Domestic Hot Water.

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peakbagger said:
Many experts are shifting away from recommending solar hot water panels. The current consensus is to install a heat pump hot water heater and some solar panels set up with net metering. .
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No authority has say over solar thermal. Getting the OK for a grid tie PV is becoming a nightmare. Not to mention the cost.
peakbagger said:
If you do want to look at SHW, you need to look at evacuated tubes versus conventional flat plate. .
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We get at least one hail storm per year and they don't make tempered glass or polycabonate evacuated tubes.
peakbagger said:
Flat plates at best raise the water temp 70 degrees. Evac tubes are far more expensive but they can boost water 140 degrees so they can cover you in the winter.
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The costs of boosting water temperature for 3 months from a flat panel is trivial.
Top performance isn't everything. DIY flat panel based systems sheds snow, cheap, tough, no monitoring needed and seldom need repair.
 
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Enzo's Dad said:
I hate my boiler running in the summer, however i started reading about Indirect water heaters tied to the boiler, This may be the best use of money.
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Again, I think that 90% of indirects on oil boilers increase standby losses, which are currently prob 75% of your operating costs. I wouldn't trust your oil company or techs to give reliable info on this. The exception would be if you had a very fancy modcon boiler, which do not seem very common in the US; nice tech but expensive fuel.

This 'standby' thing is not well understood or appreciated. In the summer, your DHW is not what is driving your oil usage. I put a timer on my boiler, and was using about 1.3 gallon of oil per day. When I went on vacation (no DHW), the boiler still used 1.1 gallons/day!! Its a double whammy...not only is oil a really expensive fuel, but you are wasting 3 gallons for every gallon you use to heat water.

Even at 18 cents, a properly insulated (2" foam) electric tank heater, and shutting down the boiler in the summer will likely reduce your DHW costs from >$1000/yr to more like $500-600. While 18 cent elec is maybe 70-100% more $ per BTU than oil, the low standby makes it cheaper.

A HPWH like the geospring will cost maybe $500 more than a conventional tank at purchase (less whatever rebates you can find), but will cost half as much as the conventional electric to operate, prob less than $300/yr.

Commercial solar DHW can easily run $5-10k installed, and will have an operating cost not much better than the HPWH (on the East Coast), like $200-300/yr, for conventional electric backup in the winter. I can't see why anyone would choose that over a HPWH.
 
Circus said:
No authority has say over solar thermal. Getting the OK for a grid tie PV is becoming a nightmare. Not to mention the cost.

We get at least one hail storm per year and they don't make tempered glass or polycabonate evacuated tubes.

The costs of boosting water temperature for 3 months from a flat panel is trivial.
Top performance isn't everything. DIY flat panel based systems sheds snow, cheap, tough, no monitoring needed and seldom need repair.
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Um. The OP didn't say anything about spending thousands on solar, thermal or PV.
 
My cold start boiler was going cold for long stretches during the winter, (note, I said WAS, as in last winter), and so, it would have similar wasteage to the summertime. I figured the cheap water heater was worth a shot. If my utility dangled a big rebate, then I'd think about a hpwh more I guess. I've insulated the walls in my basement and the joists already had insulation, so I am not sure how the thing would work down there.
 
velvetfoot said:
My cold start boiler was going cold for long stretches during the winter, (note, I said WAS, as in last winter), and so, it would have similar wasteage to the summertime. I figured the cheap water heater was worth a shot. If my utility dangled a big rebate, then I'd think about a hpwh more I guess. I've insulated the walls in my basement and the joists already had insulation, so I am not sure how the thing would work down there.
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I have spray foam in the basement and its finished, so i am not sold on the HPWH yet.
 
how big is the boiler room?
 
woodgeek said:
how big is the boiler room?
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I really need to take pictures of that. the guy that built the house had the concrete pored so that there is a room under the back porch. 4 ft by 20ft
 
