Need cold climate solution

[ICanHas]

You already use a water heated system. So... using 10PM to 6AM rates with timer and electric water heater to make a lot of hot water would be a good start

Originally Posted by Theotilus

Our outside air gets down to 15 degrees F at the coldest.

Thank here in Bellingham, Wa.

That doesn't tell much, by the way. Degree hours/days are not necessarily good indicator. A very extended period of winter in 30s really rack up the heating degree days, but heat pumps can get a decent efficiency in those temperatures. With your natural gas like off-peak rates, you'd benefit from a large, or a second water heater set to the highest temp and setup with a thermostatic valve (so you don't get 150F water out the faucet) and a timer to limit water heating to 10PM to 6AM

http://seattletimes.com/art/news/loc...s/rateplan.pdf

A considerable saving can be just a phone call to power company and thermostat button pushing away. Forget the noise about bitcoin machine or whatever. Those rigs are not free.

May I suggest subscribing to TOU plan and messing with thermostat programming patiently? You may benefit more from upgrading to a much better thermostat and adding more resistive heat stages. You'll likely have to spend a lot of time setting it up, for example, your set point doesn't need to be that high while you sleep. At 4c/kWh, the grave yard power rate is very competitive with natural gas (that you do not have). So, geothermal's possibly higher COP during graveyard off peak rates hours are not as important as COP difference during peak-hours.

At their rates, saving money and resources isn't about just saving kWh. sometimes, some wisdom and trial and error can get you ahead quite a bit

Geothermal equipment are extremely expensive upfront just because they're premium market stuff. They usually use an embedded syscrap design with high voltage power electronics up the wazoo. Power electronics is basically computer chips exposed to the weather and they fail in manners that our calculators and phones don't. :\


If integrated COP(taking into account of defrost cycles) of heat pump can remain well above 1.0 during sleep set point temp, leave it on. If not, use heat strips. Check performance data. Key to improving heat pump efficiency is reducing the temperature difference between the indoor return air and outdoor ambient. A heat pump can provide an acceptable efficiency at 65F sleep time temperature. For maximum COP, get creative with the return air location, so you're scooping it from the coldest area rather than from warmer ceiling areas.

You could be wasting $$ if you have to set it at 68F only because the heat pump doesn't have capacity to quickly pull up to desired temperature in the morning. Set back thermostat to 65F, but upgrade backup heating strips to a very high wattage, then start raising the temperature using resistive heaters starting at about 5 or 5:30AM and you overshoot the temp to 75F and have it shut off by 5:59AM, because your $/kWh goes up 60% at 6AM. When you suddenly raise the temperature, it will drop after temperature is satisfied as the heat absorbs into your furnishings. With expected outdoor temperatures at 4-6AM, heat pump likely will not have a lot of capacity, but resistive heaters can provide extreme amounts of BTUs in a short time.
You have to play around with when to start heating, how much to overshoot and a balance between comfort and cost.

The amount of overshooting you need to do depends on if anyone will be home during the day and if so, how long it generally takes before the outdoor temperature warms up to where COP is better than 1.6 (because... day time rate is 1.6x as much...). By using off-peak hours to overshoot and delaying the heat pump from kicking by riding through/reducing 6-8AM time frame when the power rate is at mid or on peak, and also the coldest time of the day when ASHP is the least efficient. With off-peak pre-heat, you can hopefully delay the heat pump start up until the ambient temperature has risen quite a bit so you can reduce running it on low COP during peak-hours.

Unlike heat pump, heat strips do not lose efficiency by increasing the set point.

If your winter is in teens for a very long portion of the day for weeks on the end, ASHP efficiency suffers. keep in mind that if the coldest times are during grave yard hours, the efficiency during these hours can be less important depending on plans available through your power company.

[randen]

SDMCF

Yes you are correct. A direct powering of a heat-pump with solar PV would be unwise. However in the USA and Canada electrical distribution companies are supporting net metering. During the day with sunshine and expecially during summer you are banking KWH's on the grid. During the night you withdraw your KWH credit to heat your home.

As the price of PV solar is dropping and programs of net metering are supported as well as the great efficiency of Geo thermal its like a dream come true for home owners. Couple this to an electric car in the driveway. Space heating, lighting and transportation paid by all with the sun landing on your roof.

