Please explain heat pumps to me like I'm an 8 year old

I'm trying to understand how they work and their environmental impact in terms of embodied energy and pollution potential.  Massachusetts is all in a fizz about banning fossil fuels (a good thing), but I feel like there is a sudden rush to a technology about which we know (about which *I* know) very little.  

So, explain this to me like I'm an 8 year old and please offer examples of other technologies that might be more appropriate and serve as well.  I'm building a small home to look after a loved one and I'd like it to be as lightweight as possible, environmentally speaking.  

It may or may not be helpful to mention that in MA, we are required by law to be tied to the grid.  So I have to go to the expense of having the house done up with a primary electrical heat source, as things appear to be going.  It can not be solid fuel as the official primary, and oil/gas are on their way out.

And while we're at it... if someone wants to explain an induction cooktop, I'm all ears.

Thanks!

I'll take a shot at it but people who know better are welcome to correct me!

Super simple:  

A heat pump sends a liquidy material from inside to outside and back.  In the summer, the heat in the house is moved outside in that material and dumped into the air outside.  Exactly like how when an air conditioner is running it's very hot outside by its fan.  Once the heat is dumped out there, the material comes back into the house much colder and that cools the house air.  Exactly like an air conditioner does.

In the winter it does the same thing only kinda in reverse.  It takes heat from outside (that magic material can pull heat out of cold winter air) and pushes it inside.  There it's spread around the house like a gas furnace would.  In doing so the material gets colder and goes back outside to pick up more heat.

This whole process is done with electricity.  When it gets really really cold outside, it doesn't work that well.

More complicated description:

Same as above but the material is a "refrigerant".  It spends some of its time as a liquid and some of its time as a gas.  The heat pump compresses it into a liquid at times and uncompresses it into a gas at others.  It's always doing one on the inside of the house and the other process outside.  When the refrigerant is compressed, it gets hot, when it's uncompressed it gets cold.  So, in the winter, I believe it's compressed once it's in the house where the heat is easy to pull out of it.  Then it's uncompressed outside where it gets really cold and the slightly warmer outside air can heat it up a bit.  Then it goes back inside to get compressed and that added heat is removed.  Opposite in the summer.

Super, so what kind of scary toxic gick is the refrigerant?  I'm kinda worried about messing with the heat outside.  Is that, on a very large scale, just creating a new problem?  Or is it no more harmful than sending steam from a RMH out into the air?  And then there is the embodied energy int he equipment and lifespan and all of the potential waste involved in maintenance...  any more than a more appropriate technology, if such a thing exists?

Kind of irritating that the electricity thing is less efficient in the cold, since Massachusetts is cold for a not-insignificant portion of the year.  

Rome wasn't built in a day, I realise.  I'm just trying to understand the current landscape and make wise decisions that don't come back to bite me or my progeny in the future.

Thanks so much for that explanation!

Nissa,

The original refrigerant used in most heat pumps/AC units was freon which was excellent at moving large quantities of heat easily.  Unfortunately, freon ate away at the ozone layer so it is now banned and several replacements have been used, each somewhat more benign that the previous but each still with their own problems.

There is one technology that is currently in a prototype stage called Supercritical Carbon Dioxide, or sCO2.  sCO2 is carbon dioxide compressed to a state where it can't decide if it is a liquid or a gas so it has the properties of both.  It is about 2/3 the density of water but fills a chamber like a gas.  It is very good at moving heat.  And if it leaks, it is no more harmful than CO2 released by any other CO2 source, and hopefully, one would catch these leaks early, if for no other reason than to make sure that your AC does not quit working!  I know that CO2 is a greenhouse gas, but this is not something that is dumped into the air on a daily basis.  On a year-to-year basis, it is pretty benign.

Hope that helps.

Eric

Well, the refrigerant used to be bad and make holes in the ozone.  Now they have better refrigerants.  This is the same stuff that's in air conditioners, vehicles air conditioners, refrigerators and lots of other things that play with cold air.

