• Post Reply Bookmark Topic Watch Topic
  • New Topic
permaculture forums growies critters building homesteading energy monies kitchen purity ungarbage community wilderness fiber arts art permaculture artisans regional education skip experiences global resources the cider press projects digital market permies.com private forums all forums
this forum made possible by our volunteer staff, including ...
master stewards:
  • Nicole Alderman
  • r ranson
  • Anne Miller
  • Pearl Sutton
  • James Freyr
  • Mike Haasl
  • paul wheaton
  • Dave Burton
stewards:
  • Joylynn Hardesty
  • Jocelyn Campbell
  • Joseph Lofthouse
garden masters:
gardeners:
  • Carla Burke
  • Steve Thorn
  • Eric Hanson

Micro Heat Pumps, DIY

 
pollinator
Posts: 583
Location: Southwest U.S.
12
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
See how easy it is to convert a small window a/c unit for water heating using the condenser:
I considered this idea a while back. I'm glad I stumbled on this video as it's great to get a visual with videos like this. Now, note the energy recovered at 7500 btu/hour! This represents the energy removed from the air at the evaporator and most of the energy consumed by the compressor motor. That's a lot of energy at more than 2 KWh per hour (i.e. 2 KW for a roughly 500 watt compressor motor). This unit would have to be operated for only a few hundred hours to fully pay for itself with the electricity savings alone. Kinda seems absurd to consume energy in operating an a/c system while also consuming energy to heat water, doesn't it?

It should be possible to enclose the condenser with an insulated shroud, then pump water slowly through for heating. Also, while the evaporator doesn't look quite as accessible as the condenser, it may be possible to do the same for the evaporator. This latter configuration might make it practical to send solar heated water to the evaporator, and this can allow the unit to take the condenser temperature a little higher for efficient space heating during winter. Since solar heated water can be stored fairly easily at relatively low temperatures, then this might yield good results. Note that this seems to make sense only for quite cold regions where heat pumps don't do well due to the high temperature differentials. What I'm thinking is a water/glycol solution might be heated to a warm temperature that may not be useful for direct space heating, but can be used efficiently by a heat pump. Not having to take the fluid temperatures high with the solar system will reduce thermal losses a great deal, and this should allow a DIY solar water heating system to work well. However, for regions with very mild winters it makes a lot more sense to just install a window a/c unit in reverse for space heating.

Also note that water cooling the unit would allow the "window" unit to NOT have to be mounted in a window. This is great since these are rather unsightly.
 
Marcos Buenijo
pollinator
Posts: 583
Location: Southwest U.S.
12
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
This is a continuation of the previous post. Note that since the fan is removed on the fan motor shaft on the water cooled side (the motor has a shaft penetrating both ends, one for the condenser fan and one for the evaporator fan), then perhaps it can be practical to install a small pulley on the freed shaft for driving a water pump. The cover for the unit might be replaced and one of the heat exchangers (condenser or evaporator) could be enclosed in an insulated enclosure that can be mounted to the outside of the unit. I was thinking that even without the heat recovery, then perhaps this kind of conversion would be worthwhile by allowing the unit more versatility with respect to mounting. The pump might also circulate water that is cooled (or heated) with a nearby water source or other ground source heat sink (i.e. geothermal). Basically, there are more options when water is the heat transfer medium, and installing a water pump integral with the unit could make for a practical system. Also, I believe water cooling the condenser, even assuming the water pump has the same work load as the fan it replaced, would increase efficiency (even w/o heat recovery).
 
Marcos Buenijo
pollinator
Posts: 583
Location: Southwest U.S.
12
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
(COOLING) This is just another discussion of a means to devise a heat pump for cooling an off grid home. I have yet to see this done or discussed elsewhere, but it seems reasonable to me that a photovoltaic array can be used to power an automotive a/c compressor by using a dc motor. The system can be configured to freeze a mass of water (at least partially) for providing a chilled water system. I see many advantages to this configuration. For example, one would not have to worry about the massive current draw (especially starting current) on such a motor because it can be powered directly by a battery system vs. a large inverter. This would allow a modest battery system to be used since the system is operated only while the PV array is putting out, so little battery storage is required. BTW, what I considered was using "small" dc motors often used for EV conversions. Many of these are reasonably priced at a few hundred dollars and operate at 48 volts. Many also have a continuous rating compatible with common automotive a/c compressors, most of which can handle 3-5 hp at 2000-3000 rpm. The system could be configured to power the compressor at a rate roughly proportional to the output of the PV array to minimize battery discharge and charge rates. The simplest way to do this that I've considered is to start the motor with a continuous duty solenoid switch using a control circuit that prevents operation when battery voltage drops below a certain value (various ways to do this).

