh such a water heater will consume. Are there some guidelines? Unfortunately, I don't know how many gallons of hot water we consume, only how many gallons of cold water.

A typical integrated heat pump water heater uses roughly 2–5 kWh per day per person, depending on usage and climate. A practical sizing rule is about 0.1–0.15 kWh per gallon of hot water produced, or roughly 10–20 kWh/day for an average household of 2–4 people. For solar planning, it’s usually safe to assume around 3–5 kWh per person per day as a design estimate.

[Rade]

We migrated from an oil-burning hot water tank to a heat-pump version. I keep the tank in heat pump mode; the settings are "Electric" (pulling 100% from the grid to heat water), "Hybrid" (combination heat-pump and electric) and Heat-pump (100% through heat-pump), oh, and vacation mode that keeps the temp above 70 degrees if we are away from the house for x-number of days.

I have not seen any increase in electric consumption between the oil-burning usage (used to power the burner and the circulating pump) and the 100% heat-pump mode. Two adults, 2 showers a day, assorted other hot-water usages. When the tank HAD been depleted (the occasion when I decide to soak in a hot tub); recovering was quick.

[jovenac]

We will install solar this year. We have a gas water heater and I am thinking of replacing it with an electric water heater with integrated heat pump within the next couple of years. When choosing a unit it is worth looking at what each heaters manufacturer offers in terms of efficiency ratings and smart controls. In order to size the solar installation with that water heater in mind, I need to know about how much kWh such a water heater will consume. Are there some guidelines? Unfortunately, I don't know how many gallons of hot water we consume, only how many gallons of cold water.

Heat pump water heater rozana 1.5 se 2 kWh use karta hai average ghar ke liye. Solar sizing ke liye 2 se 3 kWh per day ka planning figure rakhna safe hai ghar ki size ke hisaab se. Aapke cold water usage ke baare mein, hot water roughly 15 se 20 percent hota hai total household water consumption ka, toh wahan se estimate kar sakte hain. Aur water heater ko timer pe lagao ke dopahar mein chale jab solar production peak pe hoti hai, isse kaafi farq padega ke aap grid ya battery se kitna lete hain.

[sdold]

Jovenac, why are you typing in Hinglish? Are you working for a business owner who is about to post links to a business website?

[Liam]

Been running a heat pump water heater for a while. What surprised me is how much the actual consumption depends on when you use the hot water. Shifting showers and dishes to the afternoon when the solar is pumping really cuts down on grid pull.
Added a high voltage battery to mine and it’s helped a lot with running everything off solar. This one’s worked well for me:
GRHV-rack-mounted-19-inch-lithium-battery-bank.png

Has anyone else tried timing their hot water use with solar production?

[bcroe]

For 2 houses and 5 decades I have had countless water heater failures,
first leaks, then 3 high efficiency gas units had a high failure rate. The
repair parts for the high efficiency units seem to increasingly become
quite expensive, I hate to think of the cost if I could not do the repair myself.

I very much wish to avoid finding myself in an unexpected crises situation
with no hot water. I already solved that problem with HVAC by decentralizing
to a number of independent mini split heat pumps, with enough extra capacity
to cover a failure thru a winter. After much consideration, I decided to solve
the problem with a life time tank simple electric water heater. These do have
2 heating elements, so I could bypass one until a failure was replaced. I
installed convenient shut off valves to cut off the water while an element is
being replaced, of course a spare is on the shelf.

Energy wise, operational efficiency here has greatly improved since solar was
first installed in 2013. The now excess energy has been partly used by some
luxuries such as running my old central blower 10 minutes of every 30, so my
electrostatic air filter can keep the air free of dust, as well as circulation air in
general. That has worked so well, I am sorry it was not happening most of my
life. When a beam of light slips past a shade, it cannot be seen till you put
your hand in it, as there are no dust particles to reveal it.

Still I estimate my energy surplus is large enough to run a simple electric resistance
water heater, at no cost to me. I would not turn down an opportunity to connect
an external water heating heat pump, but have not been able to get one. For the
future I can imagine a more direct connection between the solar and the heater,
possibly using it as a battery to collect energy now lost to clipping, or just to run
off panels not driving the grid. Have 7 years to think about that for when my Net
Metering contract runs out. Bruce Roe Before.jpg