Way down south in Massachusetts, you should be plenty warm for heat pumps to work efficiently.  It's just when it gets below 0F than they start to not do as good.

As for messing with the heat outside, I'm pretty sure the heat you're adding to the outside is negligible to the scale of the world.  And in the winter, you're undoing it by putting some cold out there.

There is embodied energy with making them for sure.  That's a balance that I guess you have to sort out for your own values.  It's certainly more than the equivalent appropriate technologies, if those apply to your situation.  To get the same kind of heating you might be able to burn wood (stove or rmh).  That would probably be a lower embodied energy trade off.  As for cooling, if you can't manage with windows and curtains and shades and trees and other passive techniques, then a heat pump is similar to an air conditioner.  

I think the real benefit comes in when you need both air conditioning and heating AND a heat pump can do both reasonably well for your house.

I don't have one (yet) and many other people know way more about it so hopefully they'll chime in if I'm off base or on base with my ramblings :)

Purse your lips and blow on your hand.  Feels cool, right?  Now open your mouth wide and exhale on your hand, feels warm now.  The reason it feels cool when you purse your lips is that the air is slightly compressed in your mouth (it actually warms a bit), then decompresses after it passes your lips (the decompression valve).  A heat pump does this with a compressor and refrigerant.  In the summer it cools the inside air and dumps the heat outside.  In the winter it cools the outside air and dumps the heat inside.

Look into mini-splits which are ductless heat pumps.  Perfect for a well insulated smaller house.  Ducted climate control was invented when houses were minimally insulated. If you build a very well insulated house, convection can do most of the work of circulating climate control.  Cool up high, and heat down low if possible.  Passive solar design coupled with deciduous trees can do wonders for reducing heating and cooling costs.  Just guessing, but I think dark exterior colors, shaded by trees in the summer, would be appropriate in your location.  Contractors will probably balk,  but don’t overlook 8-12” exterior walls, triple pane windows, etc.  Look into strawbale construction if alternative building methods are an option.  An on demand water heater might be a good option as well.

So we live outside of Fargo, North Dakota.......hot humid summers (and getting worse) and cold dry winters.  I've been told mini-splits may work okay for A/C and have been toying with replacing a window A/C unit with a permanently wall-mounted mini-split.  This would be for a 12 X 12 ft room.  But I've gotten mixed reviews locally about heat-pump heating for our region.  With some nights in the -30 to -40 F range complemented by daytime highs of -20 to -10 F, it's a concern as to how reliably this could heat the 900 sq ft of a two-level, poorly insulated old farmhouse.  With a wood-burner on the main floor, the real concern are pipes freezing in the basement.  Thoughts that could help both the OP and my situation here?  Thanks!

I can not speak to how a heat pump works. I can say that the equipment in my house was horrible at getting the house warm. My climate typicaly only stays below freezing for several hours at a time. We have twice had 2 week stretches of below freezing weather. Occaisonally we dip to 0* F

During our normal weather patterns, we had trouble maintaining 60* F over night. So we were also needing to run space heaters. When we bought 3 of the oil filled radiator style heaters and TURNED OFF the heat pump, we saved $100 per month in electriciy. That was 10 years ago. I have no interest in finding out if the heat pump still works. Now, we could turn on heater number 4 and get 80* F overnight no problem. But we like to sleep a bit cooler.

Maybe our heater was flawed. Maybe better designs exist.

I wish you luck finding a heating option that meets your values.

Well, heat pumps are similar to Air conditioners in that they transfer heat. One side of the system is the hot side the other side is the cold side. I would also open up the system, so they could feel the copper piping were change from hot to cold occurs. I would then mention that different systems use different chemicals to capture the heat and move it outside where it is exhausted.

