iPlug
Posts: 416
Joined: Thu Apr 28, 2016 6:47 pm
Delivery Date: 25 Apr 2016
Location: Rocklin, CA

Re: Share Your Home Electrification/Efficiency Improvements

Mon Aug 05, 2019 5:53 am

Oilpan4 wrote:
Sun Aug 04, 2019 11:14 pm
I don't use natural gas.
That's why I got the forced air coal furnace to do the lion's share of home heating in the winter.
Looks like some are going in different directions on the “electrification/efficiency improvements” ;)
'19 Model 3 SR+ (own), '19 Leaf SV (leased), '12 Plug-in Prius (sold 3/19), '16 Leaf SV (prior lease), 11.43kW Solar PV (16MWh/yr real production), 20.5 SEER/13.0 HSPF ducted air-source heat pump, 3.70 UEF heat pump water heater, Induction Cooktop

Oilpan4
Gold Member
Posts: 761
Joined: Wed Jan 09, 2019 10:51 pm
Delivery Date: 10 May 2018
Leaf Number: 004270

Re: Share Your Home Electrification/Efficiency Improvements

Mon Aug 05, 2019 9:38 am

It uses some electricity but saves megawatt hours over using the heat pump.
2011 white SL leaf with 2014 batt.
Chargers: Panasonic brick moded for 240v, duosida 16a 240v and a 10kw setec portable CHAdeMO
Location: 88103

iPlug
Posts: 416
Joined: Thu Apr 28, 2016 6:47 pm
Delivery Date: 25 Apr 2016
Location: Rocklin, CA

Re: Share Your Home Electrification/Efficiency Improvements

Mon Aug 05, 2019 11:46 am

Out of curiosity, have you calculated how many therms or kWh or other units of energy in coal you use annually with your forced air coal furnace?
'19 Model 3 SR+ (own), '19 Leaf SV (leased), '12 Plug-in Prius (sold 3/19), '16 Leaf SV (prior lease), 11.43kW Solar PV (16MWh/yr real production), 20.5 SEER/13.0 HSPF ducted air-source heat pump, 3.70 UEF heat pump water heater, Induction Cooktop

SageBrush
Posts: 4719
Joined: Sun Mar 06, 2011 2:28 am
Delivery Date: 13 Feb 2017
Location: NM

Re: Share Your Home Electrification/Efficiency Improvements

Mon Aug 05, 2019 12:55 pm

iPlug wrote:
Mon Aug 05, 2019 11:46 am
Out of curiosity, have you calculated how many therms or kWh or other units of energy in coal you use annually with your forced air coal furnace?
I'll chime in since Oil-y will not have a clue


You are asking about AFUE -- the ratio of usable heat divided by heat content. In older furnaces the AFUE was ~ 55%; modern, expensive models ($4,000 - $6,000) have AFUE in the 80 -85% range.

A good heat pump costs $1,500 - $2,000 and when run wisely has a yearly COP of ~ 4. Coupled with DIY PV at two cents a kWh, one can heat or cool for a cost of ~ 0.5 cents a kWh, often without extensive ducting losses.

Coal is more complicated because the dry heat content can vary from 3.5 - 7.0 kWh a Kg, compounded by the furnace AFUE.
It can be as low as 3.5*0.6 = 2.1 kWh a Kg,
Or as much as 7*0.85 = 6 kWh a Kg

To match a heat pump fuel costs (before considering duct losses of the furnace), the low heat coal with a low efficiency furnace has to be no more expensive than 1 cent a Kg
To match a heat pump fuel costs, high heat coal with an efficient furnace and no ducting losses, the coal has to be no more expensive than 3 cents a Kg

I have no idea how much retail coal costs in NM but power plants pay 2 - 5 cents a Kg. Perhaps 2 - 3x retail ?
Last edited by SageBrush on Mon Aug 05, 2019 1:46 pm, edited 1 time in total.
2013 LEAF 'S' Model with QC & rear-view camera
Bought off-lease Jan 2017 from N. California
Two years in Colorado, now in NM
03/2018: 58 Ahr, 28k miles
11/2018: 56.16 Ahr, 30k miles
-----
2018 Tesla Model 3 LR, Delivered 6/2018

Tortoisehead77
Posts: 61
Joined: Fri Jun 14, 2019 9:59 am
Delivery Date: 31 May 2018
Leaf Number: 307925
Location: Portland, Oregon USA

Re: Share Your Home Electrification/Efficiency Improvements

Mon Aug 05, 2019 1:16 pm

I've completed the following over an eight-year time period:
Added blown-in insulation to the walls and attic of an old house.
Removed baseboard heaters, and added ductless mini-split heat pump
Added solar panels
Removed 30 year-old electric water heater and installed Navien high efficiency tankless water heater
Replaced old windows
Replaced refrigerator with a more efficient model

It's important to note that none of the above changes made a big dent in our electric bill.
The #1 thing that reduced our electric bill by over 60% in the winter was to add a direct vent natural gas heater. It's a small house, so we can heat with just the one heater, usually. Instead of $250-300 a month in the winter, we are now looking at $110 (including charging the leaf). My gas bill is only $40-$50 a month with the new heater.

