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boogi man

join:2001-11-13
Jacksonville, FL
kudos:1
reply to laserfan

Re: Do Air Conditioners and Heat Pumps cool equally well?

additionally once you take into account the power consumption difference between a 1/2hp+ well pump and a 1/25thhp circulating pump the efficiency differences i doubt seriously would actually amount to anything on your electric bill
--
my site


iknow
Premium
join:2012-03-25
reply to boogi man

said by boogi man:

read what you posted. the inlet water temps are the problem. get them down during the cooling season and the lost efficiency returns plus the lower pump draw equals more efficient. 2+2 still equals 4 no funny math needed it's all right there. do what you want with your water there. in the end the difference in the bill is going to maybe be $10-15/m depending on your electric rates. for me the closed loop isn't nearly as much about my power bill is it is about the wanton wasting of good water so i can be cool.

show how water is wasted. »ga.water.usgs.gov/edu/watercycle.html


Jack_in_VA
Premium
join:2007-11-26
North, VA
kudos:1
Reviews:
·Millenicom

1 edit
reply to cdru

said by cdru:

There is also non-monetary considerations such as can the well support the demands, what to do with the discharge water, water quality, etc.

Exactly. Misuse of a valuable resource to gain maybe a few points of efficiency if any.

In fact the situation with the reservoirs in my old county is so critical they are getting ready to put the screeching halt to lawn watering and car washing (unless in a commercial car-wash with water reclaiming).


boogi man

join:2001-11-13
Jacksonville, FL
kudos:1
reply to iknow

talking about drinkable water resources. it takes many many years for the aquifer recharge cycle to take place. that's where it's wasted.
--
my site



Jack_in_VA
Premium
join:2007-11-26
North, VA
kudos:1
Reviews:
·Millenicom

said by boogi man:

talking about drinkable water resources. it takes many many years for the aquifer recharge cycle to take place. that's where it's wasted.

In some instances they're never replenished.


Ken
Premium,MVM
join:2003-06-16
Markle, IN
reply to Jack_in_VA

What you call misuse I call using the resource to it's full potential. If I pump roughly a million gallons a year from the aquifer to heat and cool my house while the farmer next door is pumping a million gallons a week from the same aquifer to water his field I don't see how I am misusing anything.


Netkeys

join:2000-12-08
Fort Lauderdale, FL
Reviews:
·Comcast
reply to Jack_in_VA

Not true. Water transfers heat about 30 times faster then air.

Give it a try. Put a beer in the refrigerator and an other in a iced bucket of water. Get the water to the same temperature as the refrigerator and you'll have a cold beer in minutes with the iced water.

That's why you get colder quicker when swimming then in air at the same temperature. Something I learned during scuba instructions.


Aranarth

join:2011-11-04
Stanwood, MI
Reviews:
·Frontier Communi..
reply to laserfan

I'm using an open loop geothermal system.

In the coldest months in Michigan I use about $250 to $300 worth of electricity.

I'm on a 4" well about 65' deep that can supply two showers and the geothermal all at the same time. We are using about $100 of electricity for the lights, tv's, and other appliances, meaning I'm heating my house for $150 to $200 a month. (Day's can be really short so the lights are on longer.)

The outside discharge loop runs a to a drainage tile system that is also used by our septic system. Keeps the grass green in the back yard...

The water table around here is about 10 -20 feet down and we have many swamps, ponds, streams, and rivers. (this is west MI after all).

In this system the water is never exposed directly to the air since all the piping and drainage systems are underground. While a farmer watering his crops will be loosing water to evaporation, a properly installed geothermal system will have very little water wasted in that fashion.

I would have no issues with anyone withdrawing water from an aquifer for geothermal using this system.



boogi man

join:2001-11-13
Jacksonville, FL
kudos:1

yes i agree if the water isn't being just dumped into a ditch etc but more often than not that is basically what happens. that is wasted water.
--
my site



Jack_in_VA
Premium
join:2007-11-26
North, VA
kudos:1
Reviews:
·Millenicom
reply to Aranarth

said by Aranarth:

I'm using an open loop geothermal system.

In the coldest months in Michigan I use about $250 to $300 worth of electricity.

I'm on a 4" well about 65' deep that can supply two showers and the geothermal all at the same time. We are using about $100 of electricity for the lights, tv's, and other appliances, meaning I'm heating my house for $150 to $200 a month. (Day's can be really short so the lights are on longer.)

The outside discharge loop runs a to a drainage tile system that is also used by our septic system. Keeps the grass green in the back yard...

