Electric Cars - 12 minutes worth watching

[shelkol]

The issue with horizontal geothermal! I have 4 acres, so that's not an issue. They say the coils should be 10' down. When you dig that deep, you have to shore up the walls so they don't cave in on you while working. Ok, so I have to dig out a big hole 10' deep without hitting granite and it has to stay dry long enough to put the pipes in. Not a chance!

 

[lynnmor]

The issue with horizontal geothermal! I have 4 acres, so that's not an issue. They say the coils should be 10' down. When you dig that deep, you have to shore up the walls so they don't cave in on you while working. Ok, so I have to dig out a big hole 10' deep without hitting granite and it has to stay dry long enough to put the pipes in. Not a chance!

Maybe they use a pipe laying trencher so no need to go down in?

 

[RCW]

Ammonia for air conditioning might be a tad LETHAL when it leaks.....though it is far more efficient.

Jay - ammonia was common in commercial applications. Creameries where farmers dumped their milk used ammonia systems.

While ammonia is noxious, it’s relatively benign even when there are leaks.

Not good for you, but not as bad as many other commercial products.

During my Health Department days I had a couple defunct/inactive milk plants have ammonia leaks. Stunk like hell, but wasn’t going to kill anyone.

 

[AndyM]

There is one coming your way:

First Canadian eVinci™ Microreactor Targeted for Saskatchewan

Westinghouse Electric Company today congratulated Saskatchewan Research Council on its funding to operate the first-ever eVinci™ microreactor in Canada.

info.westinghousenuclear.com

eVinci™ Microreactor | Westinghouse

Westinghouse is currently developing the eVinci™ Microreactor, a next-generation, very small modular reactor for decentralized remote applications

www.westinghousenuclear.com

I would not consider Saskatchewan Research Council funding as an example of economically self sustaining - more of our tax dollars one way or another. When the $80 million committed hits $160 million with no end in sight...

 

[wp6529]

Maybe they use a pipe laying trencher so no need to go down in?

That's exactly it, you only need like a 6" wide trench and there are plenty of trenchers that will happily cut a 10' deep x 6"+ wide trench in most any conditions. Yes, Vermeer has one that will do 15' deep in solid granite should you need it.

 

[GreensvilleJay]

yeesh 10 feet down ??,kinda hard to believe. rule of thumb used to be 1' below frost line, so for me (southern Ontario ) 4+1=5 feet. At 10 feet it'd be cheaper to dig ALL the dirt out,like for a basement ?
curious now, if there'd be enough area under a basement for a slinky system? If so it's be a 'cheap' way to install geothermal for new houses. Only pain would be if (when) a leak in the piping happens....

 

[wp6529]

yeesh 10 feet down ??,kinda hard to believe. rule of thumb used to be 1' below frost line, so for me (southern Ontario ) 4+1=5 feet. At 10 feet it'd be cheaper to dig ALL the dirt out,like for a basement ?
curious now, if there'd be enough area under a basement for a slinky system? If so it's be a 'cheap' way to install geothermal for new houses. Only pain would be if (when) a leak in the piping happens....

Don't know, the installations I've seen were not nearly 10' deep, more like 6'. At any rate, there are plenty of moderately priced machines available to trench that in decent soil conditions, far cheaper than deep drilling. In really bad conditions with bedrock drilling is probably cheaper than the big trenchers that can handle it. Of course in a lot of areas air source heat pumps work just fine.

 

[shelkol]

That's exactly it, you only need like a 6" wide trench and there are plenty of trenchers that will happily cut a 10' deep x 6"+ wide trench in most any conditions. Yes, Vermeer has one that will do 15' deep in solid granite should you need it.

At 6" wide, you still have to put sand down, the pipe, and more sand. You're working at the edge of a 10' trench that could give way. If it was digging through granite, do you really think it would be much cheaper than a well?

 

[shelkol]

yeesh 10 feet down ??,kinda hard to believe. rule of thumb used to be 1' below frost line, so for me (southern Ontario ) 4+1=5 feet. At 10 feet it'd be cheaper to dig ALL the dirt out,like for a basement ?
curious now, if there'd be enough area under a basement for a slinky system? If so it's be a 'cheap' way to install geothermal for new houses. Only pain would be if (when) a leak in the piping happens....

