I have an open loop system. No complaints.

I have an open loop system that dumps into the river behind my house. Unfortunately my evaporator coil has a leak and it’s costing me $1800 to get it replaced. Quote for a whole new unit was $12-$18k, rough idea. We’ve been running on emergency backup(electric) for almost a month and my bill is already at about$900.

Significantly?  No.  It's a challenging ROI for many applications.

It rarely gets cold enough down here to run the heater often.

I wish there was a super cheap way to cool the house when the ambient temp is in the 90s

Wasn't speaking of ROI - the ROI on solar here takes a long time.  A water sink heat pump would lower the wattage requirements of a solar/battery off-grid system.

Yes, but not exactly. Many of their hot springs, basically all, are the “waste effluent” of power or heat generation. Their swimming pools are run the same way. They all shower before swimming as the water is just water, and only so much fresh water comes through at a time.

It's not going to have any meaningful effect on your power gen requirements, because there is such a low probability of being able to cut your margins that close.  Especially with a water sink such as a pond.

Look, I love exotic thermal management systems.  I've done engineering on systems that use fuel as a heat sink for these things.  It's not going to be significant in the application you have in mind.

Most people won’t listen, they’ll believe the marketing instead.

For nearly all of the country, inverter compressor air-source heat pumps and a well-constructed house would be far cheaper, more efficient, and have longer service life. And on an off-grid system you can set either schedule air conditioning for high sun load times or easily throttle at part load to keep from over-drawing batteries.
Not to mention servicing them will be generally easier and cheaper.

Oh, I've already looked at solar and it doesn't make financial sense now, let alone a battery system to be independent of the grid.  It would seem though w/ one of these fancy systems you could reduce the # of panels & # of batteries needed to run a house completely off grid.

You're the engineer, though - you're saying the power requirement would stay the same, despite the increased efficiency of the heat pump?

Like....geothermal?

+1

My parents live on the St-Lawrence River in Canada and use the river for heating and cooling.

The only reason we got it was because we couldn't get natural gas.

A geothermal exchanges heat with the earth instead of the atmosphere.  The large surface area of the buried lines, combined with the relatively stable temperatures of the ground, make it vastly more efficient.

So what you are saying is that garbage American pseudo geothermal(tm) systems use the earth (geo) as a sink for heat (therms) and so it's not really a geothermal system. Is that like saying that a gasoline powered internal combustion engine isn't really an air pump?

Lived in Oregon almost my entire life and still haven't been in a house that has geothermal.

I was a pipe monkey for a well drilling crew.  Grout day sucked.  Drilling on the beach sucked more.  

The guy who built my place here in SW Florida was an electrical contractor from upstate NY.
The walls are concrete block with an additional r19 on the inside. The attic has about 2' of
insulation in it. Same with the attached 28x30 garage. Everything has 10' high ceilings.

In the summer my largest electric bill is in the 150 range and I also cool the garage. I'm
a huge believer in using as much insulation as possible.

My Brothers place in Ohio was built as an all electric house in the late 70's.
2x8 walls, ~r50 or so in the attic and high end windows. We converted it
to a propane furnace with central a/c. He can almost go the entire winter on a
single 1K gallon propane tank....and it's dirt cheap in the summer to keep cool.

Nothing like taking a shower a hydrating all the bentonite dust stuck to your body.

It always means fluid heated by the earth.

I think in the end, you'd just be trading one up-front cost for another.  A pond could reduce the up-front cost, but peak and min temperatures could overshoot ground temperature and reduce the overall efficiency at the peaks/mins compared to a ground loop, but you saved money on install, because digging is expensive, and drilling even more so.  It's a lot of design trades.

What excites the Rhodies in the video is that their drilling allows for them to use a thermally efficient heat pump in an area that would normally be too cold for efficient operation of a conventional air-sink heat pump.

Oh, I agree, the prices don't make sense but in certain circumstances.  Efficiency is neat in it's own right, however.  Doesn't mean it makes financial sense.

Just put the house underground....

@GTLandser

Long story, but bear with me...

I bought this house in 2017 and it still had the original geo system that was "working" when I had the inspection done.  The house was built in '99 so the geo unit was going on 18 years old.  The previous (and original) owner of the house ran a refrigeration business and he tried to service the geothermal unit himself after it suffered a catastrophic failure sometime in 2015.  Based on the parts he replaced, I think something ruptured in the unit and sprayed water on all the electronics inside.  He replaced everything but the coils and botched the job by not purging the system prior to soldering his connections (leading to internal contamination of the heat pump refrigerant system).  The service records he provided did show he hired a qualified company to acid flush the heat exchanger coil sometime after he replaced parts.  Long story short, that geo unit never worked right after I took possession of the house and I sued the previous owner for a long list of things (including lying to us about the condition of the geo unit) and won that suit in court.  So the previous owner paid for my new geo system which I had installed later that same year I bought the house.