Circus said:
Enzo's Dad needs to shut down the oil fired boiler in non heating seasons. Any other water heating scheme is preferable.
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Thats my thought, just need to figure out the best alterative. On paper solar and hphw look good, but i would be 8 years before i would recoup the cost.....if money were no object i would go geo thermal
 
Trying to follow this discussion about indirect DHW with oil boiler, and it sounds like some may be conflating indirect with tankless coil. They are two different systems. Indirect oil systems usually use a small well insulated 2" foam SS tank on a separate priority zone. The boiler fires to circulate water in the coils in the tank in the non-heating seasons only when the water temp in the insulated tank drops, mostly only when HW is used. If no HW is used the boiler eventually cools to room temp with a cold start boiler set up.

With tankless coil, the boiler is maintained to appx 160F year round and fires to maintain temp from standby losses in the boiler and when HW is used. With this type of system an electric resistance DHW tank may save energy in the summer vs. the tankless coil.

With indirect, if the boiler is efficient, there's generally no savings with a separate electric resistance DHW tank in the summer, though HPWH might be different.

Still according to this http://energy.gov/energysaver/articles/tankless-coil-and-indirect-water-heaters

With a cold start efficient boiler, indirect may be the least expensive option.
 
velvetfoot said:
Metal and circulating warm up, then cool down, stack loss. It adds up.
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My last two houses had an indirect hot water heater. Looked just like the diagram on the energy .gov web site This is a coil, the minute I start a shower the boiler kicks on . and if multiple zones are calling for heat ..good luck getting any hot water. It would be 899 plus install for this system
 
Can the oil boiler be set up to be cold-start? Make, model and year?
 
boomhour said:
Not sure if any have come across this water heater , suppose to come on line in May

http://www.kickstarter.com/projects/1132758406/heatworks-model-1-your-next-water-heater
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First I have seen it, thanks for sharing!

Interesting idea, but Im not sure how I feel about the "heats via the resistance in water". I could see issues if you had really pure water without any "stuff" in it to create resistance. I also think that unless you hook it to a 220 30 amp breaker, you wont get the full output, which will make some people grouchy if they think they will get the same results with a 120v 15A circuit. (Not people here, but general buyers).

I would like to see one in action once they hit the market.
 
I have a 30 Gallon electric water heater with 5 people on it for the last 20 years. I dont even notice a change on my light bill as i switch from boiler hot water to electric in summer. I imagine the 30 Gal is only using as much as the fan and motor on the boiler so its a wash.
 
Clarkbug said:
First I have seen it, thanks for sharing!

Interesting idea, but I'm not sure how I feel about the "heats via the resistance in water". I could see issues if you had really pure water without any "stuff" in it to create resistance. I also think that unless you hook it to a 220 30-amp breaker, you won't get the full output, which will make some people grouchy if they think they will get the same results with a 120v 15A circuit. (Not people here, but general buyers).

I would like to see one in action once they hit the market.
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I, too, have some reservations on its performance capabilities. My well water is about 49 F and I would think it would be using most of that 30-amp breaker at shower time. But the 120v 15A heater would do well in the R V and boat market would be at the top of the list for my boat. The 15 amp model could be used in small business. i.e filling hot tubs, pressure washer, etc. I hope to see it on line soon. I wonder if Home Depot would pick something like this up?
 
boomhour said:
I, too, have some reservations on its performance capabilities. My well water is about 49 F and I would think it would be using most of that 30-amp breaker at shower time. But the 120v 15A heater would do well in the R V and boat market would be at the top of the list for my boat. The 15 amp model could be used in small business. i.e filling hot tubs, pressure washer, etc. I hope to see it on line soon. I wonder if Home Depot would pick something like this up?
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Seriously? They do. On demand electric water heaters of many wattages and voltages have been available for many years.
 
Yes they have, and I have looked into them about 5 years ago, but were not recommended for my area . We have a heavy snow cover right now and my water temp is up, has been as low 44 F. Seriously.
 
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