Building Reserve and Using KWH

[bcroe]

The info says the units are pre charged for up to 15 feet of line. Since mine are only about 5
feet, about all needed was to vacuum the air out to 500 microns, then release the unit charge.
Bruce Roe

[PVAndy]

Just in time for some 40 F nights, 2 of the 3 mini splits are now operational. The entire house
remained in the 70s, that should be more uniform when the 3rd mini is operational. So far they
are just as everyone says, extremely quiet. That in gross contrast to my earlier technology heat
pump rattling the house (probably poor installation). It broke down every 2 years, and was only
effective down to 20 F. That heat pump and the backup propane furnace both relied on the
house air blower, required to avoiding freezing. Now the minis have de centralized HVAC.

Later the minis should reflect on the KWH reserve generate by the PV solar this summer and
ongoing. The most severe test will be their ability to handle the coldest weather, below zero
here. Several pretty substantial resistance electric heaters remain available, hope they are
not used at all. And the long term question is, how long will the minis last. Bruce Roe

Bruce

Curious,, did you use the factory charge or did you have the lines nitrogen purged and refilled? In many cases the factory charge is not optimum.

I run 4 minisplits and a heat pump pool heater with a 20kW PV system with surplus power banked at the March buyout (which is fixed in Conn)

Andy

[bcroe]

Just in time for some 40 F nights, 2 of the 3 mini splits are now operational. The entire house
remained in the 70s, that should be more uniform when the 3rd mini is operational. So far they
are just as everyone says, extremely quiet. That in gross contrast to my earlier technology heat
pump rattling the house (probably poor installation). It broke down every 2 years, and was only
effective down to 20 F. That heat pump and the backup propane furnace both relied on the
house air blower, required to avoiding freezing. Now the minis have de centralized HVAC.

Later the minis should reflect on the KWH reserve generate by the PV solar this summer and
ongoing. The most severe test will be their ability to handle the coldest weather, below zero
here. Several pretty substantial resistance electric heaters remain available, hope they are
not used at all. And the long term question is, how long will the minis last. Bruce Roe

[azdave]

A few years ago, we installed one at work to supplement cooling in the server room. I think we paid $4500 for the install. It included boring a 8" thick tilt-slab walI, a roof penetration and running extra long lines to get the condenser on the roof of the second story. When I am on the roof, I often can't if tell the compressor is running unless I see the fan spinning. The circulation fan inside the server room is louder than the compressor outside. Hope your's is the silent type too.

[bcroe]

I am running out of other details, about time to do the scary part, hook up the freon and see
if my 3 mini-split heat pumps actually work.

They are mounted well above the snow. I am not expecting a lot of noise from the compressor.
But if the wall transmits too much, I will need to build a ground mount platform the same height.
Bruce Roe

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[bcroe]

Anybody have experience with professional cost to install a Mini-Split, including running
the AC power to a new double breaker? I see the DIY cost as running just under $2K.

Today worked on moving some stuff to make room for the remaining units, moving right
along. Bruce Roe

[bcroe]

The mini split conversion project is moving along, despite the amount of rain received in the last
month. Sure am glad the trench project was finished before that. I see it as being done in 3 phases.

First phase is get the interior unit mounted, which includes drilling a hole through my brick wall that
conducts a pair of 410A freon tubes, a 4 conductor cable, and a drain hose outside. No thermostat
or other interior wiring needed, it has a TV style remote control. Part of the challenge here is spotting
the hole so only one brick is affected. These high tech units even have that little scanner hanging
down, which checks the temp throughout the room, and operates the vent slats to direct air as needed.

A phase is running the 240VAC power out to an outside disconnect box. Earlier this year a 40 breaker
distribution box was added, with all HVAC loads and a few other heavy hitters along with PV solar
transferred over. This provides the space for 3 or more double breakers to feed the minis. This box
runs through a bi directional spinner KWH meter, making it possible to keep track of energy reserve
at any time.

Last each outdoor compressor unit goes onto the wall, with the help of some strong friends, less
than 100 lb. 7 electrical connections are trivial, the only challenge should be properly connecting,
evacuating, and charging the lines to the indoor unit. The compressor unit is already precharged
with enough R410A for a system.

There is no shortage of Utube videos on how to install mini splits. I watched quite a few, none
cover the entire job. Hope I am getting it right. Bruce Roe

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NMSinter.JPG

[bcroe]

Today did the install of the Mini-Split indoor unit. Not very heavy, but would be easier to get everything
lined up with 2 people. As expected it was just a matter of getting some holes in the right places. With
apparently no technical difficulties, will go ahead ordering 2 more for installation this year. MiSpIn3.JPGMiSpIn5.JPG

The design puts all the freon tube connections outside, seen sticking out (plugged) with the drain. The
compressor unit is pretty light as well, seen here with the bracket for mounting on the wall (well above
any snow). Have a jug of R410 and borrowing a premium vacuum pump for the lines, unit is precharged.

MiSpIn6.JPGMiSpIn9.JPGMiSpOt1.JPG

Compressor is relatively light, plan to hang it above the flower garden on the wall. Needs proper
drain (outside), and light 240VAC with disconnect, no problem. House wiring is ready to accept 3 of
these mini-splits. These will be checked out over winter 2018/19. If they fall short of capacity, can
put in one or two more next year. Anyway my older heat pump has quit and I don't want to waste
more resources on it. Bruce Roe

[bcroe]

And, the propane system is still in place, it with my generator could supply heat for a while in
case of an extended power outage. I use just enough for clothes drying and another building
so that my supplier doesn't disown me. Got my annual refill, noting the best summer price is
now $1.30 a gallon. Just a short time ago it was $1 a gallon, solar is looking better all the time.
Bruce Roe

[bcroe]

I take it you already moved your system anniversary date once? PoCo's in NJ let you change your anniversary date once (and only once) after the install of your system to maximize self consumption prior to true it. It might be worth a call.

