Starting DIY GSHP mainly for AC - Page 2

Vlad · 07-02-12, 01:46 AM

Quote:

Originally Posted by vanderzac

I think I'm understanding it better after reading and re-reading it, unfortunately concepts are sometimes a bit too dense for me the first few times and I really struggle reading something over and over to understand and comprehend it. Anyways, as I can tell in an oversimplified fashion, the condenser of the heat pump is placed in a bath of water, and that water is cooled by dripping over the evaporation pads while circulating air (AC2 example). This will keep the water temperature equal to the wet bulb temp (which is usually about 30 degree's cooler when humidity is low), but that when air is already fully saturated the system not would work nearly as well, which is coincidentally the issue we have with our current cooler during July and August monsoon, where the air becomes so humid that it cannot be cooled by evaporation. With a GSHP my water would be circulated through the ground to keep cool, thus not affected by relative humidity, and the water temp would consistently be around 50f, instead of 80 (110-30), which should also make the system more efficient.

Does this sound conceptually correct?

Thank you again for helping me through this and providing useful suggestions.

You are right conceptually. When RH is 100% wet bulb and dry bulb are the same because water can't evaporate more and cool surface by evaporation.

But I have some questions:

Are you sure that you will have 50F water in your ground loop?

Are you sure about 50F(you actually need it lower than 50F) for your earth temperatures and depth you go? And don't forget that to get earth temperature your loop must be HUGE. If you use your loop mostly for one side (heating like mine or cooling like yours) you have to grossly oversize it. And even then your loop temperature will be higher than earth.

Also 100F outside @ 90% RH is questionable. I do understand you it is hot outside but did you check RH?

Check this links:

Geothermal Heating Contractor for Massachusetts and surrounding area

Average Relative Humidity(%)

Make sure you find answers for 2 questions

1. Your ground temperature @ 50-100feet
2. Your historical temperature and RH

You might be surprised.

vanderzac · 07-02-12, 02:44 AM

Hi Vlad. I totally agree with you that the normal day in Tucson summer does not have 90% humidity and 100F temperatures. For example, it rains about 33% of the days during monsoon season. On those days humidity is above 90%, and temperatures are frequently above 90F. Average Weather for Tucson, AZ - Temperature and Precipitation This site shows average daily high temperature, with a record option as well. 7 of the last 10 years have been record high averages in our area, attributed mostly to global warming (right or wrong is another argument). I am looking to maintain year round comfort, regardless of ****ty outside atmospheric conditions on 1 of every 3 days for 2 months, and I am sure of these numbers. As for the average ground temp in my area, your data shows the ground is 60, and I think it would reliably stay in that range as long as I have a large enough water field. I have room to do at least 10 boreholes in my back yard, and could add more in the front if absolutely needed, though I would prefer not to drill that close to the road, and can dig as deep as I choose to go if I try to build a hydrolic drill like yours.

Vlad · 07-02-12, 03:43 AM

vanderzac,

In your case (as same as in my case) you have to make sure your ground loop is as huge as possible. Also you can add desuperheater for domestic hot water and enjoy free hot water. This will add extra capacity to your system.

If you are dead serious about building a rig I can only suggest to you to build it right and strong.

Don't go with toys they don't drill (actually they drill your brain

). Make sure you buy a GOOD drill bit. My bit is as sharp as new no even a sign of wear or chip after about 1000 feet of drilling. Yes it was mostly clay and very compacted sand but I had few very nasty rocks.

Go over my pictures and component's specs. I spend a lot of time experimenting you can just copy/paste and save a ton of time.

If you have any questions I will gladly try to give you an answer.

vanderzac · 07-02-12, 11:44 AM

When you say as huge as possible, I'm still floundering figuring out what extreme I should be going to through... My house is only 1100sqft, though it is all brick and I'm pretty sure I'm loosing a lot of BTU's from lack of insulation. Once I figure out if I can drill (permits) I'll look into what I should plan my BTU usage to be, and I'm sure I'll be asking sizing questions for the field then, but I have a hard time believing 1000ft wouldn't be enough so long as they are each at least 100ft deep when comparing AC's results on 16 boreholes only 20ft each, Though I could be wrong and love input and food for thought

I appreciate the offer and I'm sure I will have lots of questions building my drill. I fully agree cutting corners is not worthwhile, and knowing that less robust drills sell for $3K+ I figure I can recover the cost on the drill once I'm done so long as I build it right. I have been over the drill thread 3 or 4 times, and am going to start planning out the drill soon.

