Building Reserve and Using KWH

[azdave]

Seems like a logical use of excess kWh to pre-heat the water to the propane fired WH. I've been able to eek more years out of my water heater tanks by changing the sacrificial anode every 2 years regardless of whether I think they are due or not. Too many variables to know if that is really why mine last longer than the neighbors but some of them get leaks at 5-6 years and I've gone over 10 years so far.

Building kWh Reserve?
This was (and still is) a brutal summer here in Phoenix but we've made it though the worst of it without having any billable energy. We had less than 45kWh in reserve (1 day supply in the summer) as we ended August and only built up the reserve a measly 13kWh more after September. We've had 50 days over 110F and will very likely beat the all time record of 143 days above 100. Might not see a day below 100 here until Oct 11. Our mini-split in the master bedroom saved us for sure from purchasing energy this summer.

[J.P.M.]

My latest PoCo bill shows a winter reserve built up to 13,000 KWH, running with my best past
years. I was sort of hoping for a week of good sun to make it the highest ever, but that seems
unlikely. Rather optimistic, since the heat pump in the car shop is now on line. I collect energy
all year, but the reserve usually usually peaks about 1 Nov, with limited sun and increasing
heating load. System efficiency is as good as ever, now with my peak AC losses over the long
run from the inverters to the PoCo meter at around 1%, and with even better efficiency under clouds.

With annual generation running near 20% in excess of consumption here, the thought is of adding
an electric water heater. The 3rd water heater I have had in 16 years uses propane I paid $1.09
a gallon for this summer, avoiding any winter purchases at up to a manipulated $5 a gallon. The
propane heater is vented, and I note cold air back feeding through it into the house winters when
not running.

To begin the trial, cold water might come into the electric heater, then feed the input of the propane
heater. If I got hit with a supper cold winter eating my KWH reserve, the electric water could be
shut down for a while. Perhaps if this proves to be a very rare situation, the propane water heater
will disappear.

I would like to limit the too frequent heater replacement, maybe a glass tank like marathon 40
gallon lifetime electric water heater would be the answer? I read of heat pump water heaters, but
in winter I would just have to replace the heat inside the house anyway, is that really an advantage?
There is always the thought of an incoming pipe running just under the quite hot roof peak in my attic,
but that requires either seasonal management, or the big complications of a system with antifreeze.

Bruce Roe

Any measures considered that would lower the DHW usage or lower line or standby losses ? You won't heat what you don't use.

[bcroe]

Any measures considered that would lower the DHW usage or lower
line or standby losses ? You won't heat what you don't use.

I try to improve a weaker link every year, and there is opportunity in the hot water sys.
The PO was apparently an even worse plumber than me, pretty bad. I found one HW
copper pipe that actually wrapped around and crossed itself, and the leaks I have repaired.....

Part of the problem is a narrow ranch with a 37 deg bend in the middle, and a stairway at
that point make it difficult for utilities to pass there. So all the pipes have the furnace air
ducting passing underneath, making access extremely difficult. I may need to make the
ducts removable or just move the furnace to solve the problem, has not been used in a
while.

With only a couple people and limited laundry, I do not think the quantity of hot water used
can be reduced. Dishwasher runs 2 or 3 times a week. What I do think could improve is
pipe insulation. When I started out with a lot of resistance heat, the water just helped out
for many months, but now with Heat Pumps it is looking inefficient. The big box snap on
insulation is tightly wrapped to keep it in place, unlike that I removed. But it is quite warm
to the touch. I noted the 1 inch foam I attached to garage doors is never cold to the touch
despite outside cold. The thought is get the pipe straightened out, then mill a deep slot in
inches of that foam to push over the pipe. Then a flat foam piece would be friction fitted
into the grove. My recirculating return line would be strapped directly to the main pipe and
included in the foam groove. This is about as far as the thought has gotten to date.
Bruce Roe

[J.P.M.]

I try to improve a weaker link every year, and there is opportunity in the hot water sys.
The PO was apparently an even worse plumber than me, pretty bad. I found one HW
copper pipe that actually wrapped around and crossed itself, and the leaks I have repaired.....

Part of the problem is a narrow ranch with a 37 deg bend in the middle, and a stairway at
that point make it difficult for utilities to pass there. So all the pipes have the furnace air
ducting passing underneath, making access extremely difficult. I may need to make the
ducts removable or just move the furnace to solve the problem, has not been used in a
while.

