Ge Hybrid VS. Oil

traderfjp

Hi,



I'm trying to figure out if I'm better off keeping my oil fired hot water heater or buying an Electric Hybrid Unit from GE.

I currently have a Boch oil fired Hot Water heater that is close to 20 years old. Last year I replaced the anode rods and the retention head was replaced 3 years ago. The tank seems to be in good shape but it's hard to tell.



I live in NY so electric rates are about 18 cents a KW and no discount for off peak unless you're a business. Oil is about 3.80 a gallon. I use coal to heat the two top floors of my house. 

I use the basement as a living space so my boiler is kept at a lower temp and doesn't run much so an indirect tank wouldn't make sense. I even have a S.S. coil in the fire box of the coal stove which pre-heats the water in the boiler. My boiler room stays around 80 degrees in the winter and about the same in the summer (on average).



We have 3 adults in the house and 1 teenager in H.S. The teenager takes 15-20 minute showers and then my wife follows (10 minute shower) after her and I shower about an hour later. (10 minutes).



I'm concerned that we will be running out of hot water with the GE heat pump water heater unit and that I might not be saving any money by converting from oil to electric. 



My options:



1. Stay with what I have and be a hostage to high oil prices. If they get too high I can go electric down the road. (NG is not an option)



2. Install the GE heater in series with my current oil fired unit until my daughter leaved for college in 2 years and then our showers will be spread apart more.



3. Take the plunge and install the new GE water heater and don't look back but if showers are miserable I'll be re-installing the oil unit (my best guess).

4. Do nothing

Unknown

Nyle Geyser

is a standalone heatpump which can be interffaced with any tank so if tank leaks, tank alone can be changed. If configured with electric, the HP will crank ~7kBTU/hr & will interact with heating elements for faster recovery. Also dehumidifies as it heats water. Local built a cooler on the cold dump side.

icesailor

Hybrid Oil:

If you have a Bock oil fired water heater 20 years old, it is living on borrowed time and is on life support and you don't know it.

If you use an electric hot water heater, a 4500 watt element will recover 18 GPH. It doesn't matter that there are two elements in the tank, only one runs at a time.

The GE combo unit (in my opinion) is rated (?) at 7 KW. That's a little more than your element in the tank which is probably 4.5 KW (4500 Watts). If it is a heat pump driven ( by a compressor, you need to calculate the cost of compressing all that refrigerant

In my opinion, a far better choice (from what you describe), would be a gas water heater. A 30, 40 or 50 gallon gas water heater are fired at around 36,000 BTU's per hour and recover 36 GPH. You are better off going to LP. You can have a tank and have delivery like your oil. If you use a 30, 40, 50 or 80 gallon electric water heater, it will still only recover 18 GPH.

If you crunch numbers, you can buy a lot of competitive gas water heater for the price of a combination electric/heat pump water heater. It is still heated by electricity. The most expensive way to heat water. 

If you really want to do it right, put in a Vitodens 100 and an indirect or a flat plate heater. Then you are set to move up in the world.

NRT_Rob

first off

a bit depends on your showerheads. you have 40 minutes of full shower draw/day? that's 40 gallons of hot water difference between regular and low flow heads. about 20kBTUs per day. with a 0.65 EF water heater that's a gallon of oil every 5 days or about 0.75/day if you don't have low flow and can switch.



it also takes your peak demand to 45 gallons which would likely be in range for heat pump water heater to service by itself.



Secondly, the heat pump runs at about a 2.3 COP or so. that's about 435 BTUs per penny at your current rates.. Oil at $3.80 and 0.65 EF is only 280 BTUs per penny. Propane is unlikely to be much better, if any, than the oil price.



I would say low flow head and the heat pump water heater and you should dramatically slash your domestic hot water bill.

traderfjp

Still Confused

My shower heads are just under 2 gallons per minute.  That is very accurate since I just measured the flow of each shower head.  NRT_Rob:  I agree that my water heater may be on its last legs.  The tank is glass lined and the anode rods were just replaced.  The old ones didn't have much left.  Do you think I'll run out of hot water and then have to use the 4500 watt element?  If so I'm thinking that oil may still be cheaper.

NRT_Rob

even with no input

a 50 gallon hot water heater can cruise through a 35+ gallon demand.



if you have 2 GPM per shower, and it runs for 30 minutes straight, that's sixty gallons.



A switch of heads would save you 15 gallons, and you'd be in range for the heat pump to be definitely ahead.



without a switch, not unless there is an 80 gallon model.

icesailor

Hybrid Vs Oil:

You will never get the hot water performance from the heat pump.

