# Not a night for a minisplit



## peakbagger (Jan 7, 2015)

Forecast is for -20 deg F tonight. I expect my storage will cover things and worse case I have oil.


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## woodgeek (Jan 7, 2015)

Yar.  With all my tweaks to my house envelope and my heat pump, I got this far into the season only needing resistive 'aux' backup for 0.5 run hours (7 kWhs) total, versus about 50 run hours (600 kWh) total aux by this point last year.  I'll prob need 2 hours of aux just today and 4-6 more hours tomorrow.

And its only supposed to get down to 6°F or so here in 'the south'.

Whattya gonna do?  My oil boiler was scrapped 2.5 years ago.


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## sesmith (Jan 7, 2015)

Aux just came on for the first time tonight for about 15 min to help boost things a little.  As far as my gshp is concerned, it's about 40 degrees outside (incoming water temp).  In reality, we're already down to -2 with some wind to help it feel colder.  It's a good night for ground source


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## begreen (Jan 7, 2015)

With the windchill you folks are colder than daytime Mars temps!


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## johnny1720 (Jan 7, 2015)

I am trying something different since my kwh charge is going to be like $.11 this month. 

I enabled the electric resistance on my gshp. I turned off the pellet stove and I did not load the little wood burner. 

It is 0 now, the wind is kicking up supposed to be -20 windchill in the morning.

The unit went into the 3rd stage (electric resistance) for 15 minutes then turned off.

I am going to see if it will hold up as well as it did last year.


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## sloeffle (Jan 8, 2015)

I am too cheap to run my geo during the really cold weather so I have been burning my wood furnace non-stop since last weekend. House usually stays around 70 - 72. I burn around half a wheelbarrow load ( 12 - 15 pieces ) a day. Mostly ash due to EAB.


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## johnny1720 (Jan 8, 2015)

According to my energy monitor it cost me $13.27 for all my electric on 1/7/2015.  It usually costs me about $6.00 per day during non heating season.  So it roughly cost me $7.27 to heat my home on the coldest day of the year.   A bag of pellets is $5.99 in my community.  I would have needed at least one and a half bags yesterday.


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## sloeffle (Jan 8, 2015)

johnny1720 said:


> According to my energy monitor it cost me $13.27 for all my electric on 1/7/2015.  It usually costs me about $6.00 per day during non heating season.  So it roughly cost me $7.27 to heat my home on the coldest day of the year.   A bag of pellets is $5.99 in my community.  I would have needed at least one and a half bags yesterday.


According to my Efergy it costs me 36 cents ( 2.2Kwh * 0.16 ) to run my geo per hour in first stage. So my costs are pretty similar to yours. I have a 4 ton Waterfurnace.

We have 30 acres of trees, so the wood is easily harvestable. I probably don't want to figure out the actual true cost ( time, fuel, wear / tear ) though as I am probably not that far ahead compared to the geo. I do usually buy a cord every year from a buddy and stockpile it for the next year just to make sure I have enough for the winter. I guess I like the idea of not making the electric company any richer than what they are.


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## Where2 (Jan 8, 2015)

sloeffle said:


> I guess I like the idea of not making the electric company any richer than what they are.


I'm with you on that, and I don't even have the heat on at our place in FL. Buddy of mine outside Roanoke, VA sent me a shot of his TED energy monitor this evening: 120kWh by just 6pm today. Last night, he sent me a photo of his IR thermometer pointed at the wall: showed the wall was 43.5°F on the inside, and that was near the gas fire place!! His house was built in the 1920's.

Speaking of minisplits, my next project is a single floor '70s ranch house in northeastern Maine with an unfinished walkout basement on the east side of the house. Prevailing winter wind seems to come from the west, northwest and southwest. Should I just mount the minisplit on wall brackets attached to the main floor level of the house? The mount would be 8'-10' above the finished grade at the walk out level. This appears to be my best option to keep the outdoor unit out of the snow, and prevailing wind.


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## woodgeek (Jan 8, 2015)

Above the snow line (no burial), out of the prevailing wind (for fast defrost), and far from any bedroom (for noise issues) is the checklist.


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## peakbagger (Jan 8, 2015)

Yup, you want it out of the prevailing wind, well up off the ground and preferably under a high overhang or build a roof over it with an overhang to prevent any snow from falling onto the coils I have a removable 45 degree pitch on the roof. Some folks also build snow shields on the sides to redirect snow. The trick is to not limit airflow but to limit snow entry. At my place the location is on a east wall next to driveway so its gets the morning sun which seems to help knock off frost from the coils.


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## Jerry_NJ (Jan 10, 2015)

My new Series 5, 4 ton is getting a good check out and seems to be holding without going to resistive aux heat.  It was installed in November to replace my 21 year old Premier Water Furnace.  I went around and around on the idea of installing a smaller hp, and taking some Stage III heating, the computer model showed my house could handle a few hours at 0 degrees (and running aux heat) and still come out ahead of the larger 4 ton. My installer was willing to go either way, and I went with his recommendation.  Right now I have a fire going in my insert (wood stove) and the geothermal is off and will be off for at least 6 hours while the stove handles the load (yes far corners of the house are down to 60 degrees or so).  i think this helps the HP efficiency as the off time gives my vertical loops time to warm up, including the water table near the pipes.  Most of the pipe length is in the water table. 

I've been tracking my KW usage, and with this approach of running on wood from about 10 PM to 2 PM the total electric usage has been 70 KWH per 24 hours with overnight temps single digit and daytime below 30 degrees.  At 15 Cents per KWH that's $10.50 per day.  I enjoy the wood fire too as I sit here on the blog and plan to go to bed at about midnight.


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