(HEATING) Example of a large DIY solar water heating system:
. Something like this might be used to provide heated water for use in air heating using the same "chilled" water system described in the paragraph above. The additional electricity provided by a large PV array required to power a chilled water system could be used during the winter months to power electric space heaters. Furthermore, a simple biomass furnace could be used to heat the water store via a thermosiphon heat exchange system when solar is insufficient (redundancy is nice). A simple rocket furnace could work well: http://www.youtube.com/watch?v=5IRLVCJ1olA .

Specs on common automotive a/c compressors: http://sanden.com/index.php?tag=U5H0AMX7Q
A source for dc motors and controllers: http://www.electricmotorsport.com/
(one of many sources)

 
Marcos Buenijo
pollinator
Posts: 583
Location: Southwest U.S.
12
  • Likes 2
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
It's interesting to consider how a window a/c unit might be configured for different uses. Consider placing a window a/c unit in a window backwards for heating a room. Now, enclose part of the exterior wall of the home that includes the window in what is essentially a green house (or trombe wall). Place the unit on a thermostat to ensure it operates only when the air temperature is high enough for efficient operation. Heat pumps are not normally a good idea for cold climates, but enough solar gain here should make for efficient operation. If someone is already heating with electricity, then this approach seems reasonable.



 
gardener
Posts: 2521
Location: Cincinnati, Ohio,Price Hill 45205
186
forest garden trees urban
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Found this thread while googling .

I often wait for water to come up to the tempature I desire,and waste the cooler water down the drain.
I started out noodling about a small (less than 3 gpm)electric point of use water heater as my only water heater.
We wash clothes in cold water only and our fixtures are low flow.

I thought we might be able to run it off of a small photovoltaic array,and looking into that,found a suggestion that this could be more effective than thermal solar water heating

The trick was using the PV to power a heat pump water heater,which are pricey.
This led me to DIY solutions, which led me here.
Somehow I'm not surprised.
😏
If one repurpused a RV air conditioner , it would presumably be DC to start with.
This is cool,but isn't solving my water wasting issue.

 
pollinator
Posts: 1284
Location: Massachusetts, 6b, urban, nearish coast, apartment building, landscaping, help!
89
kids trees urban
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
HeatSmart or HeatNotSoSmart?
My state offers rebates to incentivize installing ductless heat pumps, air source or ground source.  Bit should I?

We have a wall-mounted AC that came with the building (circa 1950??? It has dinosaur prints on it).  For heating, we have (trigger warning) baseboard electric.  

If we replaced it, what would happen to the cfc's, hcfc's or whatever is kn there? What about production of new hcfcs? Embodied energy of creating the heat pump?

A rocket mass heater is extremely out f the question for here--an apartment bld of 12 units.  But I think I could sell the landlord on a heat pump with the argument, "Do you hate money or something? " plus the word "rebate".  However, I have trust issues.  I saw the trash pickup the other day throw a window ac unit in the compactor (!). It had been left out in the dumpster, probably by someone who didn't know the laws about ac disposal. But how do I know if the dump really handles the hcfc's or whatever resposibly??

So I am looking into the retrofit option...and I am not a techy.  

One source says "you have to replace the outdoor tube with a wider tube" and open up the cfc tube in the process. That's above my pay grade.

I've got the "heat the person not the air" memo.  But sometimes the air is complaining that it's too cold in here.  I guess I need to get her some heat pads and incandescents, but should I also pursue the heat pump thing?  It's so tantalizing...

I haven't checked but I assume that a home repair cannot simply turn the ac around and aim the cold end out at the bitter New  England winter.  

