After 8 years in the house I’m still amazed. We have had the heat off for a week or so, don’t pay a lot of attention anymore. Last night we left some windows in vent for the night. It went down into the 30 outside overnight and in the AM the house was at 65 degrees. We didn’t turn on the heat. Now, at 2PM it’s in the upper 50s outside and the house is up to 69. No extra heat, just heating itself.

This should be the last update.  The Mitsubishi min-split models we have are supposed to produce 100% down to a -5 degrees F.   This past January they got tested and preformed perfectly. We didn’t get to a -5 but did get to and near 0  a couple nights.   We had a two week spell where it was exceptionally cold, 12 day with the night time low in the teens and single numbers and only in the 20ds during the daytime..  The one mini-split in the family room kept the house between 68 to 70 down to around 15 degrees F,  below that we had to supplement it with the one in the bedroom.  We’d run the bedroom unit from noon ish or late afternoon  to 10:00 or 11:00PM.  It was our highest electrical usage so far, 1,100 kWh compared to last Jan at 992kWh..  Our old house averaged 1,200kWh for all the winter months (which didn’t include heat nor hot water).  Solar production was down a little because the penal were snow covered more days then last year.

Amazing performance.  The house was comfy, no drafts.   Now we are back to the cycle where the TV and cooking will,  on some day produce enough heat to turn off the mini-splits in the evening and over night to the next afternoon.

The summer’s been good as for energy usage and generation. April’s usage was 457kWh and generation was 435 kWh thus a $6.08 electric bill.  Since then we’ve over generated by 1,044.  Our electric bill has been $2.98 (the connection fee) for; May, June, July, August, September & October.  That’s 6 months with no energy bills and we have 1,044 kWh credit with JC P&L.

Our year ends with the November Meter Readings, around 11/25.  Our full year usage as of Oct 25  was 5,977 kWh and generation 6,493 kWh. I’m estimate a Nov usage of 678kWh and a generation of 434kWh thus ending the year with 6,612kWh usage and 6,819kWh generation.  I think we will be in 100kWh =/- of Zero.   That’s about as close as one can get.

Now our HERS rating is 11, but as I’ve written before the HERS model uses only design perimeters and assumes the a three bedroom 2.5 bath house has 2 adults and X children using electricity  and a different rate that just my wife and I use.

One of the things I’ve noticed is how many cloudy or partially cloudy day you get.   Oct was a good example we had 8 days where we only generated 9kWh or less and one day where we only generated 932Wh. That’s 26% of the days undegenerating. I don’t know how the estimates factor in cloudy days.  One estimate shows Oct should have generated 537kWh and actual was 480.

Watch for the full year report in early Dec.

I’m still waiting for NJ CleanEnergy to do it’s final review and cut me the check. Any day I hear.

ED

Just processed my August generation meter readings.   The house modeled at a HERS 16 because the model assumes the family size to match the bedrooms and bath rooms in the house.  It doesn’t allow the modification of the usage to match how the house will really be used.

Because on NJ’s Net Metering I adjusted our usage to match my estimate of what I though I’d use.   Now that I’ve got actuals up to the end of August I plugged in the last three month of the years estimate based on their matching months from the beginning of the year.

My estimate to usage is  6,929 kWh and my estimate usage is 7,078.    I’d call that a Net-Zero.

Just an quickie on the house’s performance.

Last night the house was 69 degrees.  I use a laser thermometer gun to check temperatures. The temps varied between 69.0 to 69.5.  at 11:00 before I went to bed. We left two windows in vent mode, one in the Kitchen and one in the bedroom.

At 7:30 in the morning the house lost about 2 degrees overnight to 67.0 to 67.5.  The outside air temperature was 43, but more interesting the hard services, the deck, and siding were at 32 degrees.

At this point there is no sense of a draft.  Again waiting for winter.

I’m over due for a performance update. been busy doing the things that make a house live able, shelves; hanging clocks and pictures; setting up the garage;………… I just got the basement work shop functional but lots of work still do down there.

