GREAT source for water-air coils for hybrid hydronic/ air systems

Pyro,

I am heading in the same direction as you.

I have the tarm and a 1500 gallon insulated storage tank. My current coil is a hot water coil which barely keeps up at 140-180F. I am looking for an excessively large coil for chilled water in the summer.

There are so many options that I am lost with HX, heating, storage, and airconditioning. The 1500 gallon tank would be nice to cool off and use for AC in the summer. With water temps in the 40's to 50's, it will need a LARGE chiller. I don't know if I could find one big enough.

I am contemplating using a geothermal heat pump to take heat from the tank and run it through a new air handler. This would boost the temps (by running the compressor $$$) to help with the moderate temp storage. With the tax incentives this year, it may be something I could use.

I have noticed using my oil furnace for the water HX, that the hot air heats up the oil box. This creates a good draft to run the hot air out the chimney. If I moved the wood boiler/storage to the air handler, this loss will be reduced.

This "plan" would have three systems parralleled. Oil furnace, air handler with hot water from boiler/storage,or geothermal heat pump from the tepid storage for heat or AC. They can all be prioritized to use the most efficient one.

I am currently trying to figure out how to cool off my storage tank when the AC is heating it. I would get about 1 ton(12,000 BTU's) for every degree F it rises. After a day or so, the temps will rise to the point that the efficiency would drop. I would like to cool it at nights to benefit from the cool air.

diyer said:

Pyro,

I am heading in the same direction as you.

I have the tarm and a 1500 gallon insulated storage tank. My current coil is a hot water coil which barely keeps up at 140-180F. I am looking for an excessively large coil for chilled water in the summer.

There are so many options that I am lost with HX, heating, storage, and airconditioning. The 1500 gallon tank would be nice to cool off and use for AC in the summer. With water temps in the 40's to 50's, it will need a LARGE chiller. I don't know if I could find one big enough.

I am contemplating using a geothermal heat pump to take heat from the tank and run it through a new air handler. This would boost the temps (by running the compressor $$$) to help with the moderate temp storage. With the tax incentives this year, it may be something I could use.

I have noticed using my oil furnace for the water HX, that the hot air heats up the oil box. This creates a good draft to run the hot air out the chimney. If I moved the wood boiler/storage to the air handler, this loss will be reduced.

This "plan" would have three systems parralleled. Oil furnace, air handler with hot water from boiler/storage,or geothermal heat pump from the tepid storage for heat or AC. They can all be prioritized to use the most efficient one.

I am currently trying to figure out how to cool off my storage tank when the AC is heating it. I would get about 1 ton(12,000 BTU's) for every degree F it rises. After a day or so, the temps will rise to the point that the efficiency would drop. I would like to cool it at nights to benefit from the cool air.

Click to expand...

Horizontal geothermal loops of pex. Roughly 1000 ft. required per ton of AC. Installed at 8' below grade in 5-6 ft. loops. BTUs for HX should be simple enough to figure out.

PYBYR......thanks for the info.

Der Fiur Meister said:

diyer said:

Pyro,

I am heading in the same direction as you.

I have the tarm and a 1500 gallon insulated storage tank. My current coil is a hot water coil which barely keeps up at 140-180F. I am looking for an excessively large coil for chilled water in the summer.

There are so many options that I am lost with HX, heating, storage, and airconditioning. The 1500 gallon tank would be nice to cool off and use for AC in the summer. With water temps in the 40's to 50's, it will need a LARGE chiller. I don't know if I could find one big enough.

I am contemplating using a geothermal heat pump to take heat from the tank and run it through a new air handler. This would boost the temps (by running the compressor $$$) to help with the moderate temp storage. With the tax incentives this year, it may be something I could use.

I have noticed using my oil furnace for the water HX, that the hot air heats up the oil box. This creates a good draft to run the hot air out the chimney. If I moved the wood boiler/storage to the air handler, this loss will be reduced.

This "plan" would have three systems parralleled. Oil furnace, air handler with hot water from boiler/storage,or geothermal heat pump from the tepid storage for heat or AC. They can all be prioritized to use the most efficient one.

I am currently trying to figure out how to cool off my storage tank when the AC is heating it. I would get about 1 ton(12,000 BTU's) for every degree F it rises. After a day or so, the temps will rise to the point that the efficiency would drop. I would like to cool it at nights to benefit from the cool air.

Click to expand...

Horizontal geothermal loops of pex. Roughly 1000 ft. required per ton of AC. Installed at 8' below grade in 5-6 ft. loops. BTUs for HX should be simple enough to figure out.

Click to expand...

Thanks Der Fiur,

The heat exchanger that I was looking for was the chiller coil in the furnace/air handler. The one that I have for the wood boiler works with 160F water. Using it for airconditioning would require something about 4 times bigger (160F - 70F =90F temp diff for heating, 45F to 70F =25F temp diff for A/C). This is considerably large for my furnace plenum. The pressure drop for the fan would be considerable. If I can get to 32F water, then I would only need about 2x the current one. This could be possible.

From what I have seen in New Hampshire, they design the geothermals for the high 70F/ low 80F source water. If I can keep my tank below this temperature with night time ambient cooling or usage/makeup from the well, there is no need for a geothermal loop. It is sort of an open well system.

My first idea was to freeze the 1500 gallon tank. This is similar to the ice storage machines for commercial use. They create ice during the night and melt it during the day. This required a 1 ton heat pump to run at night. The ice water would be pumped through the chiller coil in the furnace/handler.

I am now looking at getting a water(tank water) to air geothermal pump. This uses the refrigerants in a coil to cool the air. This downsizes the coil in the furnace drastically. If I run it about 8 hours a day, the tank will only gain 8-12F per day. Adding the desuperheater for my hot water would decrease the tank gain.

I can cool the tank on cool evenings with a water tower. The tank is unpressurized. Open air cooling would be better/faster than a geothermal loop.

I will be running more calculations before I get too far. Just looking at the possibilities right now.

I also would like to use some of the water for the lawn/ washing the car. It will be replenished with rain and well water makeup.

Thanks
Carl