For now I need to make sure I'm not dead in the water before I even start by getting in touch with the local bureaucrats about whether I need a permit or not; I know well water permits here cost 10K... As for the desuperheater, I will absolutely take advantage of my free hot water. While I'm at it, I have a 1970's Jacuzzi shell that needs a serious DIY effort to get running (no frame, pumps, or heater currently) and will be using the system to heat that too. As I look I am constantly seeing applications where I could tie into the system and gain extra efficiency, I love that.

vanderzac · 07-03-12, 03:17 PM

It looks like I'm good on the permits front. The water department does not regulate boreholes drilled less than 100ft, so that will be my guideline. I was originally worried because the gas and oil development documentation had 10K permit prices, but after contacting them I found out they only apply to commercial installations. It seems I'm on to steps 2 and 3, deciding how many boreholes I need (or if I just want to put in as many as I can while I still have the drill), and learning how to build a giant drill.

Vlad, I am a computer programmer by trade, and unfortunately have almost know knowledge of the mechanical world. I don't suppose you could recommend any links on hydrolic motors that explain how they work and how to engineer/build things with them? Personal development is actually the largest reason for me undertaking this project; I realize that knowing how motors work and how to manipulate mechanical force was a cornerstone of industrialization, and that I have managed to grow up without understanding how machines work, which is something I need to fix.

Vlad · 07-04-12, 03:41 AM

Quote:

Originally Posted by vanderzac

It looks like I'm good on the permits front. The water department does not regulate boreholes drilled less than 100ft, so that will be my guideline. I was originally worried because the gas and oil development documentation had 10K permit prices, but after contacting them I found out they only apply to commercial installations. It seems I'm on to steps 2 and 3, deciding how many boreholes I need (or if I just want to put in as many as I can while I still have the drill), and learning how to build a giant drill.

Vlad, I am a computer programmer by trade, and unfortunately have almost know knowledge of the mechanical world. I don't suppose you could recommend any links on hydrolic motors that explain how they work and how to engineer/build things with them? Personal development is actually the largest reason for me undertaking this project; I realize that knowing how motors work and how to manipulate mechanical force was a cornerstone of industrialization, and that I have managed to grow up without understanding how machines work, which is something I need to fix.

I don't think theory is your biggest problem. You need skills many different ones. Otherwise you will end up with unfinished project very frustrated or you will have to hire many different people to do the real job making your rig very expensive.

Here some skills I had to have to build my rig :

Welding, drilling, machinist ( I have my own lathe), hydraulics knowledge, mechanic(I worked as professional mechanic for 6 years fixing bikes, boats ATVs, power equipment etc.)

I don't want to discourage you but you have to understand this project was very complicated for me even with all the skills I have. I spent few hundred hours building the rig.

Try to find used rig or somebody who can drill cheap for you.

AC_Hacker · 07-05-12, 10:15 AM

Quote:

Originally Posted by vanderzac

My house is only 1100sqft, though it is all brick and I'm pretty sure I'm loosing a lot of BTU's from lack of insulation.

Wow! This would be a perfect setup for outside insulation house-wrap.

If you put 2 inches of rigid foam over your bricks, your bricks would no longer be a solar collector/heat-storage/heat-radiator structure (the brickwork radiates into your living space throughout the night, also). This alone will reduce the heat-related misery you are subjected to. It will also reduce the required size of the geo-thermal cooler system you are cooking up there.

Insulate, insulate, insulate... then dig, dig, dig.