A heat pump has an extra part on the outside. A reversing valve has been added so that the roles of the inside and outside coils change be switched. The outside coil can now capture the outdoor heat, and the indoor coil can exhaust that heat into the house. Even when the temp is 40 degrees, there is enough heat that can be transferred into the house. The closer we get to 32 degrees F the less heat is available, and from my experience, the system starts to run more than it should, which is why you should have a backup heat source.

How I explained it to a 9-year-old last week.

you know the fridge right?  It keeps things cold inside?  
And on the back of the fridge, it produce heat like this?  (we go to the back of the fridge).

It uses electricity to move goo around inside those coils making one side hot and one side cold.  It uses the same principle only in reverse and using different substances depending on the kind of pump

Then we went into a bit about compression and expansion and how that can produce or absorb heat, but try to keep it light enough that she can absorb the info without getting overwhelmed.  Since the pond is low enough and we have a geothermal heat pump, we can see the coils in the pond and compare them to what the fridge looks like when we take off the back cover.

And then we talked about the spillover heat and how it gets stored in the hot water tank for the tap water.  

...

On the whole, it's a stepping stone technology like recycling.  

From one point of view, it's awesome in that it gets people a step away from their addiction to fossil fuels.  From another point of view, it keeps people living in enough comfort that they aren't willing to risk the larger changes that would make a bigger difference.   I find it's a little of each, but our electric bill (that's heat, well, light, computers, everything) is only $100-150 a month when the average for our neighbourhood for the same house size is about $1200-1600 per month.  I like saving money and it's simple to use, so I'm good with having a heat pump.  Although with the last two summers in BC, I'm considering getting the A/C upgrade.  But that would up the electric bill so...it's unlikely.  

As to how green it is - that depends a lot on how your electricity is produced.  

Eco-wise, if you get proper winters (like with snow), then A Rocket Mass Heater would be a better bet.  Less initial investment and made locally sourced materials.  This video shows how it can be used to cool the house in the summer

Hi,  What size is your home?  A mini split is ok for small spaces. If you are going to use a Rocket Mass Heater, (as the "official" secondary heat source, but really "unofficially" as the primary one,) then go with the cheepest option and get a mini split.  If the home is a bit larger, then a mini split will not meet code for the size of the house and you might need 2 or 3. The electricity costs will be high, and are going up with new taxes and surcharges. I do not know what your winters are like but without an additional heat source you could be cold.   I also do not like using electricity to heat my home because it is the most expensive here where I live, and the source electric plant could be using coal, gas, oil, or uranium.  

Some people with a well use the constant temperature of the water underground to transfer heat into and out of the home.
I think it is good you are looking at options and are getting informed about them. Keep looking, there may be others besides the "established narrative."

As a caretaker sometimes I have to compromise my perfect ideal to meet someone elses needs. I have a belief system that prioritize people above things, yet I will not violate my inner being for another.

Those are some good and simple explainers of heat pump basics, so I won't add much except to say that from an efficiency angle, they're far better than plain old resistive electric heat. If we put 1 kWh of energy into a standard electric heater (baseboard, oil radiator, or one of the glowy ones) we will get 1 kWh of heat energy out. 1:1 efficiency, really simple operation. But a heat pump, because of the way the refrigerant acts when it goes through the compression and expansion parts of the cycle, does some extra juju and because of this, under normal conditions we can get more like 4:1 heating efficiency or better. It starts to drop off if the outside temperature is really cold, but we can fix this by using the earth instead of the air as a source of heat...of course this will cost more to install and set up but in places with proper cold winters it's a viable way to roll.

Induction cooktops: they're basically like a special sort of transformer. We use transformers in lots of ways...you see them in the power grid where they change the voltage from high to low to go from the long-distance lines onto the subdivision feeder networks. A transformer works when the alternating current goes back and forth in a coil and creates a magnetic field that is changing at the same rate (this often creates a low hum or buzz in the metal case). A second coil next to the first one reacts to the changing magnetic field and this creates an alternating current in that coil. The wires on the primary side don't connect to the wires on the secondary, so they can be at different voltages without causing problems.