You are right again with the solar hot water. It adds significantly to your heating requirements. We have utilized flat plat solar and store the heat in our concrete floor. 6 hrs of full sun provides us with 24 hrs of heat. And a special bonus of abundant domestic hot water for the spring, summer, fall. I refer to our Geo thermal as our back-up heat source during the extended overcast and bitter cold Canadian winter.

Getting back to Theotilus dilemma. Not enough heat to be comfortable. He is very much on the right track with the heat-pump but he needs more heat at the time when the air doesn't have enough. There are ASHP that can extract heat at lower ambient temps but again its a larger influx of cash. I still believe a vertical ground loop will give him the results he will be happy with.

IcanHas has bought up a point with using resistance strip heating during off peak hours. I have had some first hand experience with this one!! Expensive. Even with time of use. Check out having some bore holes done. You will be comfortable all winter and know your feet are warm for pennies.

Randen

[ICanHas]

Originally Posted by randen

IcanHas has bought up a point with using resistance strip heating during off peak hours. I have had some first hand experience with this one!! Expensive. Even with time of use. Check out having some bore holes done. You will be comfortable all winter and know your feet are warm for pennies.

Randen

Resistive heating is by definition, 1.0 COP. The key is proper controls. A thermostat that is aware of outdoor temperature, the balance point, time of use rates, etc.

First hand experience in one area is useless in another area when you're comparing heat pump experience unless climatic data shows similarly and you express expensiveness in terms of time of day kWh usage.

You're in a Geothermal GSHP, water sourced, alternate energy sales rep showcase climate given that it stays at temperatures where ice cream will stay frozen solid around the clock and ASHP would struggle to keep a COP much above 1.0 and your utility rates are about double his cost which makes the payback period compared to electric strips look good on paper. Given the huge climatic differences, your experience would be about as good as telling how well your clothes fits you which might not fit him at all.

I pulled up the daily weather data for Bellingham, WA and London airport, ON, Can. Nothing alike. You will see that Bellingham's temperatures is much more conducive to ASHP opereation in a bit below refrigerator range temperatures around the clock while your climate is mostly ice cream temperatures around the clock around the same time of the year.

Your city: around 0F all day long.
Your PoCo: (In Canadia cents)
12.9 peak, 10.9 mid, 7.2 off Canada cents per kWh
http://vpn.londonhydro.com/residenti...ctricityrates/

His city: around 32F all day long:

Puget Sound Energy
3.8 US cents per kWh 9PM-5AM
6.8 US cents per kWh peak

00 = midnight 23=11PM
temperatures right below hours = temp.
temp on right side = dew point.
JAN 3 2014

LONDON, ON providence, country of CANADA:
00 Mainly Clear -17.1°C 102.2 kPa rising 24.1 km 77 % -20.2°C NNW 18 km/h
01 Mainly Clear -18.1°C 102.3 kPa rising 24.1 km 78 % -21.1°C NW 19 km/h
02 Mainly Clear -18.7°C 102.4 kPa rising 24.1 km 77 % -21.8°C NNW 17 km/h
03 Mainly Clear -19.3°C 102.5 kPa rising 24.1 km 77 % -22.4°C NNW 14 km/h
04 Mainly Clear -19.0°C 102.6 kPa rising 24.1 km 76 % -22.2°C N 15 km/h
05 Mainly Clear -19.3°C 102.6 kPa rising 24.1 km 75 % -22.7°C N 16 km/h
06 Mainly Clear -19.9°C 102.7 kPa rising 24.1 km 74 % -23.4°C N 12 km/h
07 Mainly Clear -20.8°C 102.8 kPa rising 24.1 km 74 % -24.3°C NE 13 km/h
08 Mainly Sunny -21.5°C 102.9 kPa rising 24.1 km 80 % -24.1°C NW 4 km/h
09 Mainly Sunny -20.7°C 102.9 kPa rising 24.1 km 75 % -24.0°C W 4 km/h
10 Mainly Sunny -18.4°C 103.0 kPa rising 24.1 km 68 % -22.9°C W 4 km/h
11 Mainly Sunny -17.1°C 103.0 kPa rising 24.1 km 64 % -22.4°C SSE 6 km/h
12 Mainly Sunny -15.9°C 103.0 kPa rising 24.1 km 61 % -21.8°C ESE 3 km/h
13 Partly Cloudy -14.1°C 103.0 kPa falling 24.1 km 62 % -19.9°C SW 10 km/h
14 Partly Cloudy -13.8°C 103.0 kPa falling 24.1 km 61 % -19.8°C S 10 km/h
15 Mainly Sunny -13.6°C 103.0 kPa falling 24.1 km 61 % -19.6°C SSW 19 km/h
16 Mainly Sunny -13.3°C 102.9 kPa falling 24.1 km 62 % -19.1°C SSW 13 km/h
17 Mainly Sunny -13.8°C 102.9 kPa falling 24.1 km 69 % -18.3°C S 15 km/h
18 Mainly Clear -14.4°C 102.9 kPa falling 24.1 km 77 % -17.6°C S 11 km/h
19 Partly Cloudy -13.9°C 102.9 kPa falling 24.1 km 73 % -17.8°C S 10 km/h
20 Light Snow -13.2°C 102.8 kPa falling 24.1 km 74 % -16.9°C SSW 15 km/h
21 Mostly Cloudy -13.0°C 102.7 kPa falling 24.1 km 76 % -16.4°C SSW 17 km/h
22 Mostly Cloudy -12.1°C 102.5 kPa falling 24.1 km 77 % -15.4°C SSW 15 km/h
23 Mostly Cloudy -9.9°C 102.4 kPa falling 24.1 km 71 % -14.2°C SSW 23 km/h