-AC

vanderzac · 07-05-12, 12:47 PM

Vlad, I understand I am lacking a ton of experience, but the only way to get it is to get my hands dirty. I have access to tools and people who have much of the knowledge I need. About the only thing I don't know anyone for is hydrolics, but I am aware that it is a cornerstone of mechanization and as such would like to learn. I have a 9-5 job in computers, and financial responsibilities that do not allow me to quit and go be an auto mechanic or work in a machine shop for 5 years, but I do have a cheap community college I plan on taking classes at, and have access to a machine shop and more scrap parts than I know what to do with. I feel the amount of knowledge I will need to gain in this project will help me develop as an individual, and feel less powerless about my lack of ability to shape the real world (as opposed to a computer one), and as such am consuming every bit of information I can when I have free time. The concepts underlying welding, motors, and mechanics in general are not so difficult that I can't learn them, and I want to invest the time, as I would eventually like to be able to DIY hundreds of other things, and will never have the knowledge if I don't start somewhere.

AC, I agree with you that insulation would be the best long term investment, but it doesn't necessarily make the most sense in my situation. the exterior of my house has been stucco'd, so I'm not actually sure that there isn't hidden insulation already there, but it would surprise me; either way the cost to insulate, re-stucco, and re-paint would be several thousand dollars. An evaporation cooler (swamp as their known here) work by pushing in constant air from outside, such that a complete air exchange occurs every 3 to 4 hours, and as such the house is not currently being kept cool by insulation but rather by constant influx of cool air, and this is not something that can be dialed back, it basically runs all the time, so insulation would have little effect (it would still run all the time with good insulation). During winter we loose more heat than we would if insulated, but my gas bill is only $80/mo anyways, so even if I no longer needed to heat at all it would take a LONG time to recover my investment. Until I switch to AC there is no reason to insulate, and AC will make the fastest and most drastic impact on comfort levels in the house, so is much more justifiable financially. In addition, we are planning the house become a rental unit in the next 3 to 5 years. Having AC makes the house much easier to rent, but renters are much less concerned about the monthly operating cost of AC.

Over the last few days of research I have discovered units that have a 2 step compressor, where instead of shutting off it slows down, which is more efficient, as you normally are not cooling to design capacity all the time. In my climate this may hold true more than many other places, where design capacity extremes are 115F, and I honestly want to size the system to work in 125F (I hear global warming temp rises expected to be 4.5C over the next 100 years), while 80% of the year the swamp works amazing and only uses 400 watts (1/4hp blower and 50watt water pump). As such I think I want to leave the swamp in the system, and make it optional to use the AC without the swamp for the high demand summer.

Vlad · 07-08-12, 12:46 AM

Quote:

Originally Posted by vanderzac

Vlad, I understand I am lacking a ton of experience, but the only way to get it is to get my hands dirty. I have access to tools and people who have much of the knowledge I need. About the only thing I don't know anyone for is hydrolics, but I am aware that it is a cornerstone of mechanization and as such would like to learn. I have a 9-5 job in computers, and financial responsibilities that do not allow me to quit and go be an auto mechanic or work in a machine shop for 5 years, but I do have a cheap community college I plan on taking classes at, and have access to a machine shop and more scrap parts than I know what to do with. I feel the amount of knowledge I will need to gain in this project will help me develop as an individual, and feel less powerless about my lack of ability to shape the real world (as opposed to a computer one), and as such am consuming every bit of information I can when I have free time. The concepts underlying welding, motors, and mechanics in general are not so difficult that I can't learn them, and I want to invest the time, as I would eventually like to be able to DIY hundreds of other things, and will never have the knowledge if I don't start somewhere.

OK. I think you picked very complicated project but this is your choice.

Hydraulics used on drilling rig are not really complicated. Here is simplified flow diagram:

Oil from reservoir goes (sucked by pump ) to hydraulic pump after pump high pressure oil goes to regulating valve (when valve in neutral position oil is directed back to reservoir) when valve is turned to one side or another (reversing direction) high pressure oil is directed to to inlet/outlet (for changing direction inlet/outlet are switched by valve) of high torque slow speed hydraulic motor. Hydraulic motor turns your drilling pipe.

The high pressure from your pump is regulated by regulating valve. You can set max pressure and if it is reached oil is directed back to reservoir.

High pressure is your torque (the more psi you have the higher torque on your hydraulic motor)

The volume of oil that pump can pump is your motor speed. The more GPM the faster your motor will turn.

You need to turn drilling pipe @ about 60-70 RPM.

I recommend you to buy very basic hydraulic book that can explain hydraulics in normal human language.

You can check components list in some of my posts.