If you are 1" below frost line, you are not deep enough. Geothermal relies on the ground being about 50 degrees.

 

[shelkol]

All of these comments about trenching machines are great, but what to do about the water table. My water table is at about 4', that means I'd have to work 6' under water.

 

[wp6529]

All of these comments about trenching machines are great, but what to do about the water table. My water table is at about 4', that means I'd have to work 6' under water.

Nobody is going into a trench for trenched coil installation, this is no different than installing a deep water line to a house. The coil is vertically orietnded, the trench is inches wide. OSHA has no requirements for this stuff it's done millions of times a day. An no, the water table is not an issue at all, in fact it improves the grounds thermal conductivity.

As for depth, a ground source heat pump does not rely on 50F ground temperature. Perhaps early units did, but just like current air source heat pumps work well below freezing air temps (mine do fine at -5F), ground source heat pumps also work fine at low temps. Below frost line is plenty deep.

 

[The Evil Twin]

I'm thinking ice rinks may use ammonia as well to freeze the water into ice for the rink surface ?

The rinks we have equipment in are a mix of absorption (ammonia) and traditional chillers.

 

[fried1765]

The issue with horizontal geothermal! I have 4 acres, so that's not an issue. They say the coils should be 10' down. When you dig that deep, you have to shore up the walls so they don't cave in on you while working. Ok, so I have to dig out a big hole 10' deep without hitting granite and it has to stay dry long enough to put the pipes in. Not a chance!

You live where geothermal heating installation is going to be VERY expensive.

 

[GreensvilleJay]

All the basements dug in my area are 10-12' deep from grade, so at least 5' below the frost line( 4'- ).
There's 2 kinds of 'slinky' installs, a 'horizontal' , 3' wide trench or a 'vertical', large diameter hole. depends on what the soil is made of.
My friends house ,he could only go down 7' and hit a HUGE slab. Kind funny to see bulldozer tracks spinning and him not going anywhere.In my case I just have 'soil', no rock. Go 2000' southwest, he has every size of stones,rocks, boulders...probably a terminal moraine, to the south east, neighbour has sand ! I used BX23S to dig then haul 20-30 dump trailer loads of it away...
Most heatpump installs here, they put in electric backup heaters( $$$$$ when being used...) Pity the homeowners who have those when the power goes out....
I'm on natgas, in 35 years never been off. Got low ONCE,but full flow after 3-4 hours.

 

[wp6529]

Most heatpump installs here, they put in electric backup heaters( $$$$$ when being used...) Pity the homeowners who have those when the power goes out....
I'm on natgas, in 35 years never been off. Got low ONCE,but full flow after 3-4 hours.

The need for a backup heater (can be electric, LP, nat gas, etc.) on a heat pump depends on the climate. Modern heat pumps can work to quite low temps so a secondary heater may not be needed *. My Mitsubishi air source mini-split heat pumps have repeatedly worked fine in -5F air temps which is the lowest we've ever seen here in almost 20 years, they kept the house within a couple degrees of setpoint which is entirely acceptable. My cheaper Pioneer mini-splits that I use in my shop struggled a bit more but still kept the shop in the 50s which is fine for the application.

* You do need backup power for your heat pump of course, but since you should also have backup for your refrigerator, freezer, well, etc. heat pumps are great since all you need to backup is the electric. Modern heat pumps are typically inverter drives so that makes things even easier with their lack of the huge starting surge of older units. One appropriately sized backup generator and you just get on with your life as normal in a power outage.

Outside of the peak heating and cooling times of the year a 7,500W gas generator handles everything here which includes 4 heat pumps, 2 conventional smaller A/C units, 3 refrigerators, 4 freezers, well, aerobic septic, lighting, etc. Just no electric clothes dryer. For the peak heating or cooling times the 7,500W gas generator isn't quite enough so the 50KW diesel generator takes over.

 

[The Evil Twin]

Modern HPs will indeed work to -5°f. They are not the standard units, but called low temp heat pumps. The problem is their heat output is cut significantly. A 2 ton unit can lose about half of its capacity at 0°f.
When you get to the numbers, the COP dwindles as well. Above 40°f, the unit can move 4 times the btus that it consumes. Below 0, it is not much more efficient than electric heaters. Well, except there is not the inrush current of a traditional HP due to the inverter.