In an induction stove, there is an alternating current going back and forth in a coil under the ceramic top. When you put a pan on this surface, if it is high enough in iron then the magnetic field will try to set up a current in the metal. Since the pan metal is a pretty good, but not perfect, conductor of electricity, it acts just like the element in a resistive electric heater and gets hot.

We're in the Missouri Ozarks, and pretty much everyone down here goes with a heat pump - and freeze our butts off, in the winter, as soon as the temps get below about 35°F. The heat pump can't pull heat from outside, if there isn't any to pull. If you answer 'how are you heating this place?" with "heat pump", the automatic answer is, "what's your back up?" or, "do you live here, full time?" (this is a huge vacation home area). When we moved from the Great Lakes region, and got this place, we were thrilled that there were several backups that we thought were for emergencies. But, they're not for emergencies - they're necessary even in normal situations. Personally, that far north, I wouldn't have one. Here, it is cheaper during the summer, than running typical a/c, and very effective. But, in the winter, we struggle to keep the heat up much above freezing. Last winter, we were constantly flipping between heat-pump and 'emergency heat' in our electric system, and our electric bills pretty much doubled.

Last year we also looked into mini-splits, thinking to add them to a couple rooms we really struggle to keep warm - and discovered they work very similarly to the heat pump. So, we abandoned that idea, quickly.

Carla Burke wrote:
Last year we also looked into mini-splits, ....

Carla, are you using mini-splits for A/C as well in Missouri and if so, how is that working out with the humidity?  Thanks!....

There are lots of different kinds of heat pumps.  Air to Air is most common here, but there are very few days it gets below freezing or above 80F/30C so no one bothers with backup heat.

Some heat pumps work better than others - but I've also noticed that the people that complain they don't work are in homes with very little if any insulation (due to the lack of extreme weather, why insulate? Oh, THAT's why? ... and so the conversation goes).  

The current advice in our city is that one needs a much less powerful heat pump if one can invest in insulation and change their behaviour like getting honeycomb blinds that they lower during the day in the summer an lower during the night in the winter.  

Less need for the heat pump to be on means less electricity and less wear and tear on the machine which means more eco-friendly and wallet-friendly climate control.  

John Weiland wrote:

Carla Burke wrote:
Last year we also looked into mini-splits, ....

Carla, are you using mini-splits for A/C as well in Missouri and if so, how is that working out with the humidity?  Thanks!....

John, we looked into them, but with what we learned, decided we wouldn't be any better off, so we didn't buy any. Other folks around here that we talked to said they didn't do any better than the heat pumps, when it gets very cold.

R.Ranson has good points, too. Our house is actually pretty well insulated, but we also have big, open spaces, and cathedral ceilings, both upstairs and down. So, it's great for keeping cool, in summer, but not so much for keeping warm, in winter. But, this house was built as the previous owners summer home, so they never expected to need substantial heat.

<TANGENT WARNING>

r ranson wrote:change their behaviour like getting honeycomb blinds that they lower during the day in the summer an lower during the night in the winter.  

Kind of wondering if window quilts would do as well.  I'd never considered such a thing in summer.  I know nothing about the science of honeycomb blinds.

Window quilts should work so long as they don't become a heat sink and keep the house warm at night.

For people heating their houses with supplemental heat because the heat pump can't deal with the temperature differential in the winter, is it possible they'd be better off putting some kind of insulated shed around the outside portion of the unit and heating the air in there?

Jan White wrote:For people heating their houses with supplemental heat because the heat pump can't deal with the temperature differential in the winter, is it possible they'd be better off putting some kind of insulated shed around the outside portion of the unit and heating the air in there?

I've brought this up several times, and each time, I'm met with blank stares... I think it's worth looking into.

Arthur Angaran wrote:Hi,  What size is your home?

 

It will be right around 1000 sqft.  Most of that on the ground floor, with a 200 sqft space upstairs.

