Advice on Electric backup for Oil DHW -- custom setup. - Page 3

> Hi, my house currently has a DHW coil sitting in a relatively OK oil
> boiler (Burnham RSA 110). I put a Hobbs meter on the boiler, and find
> that the thing is blowing somewhere around almost 3/4 gal of oil up the
> chimney in standby losses per day -- that is just the standby usage with
> no DHW or heating load, just to sit there. That is with the Aquastat set
> to 125 for the low setpoint, which is about as cool as I want to get it
> since I like my water to the washer, dishwasher, etc at least that hot.
> So I am thinking about putting in a 50 gal high-efficiency electric hot
> water heater to augment it, so that I can turn the boiler off when the
> domestic heat is not needed, e.g. over the summer. I understand others
> have done this, and have done quite alright saving money with a manual
> switch-over, so that their DHW is electric during the warm months and the
> oil boiler is "off" during the summer months.
> However, being a bit of an engineer, I want to complicate this setup --
> can anyone give me advice or gotchas on my plans?
> - Electric HW heater is on full-time.
> - DHW comes from either electric, or boiler, and is switched by a zone
> valve, e.g. like a Taco 3-way.
> - A second Aquastat / temp switch installed on the boiler flips the zone
> valve to draw hot water from the boiler whenever the boiler temp is over a
> certain setpoint, say 120F.
> - A timer is rigged into the boiler Aquastat, so that the boiler is
> normally off (full cold), but goes on to the lower setpoint (~130F) when
> the timer is on -- this would be for anticipated high hot-water demand
> days / times, I am thinking 2x / week when a lot of laundry is done. The
> boiler is also on to the higher setpoint (~180F) whenever there is a call
> for domestic heating, (of course).
> My aim is to utilize the lower fuel costs of the oil boiler when the thing
> is hot anyways due to a domestic heat call, or at certain limited times of
> the week when it switches on in order to supply a heavy hot-water demand
> (and economize the fuel cost). The aim is to keep the boiler cool, and
> supply hot water from the electric tank, at all other times.
> Kind of different, does anyone see any gotchas?
> And two more questions along this thread, if anyone has any advice.
> - Where can I get an idea of anticpated future electric costs -- I am in
> CT, and pay $0.16 / KWH which is kind of high -- but the price has not
> escalated to the rate that oil, gasoline, etc. have in the last 4-6
> months.
> - Where can I get some info on the standby heat loss from an electic hot
> water heater -- I don't see much on the manuf websites.
> Thanks much for any advice!!!
> T

> > to 125 for the low setpoint, which is about as cool as I want to get it
> > since I like my water to the washer, dishwasher, etc at least that hot.
> > So I am thinking about putting in a 50 gal high-efficiency electric hot
> > water heater to augment it, so that I can turn the boiler off when the
> > domestic heat is not needed, e.g. over the summer. =A0I understand other=
> > have done this, and have done quite alright saving money with a manual
> > switch-over, so that their DHW is electric during the warm months and th=
> > oil boiler is "off" during the summer months.
> > However, being a bit of an engineer, I want to complicate this setup --
> > can anyone give me advice or gotchas on my plans?
> > - Electric HW heater is on full-time.
> > - DHW comes from either electric, or boiler, and is switched by a zone
> > valve, e.g. like a Taco 3-way.
> > - A second Aquastat / temp switch installed on the boiler flips the zone=
> > valve to draw hot water from the boiler whenever the boiler temp is over=
> > certain setpoint, say 120F.
> > - A timer is rigged into the boiler Aquastat, so that the boiler is
> > normally off (full cold), but goes on to the lower setpoint (~130F) when=
> > the timer is on -- this would be for anticipated high hot-water demand
> > days / times, I am thinking 2x / week when a lot of laundry is done. The=
> > boiler is also on to the higher setpoint (~180F) whenever there is a cal=
> > for domestic heating, (of course).
> > My aim is to utilize the lower fuel costs of the oil boiler when the thi=
> > is hot anyways due to a domestic heat call, or at certain limited times =
> > the week when it switches on in order to supply a heavy hot-water demand=
> > (and economize the fuel cost). =A0The aim is to keep the boiler cool, an=
> > supply hot water from the electric tank, at all other times.
> > Kind of different, does anyone see any gotchas?
> > And two more questions along this thread, if anyone has any advice.
> > - Where can I get an idea of anticpated future electric costs -- I am in=
> > CT, and pay $0.16 / KWH which is kind of high -- but the price has not
> > escalated to the rate that oil, gasoline, etc. have in the last 4-6
> > months.
> > - Where can I get some info on the standby heat loss from an electic hot=
> > water heater -- I don't see much on the manuf websites.
> > Thanks much for any advice!!!
> > T- Hide quoted text -
> - Show quoted text -

> ask the electric company about "off peak" metering
>
> Mark