Heat pumps

[Chas]

In the entry about the noisy heat pump I notice that the pump is rigidly
mounted (with bands) to a 90 degree plate that is fixed to a concrete wall.
The plumbing is flex so it should not be the problem, but the mounting sure
is. If it were mine I would add at least 1/2" of soft rubber between the
mounting plate and the pump motor. Additionally, I would also put that much
rubber where the bands surround the pump. There does not seem to be any
rigid electrical conduit involved, so if the noise should still persist then
one would have to consider getting a less noisy pump.
. . . .I am not selling but when I was doing that kind of work I found the
'Bell & Gossit' pumps easiest to work on. They came with 2 bolt flanges on
intake and outlet sides, and the motor was isolated from the pump scroll
case itself. The pump sat in its own rubber bushed mount and the shaft
connection between the pump impeller shaft and the motor shaft was indirect.
Each shaft had centered on its end a plate approx 2.5" by 3/4". These two
plates (one on each shaft) were inturn connected to each to each other at 90
degrees, and held in that position with 4 small coil tension springs at the
ends of the plates. A nice an effective design.
. . . .Other than leaking pump seals, not very common, the other problem was
with very old installations the rubber motor bushing would eventually crush
under the motors weight and vibration, and then there would be vibration
noise induced into the plumbing.