Can the outside tube instead of replacement be fitted with "wings" (like they have on baseboard electric heaters and steam radiators to disperse the heat) that increase its surface area? Would these wings accumulate more heat or just cool the outside tube even more? Is there an easy way to change the order of the components in the unit (I understand the order is what differentiates an ac from a heat pump--exchanger, condenser,  evaporator,  etc.).

Thanks team!


 
 
master pollinator
Posts: 4678
1072
transportation cat duck trees rabbit books chicken woodworking
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator

Marcos Buenijo wrote:It's interesting to consider how a window a/c unit might be configured for different uses. Consider placing a window a/c unit in a window backwards for heating a room. Now, enclose part of the exterior wall of the home that includes the window in what is essentially a green house (or trombe wall). Place the unit on a thermostat to ensure it operates only when the air temperature is high enough for efficient operation. Heat pumps are not normally a good idea for cold climates, but enough solar gain here should make for efficient operation. If someone is already heating with electricity, then this approach seems reasonable.



I have thought long and hard about this because I have the ideal spot to try this, but after a lot of thinking, it would seem to me, just building what amounts to a micro-greenhouse on the outside of the house would get some significant heat, but instead of even bothering with a air conditioner and some inefficiencies of running electricity, why not just open the window when it gets warm? I call them "Windowstats" affectionately enough. I think enough cool air of the room, with the warm air of the outside greenhouse, would mix to provide heating of the room with very little costs. I cannot see how the air conditioner would really help in that situation.
 
Joshua Myrvaagnes
pollinator
Posts: 1284
Location: Massachusetts, 6b, urban, nearish coast, apartment building, landscaping, help!
89
kids trees urban
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
That's a good point,  except humidity from a greenhouse can be a lot.  Ben Falk had built one and then had a mold problem.  Now I think it was because it was an active greenhouse (the plants inside raised the humidity a lot), but uf you dont stack functions it can work.

Other thoughts--
It may be necessary to augment with the heat pump on very cold or cloudy days.
A thermal mass---big black plastic or painted black cedar bin of water? (Metal will rust!)

---
I'm on the north side of the building, so I need a different solution...





 I

Travis Johnson wrote:

Marcos Buenijo wrote:It's interesting to consider how a window a/c unit might be configured for different uses. Consider placing a window a/c unit in a window backwards for heating a room. Now, enclose part of the exterior wall of the home that includes the window in what is essentially a green house (or trombe wall). Place the unit on a thermostat to ensure it operates only when the air temperature is high enough for efficient operation. Heat pumps are not normally a good idea for cold climates, but enough solar gain here should make for efficient operation. If someone is already heating with electricity, then this approach seems reasonable.



I have thought long and hard about this because I have the ideal spot to try this, but after a lot of thinking, it would seem to me, just building what amounts to a micro-greenhouse on the outside of the house would get some significant heat, but instead of even bothering with a air conditioner and some inefficiencies of running electricity, why not just open the window when it gets warm? I call them "Windowstats" affectionately enough. I think enough cool air of the room, with the warm air of the outside greenhouse, would mix to provide heating of the room with very little costs. I cannot see how the air conditioner would really help in that situation.

 
Travis Johnson
master pollinator
Posts: 4678
1072
transportation cat duck trees rabbit books chicken woodworking
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I think the more efficient situation in my situation would be to make a greenhouse out in my field of decent size, and then berm the north wall to keep the wind from reducing its effectiveness. And then with a thermostat, switch on a fan when the temp gets warm enough and blow that heat into different areas of the house. In that way, I could build the greenhouse to capture the best sun, and be sized o heat my home.. Then through insulated duct work, send it into the house when, and where it is needed. But that is why I have always liked Active Solar over passive solar, there is a lot more control over the heat.
 
Joshua Myrvaagnes
pollinator
Posts: 1284
Location: Massachusetts, 6b, urban, nearish coast, apartment building, landscaping, help!
89
kids trees urban
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
By the way, forgot to mention they did suggest a similar thing in course from Dancing Rabbit ecovillage--take black plant potting trays or something black, cover with a transparent plastic garbage bag, and hang it out the south window at a 45 degree angle or so, with the opening up to the opening at the bottom of your window (you open your window 6 inches or so in daytime).  The hot air drafts up into your living space.  