With only a couple people and limited laundry, I do not think the quantity of hot water used
can be reduced. Dishwasher runs 2 or 3 times a week. What I do think could improve is
pipe insulation. When I started out with a lot of resistance heat, the water just helped out
for many months, but now with Heat Pumps it is looking inefficient. The big box snap on
insulation is tightly wrapped to keep it in place, unlike that I removed. But it is quite warm
to the touch. I noted the 1 inch foam I attached to garage doors is never cold to the touch
despite outside cold. The thought is get the pipe straightened out, then mill a deep slot in
inches of that foam to push over the pipe. Then a flat foam piece would be friction fitted
into the grove. My recirculating return line would be strapped directly to the main pipe and
included in the foam groove. This is about as far as the thought has gotten to date.
Bruce Roe

Sounds (Reads) like you've got a cross between a rat's next and a Rube Goldberg system for some of your piping.

On the temps of insulation surfaces: The pipe insulation outside surface is hotter/warmer relative to the interior side of the garage door insulation most likely because:
1.) The DHW temp. is most likely a fair amount warmer than the conditioned space the pipe is running through compared to the temp. diff. between the garage interior and the outside environment.
2.) Unless it's the black, closed cell foam ("Armaflex" type stuff), the stuff on your pipes is probably the cheap "Frost King" stuff which is mostly crap. Additionally, it's probably ~ 1/2" thickness or less, or ~ 1/2 as thick as the 1" garage door insulation thickness. BTW, warping compressible insulation too tightly will reduce its thickness and so decrease its effectiveness. Just close the seams as best as possible but don't "snug up " compressible insulation. FWIW, I use 1" Armaflex on all the hot water runs and wrap it completely with aluminum tape (note: NOT duct tape).

My tank and piping are pretty well buttoned up - the piping as described above and an additional 6" fiberglass around the tank w/2" rigid polyurethane foam top and bottom. My total annual DHW load is ~ 2675 kWh/yr. (~ 9.1 MM BTU /yr.), with ~ 90-95 % of that load met with ~ 5.5 m^2 of solar thermal in any given year. Of the 2,675 kWh/yr. total DHW load, the tank standby losses and piping losses are ~ 1,250 - 1,300 kWh/yr. All that comes down to if your usage and piping lengths are somewhat like mine (which sounds likely), your tank standby losses and piping losses are probably as great or greater than your actual DHW loads.

[bcroe]

Finally got a prediction of 10 days with a lot of sun. Not cloudless, but this array can
deliver very substantial energy even under lighter clouds. Meter spinning today.

The propane for drying clothes, Hot Water, and leaks amounts to 271 gallons a year.
Have fixed more than 1 leak, hope that is now zero. The (now backup) propane furnace
has not run in a while. Multiplying 271 g/y by 27 KWH per gallon, and times 0.8 burner
efficiency, comes to 5850 KWH per year, my guess mostly for the HW. That in turn can
be broken into actual use and standby losses. That is more than my KWH surplus, so
efficiency improvement would be good.

The HW source is reading 105F, insulation about 82F, basement air around 70F. The
door foam may be in 60F air, other side 0F, still it does not chill the finger. No Armaflex
was used in 2004, at $1 per foot would consider that in the future. My duct tape assured
the cheap insulation would at least stay in place and sealed longer, not adding any
thermal properties.

Heat Pump water heaters probably ARE NOT the inverter driven variable speed compressor,
COP approaching 4, that my house HPs are. So I am avoiding them for now.

The temp in the attic peak needs to be monitored over days and season, to determine
just how much time it is far above the 55F incoming water. If that time is substantial,
it could be used, and be bypassed and drained for the remaining time.

For the moment, an electric water heater would at least let me consume my annual
KWH surplus and save propane, even if not a 100% changeover. A non vented
electric clothes drier would be the other item, except they are pretty small.

For the future, I need to figure out how to make the furnace air ducting easily removable,
then redesign the revealed hot water pipes for minimum length and max insulation. Not
likely this year though. Bruce Roe

[DanS26]

I use a Nyle system. I only run it during late spring, summer and early fall. It is also on a timer so that it only operates during daylight hours. In the warm months it will use ~50 to 60 kWh per month and generate most of our hot water requirements.