My Solar City solar panels from 7 years ago are a joke. We barely generate any energy from those, even in the middle of the summer with a lot of direct sunlight.

I'm going to replace the back door and re-frame next. There are a lot of gaps where cold air can get in, and my band-aid fixes haven't worked very well so far.

iPlug
Posts: 416
Joined: Thu Apr 28, 2016 6:47 pm
Delivery Date: 25 Apr 2016
Location: Rocklin, CA

Re: Share Your Home Electrification/Efficiency Improvements

Mon Aug 05, 2019 1:22 pm

SageBrush wrote:
Mon Aug 05, 2019 12:55 pm
I'll chime in...
Very informative. Thanks.

I don’t agree with many of his viewpoints/philosophies, sometimes math as well, but see his input as overall valuable, sharing information and know how and even if disagreeing, cross checking ourselves and others hopefully learning something the process.
Last edited by iPlug on Mon Aug 05, 2019 1:24 pm, edited 1 time in total.
'19 Model 3 SR+ (own), '19 Leaf SV (leased), '12 Plug-in Prius (sold 3/19), '16 Leaf SV (prior lease), 11.43kW Solar PV (16MWh/yr real production), 20.5 SEER/13.0 HSPF ducted air-source heat pump, 3.70 UEF heat pump water heater, Induction Cooktop

SageBrush
Posts: 4719
Joined: Sun Mar 06, 2011 2:28 am
Delivery Date: 13 Feb 2017
Location: NM

Re: Share Your Home Electrification/Efficiency Improvements

Mon Aug 05, 2019 1:24 pm

Tortoisehead77 wrote:
Mon Aug 05, 2019 1:16 pm
I'm going to replace the back door and re-frame next. There are a lot of gaps where cold air can get in, and my band-aid fixes haven't worked very well so far.
-
I contend that fixing air leaks is job #1 for any home. The thing is though, if you do a good job then job #2 is a heat exchanger to have good air quality.
2013 LEAF 'S' Model with QC & rear-view camera
Bought off-lease Jan 2017 from N. California
Two years in Colorado, now in NM
03/2018: 58 Ahr, 28k miles
11/2018: 56.16 Ahr, 30k miles
-----
2018 Tesla Model 3 LR, Delivered 6/2018

iPlug
Posts: 416
Joined: Thu Apr 28, 2016 6:47 pm
Delivery Date: 25 Apr 2016
Location: Rocklin, CA

Re: Share Your Home Electrification/Efficiency Improvements

Mon Aug 05, 2019 1:28 pm

Maybe get HERS testing for air leaks.

That was included when I upgraded our ducted central air heating system to a heat pump last year. We’re pretty air tight, but an informative excercise.

Not sure how much that costs a la carte but it was cool to identify leaking areas with real pressure/volume data.
'19 Model 3 SR+ (own), '19 Leaf SV (leased), '12 Plug-in Prius (sold 3/19), '16 Leaf SV (prior lease), 11.43kW Solar PV (16MWh/yr real production), 20.5 SEER/13.0 HSPF ducted air-source heat pump, 3.70 UEF heat pump water heater, Induction Cooktop

SageBrush
Posts: 4719
Joined: Sun Mar 06, 2011 2:28 am
Delivery Date: 13 Feb 2017
Location: NM

Re: Share Your Home Electrification/Efficiency Improvements

Mon Aug 05, 2019 1:53 pm

iPlug wrote:
Mon Aug 05, 2019 1:28 pm
Maybe get HERS testing for air leaks.
I'm actually waiting for a couple of home energy auditors to give me price quotes so I'll report back.
It seems like the standard service is ID of air leaks by air pressure testing and IR photos. I'm looking for an engineer who can model my home for an energy refit that balances home envelope improvement with installation of mini-splits and a HX.

We'll see how it goes. I personally plan to avoid HERS or any other certification. They are complicated and cumbersome, and mostly serve the rebate/subsidy industry. I'm not saying that they are inaccurate, but that they are rather expensive because they are bureaucratic.
2013 LEAF 'S' Model with QC & rear-view camera
Bought off-lease Jan 2017 from N. California
Two years in Colorado, now in NM
03/2018: 58 Ahr, 28k miles
11/2018: 56.16 Ahr, 30k miles
-----
2018 Tesla Model 3 LR, Delivered 6/2018

goldbrick
Posts: 568
Joined: Tue Aug 01, 2017 3:33 pm
Delivery Date: 01 Aug 2017
Leaf Number: 311806
Location: Boulder, CO

Re: Share Your Home Electrification/Efficiency Improvements

Mon Aug 05, 2019 2:47 pm

FLIR makes a nice IR camera that attaches to a smart phone. It yields very high quality data IMO and costs about $300. Just an FYI for those who are considering IR analysis of insulation performance. I think our local 'tool library' actually rents them although I have my own personal unit since it is such a cool (and useful) appliance.

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