Again, I'm on the north side.

I think the building management company, and the Town, would frown upon my building a greenhouse in the front yard and an insulated pipe to the back where my apt. is and then berming the north side, but hey, you never know if you don't try...
 
Travis Johnson
master pollinator
Posts: 4678
1072
transportation cat duck trees rabbit books chicken woodworking
  • Likes 1
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator

Joshua Myrvaagnes wrote:By the way, forgot to mention they did suggest a similar thing in course from Dancing Rabbit ecovillage--take black plant potting trays or something black, cover with a transparent plastic garbage bag, and hang it out the south window at a 45 degree angle or so, with the opening up to the opening at the bottom of your window (you open your window 6 inches or so in daytime).  The hot air drafts up into your living space.  

Again, I'm on the north side.

I think the building management company, and the Town, would frown upon my building a greenhouse in the front yard and an insulated pipe to the back where my apt. is and then berming the north side, but hey, you never know if you don't try...



Yeah for everyone it is different, so ultimately how a home is heated varies greatly.

Believe it or not, my curse is having a few resources. Solar to me is the same as compost heat when I finally think it all through. There is no question it would work, and it would heat my house, but then at what cost? With compost heat, I have everything here to do it...just as I have a nice southern exposure...BUT I also have a woodlot. So in less time then it would take to put up a compost heating pile, I could cut enough wood to heat my house, so I don't do the other things.

And worse yet, now that I have got used to a wood pellet stove, I have realized I do not even have to firewood. I cut up a load of tree length hardwood, which I can do in a day, and sell that to someone who needs firewood, or a papermill. Using the money from that single load of wood, I can buy enough pellets to heat my home for a year.

It is not that some of this stuff will not work, but is just that time wise, there are better ways to accomplish the task.

 
Joshua Myrvaagnes
pollinator
Posts: 1284
Location: Massachusetts, 6b, urban, nearish coast, apartment building, landscaping, help!
89
kids trees urban
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Well it sounds like it comes out about the same materially as if you burned your own cut wood.  How much energy goes into cutting the wood into pellets?

The solar heat thing could be done for pennies, the plastic one, and then you just leave it in place. It would just take opening the window and closing each day.
 
Travis Johnson
master pollinator
Posts: 4678
1072
transportation cat duck trees rabbit books chicken woodworking
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator

Joshua Myrvaagnes wrote:Well it sounds like it comes out about the same materially as if you burned your own cut wood.  How much energy goes into cutting the wood into pellets?



No, you kind of have that backwards. My method uses more material, but there is no energy or money spent in getting pellets for it.

I take a load of tree length hardwood, which is ten cords, or about 26 tons, and then sell it, and then take the money gained, and buy 4 ton of pellets. I do that because I got plenty of trees, and it only takes me a day to get that 26 ton of wood.

It would be the equivalent of a person spending an hour gathering 10 quarts of strawberries, and then trading it with a neighbor, and getting back 4 quarts of strawberry jam ready for the pantry. In that way, you trade what you have plenty of, and while you get less back, it is 100% done for you with no work or expense. So instead of spending 4 hours in the kitchen, you get a years worth of strawberry jam for an hours worth of your time. Its the same thing for me. A day of cutting wood nets me enough wood pellets to heat my home for a year.

Joshua Myrvaagnes wrote:The solar heat thing could be done for pennies, the plastic one, and then you just leave it in place. It would just take opening the window and closing each day.



Yes, but there is some other aspects at play too. You would lose the view from the window, and there is egress too in terms of life safety in case of a fire. I would want everyone to be able to get out quickly without having to fight their way through plastic sheeting or glass glazing. Again, none of these things are really a big deal, but they can be.

In the business world such things are known as "hidden costs". With alternative energy there are often "hidden costs" which may not be monetary in value, but not being able to look out the window at distant fields is still a "cost" of sorts. For some that is a cost worth doing, and for others it may be too much. For me, I would live in an RV inside a greenhouse and get my costs down to nothing...if my family was to all perish in a car accident and I was suddenly to be alone. BUT as a father of four, and a husband, I have to take into the desires of all of my family, and so my decisions are based upon that.