The water table around here is about 10 -20 feet down and we have many swamps, ponds, streams, and rivers. (this is west MI after all).

In this system the water is never exposed directly to the air since all the piping and drainage systems are underground. While a farmer watering his crops will be loosing water to evaporation, a properly installed geothermal system will have very little water wasted in that fashion.

I would have no issues with anyone withdrawing water from an aquifer for geothermal using this system.

Let me see if I understand this:

The outside discharge loop runs a to a drainage tile system that is also used by our septic system.

The water table around here is about 10 -20 feet down and we have many swamps, ponds, streams, and rivers. (this is west MI after all).

You have your open loop heat pump discharge piped into your septic drain field which is only about 10 - 20 feet above the water table?

You do realize all that water causes the sewage to peculate (wash) into the groundwater contaminating it. Around here it would be illegal to pipe anything like this into the drain field.

garys_2k
Premium
join:2004-05-07
Farmington, MI
Reviews:
·Callcentric
·callwithus

said by Jack_in_VA:

You have your open loop heat pump discharge piped into your septic drain field which is only about 10 - 20 feet above the water table?

You do realize all that water causes the sewage to peculate (wash) into the groundwater contaminating it. Around here it would be illegal to pipe anything like this into the drain field.

Ewwww! I thought the same thing! Septic drain fields have to have a minimum "transport time" to enable the bacteria time to work. Tossing on a ton of water like this will DEFINITELY screw that up.

As for open loop WSHPs, I guess the only way it wouldn't be wasting water would be to return the discharge water to the same aquifer (depth) that it's being drawn from. Dumping it onto the surface is NOT "recycling" the water. It can take thousands of years for water to percolate from the surface to a hundred plus feet down.


Jack_in_VA
Premium
join:2007-11-26
North, VA
kudos:1
Reviews:
·Millenicom

said by garys_2k:

said by Jack_in_VA:

You have your open loop heat pump discharge piped into your septic drain field which is only about 10 - 20 feet above the water table?

You do realize all that water causes the sewage to peculate (wash) into the groundwater contaminating it. Around here it would be illegal to pipe anything like this into the drain field.

Ewwww! I thought the same thing! Septic drain fields have to have a minimum "transport time" to enable the bacteria time to work. Tossing on a ton of water like this will DEFINITELY screw that up.

As for open loop WSHPs, I guess the only way it wouldn't be wasting water would be to return the discharge water to the same aquifer (depth) that it's being drawn from. Dumping it onto the surface is NOT "recycling" the water. It can take thousands of years for water to percolate from the surface to a hundred plus feet down.

+1 Points that I don't think some are considering. That's why no permits are issued for open systems here anymore. They have to be closed with no impact other than temperature exchange.

MrIcehouse

join:2006-02-07
Saint Petersburg, FL
reply to linicx

said by linicx:

Heat Pumps don't work well above 80F or below 20F - at least in the Mid-US. Swamp coolers do not work in humid areas. If you want to be warm and cool you use a device that heats and a device that cools or a single device that can do either.

I will disagree 100% on a heat pump not working well over 80F, I live in South Florida and we have a Trane 2.5 ton unit, it was 95 outside and 75 in the house and the unit was not strained or on all day, now it's 83 outside and still 75 inside and the unit hasn't been on for hours. I know the heat pump works at 35F that is the coldest it has gotten here, it does have an electrical power strip as an assist. Good insulation helps too.

whoaru99

join:2003-12-17
reply to Ken

said by Ken:

What you call misuse I call using the resource to it's full potential. If I pump roughly a million gallons a year from the aquifer to heat and cool my house while the farmer next door is pumping a million gallons a week from the same aquifer to water his field I don't see how I am misusing anything.

I've seen it said that the average US farmer feeds 155 people.

Are you having 155 people over for dinner tonight in your nice cool house?


tmh

@tmodns.net
reply to Jack_in_VA

said by Jack_in_VA:

If the air temperature for an air source and the water temperature for a geothermal are equal then the efficiency for both are roughly exactly equal. A high efficiency air source may have an edge given it's larger coil surface vs the small heat exchanger surface area for a geothermal.

Not necessarily. The heat capacity of water is considerably greater than air. i.e., water can "absorb" more heat than air before its temperature goes up one degree. Water also conducts heat more efficiently than air, so a smaller exchanger for water can transfer heat more quickly than an air cooled exchanger.