If you got 20 years out of a Bock Oil fired WH, you are way ahead of the game. Consider buying another Bock.

If you are willing to buy a heat pump heater, consider buying a Veissmann Vitodens 100 and a small indirect. It will heat water ion the cheap and save you piles of cash. It will give you a lot of flexibility and it will do heat. It is direct vent/sealed combustion so you don't need a chimney and will run LPG or Nat Gas. You can get outside LP tanks. They are really well priced at this time and is something I would ask you to consider. It is modulating and condensing.

The choices are endless.

NRT_Rob

seriously?

what are you smoking?



the hybrid heater is $1400 online. It will cost less to operate.



A vitodens and indirect is several thousand installed. And propane is even pricier than oil.

traderfjp

Lp not an Option

I have propane and I'm paying 6.00 a gallon.  Propane is very expensive on Long Island. The price goes down to about 3.00 a gallon if you are using it for heat. There are many small independent dealers that sell propane and their prices fluctuate.  I don't want to go that route.

I hate to buy another Boch until I see a leak in my current tank.  If the glass lining is not compromised the tank can go on performing.  I have kept it maintained.  My goal is to get off oil.  However, I don't want to pay more with electricity.  I was thinking about solar but on Long island we have many cloudy days.  If I did solar I would run it on a loop through my current tank and only use it for the summer months. 

I'm still thinking about running the GE hybrid unit in series with my Boch.  I could play with the settings and perhaps bring the aquastat down to about 80 degress and then let the electric do its thing.  The Boch would pre-heat the water so the GE could keep up.

VictoriaEnergy

Not in winter

Don't pick on IceSailor, he just installed his 1st Vito, so he's got that Viessmann Oktoberfest like euphoria thing going on.  Quality will do that to people.



Hybrid HWHs that are located inside the heated envelope of your house should only be run in the back up mode during the heating season.  If you think about it, you are heating your house, and then cooling the house by running the heat pump. 



So to keep things simple, say you're heating your house with electric baseboard heaters.  The room the HWH is in has a 1000 watt heater. That heater runs for 1 hour per day now (1 kw/hr).  Tomorrow you install the heat-pump water heater.  When it runs, it draws 250 watts of power per hour, but it adds the equivalent of 1000 watts of heat to the water.  Sounds great: you invest 250 watts and get 1000 in return.  But the heat pump doesn't create heat, it moves it (hence the name, right?).  So as the heat pump runs it cools the room down.  In turn, the baseboard heater has to run an extra hour for every hour the heat pump runs.  So after you install the heat pump, it runs for 6 hours in a day.  250 x 6 = 1.5 kw/hr used directly, plus the 6 kw/hr extra into the baseboard heater since it now has to run for 7 hours per day instead of 1.  This totals 7.5 kw/hr of power to deliver the same amount of heat you could have got from a standard electric HWH using just the 6kw/hr.



Where these units shine is during the summer when higher ambient temps make the unit run more efficiently, plus the small air conditioning effect and de-humidification is a bonus.



You are also going from one extreme to the other in the recovery side.  In heat pump mode it will be relatively slow to recover, where the nice thing about oil fired hot water heaters is you could water your lawn all day with hot water, if you wanted to.

traderfjp

Not a problem

The hear pump unit would be located in a boiler room that stays hot from my boiler and water that runs to the boiler from my coal stove's coil.  If that rooms gets cool from the GE unit it wouldn't be a problem.

fcrawley

I love my HPWH

I installed a Stiebel Eltron Accelera 300 a year ago and it's great. 80 gallons. 500 watts with a 1700 watt booster. At 80 degrees ambient you will get a COP much greater than 3, almost 4. I have a tempering valve behind it so the heater heats to 140 and the valve is at 118. One night after washing dishes, we had two kid baths, a kid shower and then my wife filled her garden tub about an hour later. I then took a shower and it was still hot. The trick is the tempering valve, which you can use on any heater. It effectively increases the capacity of the heater. I can't say enough good things about this heater. It has the lowest consumption on the market because it has a fixed condenser instead of a pump and heat exchanger like the US models. Go check it out. http://www.stiebel-eltron-usa.com/accelera.html

traderfjp

Update

After a few months with my heater I'm totally satisified and I don't have to buy oil.  The GE came with a 10 year warranty for parts and labor so I stopped looking once I discovered the incredible warranty that was offered with this unit.  I've has 0 problems so far and pleanty of hotwater with 2 ladies and me showering daily.