To some degree, deciding not to do some of these things is Paralysis By Analysis, but kind of not. That is when a person overthinks things, but sometimes it is good to think through all the pros and cons too.

I think the biggest problem is only having 24 hours in a day. I can only do so much, so I have to really prioritize what I do, and keep in mind this is coming from a retired guy! I got lots of time, but not nearly enough of it still. As an example, I used to think spending 3 days doing firewood was a justified use of my time, but now that I have got it down to only one day, it is pretty hard to spend additional time building something to heat my home, when I am already warm.

 
Posts: 127
Location: Southern New Hampshire (Zone 5)
8
  • Likes 3
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator

Joshua Myrvaagnes wrote:HeatSmart or HeatNotSoSmart?
My state offers rebates to incentivize installing ductless heat pumps, air source or ground source.  Bit should I?

We have a wall-mounted AC that came with the building (circa 1950??? It has dinosaur prints on it).  For heating, we have (trigger warning) baseboard electric.  

If we replaced it, what would happen to the cfc's, hcfc's or whatever is kn there? What about production of new hcfcs? Embodied energy of creating the heat pump?

A rocket mass heater is extremely out f the question for here--an apartment bld of 12 units.  But I think I could sell the landlord on a heat pump with the argument, "Do you hate money or something? " plus the word "rebate".  However, I have trust issues.  I saw the trash pickup the other day throw a window ac unit in the compactor (!). It had been left out in the dumpster, probably by someone who didn't know the laws about ac disposal. But how do I know if the dump really handles the hcfc's or whatever resposibly??

So I am looking into the retrofit option...and I am not a techy.  

One source says "you have to replace the outdoor tube with a wider tube" and open up the cfc tube in the process. That's above my pay grade.

I've got the "heat the person not the air" memo.  But sometimes the air is complaining that it's too cold in here.  I guess I need to get her some heat pads and incandescents, but should I also pursue the heat pump thing?  It's so tantalizing...

I haven't checked but I assume that a home repair cannot simply turn the ac around and aim the cold end out at the bitter New  England winter.  

Can the outside tube instead of replacement be fitted with "wings" (like they have on baseboard electric heaters and steam radiators to disperse the heat) that increase its surface area? Would these wings accumulate more heat or just cool the outside tube even more? Is there an easy way to change the order of the components in the unit (I understand the order is what differentiates an ac from a heat pump--exchanger, condenser,  evaporator,  etc.).

Thanks team!


 



the ductless minisplit heat pump was pretty much invented for this application use-case

they run 3x-4x more efficient than the electric baseboard heaters, and god-knows-how-much-more-efficient than that old 1950s rattle-box.  

Take the MassSaves discount for a minisplit heat pump, and enjoy the comfort and lower electric bill

recycle the old A/C at your Town Transfer Station.  They have contractors who will pump down the old freon and dispose of it safely.
 
Travis Johnson
master pollinator
Posts: 4678
1072
transportation cat duck trees rabbit books chicken woodworking
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Joshua has really got me researching these things, and it is surprising how simple they are.

As far as what I can see, if a person disabled the thermostat in an room air conditioner, then mounted two in their house, one in the normal configuration, and then the second in backwards, then wired two thermostats to the start circuits, they would have a fully functional heat pump for $300 that both cooled and heated a home.

If a person was semi-ambitious, they could pull the evaporator off the air conditioner that is in backwards, and then put it where it was submerged in warmth. A person would have to add in longer copper tubing, and then connect the cut lines to make the necessary length, but that is pretty simple. As for where to place the evaporator, I had a few thoughts on that.

1) A person could run loops of PEX through a trench four feet underground, but that would only net 57 degree water.

2) For a quick minimum-dig option for even more btu's, a homeowner could stick the evaporator in their septic tank. That would be semi-compost heat that would help heat the home. It would be a lot warmer then 57 degree geo thermal heat.

3) I think a person could gain a whole lot more BTU's though if they stuck the evaporator in a compost pile. That would pump some serious heat into the house. That would be a modern spin on the Jean Paine compost heat way, yet without troubling the homeowner with trying to loop a lot of tubing through a compost pile.

In any case Joshua, thanks for gtting me to look into these things. They look like they are very easy to make in a do it yourself setting!
 