Very efficient and quiet. Since it is also rated as a one ton AC I have it connected to the cold return duct work but as you see I also installed a louver to redirect the cold air during late spring and early fall when the house is too cool for additional AC.

CIMG0870.JPGCIMG0871.JPG

[bcroe]

I use a Nyle system. I only run it during late spring, summer and early fall. It is also on a timer so that it only operates during daylight hours. In the warm months it will use ~50 to 60 kWh per month and generate most of our hot water requirements.

Very efficient and quiet. Since it is also rated as a one ton AC I have it connected to the cold return duct work but as you see I also installed a louver to redirect the cold air during late spring and early fall when the house is too cool for additional AC.

I see a claim of COP up to 5, impressive. Is the room supplying source air? Bruce Roe

[DanS26]

I see a claim of COP up to 5, impressive. Is the room supplying source air? Bruce Roe

Yes, that is why I only run it during warm weather. Nyle has discontinued this model will replace with the C-8 series. Not sure when.

I self installed the unit April, 2012. About 2 years ago a relay failed but that was the only maintenance I have performed on the unit in eight years. Very pleased with its output and operation. I monitor the operation of the unit with the Sunnovations Ohm Monitoring system....

http://ohm.sunnovations.com/

The Ohm system is really to monitor solar water heating but I hacked it monitor the Nyle. I get great information about my Nyle performance....top of tank temps, input and output temps, graphs of enthalpy, etc.

Best part about the whole installation is the cost. I purchased the unit for $900, my REMC gave me $300 for installing a heat pump, and the IRS gave me another $300 for installing efficient energy equipment. My out of pocket was only $300.

[bcroe]

Yes, that is why I only run it during warm weather. Nyle has discontinued this model will replace with the C-8 series. Not sure when.

I self installed the unit April, 2012. About 2 years ago a relay failed but that was the only maintenance I have performed on the unit in eight years. Very pleased with its output and operation. I monitor the operation of the unit with the Sunnovations Ohm Monitoring system....

http://ohm.sunnovations.com/

The Ohm system is really to monitor solar water heating but I hacked it monitor the Nyle. I get great information about my Nyle performance....top of tank temps, input and output temps, graphs of enthalpy, etc.

That Ohm monitor looks a bit more complex than I need. I did add temp readouts with the circulator
in 2005, switch selects points monitored. Based on the LM135 linear temp sensor.

The Nyle appears to be connected to a propane water heater at the pressure valve and the drain, the
regular plumbing left alone? Guess it would work on an electric heater as well, how it it determined if
the heater or the Nyle should run? Perhaps I should try that approach first, then switch to an electric
water heater. Bruce Roe

HotWatCirc.png

[DanS26]

That Ohm monitor looks a bit more complex than I need. I did add temp readouts with the circulator
in 2005, switch selects points monitored. Based on the LM135 linear temp sensor.

The Nyle appears to be connected to a propane water heater at the pressure valve and the drain, the
regular plumbing left alone? Guess it would work on an electric heater as well, how it it determined if
the heater or the Nyle should run? Perhaps I should try that approach first, then switch to an electric
water heater. Bruce Roe

The Nyle works well with either gas or electric WH. The plumbing connections are all with the drain assembly at the bottom of the heater. The temp sensors are also on the bottom for the Nyle. The Ohm monitor has top of tank sensor at the pressure relief valve and a couple for the input and output on the Nyle unit.

As usual I modified the systems to my preferences. The propane heater is a power vent model which makes a little noise when operating. No problem during the day but at night I can hear it run. So I just put it on a timer system to only operate during waking hours. If some family member wants to take a long hot shower in the middle of the night.....that's their problem if they run out of hot water. They have been forewarned of how I value my sleep.

My timer is a dual throw system which controls both the WH and the Nyle and thus will keep them from running at the same time. So here is the schedule....

Warm weather schedule:
6am to 8am WH
8am to 4pm Nyle (ie solar powered)
4pm to 10pm WH

Cold weather schedule:
6am to 10pm WH

The beauty of a gas power vent WH is that when the power is cut the heater shuts down thus I can control the WH with a simple 120v low amp timer. An electric WH would require a much more robust 240v high amp timer switch or some type of relay system.