The new geo system cost $17k but hooked up to the existing open loop well water supply, so there was no expense for well drilling or excavation factored in (as there would have been if I decided to go with a closed loop geo system instead of staying with the open loop).  The company that did the work is one of the leading geothermal installers in this area.  They said the open loop systems are more efficient in this area of the country than the horizontal closed loop systems because the relatively shallow depth that horizontal loops are installed really struggle in the early spring months due to cold ground temps.  Basically, the way they explained it - horizontal closed loop geo systems claim a majority of their heat from the ground by solar warming of the ground.  And since the winter months here are mostly filled with cloudy days, there isn't much sunlight to warm the ground.  Of course, matters are made worse if we have a lot of snow cover that persists.

From what I understand, vertical closed loop geo systems are a relatively "new" concept but basically require a well be drilled to install them so the loop can be "submerged" in ground water.  The water table on my property is 125' deep, so considerable cost would be involved paying a well drilling company to poke a hole deep enough for such a loop to be installed (probably at least $4000 just for the well drilling, not including installation of the loop piping).

As far as maintenance costs for an open loop geo system are concerned - yes, I will need to have the heat exchanger coil in my geo acid flushed periodically to remove lime scale and other buildup.  I have yet to need this done so I can't comment on the cost of such a service.  Of course, the other expense to consider is an open loop geo system uses well water, and thus, the well pump gets more use than it would normally see.

Can I even do that down here?

sounds like I need more insulation

I have two of them one in my house and one in the garage. I don't think they are that great. If we had natural gas I'd do that.

Cheaper to just swing in a banana hammock.

Yes.
Ground temp is pretty stable and consistent at the depth the geothermal loops are placed.
In simple terms the heat in your home gets transfered to the loop and as it flows, dissipates into the earth where it then cools the refrigerant in the loop and gets pumped back into your home.
Equipment costs about the same as a conventional hvac system. The expensive part though is installation of the loops. Because digging a big hole isn't cheap.

Vertical, closed-loop systems were undergrad textbook stuff 30 years ago, at least.

Don't any of you fuckers watch "This Old House"?
https://dandelionenergy.com/affordable-geothermal-this-old-house

Plenty of mini-split systems are well above 30 SEER, with reasonably efficient heat down to -20 degrees F.

What does SEER mean?  And what are the typical ranges?

Single family home? Off-grid? With solar and batteries?

Use a DC mini-split sized so that it can appropriately modulate down. The condenser is usually the limiting factor, so it may be more effective to have 2x single zone systems than a 2-zone system with a single condenser running 2 heads. Site the house and solar system so that your solar panels max output coincides with the period of maximum solar heat gain. For heat, use the output from the solar panels to heat hot water in a storage tank (like Stiebel-Eltron's) and then use a either hydro-air or radiant distribution to heat the structure.  I'd use radiant if I went with the higher SEER wall-units for cooling, and hydro-air if I was retrofitting a place that already had ductwork or was using the lower-SEER concealed duct units and had ductwork.

In either case, focusing on the envelope details is paramount if you're trying to limit energy consumption. And being self-sufficient, you may need to have backups of backups (i.e. wood-fueled outdoor boiler) in order to make it through those 99th percentile days safely.

Again, what does SEER mean?

There's no point to us taking our suburban house off grid when we're hooked to cheap gas & electric, but it's interesting to look @.

We looked into it when we remodeled our house in 2007. The requisite wells would have cost an additional $25,000 so we went with conventional AC, heat pump, and gas furnace for a little over half that.

For new construction you can do trenching to make a horizontal field, and that is probably cost effective.

The best option would be if you were close to a body of water. You can sink the coils of plastic pipe at the bottom of a pond or lake and if it is something like 10 feet deep, it is as good as buried in dirt.

heat pumps have been around for years??

do you guys live in some sort of bubble??

Seasonal Energy Efficiency Ratio. This is the ratio of the cooling output of an air conditioner over a typical cooling season, divided by the energy it uses in Watt-Hours. It may also be called a Seasonal Energy Efficiency Rating.

Ive been down to -8 for 12 hours,  stayed below 10 for 24.   Geothermal kept up fine,  never had to use emergency heat

We designed one in Pensacola...maybe at Whiting Field. That's what the .gov statement of work called for, even though it doesn't make much sense around here.

You finally gave me a reason to appreciate the Biden voter next door - he blocks the sun.  

30 years ago Gulf Power told people at Tyndall that geothermal would save them six figures over 5 years.

The Corps of Engineers still decided on chillers and boilers after running the numbers themselves. Hard to get the theoretical numbers when the ground temp is 72 degrees.

As long as you can keep the house from being under a big negative pressure...yes.

planning an open loop system for the house we'll be building this year.

Expecting the left to start crushing fossil fuels with taxes and other suppression. Trying to get the house as energy efficient as possible.

If you are going to heat with solar, then solar thermal is the only way to do it.  

Using solar panels, the efficiency is total crap as you have to convert solar to electricity and then use it to heat water.

If you're using a heat pump, you aren't creating heat - you're just moving it around.

Heat pump energy efficiency is around 3 times higher than resistance heat.

I was replying to the poster about this statement "For heat, use the output from the solar panels to heat hot water in a storage tank (like Stiebel-Eltron's) and then use a either hydro-air or radiant distribution to heat the structure."

Understand what a heat pump does.

The Steibel-Eltron water heater is a heat pump system.