Jack_in_VA
Premium
join:2007-11-26
North, VA
kudos:1
Reviews:
·Millenicom

said by tmh :

said by Jack_in_VA:

If the air temperature for an air source and the water temperature for a geothermal are equal then the efficiency for both are roughly exactly equal. A high efficiency air source may have an edge given it's larger coil surface vs the small heat exchanger surface area for a geothermal.

Not necessarily. The heat capacity of water is considerably greater than air. i.e., water can "absorb" more heat than air before its temperature goes up one degree. Water also conducts heat more efficiently than air, so a smaller exchanger for water can transfer heat more quickly than an air cooled exchanger.

That's true but the heat exchanger is a fixed device. The water temp is essentially fixed so the amount of heat/cold exchanged is essentially fixed compared to the newer high efficiency heat pumps that vary the condenser and evaporator fan speed depending on load. When the air temp and water temp are equal the air source with the large coil surface area and variable fan speed will match or exceed the performance of the` heat exchanger which is fixed. The output temperature of the heat exchanger will vary according to the load placed on it and the output of the condenser on an air source will remain constant within the limits of the variable fan speed and electronic expansion valve.

laserfan

join:2005-01-14
Texas
reply to MrIcehouse

said by MrIcehouse:

said by linicx:

Heat Pumps don't work well above 80F or below 20F - at least in the Mid-US. Swamp coolers do not work in humid areas. If you want to be warm and cool you use a device that heats and a device that cools or a single device that can do either.

I will disagree 100% on a heat pump not working well over 80F, I live in South Florida and we have a Trane 2.5 ton unit, it was 95 outside and 75 in the house and the unit was not strained or on all day, now it's 83 outside and still 75 inside and the unit hasn't been on for hours. I know the heat pump works at 35F that is the coldest it has gotten here, it does have an electrical power strip as an assist. Good insulation helps too.

We had OATs above 100deg for 100+ days last summer and our heat pumps managed just fine. The discharge air at our supply registers gets a little higher (68deg last time I checked, when OAT was 103deg in the shade) where it's usually below 65deg discharge.

I don't run the heat pumps below 35deg; they'll work down to below 32 but they are noisier in the winter and the heat strips are silent (albeit expensive).

MrIcehouse

join:2006-02-07
Saint Petersburg, FL

We do have the heat strip, it didn't cost to much extra, I doubt it will ever turn on it doesn't get town to 32 here, usually a few weeks of low 40's. My main concern is keeping it cool. We also opted for the dehumidifier and Heppa filter.



boogi man

join:2001-11-13
Jacksonville, FL
kudos:1
reply to Jack_in_VA

the newer geo units at least from FHP are also variable speed blowers and multi-stage compressors all the same regulating tech that is available on air to air is being applied to geo still giving geo the edge due to waters greater ability to move energy. i honestly don't know much about what water furnace and the other guys are doing but i do know that FHP was bought by bosch some time ago and the stuff they are building now is even better than the stuff they made before which was already high quality.
--
my site



Jack_in_VA
Premium
join:2007-11-26
North, VA
kudos:1
Reviews:
·Millenicom

said by boogi man:

the newer geo units at least from FHP are also variable speed blowers and multi-stage compressors all the same regulating tech that is available on air to air is being applied to geo still giving geo the edge due to waters greater ability to move energy. i honestly don't know much about what water furnace and the other guys are doing but i do know that FHP was bought by bosch some time ago and the stuff they are building now is even better than the stuff they made before which was already high quality.

There is one big difference. New high efficiency air source Heat Pumps also vary the condenser fan speed to regulate the controlled medium (Freon) within the limits of fan speed and outside air temperature. Unless the pump is variable speed the heat exchanger is a fixed capacity device. Heat exchanger tube surface area and water flow in the Heat exchanger. The process being controlled is the freon gas temperature and the method in this case to achieve it is the temperature of the water in the heat exchanger. As the heat load increases the temperature of the gas into the heat exchanger increases which means the exit gas temperature increases also reducing the efficiency of the unit.

Aranarth

join:2011-11-04
Stanwood, MI
Reviews:
·Frontier Communi..
reply to Jack_in_VA

said by Jack_in_VA:

Let me see if I understand this:

The outside discharge loop runs a to a drainage tile system that is also used by our septic system.

The water table around here is about 10 -20 feet down and we have many swamps, ponds, streams, and rivers. (this is west MI after all).

You have your open loop heat pump discharge piped into your septic drain field which is only about 10 - 20 feet above the water table?