Davis Tyler
Posts: 127
Location: Southern New Hampshire (Zone 5)
8
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
it might be a fun project for someone, but the incentives through MassSave gives you $1,000 rebate per ton of capacity.  A $1,300 minisplit would only cost you $300.  And it's guaranteed to work.  The backwards A/C will freeze the coil in cold weather since there is no reversing valve or defrost cycle.
 
Travis Johnson
master pollinator
Posts: 4678
1072
transportation cat duck trees rabbit books chicken woodworking
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
That is true, but not if the evaporator coil was in the ground, in a septic tank, or in a compost heap...
 
Joshua Myrvaagnes
pollinator
Posts: 1284
Location: Massachusetts, 6b, urban, nearish coast, apartment building, landscaping, help!
89
kids trees urban
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Thanks Davis.

I checked my town dump, and they say:

No appliances accepted (A/C, dishwasher, water heater) - you can dispose of these ($20 each) by calling JRM at 800-3XX-XXXX, paying over the phone, then making an appointment for them to be picked up at the curb.
(I blacked out JRM's # because I don't really want to do product placement for them.  I don't know them.  What I do know is that some of the workers for them recently took an AC unit that was in a dumpster from our building or next to it, I can't remember now, and tossed it in the compactor (this part I do remember clearly).  I want some more reassurance.

I emailed back the ductless air pump company and asked them how they dispose of old CFC's, and they said they bring them to their distributor.  I called their distributor and left a message, and have not heard back.  They advertise on their site that they prioritize service "with urgency," and I do not feel a sense of their urgency on this issue.  

I'm thinking it would be most efficient, at this moment, simply to keep the heat down at 55 degrees, use the space heater (off our wind power purchase agreement, this is pretty much clean energy), and use heating pads.  I also don't know the embodied energy of creating another air-source heat pump.  (The ground source ones seem much more reasonable.  They just use water and a bit of anti-freeze, the MIT professor said.)

Thanks for sharing thoughts.  If I get more clear info I'll share it here.  

I just want to register my disappointment that people aren't on top of this more--all people.  Including the distributor company returning my call about an issue that's more important than how much money people make.  If you get a question from someone asking about the sustainability of something you're doing, please take the time to get back to them, even if it's just to say "I don't know."  


Davis Tyler wrote:

Joshua Myrvaagnes wrote:HeatSmart or HeatNotSoSmart?
My state offers rebates to incentivize installing ductless heat pumps, air source or ground source.  Bit should I?

We have a wall-mounted AC that came with the building (circa 1950??? It has dinosaur prints on it).  For heating, we have (trigger warning) baseboard electric.  

If we replaced it, what would happen to the cfc's, hcfc's or whatever is kn there? What about production of new hcfcs? Embodied energy of creating the heat pump?

A rocket mass heater is extremely out f the question for here--an apartment bld of 12 units.  But I think I could sell the landlord on a heat pump with the argument, "Do you hate money or something? " plus the word "rebate".  However, I have trust issues.  I saw the trash pickup the other day throw a window ac unit in the compactor (!). It had been left out in the dumpster, probably by someone who didn't know the laws about ac disposal. But how do I know if the dump really handles the hcfc's or whatever resposibly??

So I am looking into the retrofit option...and I am not a techy.  

One source says "you have to replace the outdoor tube with a wider tube" and open up the cfc tube in the process. That's above my pay grade.

I've got the "heat the person not the air" memo.  But sometimes the air is complaining that it's too cold in here.  I guess I need to get her some heat pads and incandescents, but should I also pursue the heat pump thing?  It's so tantalizing...

I haven't checked but I assume that a home repair cannot simply turn the ac around and aim the cold end out at the bitter New  England winter.  

Can the outside tube instead of replacement be fitted with "wings" (like they have on baseboard electric heaters and steam radiators to disperse the heat) that increase its surface area? Would these wings accumulate more heat or just cool the outside tube even more? Is there an easy way to change the order of the components in the unit (I understand the order is what differentiates an ac from a heat pump--exchanger, condenser,  evaporator,  etc.).

Thanks team!


 



the ductless minisplit heat pump was pretty much invented for this application use-case

they run 3x-4x more efficient than the electric baseboard heaters, and god-knows-how-much-more-efficient than that old 1950s rattle-box.  