Vlad · 07-08-12, 12:55 AM

vanderzac

Also what you have now for cooling your house can't compete with normal refrigeration system. The system you have now is very antique. Modern refrigeration system can be efficient enough even at high outside temperature. Your place is very small just over 1000 sqft. Even regular AC can cool it down. Think about investing some money into solar power you might have enough sun to run your AC. My situation is different. I need heat most of the time.

07-02-12, 11:44 AM	#14
vanderzac Lurking Renovator Join Date: Jun 2012 Location: Tucson, Arizona Posts: 10 Thanks: 0 Thanked 0 Times in 0 Posts	When you say as huge as possible, I'm still floundering figuring out what extreme I should be going to through... My house is only 1100sqft, though it is all brick and I'm pretty sure I'm loosing a lot of BTU's from lack of insulation. Once I figure out if I can drill (permits) I'll look into what I should plan my BTU usage to be, and I'm sure I'll be asking sizing questions for the field then, but I have a hard time believing 1000ft wouldn't be enough so long as they are each at least 100ft deep when comparing AC's results on 16 boreholes only 20ft each, Though I could be wrong and love input and food for thought I appreciate the offer and I'm sure I will have lots of questions building my drill. I fully agree cutting corners is not worthwhile, and knowing that less robust drills sell for $3K+ I figure I can recover the cost on the drill once I'm done so long as I build it right. I have been over the drill thread 3 or 4 times, and am going to start planning out the drill soon. For now I need to make sure I'm not dead in the water before I even start by getting in touch with the local bureaucrats about whether I need a permit or not; I know well water permits here cost 10K... As for the desuperheater, I will absolutely take advantage of my free hot water. While I'm at it, I have a 1970's Jacuzzi shell that needs a serious DIY effort to get running (no frame, pumps, or heater currently) and will be using the system to heat that too. As I look I am constantly seeing applications where I could tie into the system and gain extra efficiency, I love that. Last edited by vanderzac; 07-02-12 at 11:51 AM..

07-05-12, 12:47 PM	#18
vanderzac Lurking Renovator Join Date: Jun 2012 Location: Tucson, Arizona Posts: 10 Thanks: 0 Thanked 0 Times in 0 Posts	Vlad, I understand I am lacking a ton of experience, but the only way to get it is to get my hands dirty. I have access to tools and people who have much of the knowledge I need. About the only thing I don't know anyone for is hydrolics, but I am aware that it is a cornerstone of mechanization and as such would like to learn. I have a 9-5 job in computers, and financial responsibilities that do not allow me to quit and go be an auto mechanic or work in a machine shop for 5 years, but I do have a cheap community college I plan on taking classes at, and have access to a machine shop and more scrap parts than I know what to do with. I feel the amount of knowledge I will need to gain in this project will help me develop as an individual, and feel less powerless about my lack of ability to shape the real world (as opposed to a computer one), and as such am consuming every bit of information I can when I have free time. The concepts underlying welding, motors, and mechanics in general are not so difficult that I can't learn them, and I want to invest the time, as I would eventually like to be able to DIY hundreds of other things, and will never have the knowledge if I don't start somewhere. AC, I agree with you that insulation would be the best long term investment, but it doesn't necessarily make the most sense in my situation. the exterior of my house has been stucco'd, so I'm not actually sure that there isn't hidden insulation already there, but it would surprise me; either way the cost to insulate, re-stucco, and re-paint would be several thousand dollars. An evaporation cooler (swamp as their known here) work by pushing in constant air from outside, such that a complete air exchange occurs every 3 to 4 hours, and as such the house is not currently being kept cool by insulation but rather by constant influx of cool air, and this is not something that can be dialed back, it basically runs all the time, so insulation would have little effect (it would still run all the time with good insulation). During winter we loose more heat than we would if insulated, but my gas bill is only $80/mo anyways, so even if I no longer needed to heat at all it would take a LONG time to recover my investment. Until I switch to AC there is no reason to insulate, and AC will make the fastest and most drastic impact on comfort levels in the house, so is much more justifiable financially. In addition, we are planning the house become a rental unit in the next 3 to 5 years. Having AC makes the house much easier to rent, but renters are much less concerned about the monthly operating cost of AC. Over the last few days of research I have discovered units that have a 2 step compressor, where instead of shutting off it slows down, which is more efficient, as you normally are not cooling to design capacity all the time. In my climate this may hold true more than many other places, where design capacity extremes are 115F, and I honestly want to size the system to work in 125F (I hear global warming temp rises expected to be 4.5C over the next 100 years), while 80% of the year the swamp works amazing and only uses 400 watts (1/4hp blower and 50watt water pump). As such I think I want to leave the swamp in the system, and make it optional to use the AC without the swamp for the high demand summer. Last edited by vanderzac; 07-05-12 at 01:16 PM..

