Hi all, been lurking in the forums for a while and have a quick question.

We are in the early stages of planning to build a home (2800 sq feet) The house will be located near (500ft) from a tidal salt water river on the Chesapeake Bay. The house will be (+/- 5 ft above) the MHW (Mean High Water Level). We are also on well water with an aquifer @(100'-120'). I have a relatively small footprint of a yard. (100' x 100'). Soil is primarily sand.

I'm trying to figure out what effect if any the high water table will have on a geotherm install. Is there a particular system that would work best for my situation. It seems like the incoming and outgoing water should have an effect on the calculations but I'm not exactly  sure how to calculate the effect.

Thanks

Michael

We take this into account with beachfront houses. Quite a bit depends on the local geology - if system has multiple shallow bores and much of the depth consists of sand which "sees" the bay water then the bay will affect the system more than the deep ground water. Normally, aquifer advection (lateral movement of the water, perpendicular to the bores) is a helpful phenomenon when it occurs.

However, if the bay water is substantially warmer in summer or cooler in winter than the local deep ground temperature, that will eat into efficiency a bit

If a confining layer is encountered fairly high up in the bores, then they bay should have less of an effect. Loop designer should account for all this and more

It has been our experiance that homes along the tidal regions due exceptionaly well due to the water present adding to the exchange process. Also we have found that the tidal influence really does not effect the operating temp of the vertical bore. If you are on the eastern shore give me a call and stop by our website.
Eric

Our most recent project concerns a new construction system with multiple shallow bores (15 @ 80') at a beach front house. Summer ocean temp is mid 80s, so I anticipate some EWT impact owing to the tidal advection. Fortunately I got in on some of the load side decisions in time to (I hope) provide some headroom.

Thanks all for your expert opinions!

WP is much closer to your area than I am, so his experience is likely more relevant than mine to your situation.