BELLINGHAM WASHINGTON:
Within a few degrees of freezing point all day.

00 A Few Clouds 44.0 F (6.7 C) 29.96 10.00 71 35.1 F (1.7 C) Variable at 4.6 MPH (4 KT)
01 Partly Cloudy 44.0 F (6.7 C) 29.98 10.00 65 33.1 F (0.6 C) Variable at 6.9 MPH (6 KT)
02 Mostly Cloudy 43.0 F (6.1 C) 30.01 10.00 68 33.1 F (0.6 C) Variable at 5.8 MPH (5 KT)
03 Overcast 44.0 F (6.7 C) 30.06 10.00 65 33.1 F (0.6 C) Variable at 5.8 MPH (5 KT)
04 Mostly Cloudy 43.0 F (6.1 C) 30.07 10.00 65 32.0 F (0.0 C) from the Variable at 4.6 gusting to 16.1 MPH (4 gusting to 14 KT)
05 Overcast 44.0 F (6.7 C) 30.08 10.00 63 32.0 F (0.0 C) West at 4.6 MPH (4 KT)
06 Mostly Cloudy 43.0 F (6.1 C) 30.10 10.00 65 32.0 F (0.0 C) South at 6.9 MPH (6 KT)
07 Mostly Cloudy 42.0 F (5.6 C) 30.11 10.00 68 32.0 F (0.0 C) Southwest at 4.6 MPH (4 KT)
08 N/A N/A N/A N/A N/A N/A N/A N/A N/A
09 Overcast 42.0 F (5.6 C) 30.14 10.00 76 35.1 F (1.7 C) South at 6.9 MPH (6 KT)
10 Overcast 43.0 F (6.1 C) 30.15 10.00 74 35.1 F (1.7 C) South at 6.9 MPH (6 KT)
11 N/A N/A N/A N/A N/A N/A N/A N/A N/A
12 Overcast 44.0 F (6.7 C) 30.18 10.00 71 35.1 F (1.7 C) Southwest at 5.8 MPH (5 KT)
13 Overcast 44.0 F (6.7 C) 30.18 10.00 63 32.0 F (0.0 C) Variable at 6.9 MPH (6 KT)
14 Overcast 43.0 F (6.1 C) 30.19 10.00 71 34.0 F (1.1 C) from the West at 6.9 gusting to 16.1 MPH (6 gusting to 14 KT)
15 Light Rain 42.0 F (5.6 C) 30.28 8.00 92 39.9 F (4.4 C) Calm
16 Partly Cloudy 44.0 F (6.7 C) 30.23 10.00 68 34.0 F (1.1 C) Calm
17 Partly Cloudy 41.0 F (5.0 C) 30.25 10.00 76 34.0 F (1.1 C) Calm
18 Fair 34.0 F (1.1 C) 30.27 10.00 97 33.1 F (0.6 C) Calm
19 Fair 33.0 F (0.6 C) 30.29 10.00 92 30.9 F (-0.6 C) Northeast at 3.5 MPH (3 KT)
20 Fair 33.0 F (0.6 C) 30.31 10.00 92 30.9 F (-0.6 C) Northeast at 4.6 MPH (4 KT)
21 Fair 32.0 F (0.0 C) 30.31 9.00 88 28.9 F (-1.7 C) Calm
22 Fair 31.0 F (-0.6 C) 30.34 10.00 92 28.9 F (-1.7 C) North at 4.6 MPH (4 KT)
23 Fog/Mist 30.0 F (-1.1 C) 30.36 3.00 96 28.9 F (-1.7 C) Calm

[NiHaoMike]

No need to bother with heat strips when reflector incandescent heat lamps and Bitcoin miners are out there. Heat lamps for spot heating and Bitcoin for "subsidized" heat.

