Hey All I have a cottage MA that I use year round 600 sq.ft. There is electric baseboard in the cottage but I was looking at alternatives like a small pellet stove but those are $1k... an came across geo.. and love the concept and I get cooling in the summer... I'm Looking to make it practical for this particular environment. I live on an island, the cottage is close the water on very sandy soil,a beach, there is well water from a near well. I was thinking of a 1 ton open system where the water can drain back through the sand near the well and essentially circulate. Or a closed system if the water tests bad, then use a heat exchanger. I'm not sure installing a underground loop would be practical in sand with the water level only a few feed below? and since I already have the well setup I could expand that to accommodate a closed or open loop system cooled/heated by well water. Does this sound feasible?

forgot to mention, the island has no bridge or roads so no heavy equipment can be used, digging is a manual affair, in sand. otherwise I would be considering the underground closed loop.

I was told Titanium HX was the way to go!


Also


Digging is a pain...why not use air? Once you are in the water, Boyles law can be your friend! Could you get access to a decent air compressor?

Was the well dug by hand?
Open loop isn't a problem, how reliable is the electricity?

lillianhofstader & nooboo
Yes, I can get a decent size air compressor (whatever will fit in a 13ft skiff)... but do what with it... blow the sand away?
Titanium HX? do you mean heat pump with Titanium HX? or find a Titanium heat exchanger?

Joe
Yeah, the well was dug by hand, & the electricity is very reliable, since it's underground cables prob more reliable than some of the main land.

The GSHP open loop system that I have has a Titanium HX in between the production and injection wells, so in a salt environment, yes, GSHP with Titanium HX.

Using air to dig a well, once you are deep enough in the water with your well casing (lets say 8" PVC), while holding the casing down in the hole (the casing will want to blow back out of the hole) surge air into the bottom of the casing.

Because pressure and volume are inversely proportional (pressure of the air reduces and the volume will increase) a big geyser of air and water and sand and rocks will come shooting out of the hole. It is a very fun thing to see and do. I recommend a raincoat and safety goggles. A bit of scaffolding can come in handy in such an operation. As the sand is removed, the casing can be driven down. 8" pipe is good as you can use a wide diameter, high volume, low head pump for the production well pump.

Looks like I'm running a bit slow today, just realized HX stood for heat exchanger!
Awesome idea on digging, nooboo, makes perfect sense.. definitely going to try that air trick.

Maybe I can get one of those efficient low amp variable speed submersible pumps into a new well and use the old one as a rejection/backup well. Although it's so sandy here I could just let it run out on the ground...

Apox. how man ton/what size GSHP would you recommend for 600 sq.ft.? I've just insulated the cottage all round (including under), all windows are double and doors weatherproofed. It can get reasonably nasty here being exposed, zero degree & 35 mph blow. But due to insulation can keep the heat reasonable with 2x1.5kw space heaters.

is cooling an issue?

I would like cooling in the summer, don't have any at the moment besides fans

well you have given us an idea of your heat load (3kw) but not your cooling load. Are there ducts? is this one room?

It's a small 2 bed beach cottage.
No ducts (yet), the place I have earmarked for installation of the pump is right next to the main room so a few feet of ducting at most The cooling requirements (btu's) will be less than heating requirements in new England (MA)... so I figured if it's sized enough for heating it should do fine with cooling? Rule of thumb here is around 30-35 btu per sq.ft I'm told so 1.5-1.75 ton unit?

With that small of space, have you thought about a mini-split?

I think I would look at a minisplit system- either Mitsubishi or Fujitsu, for cold temp operation. IF your current 3 KW of resistance heat is enough that indicates that ~ 10,000 BTU of heat will be enough. Based on this I would go for a 9kBTU like a fujitsu 9RLS2H minisplit. You can use existing baseboard to supplement on really cold days.
What I don’t know is how well these units hold up in a salt water environment. I would find a local HVAC contractor that installs them and ask.

Cheers,
Eric Anderson

I suspect the sea would be unkind to any metal outside, so the geo heat pump likely would be advantageous. Small units are available, you want to watch energy star ratings to ensure you qualify for tax credits.

Joe, do the mfn make units specifically for the coast? There are 'thousands' of miles of coast.

I do not know Robin....it's hardly a concern we encounter in MI.
So no, seriously I have never researched it, though I hear of frequent replacement for units along the coast.