Take the MassSaves discount for a minisplit heat pump, and enjoy the comfort and lower electric bill

recycle the old A/C at your Town Transfer Station.  They have contractors who will pump down the old freon and dispose of it safely.

 
pollinator
Posts: 2441
Location: Massachusetts, Zone:6/7, AHS:4, Rainfall:48in even Soil:SandyLoam pH6 Flat
154
forest garden solar
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
A half ton (6,000BTU) window ac unit will not heat your apartment. Your house most likely needs 60,000BTU (5ton unit). The easiest fix would be to take your domestic hot water and send it to a fan coil unit (radiator). And have that heat your house. You can produce that hot water in a myriad of ways: Instant water heater or regular hot water tank (gas or electric), heat pump, wood stove/broiler, compost, solar collector, wind/hydro-electric, etc). All that said getting a new mini-split sounds like a wonderful solution. The newer ones that uses only super-critical carbon dioxide as the refrigerant are great, but even a MrCool DIY is good too.


For myself personally I would like to have a in-floor water loop to distribute heat. I would heat this water with a 1)heat pump or 2)instant water heater or 3)wood stove/etc. A fan-coil unit could be added to the unit to heat up the air quickly. In the summer I could use this same loop to cool the house. But then there is condensation issues on the floor and humidity. So I could would build a fan coil unit. With the fan coil having the lowest temperature in the loop (1st in the loop) it would handle the de-humidification and then the in-floor loop would handle the regular cooling. A water to water heat pump is probably the best source for the cold water. But a air-water heat pump also works and if we want to get even more low tech just a spring or well could directly provide the cold water. On another note alot of these heat pumps will also take some of waste summer heat to produce domestic hot water

Humidifier (Indoor Plants, Aquarium, Fan+Wet Filter Evaporator Unit passive 60% RH limit)
De-Humidifier (Fan Coil Unit, etc)
Air Filtration (Indoor Plants, Aquarium with air stone, Fan+Filter Unit)
Ventilation (Indoor Plants, Open a window, ERV/HRV)
Point Source Removal (Kitchen/Bathroom Exhaust Fan, off-gassing sofa/mattress foam & plywood/particle board furniture)

PEX-pipe water loop in floor (1,000ft of pipe for 1,000sqft of house)
Fan Coil Unit (Radiator + Fan + Drain pan to change the air temp more quickly and to fix humidity/moisture problem)
Buffer Tank (optional but would allow more flexibility in heat source and time of production efficiencies)
Domestic Hot Water (optional summer waste heat could make DHW, and 1 less appliance for winter DHW)
Engine (Heat Pump, Wood Stove, Gas, Electric Resistive, Compost, etc)
Outside (Heat Pump could be air or water/geothermal loop, Gas/Wood Stove would need ventilation)
Sensor (Temperature, Humidity, Air Particulates and assumed speed of fans/pumps/motors)
Controller (with so many fans and pumps and sensors a controller could automate and optimize the setup or it could just be mostly manual but alot of folks have a thermostat of sorts)
 
pollinator
Posts: 370
Location: Boston, Massachusetts
111
urban books building solar rocket stoves ungarbage
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Joshua Myrvaagnes, I think you are conflating the heat pump company's service urgency policy, which I would think to refer to "equipment service" like a technician coming to fix it, with "customer service" like the staff at the office answering your calls and requests for information.

(since were neighbors...) My town does take appliances/"Freon units" (AC, refrigerator, freezer)... similar cost (maybe less?) and I know they have them pumped out, I've seen the guy there doing it.

If I were your landlord, I wouldn't want any sort of DIY heater, too much of a liability. A "real" unit with a warranty, etc... would be different, if it made sense for the upgrade/update. Since the operational costs are the tenant's (old/inefficient or new/efficient), a landlord is unlikely to see a benefit unless it saves them service/repair costs, or warrants a rise in rent.
 
We don't have time for this. We've gotta save the moon! Or check this out:
permaculture bootcamp - learn permaculture through a little hard work
https://permies.com/wiki/bootcamp
  • Post Reply Bookmark Topic Watch Topic
  • New Topic
Boost this thread!