Currently in the process of getting a ground source heat pump installed in MA. The install for it goes like this:

-You contact the install company (in my case, Dandelion, if you decide to go with them i can get you $500 off an install, my total will be $28,000 for a 2000 sq ft house)
-The company does a digital scan of your house so they have exact measurements for sizing the system, as well as a layout in case you need to resize or install ducts.
-You get your total quote, and if you agree to continue, you make your first payment.
-A drill rig and supporting vehicles comes to your house and digs 1-3 wells (in our case, 1 well, 486 ft deep). They then install tubes into the hole(s) that are connected at the bottom, and they cap the ends at the top. The hole is then filled with a special cement grout that conducts temperature but doesnt allow liquid through. (This stops any toxic gick from getting in your ground water, and should last forever unless you are at the site of an earthquake or something)
-A trenching rig comes and trenches from the well to your house. In this case the trench only needed to be about 3 ft deep, because they have a higher glycol amount in the lines, so freezing isnt a concern. This crew drills 2 holes in your foundation to put the pipes through, and seals in the pipes, connecting the other end to the well tubes.
-A crew comes and does the interior install based on what you needed done (in our case we are re-using the ducts from forced hot air oil system, and they are just swapping out the furnace for the heat pump, then piping over to it from the pipes they put in the wall. We are also having an aeroseal of our ducts, where they spray an adhesive similar to elmers glue into the duct spaces to fill in any air gaps under 1/8 inch, and protect against condensation, since we have duct channels that are just wood.)

The advantage of ground source heat pumps is that the ground temperature in that well is always around 55°f, so you arent losing efficiency in the hottest or coldest days. The liquid in the pipes is basically windshield washer fluid, with a bit extra glycol in it so its not dangerous to you if it leaks, just dont drink the stuff. The main unit is almost the same thing as an air conditioner, just bigger.

Side note: between each step is about 1-2 months, and Dandelion is booked out about 2 years in MA. They are FAR cheaper than anyone else though. My other quote for the same install was $80,000 from a local place.)

We plan to go solar, so this is a way to get the whole house on 1 energy type, and break out reliance on fossil fuels. We will be over sizing our solar install so that it will still be good after 50 years (the panels we will be using degrade slower, and should be at over 90% of their original capacity after 25 years. When they degrade lower, we will still have space to easily add panels, and if i need to swap them out, i can always use them for irrigation pumps or whatever else)

I figure function of a heat pump was covered pretty well by others, and i would just weigh in on install, since that wasnt really covered, but could be of concern for some.
If anyone has questions, I would be happy to answer them!

We added a mini split to an area of our house that was quite hot in summer and quite cold in winter. House is in a city and zone 7a (typically 90s-100s in summer and 10-40 in winter). That thing is magic. Our electricity usage dropped, both the heat and cooling are great, no seasonal maintenance needs. We will likely upgrade the rest of the house from evap cooling and gas furnace to a heat pump.

So we live outside of Fargo, North Dakota.......hot humid summers (and getting worse) and cold dry winters.  I've been told mini-splits may work okay for A/C and have been toying with replacing a window A/C unit with a permanently wall-mounted mini-split.  This would be for a 12 X 12 ft room.  But I've gotten mixed reviews locally about heat-pump heating for our region.  With some nights in the -30 to -40 F range complemented by daytime highs of -20 to -10 F, it's a concern as to how reliably this could heat the 900 sq ft of a two-level, poorly insulated old farmhouse.  With a wood-burner on the main floor, the real concern are pipes freezing in the basement.  Thoughts that could help both the OP and my situation here?  Thanks!