Now after living in the house for two and a half months, all I can say is wow. This concept, and it is still only a concept, it amazes me on how well it works.   The second month’s electrical usage was 628kWh which is 42% of the last house’s usage for the same period last year, and the old house had a gas hot water heater.  I’m guessing my big ticket item for usage is my 52″ plasma TV which is on about 4 hours or less a day.

My number 1 goal was a comfortable house. At this point that goal has been achieved. In the heat wave of mid August, 90 to 95 highs for a week, with the index above 110. Testing all the combination I could, it turns out the mini-split in the great room can cool the whole first floor.  I turn it on between 8 to 9AM and off between 9 to 10PM.  Over night the house will hold it temperature or  if I vent the windows lower to the outside temp.  The is 1 9,000 btu, 30.5 SEER is cooling the 1640 sqft area of the first floor.  The early modeling didn’t project that that would happen. I’m guessing that in heat mode it will do the same.

The basement:  many said I was NUTS with my salutation to insulate the basement, but it just made sense to my limited knowledge of physics. A technician working on the hot water heater said “This basement is amazingly warm, and dry”.  When I walk down the cellar steps the basement is noticeably warmer the first floor.  Because of the thermal mas of the interior wall it changes the temperature  very slowly. One worry was the heat exchanger  hot water heater would  pull the basement’s temp down. So far it doesn’t.  Again wanting to see what winter brings.

In September it finally cooled down, 70s during the day & 55-65 at nights.  We find leaving the windows in vent mode over night and closing it up from around 8 AM to 10 PM the house’s temperature would very from 68 to 72 degrees.  If the house was around 70 at 5:00 it would go up a degree or two by just living in the house.  It feels just our bodies in the bedroom will push the temperature up over night.  Both my wife and I feel the house wants to heat it’s self.  Today, 10/6, I was out all morning. Out side air temp was 55 to a nice 68, when I went in the house felt warm, so I opened some windows.

The second goal was spaceial comfort. That was achieved too.  My wife and I drew up the floor plan to meet what we thought our space needs were, then gave our drawings to our architect Jim Wentling, to make it work as a house. To make the pieces work we added space as needed.  We eventually turned the kitchen around and opened the wall to the great room.  And it all works as we wanted it to.  We wouldn’t change a thing.

Third goal is energy efficiency. We  won’t know for sure until we are in for a year but it looks like we will use between 6,000 to 7,000 kWh for a full year.  I was waiting for a year so I could be sure to size the solar system to match our usage, since NJ is not a Net Meter state, and I won’t get paid for over production.  But I’m comfortable we will be under that 7,000 kWh, and why waist a year so I’m installing a solar system starting this weekend.  See up and coming blog entries.

Living in the woods is

Been in for three weeks today.  The past week plus it’s been over 90 everyday with heat index getting above 110 some days and staying above 70 at nights and some nights 75 plus.  A good test for the A/C.

The past week I’ve only been running the great room mini-split from 8 AM to about 10 PM.  set of 72.  The hole first floor is at temperature and a very comfortable, low humidity.  That mini-split is only a 9,000 btu unit.  Looking forward to getting a full month electrical bill.

Update:  your first month’s meter reading was from July 22 to August 22 was 827 kWh which in 48% of the old house’s usage from 2015. I didn’t figure out that the first floor only needed one mini-split to cool it, so the 827kWh my guess is 50 to 100 kWh higher that it could have been with only one mini-split running.  

I will be adding a usage tracking system, and a tempeture monitor,too. In the next month or two.

Also I’m pushing forward with the solar PV arrays.  I’ve changed strategy and am putting the PV arrays on the garage roof, the ground mounted system just wasn’t cost effective.. The trick is sizing the system. NJ doesn’t pay for over producing. The current NJ Zero Energy Ready program has a big incentive to adding renewables.  Between the NJ incentive and the Fed tax rebate the system will only cost a couple thousand dollars.  And with the NJ SREC program it will be paid back in one year.