Hot water from oil in the summer time.

[Xringer]

I have this old HS Tarm multi-fuel boiler that we use for heat
(forced hotwater) in the winter and hot water in the summer..

Normally during the summer the boiler was set to about 170 F and left to run all summer.
It used from 1 to 2 gallons of oil a day, depending on hot water demands.


The Mods:

Last winter, I added a 7512 Beckett Heat manager to control the cycle time of the burner,
it cuts down short cycling. It works pretty well during the heating season..

I also replaced the burner control unit with a more modern unit that
does not keep the high voltage spark running during the entire burn cycle.
(Saving on Electricity and wear on the probes. Also cuts down the noise).
Honeywell R7184A1034 M/h R7184a-10
It also has a diagnostic button that flashes an LED to report the brightness
of the flame picked up by the light sensor inside the burner.

After finding the top cover of the boiler always felt warm to the touch,
I installed layered foil-bubble insulation on top of the boiler.
It now feels COLD to the touch! Also added better insulation to many of the
pipes going into the boiler. The rate of cooling is much lower now.

Replaced the oil wasting injector tip with a 1.0 GPH tip, which gives us
lots of hot water within 15 to 20 minutes.

Turned down the max boiler temp to 160 degrees F.
Turned on the aux heat/sani functions on the dishwasher.

Hypermiling the hotwater:
This summer, we are using the switch in the kitchen to control the amount
of time the boiler is burning oil. We call it Hot Water on the demand.

When we need water, we run the burner for 20 minutes (1/3 of a gallon).
That normally provides us with enough hot (and warm) water for the day.
If water was heated during the evening, there is water left over for
showers the next morning and it might not get turned on at all the next day..

Since April, we have used about 1/8 tank of oil (275 gal tank).
Either the meter is wrong, or we have saved a lot of oil this summer!

There is come confusion about the amount of oil used. Since we got the
Short fill up (100 gallons) in April that took the meter to the 1/2 mark.
1/2 of 275 is 137.5 gallons. This week, we got a real fill up.
That fill total was 144.5 gallons.
It seems we were still very close to having 1/2 a tank.?.

I need an SG2 for my Boiler!

[vtec-e]

10/10!! Thats an impressive saving.
I had a similar experience with my boiler last winter. I have an oil fired boiler heating the house and water. I installed a stove in the living room and plumbed it into the heating system to assist the boiler and reduce or eliminate the use of oil. I had it set up so it would heat the return water to the oil boiler and therefore reduce it's oil consumption and still heat the house. It worked well but i found i was losing 7 celsius across the boiler when the stove was doing the heating. The boiler felt warm on the outside so i had to retain this heat. Some leftover attic lagging was duly put to good use and i reduced the loss to 3 celsius. I know i should eliminate the oil boiler when the stove is heating but it just wasnt practical. I wanted one pump doing the circuit as two pumps were opposing each other and radiators were not getting hot due to the system being balanced while on the oil boiler. Anyway, it works well and is heating my house nice and toasty as i type.....with my beer in hand....

ollie

[vtec-e]

Xringer, you may find this helpful:recuperator
http://www1.eere.energy.gov/industry...pdfs/38852.pdf
Recuperator - Wikipedia, the free encyclopedia
I'm dying to try this out and am currently on a search mission for suitable materials to make this. Maybe you have easier access to scrap and a fully functional workshop??

ollie

[Xringer]

Originally Posted by vtec-e

Xringer, you may find this helpful:recuperator
http://www1.eere.energy.gov/industry...pdfs/38852.pdf
Recuperator - Wikipedia, the free encyclopedia
I'm dying to try this out and am currently on a search mission for suitable materials to make this. Maybe you have easier access to scrap and a fully functional workshop??

ollie

I've considered using heat-pipes into my boiler exhaust, but was a bit worried
that if I take out too much heat, will I have enough draft in the chimney?

Anyways, I just saw this AirTap Heat pump thing the other day and found it very
interesting.
Energy Saving Electric Water Heater | Airgenerate.com | Adaptive Energy Solutions

It uses the scavenger method just to pull the heat out of the warm
air floating around in your basement. (and acts as a dehumidifier).

AND then, I read somewhere that the guts of the AirTap is basically a lot like
the guts inside my $79 Walmart window AC unit...

Wait just a second! Yeah, it's a heat pump! How hard would it be to
build one like the AirTap to get hot water, if you already had a 5000 BTU AC unit??
How hard would it be to make a chimney scavenger work with the DIY heat pump..
(Instead of using the geo-thermo of your 50 degree basement)..

It would exhaust a blast of cold air.. which you might not want in the winter.
But, that might be useful in the summer..
Selective venting would work..

[Ryland]

our LP gas hot water heater has an exhaust fan on it that has to come on first, if the fan isn't on then gas will not turn on and the flame will not light, so we have that fan on a simple Christmas tee light timer that comes on at 6am and turns off at 8am, leaving us with hot water all day until 2pm when it comes on again for an hour this cut our LP use in half, it would be less but we use LP for cooking as well.
I wonder if you could do something simaler with your boiler, and the timer has an over ride switch so you can turn it on if you wan really hot water at 2am or something crazy.

