minisplit mod to be water sourced

[keachier]

Can this be made,I have two surface well at each corner of the house.From some reply on the site and after some reading of the manifesto I think this can be done but will be limited to the capacity of the well .I plan to try a cheap minisplit of 9000 btu and install a flat plate exchanger a little pump of around 2gpm to circulate water from well to well.To limit the risk of freese I will have to monitor the temp of water output or other idea?

[jeff5may]

This can work well for you if done right. Check out surplus city liquidators dot com. They have coaxial exchangers made for what you are doing at awesome prices. Search for "coax coil" on the main page. I believe the HX's rated for less than 2 tons were all under 75 dollars.

You will need to monitor your water temp exiting the HX to avoid freezing it.

[stevehull]

Just did some reading on coaxial heat exchangers and found a VERY interesting manufacturer of geothermal heat pumps (Boreal) that has a feature to use direct water exchange in the air exchange coil.

In the heating mode, it uses a Copeland scroll compressor. Here is the link and their write up.

This is PERFECT for those cold ground people (typically Canada and northern Europe in the northern hemisphere) that have cold ground water. Their rationale is good as the heating degree days are huge compared to cooling degree days in that northern area.

They claim that you can adjust humidity with a 50 degree F water inlet temp. Very interesting.

Steve


Geothermal Heat Pump - Passive Heating/Cooling

Direct Groundwater Cooling - "DC" Series

While the Boreal ® proves to be an outstanding performer at heating your home, it becomes even more efficient in the cooling mode. Most conventional heat pumps provide air-conditioning by reversing the refrigeration cycle, which requires the operation of the main compressor, pump and blower. Power consumption in the cooling mode is the same or higher as in the heating mode. With the Boreal unit however underground water is pumped directly to the air heat exchanger coil.

There is no need to operate the compressor which consumes approx. 80% of the power required in the heating mode since underground water below 50°F. is already sufficiently cold enough to provide direct air conditioning.

Central air conditioning and dehumidification is provided for less than 1/5 the cost of a compressor driven system. The capacity of the air-conditioning section in a Boreal unit can be adjusted by varying the flow of water to the cooling coil while that of a reversible unit is fixed to the capacity of the heating section.

This unique feature is important since a reversible heat pump large enough to supply all the heat in a Canadian home will generally be greatly oversized in the cooling mode resulting in short cycling and insufficient dehumidification of the air.

Since proper dehumidification of the air is essential in the air conditioning mode, an oversized unit will fail to remove the moisture required leaving the occupants cold and clammy, while the Boreal unit can be tailored to remove the exact amount of humidity for comfortable living.