A simple solution as I see it is, move you wood burner to the basement. That would alleviate any concerns about frozen pipes. Since hot air rises, this might just make mini-splits a viable solution for you...I would get a second professional opinion

John Weiland wrote:So we live outside of Fargo, North Dakota.......hot humid summers (and getting worse) and cold dry winters.  I've been told mini-splits may work okay for A/C and have been toying with replacing a window A/C unit with a permanently wall-mounted mini-split.  This would be for a 12 X 12 ft room.  But I've gotten mixed reviews locally about heat-pump heating for our region.  With some nights in the -30 to -40 F range complemented by daytime highs of -20 to -10 F, it's a concern as to how reliably this could heat the 900 sq ft of a two-level, poorly insulated old farmhouse.  With a wood-burner on the main floor, the real concern are pipes freezing in the basement.  Thoughts that could help both the OP and my situation here?  Thanks!

John Duffy wrote: A simple solution as I see it is, move you wood burner to the basement. That would alleviate any concerns about frozen pipes. Since hot air rises, this might just make mini-splits a viable solution for you...I would get a second professional opinion

(Splitting the two comments above for authorship...)   I certainly haven't ruled them out, but probably would concentrate on the summer cooling for the time being as that is our most uncomfortable period.  One upstairs room in particular is slated for this retrofit.....

OK, so next question (and maybe this needs to be in a separate topic), How would it be to DIY an installation for an old farmhouse?  Current system is oil-fired forced hot air.  We also have a lovely well that might be a source for a ground-source system.  Is this something that absolutely, positively has to be done by a super expensive contractor?  Because we definitely do not have the scratch if this thing is going to cost over $10K.

Maybe actually what I'm looking for are the people who HAVE done it themselves.  Not so much the folks that say "I wouldn't".  OK, you wouldn't, but I might. I've heard about the expense and the wait, and I have a horror of sales-y people tryna sell me a great new technology, etc.  I get that it's a better option for some folks to hire out that work, but I'd love to avoid it if possible.  And in order to make that final determination, I want to hear from those who did the work themselves.  

Aaaaand... go!

Nissa Gadbois wrote:OK, so next question (and maybe this needs to be in a separate topic), How would it be to DIY an installation for an old farmhouse?  Current system is oil-fired forced hot air.  We also have a lovely well that might be a source for a ground-source system.  Is this something that absolutely, positively has to be done by a super expensive contractor?  Because we definitely do not have the scratch if this thing is going to cost over $10K.

You can absolutely do it yourself! I've found that HVAC is one of those things that once you learn the fundamentals, it's no more difficult than basic car repairs.
Things get a bit more complicated when you want to have multiple indoor units run off of a single outdoor unit, but it's nothing that a reasonably handy person shouldn't be able to accomplish. You may have to buy some tools, but it will be far, far less expensive than hiring a contractor. I've heard that HVAC contractors in the US are charging astronomical amounts of money for heat pump installations, so probably best to avoid hiring out if at all possible.

As for how induction cooktops work: The short and oversimplified version is that under the cooktop surface, there is a big copper coil with electricity rapidly going back and forth in it. When a suitable metal pot/pan is placed within close distance of that coil, the circuitry in the cooktop matches the resonance of the pan (kind of like how a big bell rings at a certain note). This causes large amounts of electrical current to flow in the pan, but at super low voltage. Large electrical current = heat.
Essentially, unlike the old style electric cooktops with a heating element the pan sits on, induction cooktops turn the pan *into* the heating element. Stuff heats up super fast, and all the heat goes right into the pan.

Hopefully I've been somewhat helpful!

Nissa Gadbois wrote:OK, so next question (and maybe this needs to be in a separate topic), How would it be to DIY an installation for an old farmhouse?  Current system is oil-fired forced hot air.  We also have a lovely well that might be a source for a ground-source system.  Is this something that absolutely, positively has to be done by a super expensive contractor?  Because we definitely do not have the scratch if this thing is going to cost over $10K.

Maybe actually what I'm looking for are the people who HAVE done it themselves.  ..... And in order to make that final determination, I want to hear from those who did the work themselves.  