 

[wp6529]

Modern HPs will indeed work to -5°f. They are not the standard units, but called low temp heat pumps. The problem is their heat output is cut significantly. A 2 ton unit can lose about half of its capacity at 0°f.
When you get to the numbers, the COP dwindles as well. Above 40°f, the unit can move 4 times the btus that it consumes. Below 0, it is not much more efficient than electric heaters. Well, except there is not the inrush current of a traditional HP due to the inverter.

Yes, and it properly sized the HP will keep the space at the proper temp during those few worst case nights just fine without the added cost and complexity of an additional heat source.

Unlike the old days where you had to be careful in sizing a single speed system to avoid short cycling damage, an inverter system will run just fine at a lower capacity and have the headroom for those worst case nights.

I will also note that my Mitsubishi units are not the hyper-heat models, yet they do fine at -5F air temp. If I was in a colder climate I would have purchased the hyper-heat version.

Due to long power lines being in the middle of nowhere, low voltage is pretty common for us and again the inverter units are great as they are rated to operate normally down to 187V (the low end of 120/208V 3ph service in apartments and such). So when my nominal 240V isn't, they are still perfectly happy.

 

[GreensvilleJay]

If you have constant low voltage, get electric company to change the tap on the pole. When new house went up(200A service),volts dropped, 1/2hour later crew came and changed the tap. Course it took anothe r1/2 hr to reprogram all the dang digital clocks......

 

[Jchonline]

Yes, and it properly sized the HP will keep the space at the proper temp during those few worst case nights just fine without the added cost and complexity of an additional heat source.

Unlike the old days where you had to be careful in sizing a single speed system to avoid short cycling damage, an inverter system will run just fine at a lower capacity and have the headroom for those worst case nights.

I will also note that my Mitsubishi units are not the hyper-heat models, yet they do fine at -5F air temp. If I was in a colder climate I would have purchased the hyper-heat version.

Due to long power lines being in the middle of nowhere, low voltage is pretty common for us and again the inverter units are great as they are rated to operate normally down to 187V (the low end of 120/208V 3ph service in apartments and such). So when my nominal 240V isn't, they are still perfectly happy.

We nave non hyper mitsubishi units, not 2 years old. They are fine down to 15F, but after that they just run all night. We did the calculations on electricity usage vs propane for our radiant and its a wash....so we just use radiant because it heats more evenly.

HPs are great when temps are above 15 or 20 at night, but after that not so much for us up here. We are at 8600 ft in rockies.

Ironically the MrCool DIY HP I put in this Summer in my Shop is doing better than the mitsubishi (maybe newer tech). I did oversize it for the area. All are 240v.

To summarize in cold climate heating a home I would not use HPs as my only source of heating. We are also up in the mountains and the power can go out....we need propane. I have a whole house battery backup system that can keep everything running for days...but powering minisplits is a no go.

 

[wp6529]

We nave non hyper mitsubishi units, not 2 years old. They are fine down to 15F, but after that they just run all night. We did the calculations on electricity usage vs propane for our radiant and its a wash....so we just use radiant because it heats more evenly.

HPs are great when temps are above 15 or 20 at night, but after that not so much for us up here. We are at 8600 ft in rockies.

Ironically the MrCool DIY HP I put in this Summer in my Shop is doing better than the mitsubishi (maybe newer tech). I did oversize it for the area. All are 240v.

To summarize in cold climate heating a home I would not use HPs as my only source of heating. We are also up in the mountains and the power can go out....we need propane. I have a whole house battery backup system that can keep everything running for days...but powering minisplits is a no go.

Here in NE TX temps below 20F are pretty rare so my air source units do fine. Further north I'd do the hyper-heat models which would probably be fine where you are and further north still I'd look to the ground source heat pumps which will work well up into the north.

On the low voltage, some of that is on my side of things with long feeders. I did ask the utility to try to keep the voltage at my service pedestal more towards the top end of the spec, like 250V or so. If the voltage at the pedestal is at 250V none of my feeders get low enough to be an issue.