I’m mulling over a science project idea and I’m hoping you guys can hellp me source a part. I have spring fed creek running through my property and I’m thinking about using that with a water to water heat exchanger for my heat pump. Since designing the thing from scratch would take me a while, I was hoping you guys could point me to an off the shelf product that I could use. I would think that standard geothermal systems would use this component. Any manufacturer/part number suggestions?
It’s a 3.5 ton system and I’m running a desuperheater.
TIA.
Replies
Water evaporator for a Heat pump (condensor if used for AC) is about the easiest thing to build there is.
Get some 1-1/2 or 1-1/4 pvc or pe pipe, put (for 3.5T) 3/4" CU pipe inside that.
Freon inside the Cu pipe with txv at one end, other end to compressor. Water goes thru the annulal space between the pipes. Radially sand the Cu pipe with 36 grit to roughen the surface.
Or, just put the Cu pipe with freon directly into the creek, probably the best way to do it if the creek is close by.
My own HP puts out 58,000 BTU cooling 9 GPM water from about 56F to low 40sF. COP of 5.6, better than anything commercially available.
Total length of Cu pipe is 75 feet. Can be shorter if you spiral a 1/4" dia rope of small CU pipe around the 3/4" copper, but LOTS harder to assemble.
Fouling of the outside of the Cu pipe actually IMPROVES the operation as an evaporator over time.
E-mail me if you want more details, if I'm around next week will take some pix, maybe post them here.
Uh ... I don't think you can put refrigerant filled HX directly in creek ... not likely to meet local code and generally an [environmentally] a bad idea. If that ever broke/leaked, it would not be good. Technically, it's the best way to go, but most locations wouldn't let you do that. You need a double wall heat exchanger to detect a system leak if it occurs.
ever broke/leaked, it would not be good
Why? Other than having to fix it and recharge, esp if 410A or propane refrigerant.
Inquiring minds want to know, aside from an algore chicken little scenario.
Air-air unit if they leak all the 'bad stuff' if R-22 into the ecosphere.
So, easiest for the OP, esp if a diy science project as stated, is to use plain old propane with a couple of filter dryers on the line, huh?
I'm thinking pollution of groundwater w/ unwanted substances. Local health districts and other environmental agencies don't like the potential of polluting substances in the subsurface and/or surface waters. When it comes to using any body of water (stream, pond, lake, etc), there are often issues w/ jurisdictions having an environmental and/or health interest. Diverting a stream for power production can be an issue even if you don't alter the quality of the water.
I've got to know more on this. please?
More on what specifically?
the set up you are talking about. I have a creek that runs through my property and have been contemplating something like what you speak of.
Heat pump for winter time or AC for summer time? Totally different approaches, AC involve no compressor or freon.
actually I'd like to learn all you willing to spend the time to share. and I can learn a great deal from pictures :)
So you could use a standard type of Ground Source Heat Pump (GSHP) system configuration. One option is to 'drop a coil in a pond'. Water in the coil is the heat exchange ... runs back to a 'standard' water source heat pump ... e.g. by Water Furnace or other major manuf. (e.g. Carrier, TRANE I think both make such systems). Water Furnace has a good reputation in the GSHP industry.
The key: How to immerse a length of tubing in the creek. Another option is to run creek water through e.g. a shell and tube heat exchanger (common in commercial applications should be easy to find a 'small' one). The key will be to match the circulation of the two water streams for proper/most efficient heat exchange.
My advice ... get a little help on the design side to ensure your DIY project gets off on the right foot. Maybe Water Furnace can assist w/ some design guidance. Not sure.
Your concept is simple. Execution, though needs to be done right.