Huh, me? Never changed it, the other possible date is for wind power.

My impression is, that mini-split heat pumps are just not accepted in this area. Asked one service guy,
he said he had never seen one. But last night I was surprised by a local TV ad. Their approach was
that if you have hot water heat, your house may not have any central air distribution. But you can add
zone control with a mini-split, no ducting. I also spotted one behind an exercise place last month.

They did not mention the things that are driving me that way. Double the electrical efficiency over the
old centralized units, and ability to operate down to minus 13 F (covering 97% of the time here). Will
be noting if this starts a local trend.

Meanwhile the first of 3 house locations is ready to install, the inside and external units are next to the
wall. One year ago there was a problem of enough double breaker positions to operate this equipment,
though the total drain is decreasing. This 1978 originally all electric house (my neighbor still is) had
some heavy wiring in place for the original electric heat, unused after the PO converted to propane.

I repurposed this wiring to a new box which is dedicated to the relatively few devices that are heavy
KWH users/suppliers. With a bi directional spinning disc KWH meter in the feed, my reserve summer
buildup and winter drain down are mostly displayed, the original box has lots of circuits but very light
KWH load. The disc does 34 rpm when the sun is in position.

I also picked up a better vacuum pump, gave my R22 bottle to a friend who still uses it. The backup
of some 6KW resistance heat will stay for now.

Anyway, my last, now obsolete heat pump seems to have kicked the bucket. Bruce Roe

[JSchnee21]

I take it you already moved your system anniversary date once? PoCo's in NJ let you change your anniversary date once (and only once) after the install of your system to maximize self consumption prior to true it. It might be worth a call.

[bcroe]

Thanks for the mini split info. I did get to experience them with my cousin hundreds of miles north,
I found no fault and she likes them. The very good COP and operation to 13 F below zero should
be a big improvement over what I have.

I figure a minimum of three (at 9000 btu) should be immediately installed on this strung out ranch,
2000 sq ft. Of course the basement is the same size and treated like another floor, fully heated.
After a year, will decide if there is a place another mini is needed. Bruce Roe

The first mini split is ready for installation to begin, more of my scheduling problem than technical
I do hope. Bruce Roe

[azdave]

My POCO just zeroed out my account yesterday because it is the end of their fiscal year. I'll get a credit for about $85 for the 3150 kWh I banked. I have one month to bank before the real heat hits in June.

With strategic vacations during the hottest months and further conservation measures around the house, I've had zero net billable energy every month for the last 36 months and paid under $10 per month for the connection fee.

My POCO (SRP) is now offering up to $1800 rebates on battery storage systems but since they let me stay on the basic plan when I went solar there is no incentive or reason for me to load shift.

[bcroe]

I do encourage you to do the minisplit route. Except for the high installation markup they are hard to beat.

The big trick with minisplits in winter is set them and forget them. They are good at maintaining a space temp but struggle to catch up

I may not have a reset date on net metering but March is usually the cruelest month for determining if I need to reign back on minisplit use. I made a big dent in my surplus this winter and got surprised by a month long cold and stormy stretch in late February and most of march.

Thanks for the mini split info. I did get to experience them with my cousin hundreds of miles north,
I found no fault and she likes them. The very good COP and operation to 13 F below zero should
be a big improvement over what I have.

I figure a minimum of three (at 9000 btu) should be immediately installed on this strung out
ranch, 2000 sq ft. Of course the basement is the same size and treated like another floor,
fully heated. After a year, will decide if there is a place another mini is needed. The first one
will have the compressor hung on my brick wall, above the snow. I believe everything
needed for the job is here, have done other air conditioning years ago. DIY I expect will
REALLY save a lot of $. Already done is a new power distribution center in a good location,
and with plenty of space for those mini double breakers. Bruce Roe

[peakbagger]

I am lucky as my POCO doesn't have reset date, but they will gladly write me a check for my surplus generation at some very low rate every year

I do encourage you to do the minisplit route. Except for the high installation markup they are hard to beat. Being in northern NH, I don't tend to use the AC often but even in this extreme climate I get a lot of "free heat" on mild days in the winter and where it really saves me is in the "shoulder seasons" where I don't need to run my wood boiler and eat standby losses. It also is nice option when I am going to be gone for several days and cant put enough heat into my hot water storage tank to cover the heating demand. In this case I run the minisplit for primary heat with the wood boiler storage as secondary. I tend to run the minisplit when the overnight temps are above 30 and use it for supplemental heat during the daytime in the winter if the temps are over 20 and its sunny. I have done my own installs and have posted about it a few times but that's your call.

The big trick with minisplits in winter is set them and forget them. They are good at maintaining a space temp but struggle to catch up from a temperature setback. The air is just warm not hot going out of it and if you use it on high output the coils tend to frost up quicker which means more defrost cycles. I don't have snow baffles on mine but its located on the lee side of the house from the prevailing wind with a slanted roof with some overhang over the top of it to keep snow out. It usually stays snow free unless I accidentally aim my snow blower chute at it.

I may not have a reset date on net metering but March is usually the cruelest month for determining if I need to reign back on minisplit use. I made a big dent in my surplus this winter and got surprised by a month long cold and stormy stretch in late February and most of march. My surplus got down quite low and I had to ramp up wood use. That time is hopefully past and I am happily cranking out surplus for next winter. The only down side is without standby losses from my wood boiler and storage my basement temps drop down to ground temps. Probably a good place to hang meat and a root cellar . I sometimes fire the boiler if I am working down there and warm things up with big unit heater.