So I can't fulfill the request of someone who has done it himself, but I've spoken with enough locals about mini-splits that I feel confident it would be a pretty easy installation as home refurbishings go.  I've had a chance at work, which has a lot of 'cubby hole' type spaces heated and cooled with mini-splits, to observe how they have been installed and see them as a reasonably easy project.  Just now looking at the cost of purchase for room-sized units (~$1000-2000 USD?) without installation.  We live in an old farmhouse as well and I hope to install one next year in an upstairs bedroom.....negating the continued need for a window AC unit.  *If* you are still planning on using some amount of heating oil in your current forced-air unit, then I can see mini-splits for high-use rooms being a good alternative for the nicer winter days and using the central furnace for the cold days (reducing your need for a heating oil refill).  And it seems pretty advantageous that the mini-split can offer some measure of A/C in the summer, all depending on heat severity and needs.

It says you have to be 'tied to the grid'.
One point I remember Jack Spirko talking about with someone who said the same thing was get the utility so you are legally 'connected', then throw the switch.
Unless it's that draconian where they say you have to USE the electricity.

Nissa Gadbois wrote:OK, so next question (and maybe this needs to be in a separate topic), How would it be to DIY an installation for an old farmhouse?  Current system is oil-fired forced hot air.  We also have a lovely well that might be a source for a ground-source system.  Is this something that absolutely, positively has to be done by a super expensive contractor?  Because we definitely do not have the scratch if this thing is going to cost over $10K.

Can you do it yourself (ground source heat pump)? Possibly. Here are some things that may help you make that decision:

1. Do you care if the system is "up to code"? For example, in MA, the well is REQUIRED to be nearly 500ft deep. But you could easily get away with around 100ft if your ground water is high.

2. Do you have access to the tools needed? You will need to dig the well, place the single continuous tube with the u-bend down the well, and grout it off. The other option is using existing well water and no glycol to prevent freezing but this risks well contamination. Do you have access to equipment to dig the trench to your house? The trench should be below the frost line if you arent using glycol, you need to bore through the foundation to get the piping in.

If you can do all that, the rest should be rather simple in my opinion. There are other styles of ground source heat pumps, but the single borehole or well water are probably the simplest and least destructive to existing property. Forced hot air is great though, it means you dont need to modify your ductwork!

All good info but do not get stuck on 1 type of heatpump.  All you need is a lot of mass at modest temperature,  Basically above freezing.  

Mentioned already was a pond based heatpump,  deep well and mini splits. There are through wall units like widow air conditioners.  Might be simpler to diy.

Not much good in MA but south of there you can use a backhoe instead of a well drill.  Dig a trench and lay lots of pipe horizontally.
https://m.youtube.com/watch?v=MUWjjjFgXdg

For cooling you don't need a compressor.  Water comes out of the ground at ~55° F year round.  A fan, radiator and a cool water source is all you need. The power requirements are very low. (Fan and a pump).

Please note modern less then 10 years old heatpump designs have 2 stages.  If you need heat  from an air to air heatpump a modern 2 stage unit will work down to 0F.  

Warning last I looked they still sell single stage air to air heatpumps.  Most of the mini splits are 2 stages.  

Mrcool sells diy precharged mini splits that are plug and play ($2000).  I have heard of 1 hour installs.   If you have or can rent the tools you can diy a normal mini split for less($1200) and the have a local HVAC come out and pressure test and fill it.  The service call should be about $250.  Plus travel time if you are really out of town.
Fyi find the HVAC guy first, many will not touch the cheap Chinese mini split units.

Thank you for the explanation I didn't know how it works, I knew what it gives and in general, but exactly how it works, I haven't seen

Aj Richardson wrote:
Can you do it yourself (ground source heat pump)? Possibly. Here are some things that may help you make that decision:

1. Do you care if the system is "up to code"? For example, in MA, the well is REQUIRED to be nearly 500ft deep. But you could easily get away with around 100ft if your ground water is high.