07-02-12, 02:44 AM	#12
vanderzac Lurking Renovator Join Date: Jun 2012 Location: Tucson, Arizona Posts: 10 Thanks: 0 Thanked 0 Times in 0 Posts	Hi Vlad. I totally agree with you that the normal day in Tucson summer does not have 90% humidity and 100F temperatures. For example, it rains about 33% of the days during monsoon season. On those days humidity is above 90%, and temperatures are frequently above 90F. Average Weather for Tucson, AZ - Temperature and Precipitation This site shows average daily high temperature, with a record option as well. 7 of the last 10 years have been record high averages in our area, attributed mostly to global warming (right or wrong is another argument). I am looking to maintain year round comfort, regardless of ****ty outside atmospheric conditions on 1 of every 3 days for 2 months, and I am sure of these numbers. As for the average ground temp in my area, your data shows the ground is 60, and I think it would reliably stay in that range as long as I have a large enough water field. I have room to do at least 10 boreholes in my back yard, and could add more in the front if absolutely needed, though I would prefer not to drill that close to the road, and can dig as deep as I choose to go if I try to build a hydrolic drill like yours.

07-02-12, 03:43 AM	#13
Vlad Apprentice EcoRenovator Join Date: Aug 2010 Location: Windsor ON Canada Posts: 229 Thanks: 4 Thanked 30 Times in 22 Posts	vanderzac, In your case (as same as in my case) you have to make sure your ground loop is as huge as possible. Also you can add desuperheater for domestic hot water and enjoy free hot water. This will add extra capacity to your system. If you are dead serious about building a rig I can only suggest to you to build it right and strong. Don't go with toys they don't drill (actually they drill your brain ). Make sure you buy a GOOD drill bit. My bit is as sharp as new no even a sign of wear or chip after about 1000 feet of drilling. Yes it was mostly clay and very compacted sand but I had few very nasty rocks. Go over my pictures and component's specs. I spend a lot of time experimenting you can just copy/paste and save a ton of time. If you have any questions I will gladly try to give you an answer.

07-03-12, 03:17 PM	#15
vanderzac Lurking Renovator Join Date: Jun 2012 Location: Tucson, Arizona Posts: 10 Thanks: 0 Thanked 0 Times in 0 Posts	It looks like I'm good on the permits front. The water department does not regulate boreholes drilled less than 100ft, so that will be my guideline. I was originally worried because the gas and oil development documentation had 10K permit prices, but after contacting them I found out they only apply to commercial installations. It seems I'm on to steps 2 and 3, deciding how many boreholes I need (or if I just want to put in as many as I can while I still have the drill), and learning how to build a giant drill. Vlad, I am a computer programmer by trade, and unfortunately have almost know knowledge of the mechanical world. I don't suppose you could recommend any links on hydrolic motors that explain how they work and how to engineer/build things with them? Personal development is actually the largest reason for me undertaking this project; I realize that knowing how motors work and how to manipulate mechanical force was a cornerstone of industrialization, and that I have managed to grow up without understanding how machines work, which is something I need to fix.

07-08-12, 12:55 AM	#20
Vlad Apprentice EcoRenovator Join Date: Aug 2010 Location: Windsor ON Canada Posts: 229 Thanks: 4 Thanked 30 Times in 22 Posts	vanderzac Also what you have now for cooling your house can't compete with normal refrigeration system. The system you have now is very antique. Modern refrigeration system can be efficient enough even at high outside temperature. Your place is very small just over 1000 sqft. Even regular AC can cool it down. Think about investing some money into solar power you might have enough sun to run your AC. My situation is different. I need heat most of the time.