You do realize all that water causes the sewage to peculate (wash) into the groundwater contaminating it. Around here it would be illegal to pipe anything like this into the drain field.

We ARE NOT using a sand point well! (Though the old house we used to live in did.)

The well is on the other side of the house and the slope of the land is towards the swamp (away from the well) which is about 1/4 of a mile away. The swamp is to the North and East it covers about 50 acres though only about 15 of it is actually on our land.

There is no more risk of contamination than the local farmers spraying horse and cow manure on top of their land, and some of their fields butt right up against it. Or risk of contamination that anyone else using a septic system with a water well would have.

Yes this was all inspected and signed off on. We just put the house in 4 years ago.

NOTE: The entire system is NOT above ground, NOTHING is exposed to the air. There is no drainage pool.

And finally, the ground around here is all sand/loam mix. Any water pumped into the ground using a sock and tube or drainage tile sinks into the ground really fast even with a high water table.

garys_2k
Premium
join:2004-05-07
Farmington, MI

It is interesting that your county permitted the septic field to also be used to absorb the heat pump discharge. Was it engineered originally to do so?



Jack_in_VA
Premium
join:2007-11-26
North, VA
kudos:1
Reviews:
·Millenicom
reply to Aranarth

Spreading treated manure on the surface is an environmentally permitted operation but using that much water into a septic drain field flushing the contaminates into the water table is quite something else.

Yes this was all inspected and signed off on

Did the inspector realize that your ground source heat pump discharge was piped into the septic system?

And finally, the ground around here is all sand/loam mix. Any water pumped into the ground using a sock and tube or drainage tile sinks into the ground really fast even with a high water table.

And along with it your human waste right into the water table. I'm glad I don't live around you. In fact last year the county caught one of my neighbors discharging his washing machine water into a ditch and it was seeping into the next door neighbors well. The suds gave it away.

garys_2k
Premium
join:2004-05-07
Farmington, MI
reply to laserfan

It would be interesting to test that ground water for e-coli contamination. Wanna' bet it would be positive?



boogi man

join:2001-11-13
Jacksonville, FL
kudos:1
reply to Jack_in_VA

okay. air still isn't as efficient as water. i'm glad they are getting better as time goes by but the fact remains a pound of water can move more energy than a pound of air can.
--
my site


laserfan

join:2005-01-14
Texas

Makes me want to try an experiment, while OATs here are in the 100s, to set-up some water spray(s) on one of our condensing units, to see if I get much colder air out of my registers! Seems like when the weather's really hot I get temps that are about 5 deg warmer than usual.


garys_2k
Premium
join:2004-05-07
Farmington, MI

Just be careful that the water you spray doesn't have a lot of minerals in it. You don't want to "insulate" the fins with a layer of lime.



BillRoland
Premium
join:2001-01-21
Ocala, FL
kudos:3
reply to Aranarth

Pumping discharge from a geothermal system into a septic drain field seems like a really bad idea. When that drain field fails, I don't even want to think about what's going to happen next.



cdru
Go Colts
Premium,MVM
join:2003-05-14
Fort Wayne, IN
kudos:7
reply to garys_2k

said by garys_2k:

Just be careful that the water you spray doesn't have a lot of minerals in it. You don't want to "insulate" the fins with a layer of lime.

That, plus it can actually result in reduced efficiency. See the later part of this thread for details.

If misting was such a great idea, and it worked to lower energy bills by the touted 30% misting kit manufacturers claim, then every manufacturer would have them built in to their units. But none do. It's just like all the magic fuel economy boosters you can find for cars...if they work, they would have been included already.

iknow
Premium
join:2012-03-25

said by cdru:

said by garys_2k:

Just be careful that the water you spray doesn't have a lot of minerals in it. You don't want to "insulate" the fins with a layer of lime.

That, plus it can actually result in reduced efficiency. See the later part of this thread for details.

If misting was such a great idea, and it worked to lower energy bills by the touted 30% misting kit manufacturers claim, then every manufacturer would have them built in to their units. But none do. It's just like all the magic fuel economy boosters you can find for cars...if they work, they would have been included already.

all the window ACs have a misting system, from the condensate. built in. lowering the condensor temperature, and hence the pressure, is what makes geothermal systems so efficient!. as an experiment, block off part of your condensor, and see how well it works!. it'll be a pure temperature change experiment. you'll see that reduced condensor temperatures ALWAYS result in lower evaporator temperatures and greater efficiency!. else a geothermal system would be useless, and a thing of the past, just a failed experiment!.