6800RPM gear pump too noisy for residential market. Box?

[stabmaster]

I have this solar thermal recirculating pump that meets all necessary spec's (1 GPM, 20ft head, and 35W solar panel). All of this but it is too noisy for residential use at 6800RPM. A high pitch whine is unacceptable on a quiet day.

I've tried different boxes. The more deadening, tigher seals, and more rubber mounts the better; however, it is beginning to look a bit too complicated.

I haven't found much by way of pump mounts so I'm using a pipe hanger and EPDM rubber to mount the pump. This is robust but simply doesn't look production worthy.

Here is the pump:

http://www.fluid-o-tech.com/files/MGBR1.PDF

Any ideas for cancelling the noise?

 

[stabmaster]

tmoose- the answer to your query is yes.. it only becomes objectionable at the high end of the rpm range.

nonetheless, and unfortunately, the flowrate is just about right at just about all times of the day. this is somewhat of a "variable speed drive" due to the differing light conditions affecting the photovoltaic panel.

the oberdorfer allows for a very distinct advantage that it has such a high suction head. it can be mounted on the ROOF of a house! At $0.45 per foot of wire, this can lead to cost reductions of $20-$50!! Second phase of this little R&D run is going to be price point adjustments.. the packing seal will be a problem though because reclaiming the drip can be expensive to accomplish.

I'd love to add a swing check valve on the roof there and recover the drip that way. 3/4" swing check valve is $6.65. All of these goodies in a weather-tight box- hrmm. I see freeze conditions being the big problem here. Anyways, thanks for the comments! this will certainly be something to look into.