[Xringer]

Originally Posted by vtec-e

10/10!! Thats an impressive saving.
I had a similar experience with my boiler last winter. I have an oil fired boiler heating the house and water. I installed a stove in the living room and plumbed it into the heating system to assist the boiler and reduce or eliminate the use of oil. I had it set up so it would heat the return water to the oil boiler and therefore reduce it's oil consumption and still heat the house. It worked well but i found i was losing 7 celsius across the boiler when the stove was doing the heating. The boiler felt warm on the outside so i had to retain this heat. Some leftover attic lagging was duly put to good use and i reduced the loss to 3 celsius. I know i should eliminate the oil boiler when the stove is heating but it just wasnt practical. I wanted one pump doing the circuit as two pumps were opposing each other and radiators were not getting hot due to the system being balanced while on the oil boiler. Anyway, it works well and is heating my house nice and toasty as i type.....with my beer in hand....

ollie

Yeah, good insulation works wonders with most heating gear.
We still have a wood stove in the living room.. But it has not been
used in about 20 years..

Back in the 70s, I put three hot water solar collectors on my roof.
I had an 84 gallon tank and heat exchanger in the basement.
The system preheated the cold water input the the Tarm boiler
to a year-round average of 120 deg F. (180 on hot days).

The heat exchanger lasted about 15 years before it started to leak.
The storage tank (an electric HW heater, without the power connections)
started leaking around the same time. After a while, it became too much trouble.
I'm kicking myself now, for not repairing or replacing the bad parts.
The Novan collectors (I gave away) had another 30 years on their warranty.

I was lucky, the typical life span on that stuff around here is about 10 years.

Now, I need to get new shingles on the roof.. So, I'm already thinking about a new set of panels.. Maybe PV this time..?..

[Xringer]

Originally Posted by Ryland

our LP gas hot water heater has an exhaust fan on it that has to come on first, if the fan isn't on then gas will not turn on and the flame will not light, so we have that fan on a simple Christmas tee light timer that comes on at 6am and turns off at 8am, leaving us with hot water all day until 2pm when it comes on again for an hour this cut our LP use in half, it would be less but we use LP for cooking as well.
I wonder if you could do something similar with your boiler, and the timer has an over ride switch so you can turn it on if you wan really hot water at 2am or something crazy.

I don't know squat about gas, but there must be some kind of sensor
that detects air flow or something from that fan..
If that sensor fails to function and the fan isn't on, you might have a problem..


Timer:
My wife and I are retired / not real busy. so just using the clock or cooking timer works for us.

I was planing on buying a programmable timer and found some good ones on the web.
BUT, after a summer of using On-demand, I realized if I had set up a timer
to run 20 minutes every single day, I would have wasted a lot of oil...
Especially when we go on spur-of-the-moment short trips out of town..
The kind of trip that leaves you wondering if you left the back door open.?.

[vtec-e]

Originally Posted by Xringer

My wife and I are retired / not real busy.

I like your style!

ollie (30 years to go)ayres

[vtec-e]

Xringer, re: the draft in the chimmney? I thought of having the chimmney turn down to vertical so it exits the boiler house at the ground. Then i could take all the heat i am able to, and now and then, sweep out the soot from the flue. Sounds good in (my) theory but i'm open to suggestions. I'm all for taking as much energy as possible at the expense of a little work now and then. Anyway, as my dad used to say, "if you were working, you wouldn't be cold would you?"

ollie

[Xringer]

Originally Posted by vtec-e

Xringer, re: the draft in the chimmney? I thought of having the chimmney turn down to vertical so it exits the boiler house at the ground. Then i could take all the heat i am able to, and now and then, sweep out the soot from the flue. Sounds good in (my) theory but i'm open to suggestions. I'm all for taking as much energy as possible at the expense of a little work now and then. Anyway, as my dad used to say, "if you were working, you wouldn't be cold would you?"

ollie

When you get too old and beat to work, then it's time to get a
nice sleeping bag to keep you warm on those cold days..

My wife has been having hot flashes for about 8 years now, so she has
no interest in having a back-up sleeping bag.. (I've got mine)!

Anyways, I know very little about chimney draft,
but I think it has to be going up (since hot gas rises) and should be a path of low air resistance..
Low drag. (At least on oil, wood & coal fires)..

Someone told me, as the chimney liner heats up, it induces more draft.
Once the burner goes off, it seems like that hot chimney liner wants to
suck air outdoors from the boiler.. (Cooling it off).

So, they make this gizmo that can be installed in the boiler exhaust,
that cuts off the flow, once the burner has shut down.

But, there is a certain risk inherent in the design..
If it fails to open fully, your house might suffer a smoking up..
And of course everyone might get killed by Carbon monoxide..

Be very careful making mods to chimneys. Consult an expert or two.