2. Do you have access to the tools needed? You will need to dig the well, place the single continuous tube with the u-bend down the well, and grout it off. The other option is using existing well water and no glycol to prevent freezing but this risks well contamination. Do you have access to equipment to dig the trench to your house? The trench should be below the frost line if you arent using glycol, you need to bore through the foundation to get the piping in.

If you can do all that, the rest should be rather simple in my opinion. There are other styles of ground source heat pumps, but the single borehole or well water are probably the simplest and least destructive to existing property. Forced hot air is great though, it means you dont need to modify your ductwork!

We already have a well and so I don't know if we need to worry about code for depth or trenching.  It has been here for a long, long time.  Or do we?  So if we already have a well in place, what is there to do?  

 

Nissa Gadbois wrote:
We already have a well and so I don't know if we need to worry about code for depth or trenching.  It has been here for a long, long time.  Or do we?  So if we already have a well in place, what is there to do?  

 

The code is specifically for the geothermal well depth in MA. I also have a well for water, only 100 ft deep, ground water is higher than 80ft here. So to meet code we needed a second well drilled which is like 80% of the cost.

If you were to do the radiator method mentioned above for cooling, and return the water to the well after, you wouldn't need a new well drilled, but you risk contamination of the water, from the plastics or metals that you use for piping. I do not have experience with that method, so I cant tell you what is required for it to meet code or even if it can.

The technology improved rapidly between 2009 and 2013.  I put a mini split ductless heat pump in my well insulated 2000 foot house in Tumwater WA.  I set the thermostat for the heat pump 3 degrees higher than the existing natural gas.  I saved about 30% on my heating bills in winter.
The guy who bought the house from me when I downsized says the gas only comes on 2 or 3 days each winter.  The kicker is, the DHP was sized for a 1000 square foot area.  It’s handled most of the house most of the time.

Thank you for explaining a lot I learned a lot from this I didn't know how it is done / works but now know

Reading through a few of the posts on here, and i have to say....
I currently have a ground source heat pump combined with radiant floor heating, connected too the grid WITH a grid intertied 2 kw solar array.

Now, first thing, the ground source heat pump is exactly how it sounds - it gets it's heat from the ground - year round it is always 45 degrees in my area 5 feet down or so.  Do not confuse this with an air source heat pump that will not work in cold temperatures - since it uses the outdoor air for a heat source.   So the heat pump transfers 5 or 10 degrees of heat energy to the inside water tank, and sends out 32 degree water back outside.  As it travels through the 2,400 feet of 1 inch plastic pipe, it warms back up to the ground temperature of 45 - returning to the house to do it again a constant source of free energy, which is replenished every summer.
Just reverse the process for a/c.

I like the fact that all the heat stays in the building, no chimney.  And, when the unit shuts off, the temperature continues to rise  - since all the electrical energy that was used to run the motor - is converted to heat - that warms the tank of water up several degrees AFTER it shuts off - kinda cool when ya think about it.

I have my heat pump set at the max temp of 115 degrees F.  Since i did not realize that wood is an insulator, when i installed the radiant floor panels.... so i installed a warm water rad on a seperate thermometer, once it hits about -5 C  the rad kicks in - keeping the house at 72 F.

Clear as mud ?

Mike Haasl wrote:
As for messing with the heat outside, I'm pretty sure the heat you're adding to the outside is negligible to the scale of the world.  And in the winter, you're undoing it by putting some cold out there.

This worry about heating or cooling the outside air is a red-herring. Yes, when heating your house these units cool the air passing over them slightly. But all they are doing is "borrowing" the heat energy and moving it into your house. Your house is warmer than the surroundings so is always leaking heat back to the surrounding air. Over the course of a day these two will balance - if they don't balance then your house is either gradually getting colder or hotter each day. There may be a tiny local effect, but the moving air quickly mixes it all together again. Just don't put your delicate plants right near the output of the heat exchanger in winter, and you should be fine.