DHW - Alternates to oil

[hemlock]

Hello,
I would love to eliminate oil from the picture from my house once and for all. Currently, I heat exclusively with wood, but oil (indirect hot water) still heats DHW. Installing a wood boiler is not feasible at present. Are pellet boilers efficient, or even a high efficiency electric? Indirect oil seems very expensive, and I just hate hearing the blower come on. Any suggestions would be welcome. Thanks.

 

[woodsmaster]

I would check into the elec. heater with a built on heat pump. I believe lows offers one. or do a search on the hearh in the green room, or google.

 

[bpirger]

FWIW, the current issue of Fine Homebuilding has a review on the electric water heaters with the built in heat pump.....

 

[in hot water]

Research heat pump water heaters carefully. They produce less BTU compared to a gas or oil fired, of the same capacity, and have some limitations on the location, if you want max. output. At the end of the day they are coal fired (electric) for the most. The FHB article is a god one.

Heat pumps can be expensive to repair, compared to electric elements in electric HW tanks. And I wonder if the tank life expectancy is any longer than a gas or electric. 6-8 years is typical from modern tank style water heaters.

hr

 

[tom in maine]

We are using Geyser heat pump water heaters with our tanks.
They can interface with electric tanks or our tanks. Although our tanks are quite large, the insulation levels allow the tank to
be efficiently heated with the heat pump to just replace the DHW usage during non-heating seasons.

Regardless, the Geyser can be moved from one tank to another. If you are using an electric water heater tank, which would eventually wear out,
the heat pump can be moved to another tank--hopefully one of ours, which will not rust out.

I would consider a stand alone unit, whether it is a Geyser or someone else's. Just make sure that it can be re-used if a tank fails.
There are some stand alone units that will not make the change to another tank.

The Geysers are not cheap, but you get what you pay for.

 

[chuck172]

I'm still burning my tarm for hot water. Twice a week burns get old fast. I don't know anything about heat pumps but how would they work with a basement installation using a superstor h/w tank?

 

[tom in maine]

That would be fine. They are usually installed with 40 gallon tanks. The plumbing is slightly different on some tanks, but it is still cold in and hot out.

 

[Wood Heat Stoves]

have a sunny roof?
solar collectors, insulated holding tank, flash hot water heater to make for any loss

 

[lawandorder]

Chuck172- Im in the same boat not really wanting to burn 2-3 times a week just for hot water so I am running DHW off the oil burner. Anyone have experience with the heat pump DHW units? Are they worth the investment. My current weil storage off of the oil burner is only 5 years old so not like it needs to be replaced but I am still burning oil which I dislike anyway. Thanks

 

[in hot water]

I would like to see solar thermal be required on all new homes. In most of the US and canada a 50% or higher solar fraction is easily obtained. This is affordable and do-able with 2-3 collectors.

Larger arrays tie into hydronic systems nicely, also. Most of the summer months here in SW Missouri my LP fired HW tank is turned off.

hr

 

[lawandorder]

in hot water- do these solar systems tie into existing boiler systems easily? How does costs compare to the other options I am only really worried about dhw over the summer months when the Tarm isnt running. Or will the solar provide actual usable dhw during the winter months also? My concern would be adequate usage with the sun lower in the horizon during the winter I do have southern exposure roof lines off of my garage which is where the boiler and storage is .

 

[tom in maine]

If you are using an unpressurized tank, a solar system can be installed simply as a drainback, using the wood boiler tank water as the transfer fluid.
Two or three 4x8 flat plate collectors will work fairly well to top off the dhw usage in the summer.
If there are long periods of cloudy weather, a small firing of the wood boiler would top things up.

You can tie in with a pressurized system by using a plate hx to interface with your tank.

I find unpressurized systems easier to deal with. (Of course!)

The heat pump can work in lieu of solar collectors or with them. It offers dehumidification and AC where it is located.
The hot water cost in my system is about $20 a month and the basement is dry and quite cool.

I live right on the coast of Maine and it is always humid.
This time of year, the basement and first floor are dry and always comfortable, regardless of the weather.
My only regret was not installing some ductwork to the second floor of our Cape Cod style home to offer 100% AC this time of year.
I will do this, but it is going to be a pain.

I guess you can consider either the hot water or AC/dehumidification as free. The one that is not free costs $20 a month here in Maine
where electricity is 18 cents a kWhr.

 

[dougstove]

Hi;
I am liking my solar DHW panels from Thermodynamic in Dartmouth (installed by www.advancedsolutions.ca).
If you are handy, the installation could be DYI; I helped the crew.
We are getting at least 50% (I think more like 60%) of our annual hotwater, with electric back up for cloudy days.
I have a double tank setup; a pre-heat tank driven by the solar DHW, feeding into an ordinary electric hotwater tank.
It is all in my basement, so the waste heat contributes to keeping it warm (no air conditioning season here).
We are somewhat disciplined about doing laundry on sunny days and putting the dishwasher on time delay so it runs in the afternoon.
It is completely quiet, a big change from the previous oil system I removed. Plus, no ghastly oil tank on the property.
The payback is best if you have a high demand for hot water (teenagers).

 

[rowerwet]

I use my outdoor pellet boiler to pre-heat my hot water during the winter (6 months or so) as I have a tankless hot water heater. If I were you I would put in solar with an electric tankless hot water heater to heat if the solar storage was too cold. everything I read says indirect oil is not good as most of the heat in the oil burner is wasted when just used to DHW