Buying vs prepaid lease Solar Panels or Replacing Ac/Heating Unit

[silversaver]

Yes, really high. We had some family over around june to july and i guess a/c and washer/dryer runed little more than normal.
And you are right, the guy from some a/c heating company said that unit was only for 1600sqf home , i just remember now but also he said that because the house is 1600sqf , the unit and duck,windows must work perfect, but he said will be best if i put a 4,5 ton unit and verify duck work to make sure no air leaks.

You mention the mini-split system, so by running that only for the master , how is the bill in the summer?
Thanks!

I have nothing bad to say about mini split. I have 2 ACs right outside of Master bathroom and the noise isn't something I enjoy during Summer nights. Now, I can only heard wisper sound (If I try hard), worth every penny. These ductless mini split consume less than 1kWh (per hour) on average (12000BTU 23 SEER). Central air is good, but really waste of energy cooling spaces aren't needed.

I have almost $0 bill for my 7.1kW solar covers my 2 EVs and home.

[npa]

DON'T SIGN THAT LEASE.Its a long term contract and if you try to sell you house and the new buyer doesn't want it and you have no place to relocate it at your cost within the city limits.YOUR SCREWED .They will put a lien against your house and pursue legal action to make you pay the lease in full even if you don't have the system in your possession.

[kb58]

I also have great things to say about a mini-split AC. We bought a 8000-BTU unit Mitsubishi unit, 31.5 SEER (no kidding) for just the bedroom and barely see it on the electric bill. Granted it's small and we only run it from maybe 8PM-10PM, but yeah, big supporter.

[bcroe]

I have been looking at mini splits for a while. The inverter driven motor has a higher SEER. One claims
30.5 SEER and a NEGATIVE 13F minimum effective temp range. That would allow essentially all year
operation, with a minimum of resistance heat required. And the energy consumed would be on the order
of half used by my older 14 SEER central heat pump. I bought this 9000BTU for trial, may eventually add
enough of them for the entire house, plus keeping some car spaces above freezing with the energy saved.
Bruce Roe


MiSp2.JPG

[J.P.M.]

I have been looking at mini splits for a while. The inverter driven motor has a higher SEER. One claims
30.5 SEER and a NEGATIVE 13F minimum effective temp range. That would allow essentially all year
operation, with a minimum of resistance heat required. And the energy consumed would be on the order
of half used by my older 14 SEER central heat pump. I bought this 9000BTU for trial, may eventually add
enough of them for the entire house, plus keeping some car spaces above freezing with the energy saved.
Bruce Roe


MiSp2.JPG

Bruce:

Since you're one who seems to like to verify claims, I'd be eager to see any info you gather on how such a unit performs when it gets really cold. - as in what happens to the C.O.P. (EER) at, say close to 0 F.

Thanx,

J.P.M.

[bcroe]

Bruce:
Since you're one who seems to like to verify claims, I'd be eager to see any info you gather on how such a unit performs
when it gets really cold. - as in what happens to the C.O.P. (EER) at, say close to 0 F. Thanx, J.P.M.

Right, measuring the KW, KWH, and outside temp isn't a problem. But I don't have instrumentation to measure
COP at this point. It should at least cover the 12 month operating range here, at considerable energy savings. It
will take some time to run this trial.

My northern MN cousin has been running them year round with good results for some years, they were doing well
when I visited. Bruce Roe

[J.P.M.]

Right, measuring the KW, KWH, and outside temp isn't a problem. But I don't have instrumentation to measure
COP at this point. It should at least cover the 12 month operating range here, at considerable energy savings. It
will take some time to run this trial.

My northern MN cousin has been running them year round with good results for some years, they were doing well
when I visited. Bruce Roe

Thank you. There are ways to get a pretty good 1st approx. of an instantaneous C.O.P. while running in steady state but you need a couple to thermometers and some way to get a reasonably accurate number for the air flow rate across the coil while recording the power draw. That technique will work but it's mostly done by eccentrics like me (and you maybe ?)

Regards,

[bcroe]

MUZFHrange.png

J. P. M.,
This chart of operating range was given. If 9000 BTU/hour was assumed at 100%, and the input KW was
known, guess the COP could be calculated. The KW will probably vary a lot with outside air temp, the
inverter driven motor can vary it.

I am assuming the 9000 includes the compressor energy consumption in the heating mode. For cooling
mode that heat must be pumped outside, which will mean either more KW or less BTU/hour, either way
a lower COP. But cooling is a minor consideration at this location.

When trying to compare energy equivalents while organizing this plant, it seemed that SEER and EER were
just sort of a seasonal overview average, for comparing different equipment. These were feel good numbers
something like 3 or 4 times the COP. But the COP is a hard ratio that continually varies with conditions.

Even with the thermometers, getting the flow number might be a real challenge.

Bruce Roe

[J.P.M.]

MUZFHrange.png

J. P. M.,
This chart of operating range was given. If 9000 BTU/hour was assumed at 100%, and the input KW was
known, guess the COP could be calculated. The KW will probably vary a lot with outside air temp, the
inverter driven motor can vary it.

I am assuming the 9000 includes the compressor energy consumption in the heating mode. For cooling
mode that heat must be pumped outside, which will mean either more KW or less BTU/hour, either way
a lower COP. But cooling is a minor consideration at this location.

When trying to compare energy equivalents while organizing this plant, it seemed that SEER and EER were
just sort of a seasonal overview average, for comparing different equipment. These were feel good numbers
something like 3 or 4 times the COP. But the COP is a hard ratio that continually varies with conditions.

Even with the thermometers, getting the flow number might be a real challenge.

Bruce Roe

Understood. Thank you for the time to respond and the info. I appreciate both.

I'd be more interested in instantaneous readings at a set of inside/outside temps. For average operating conditions/purposes seasonal averages have a valid use but measured heat output and C.O.P at winter extreme/design conditions are what would interest me most, that is, in heat pump mode. Kind of academic for me anyway as it doesn't get that cold around here, in spite of what the locals may think. Coldest in 10+ yrs. at my house was 31 F., and that was just one time.

I'm more than a bit familiar with C.O.P. both from a thermodynamic and practical application standpoint. To get EER from C.O.P., multiply C.O.P. at any temp. (including design temp.) by 3.412. SEER is very approx. 10% to maybe 15% larger than EER, and is more often used for equipment comparison on a seasonal basis. It may be more appropriate for that purpose, but the idea that it's numerically greater than EER probably means it's used more often and/or inappropriately - bigger is better or at least easier to sell.