Heating and Cooling with Lake Water?

SIKSUKR · 07-18-2006, 01:43 PM

I believe the practice of removing water and returning it at a different temperature is not allowed in this state.(Except if you are nuke plant or power plant apparently).I have the Merrimack River right next to my mill building in Manchester and we have discussed this many times.As a matter of fact,with this heat we were talking about it yesterday.As far as I know,you are allowed to drill wells to use the btu's for heating/cooling.I think the payback is pretty cost prohibitive though.

jrc · 07-18-2006, 06:45 PM

I think most residential heat pumps use a closed system. A fluid (maybe water or anti-freeze) is circulated through loops of pipe in a well or a lake. The lake/well water never leaves, it just cools/warms the fluid in the loops. The heat pump uses that fluid to operate.

If it's against the law to use the lake for cooling/heating, many of the big cruisers on the lake are breaking the law. Many marine air conditioners pump lake water for cooling.

As to long term warming effects:

According to one website, the lake holds 625 billion gallons or about 5 trillion pounds. One BTU is required to raise a pound of water one degree. So 5 trillion BTU's would raise 5 trillion pounds one degree. An average home air conditioner is 10,000 BTU per hour. So it would take a million home air conditioners running for a 500 hours to heat the lake by one degree.

Orion · 07-18-2006, 09:53 PM

Quote:

Originally Posted by jrc

If it's against the law to use the lake for cooling/heating, many of the big cruisers on the lake are breaking the law. Many marine air conditioners pump lake water for cooling.

Actually, every single powered boat on the lake is exchanging hot water for cool lake water.

Mee-n-Mac · 07-18-2006, 10:47 PM

Going back to your original question of efficiency and lower cost ... I'm guessing that because Canada was pushing for such things they must be more efficient and cheaper to run. APS does a good job explaining what a simple home built system could be, whether such a thing would be cheaper to run (all legalities aside) vs a commercial heat pump or normal AC is another question. Some light reading FYI ...

http://en.wikipedia.org/wiki/Heat_pump

http://hyperphysics.phy-astr.gsu.edu.../heatpump.html

Maybe the thing to do is to move the habitat to the water and not the water to the habitat. It's been done on the Lake before ...

ApS · 07-19-2006, 04:41 AM

Quote:

Originally Posted by jrc

"...So it would take a million home air conditioners running for a 500 hours to heat the lake by one degree..."

Whilst some necessary shortcuts were used to arrive at your figure, the water heated by far fewer air conditioners would eventually arrive at the surface thermocline. [And not be a 1° increase equally-distributed amongst the lake's 625 billion gallons]. Just 1° increase at the surface would promote Winnipesaukee's present algae and milfoil woes earlier.

Why not use the mass of the Earth as a possible workaround?

Use well water instead of lake water, and call it "geothermal energy"—which I think jimbob1603 may have previously referenced. The exchanged water could then be injected at a much greater depth than the supply well (Or below a suitably-deep "impermeable clay" layer).

Quote:

Originally Posted by jimbob1603

"...Now, if someone could could find a way to exploit milfoil weed to pay property taxes; we'd really have something!

That's a good one: New Hampshire pays you to take their air-dried and compressed "milfoil logs" for the woodstove?

jimbob1603 · 07-19-2006, 08:57 AM

Using drilled 6" wells is a necessary evil for those without waterfront property ..... wells are the only way .... at about $6K each. Dropping a couple 1" polyethelyne lines into the lake would be infinitely more cost effective.

I remember way back in the college days, another tenant (an engineering student, naturally) in our building set up a radiator & fan in his bathtub; and exploited the "free" domestic hot water (included in the rent) to help defray his heating expenses. Despite our admiration for his ingenuity, it ticked the rest of us off because there was little hot water for the rest of us to use for showers, etc.

Hermit Cover · 07-19-2006, 08:15 PM

Jimbob....try this website as a possible resource.. www.radiantmax.com ..I have found them to be quite expert in the geothermal heat / cool energy field.

07-18-2006, 01:43 PM	#1
SIKSUKR Senior Member Join Date: Apr 2004 Posts: 5,075 Thanks: 215 Thanked 903 Times in 509 Posts	I believe the practice of removing water and returning it at a different temperature is not allowed in this state.(Except if you are nuke plant or power plant apparently).I have the Merrimack River right next to my mill building in Manchester and we have discussed this many times.As a matter of fact,with this heat we were talking about it yesterday.As far as I know,you are allowed to drill wells to use the btu's for heating/cooling.I think the payback is pretty cost prohibitive though. __________________ SIKSUKR

07-18-2006, 10:47 PM	#4
Mee-n-Mac Senior Member Join Date: Sep 2003 Posts: 1,943 Thanks: 23 Thanked 111 Times in 51 Posts	Efficiency of heat pump vs normal AC Going back to your original question of efficiency and lower cost ... I'm guessing that because Canada was pushing for such things they must be more efficient and cheaper to run. APS does a good job explaining what a simple home built system could be, whether such a thing would be cheaper to run (all legalities aside) vs a commercial heat pump or normal AC is another question. Some light reading FYI ... http://en.wikipedia.org/wiki/Heat_pump http://hyperphysics.phy-astr.gsu.edu.../heatpump.html Maybe the thing to do is to move the habitat to the water and not the water to the habitat. It's been done on the Lake before ... __________________ Mee'n'Mac "Never attribute to malice that which can be explained by simple stupidity or ignorance. The latter are a lot more common than the former." - RAH

07-19-2006, 08:57 AM	#6
jimbob1603 Senior Member Join Date: May 2004 Posts: 71 Thanks: 0 Thanked 0 Times in 0 Posts	Expensive Hole in the Ground Using drilled 6" wells is a necessary evil for those without waterfront property ..... wells are the only way .... at about $6K each. Dropping a couple 1" polyethelyne lines into the lake would be infinitely more cost effective. I remember way back in the college days, another tenant (an engineering student, naturally) in our building set up a radiator & fan in his bathtub; and exploited the "free" domestic hot water (included in the rent) to help defray his heating expenses. Despite our admiration for his ingenuity, it ticked the rest of us off because there was little hot water for the rest of us to use for showers, etc. Last edited by jimbob1603; 07-19-2006 at 04:16 PM.

07-19-2006, 08:15 PM	#7
Hermit Cover Senior Member Join Date: Oct 2002 Location: Hermit Cove Posts: 354 Thanks: 20 Thanked 68 Times in 40 Posts	Geothermal info... Jimbob....try this website as a possible resource.. www.radiantmax.com ..I have found them to be quite expert in the geothermal heat / cool energy field.

07-18-2006, 06:45 PM	#2
jrc Senior Member Join Date: Apr 2004 Location: NH Posts: 2,689 Thanks: 33 Thanked 439 Times in 249 Posts	I think most residential heat pumps use a closed system. A fluid (maybe water or anti-freeze) is circulated through loops of pipe in a well or a lake. The lake/well water never leaves, it just cools/warms the fluid in the loops. The heat pump uses that fluid to operate. If it's against the law to use the lake for cooling/heating, many of the big cruisers on the lake are breaking the law. Many marine air conditioners pump lake water for cooling. As to long term warming effects: According to one website, the lake holds 625 billion gallons or about 5 trillion pounds. One BTU is required to raise a pound of water one degree. So 5 trillion BTU's would raise 5 trillion pounds one degree. An average home air conditioner is 10,000 BTU per hour. So it would take a million home air conditioners running for a 500 hours to heat the lake by one degree.