[ICanHas]

Bitcoin miners are out there

Ok, come up with heat strip competitive pricing on a 23kW 80,000BTU unit. "bit coin"

Heating unit shall function in existing duct.
Shall have a >0.99PF and <10%
Shall be able to operate with a 70F temp rise just like a heat strip.
Shall have a real PBP (factoring in time value of money) not exceeding 36 months at 4.0 c/kW at 1 hour/day use.

[gtojohn]

You might consider a standard minisplit heat pump, air to air. Use it as auxilliary heat to supplement your floor heat. The benefit of heating the air is it heats more quickly so you can use it when demand requires it. With heat pumps your capacity drops as the outdoor heat drops. Usually they rate about half their capacity at 17f outdoors. Place your outdoor units for the most solar exposure if heat is your biggest concern and design permits it.
Are you making the most of your floor heat with reflectors and insulation? Optimizing what you already have might be cheapest/most efficient.

[NiHaoMike]

Bitcoin has passed the point of being a good bet, but there are alternatives including some that are apparently still profitable. (In other words, I was using "Bitcoin" in a generic sense...) Then you just build up setups that break even in a reasonable time. The profit afterwards is just a bonus. It could be possible that you end up using the miners for primary heat and the heat pump as a backup.

The heat lamps can help a lot by allowing the inside temperature to be lowered. The real goal isn't really heating up the whole building, just the people inside.

Another idea, if you are good with refrigerant system modifications, is to convert a cheap window A/C into a chiller, with a copper tubing evaporator in an insulated cooler filled with water. When the main heat pump can't keep up, the chiller will start freezing the water and extracting the heat out of it. Later, when the demand is lower, use another copper (or PEX) coil inside the cooler to melt the ice back into water using the main heat pump.

[SDMCF]

Originally Posted by randen

However in the USA and Canada electrical distribution companies are supporting net metering. During the day with sunshine and expecially during summer you are banking KWH's on the grid. During the night you withdraw your KWH credit to heat your home.

That's an excellent system. Totally eliminates the storage problem. I haven't heard of anything like that over here.
How far in advance can you bank kWhs? Is it really possible to build up enough reserve in summer to last over the winter, in a cold climate? That would be an impressive system.

[jeff88]

Originally Posted by SDMCF

That's an excellent system. Totally eliminates the storage problem. I haven't heard of anything like that over here.
How far in advance can you bank kWhs? Is it really possible to build up enough reserve in summer to last over the winter, in a cold climate? That would be an impressive system.

I can only speak for PG&E (Pacific Gas & Electric) for California as I only sell solar here...

You can usually only 'bank' your credits with NEM for a 12 month period. At the end of the 12 month period, you pay your true-up and the credits are used toward that. Depending on which model a customer goes with (investment, lease, PPA), having no credit left over after 12 months is financially the best option, but for DIYers like us, it might make more sense to have extra credits. In many cases, especially when a mounting plane is sunny in summer and shady in winter, we will oversize the system to over-produce in the summer to make up for the winter, because the credit banked will be used in winter when solar power is less viable.

This works especially well with TOU and really really well with TOU and an electric car. Most of the solar production is at the time the utility company charges the most money for usage. Under the NEM agreement, the utility has to buy solar power at the same rate they are charging for. This means that if the most usage is at night (cheap electricity), then a solar customer will be selling high and buying low. A small system will offset a large bill.

Net Energy Metering, what a beautiful thing!

[Theotilus]

Thanks to everybody out there for their ideas and advice. I will look into
Bore holes for geo thermal. If I end up using the same Unichiller RC
This winter I will probably want to see if I can make it run more efficiently. One thing the Unichiller does is run for what seems like an unusually long time before
Going into defrost mode which to my way of thinking is hard on the compressor.
Is there a simple way to get the heat pump to go into defrost mode more? Like moving a sensor or something?would this help? Any tips would be greatly appreciated.