I've also added some safety to these dual systems since I am relying on timers to control things. The TMP valve is good but I don't want to rely entirely on it so I installed another high temp switch which will shut down the system if it senses a too high temp at the tank top. Probably not needed but I don't skimp when it comes to safety.

[bcroe]

My timer is a dual throw system which controls both the WH and the Nyle and thus will keep them from running at the same time. So here is the schedule....

Warm weather schedule:
6am to 8am WH
8am to 4pm Nyle (ie solar powered)
4pm to 10pm WH

Cold weather schedule:
6am to 10pm WH

The beauty of a gas power vent WH is that when the power is cut the heater shuts down thus I can control the WH with a simple 120v low amp timer. An electric WH would require a much more robust 240v high amp timer switch or some type of relay system.

Perhaps I might run a Nyle 8 months a year, but with net metering a Nyle
could be on continuously. No time of day difference, just save energy. Too late for
this net metering year, should plan for spring.

Does the Nyle do anything about a moisture drain like a dehumidifier? Maybe turn off my
dehumidifier when it is operational? Now there is an energy opportunity. Bruce Roe

[DanS26]

Perhaps I might run a Nyle 8 months a year, but with net metering a Nyle
could be on continuously. No time of day difference, just save energy. Too late for
this net metering year, should plan for spring.

Does the Nyle do anything about a moisture drain like a dehumidifier? Maybe turn off my
dehumidifier when it is operational? Now there is an energy opportunity. Bruce Roe

Yes it does dehumidify the air in my basement and I have it plumbed to the basement drain system. It keeps my basement very dry in the spring and summer. Some people collect the water and use it for mineral-less water purposes such as batteries or steam irons......it is basically distilled water.

If you run it in cold weather the heat it takes out of the air and puts into hot water has to come from somewhere....and that will be your furnace or other heat pumps. If you vent it inside and outside in the winter I think you would lose a lot of efficiency. I also do not want to dehumidify my interior air in the winter time. So a few good reasons not to run it in the winter.

I received this message from Nyle.......

"Thank you for contacting Nyle Water Heating Systems about the Nyle Geyser heat pump water heater. We are excited to tell you that the Geyser is currently out of production for a short period of time while we upgrade the controls to a new, digital platform. Water heaters with the new controls platform will become available in early 2021.............."

So it looks like they are getting close to releasing the new product design.

[bcroe]

"Thank you for contacting Nyle Water Heating Systems about the Nyle Geyser heat pump water heater. We are excited to tell you that the Geyser is currently out of production for a short period of time while we upgrade the controls to a new, digital platform. Water heaters with the new controls platform will become available in early 2021.............."
So it looks like they are getting close to releasing the new product design.

The usual digital model is just a cost cutting and making it vulnerable to hacking. I
ought to try and find one of the older units, what is your model no? I already got a
set of replacement inverters for when mine blow up, do not want the later model.

I cannot believe all the software and monitoring swirling about so many small systems,
but I hardly ever hear of someone trying to make theirs work better. Bruce Roe

[J.P.M.]

The usual digital model is just a cost cutting and making it vulnerable to hacking. I
ought to try and find one of the older units, what is your model no? I already got a
set of replacement inverters for when mine blow up, do not want the later model.

I cannot believe all the software and monitoring swirling about so many small systems,
but I hardly ever hear of someone trying to make theirs work better. Bruce Roe

Apps are easier to create than good engineering. A consequence of the great dumbing of America.

[DanS26]

The usual digital model is just a cost cutting and making it vulnerable to hacking. I
ought to try and find one of the older units, what is your model no? I already got a
set of replacement inverters for when mine blow up, do not want the later model.

I cannot believe all the software and monitoring swirling about so many small systems,
but I hardly ever hear of someone trying to make theirs work better. Bruce Roe

When one of the relays failed a couple years ago I opened the box to see how it worked. I thought it was well engineered and built with quality parts. There is a lot going on in that small package.

I did notice one interesting electrical aspect about the product that intrigued me. Some of the circuits were controlled by switching the neutral as opposed to switching the power. I even talked to an engineer in the company to verify that they really designed a product with a switched neutral. I think the new product design will fix that questionable feature.

Good luck finding one of these older Geyser units.....they don't break down very often.