What Isolation pad for indoor unit?

[toplessHO]

unit weighs about 350# and will sit on basement concrete floor.
I would like an isolation pad to absorb noise and vibration.
I see one called PolarPad which is 3 inches thick,but have no idea how well it is at isolating.
AC unit manufacturer suggested 1 inch rubber pad 24"x24" but didnt offer any more info.

 

[BillK]

What kind of unit is it ?? My Gas furnace / AC air handler have been sitting directly vinyl floor tile on the concrete slab in my house for almost 45 years. Have never had an issue with any kind of vibration / noise.

 

[toplessHO]

geothermal
which contains air handler,compressor,evaporator,condenser

 

[Fav Onefour]

I have geo unit sitting on a regular condenser pad. It appears to be similar to the Polarpad version.

I've run geo for awhile and used the same pad with different units. Noise and vibration from standing base aren't really and issue with these units. The main noise is compressor related.
I had an early version that was a two stage piston pump. Case insulation on that thing was an afterthought. It made plenty of racket, but it wasn't from sitting on a pad. In fact, I raised it up and put cork - rubber anti damping under the unit hoping to quiet it down. That didn't change sound levels that I could verify.

With that old clanger banger unit, I ended up doing a light frame around the thing that I lined with unfaced insulation batts. That little trick helped cut down noise levels considerably.
My newer units have been pretty quiet. They are mounted on the same HVAC pad setup used on the clanger-banger.

Speaking from experience. I would mount on a pad just get the unit off the floor. I had a water heater pop in the mechanical room. It was adjacent to the geo unit. The water heater blowout ran full bore for awhile before my wife got the water shut down. She says the water was only an inch deep before running into the drain. Water stains on the wall say otherwise. Either way, the geo unit was not damaged sitting a couple inches up on the pad.
Put it on a pad just for the extra insurance.

 

[pcmeiners]

If sound/vibration is an issue the company linked below has good sound dampening materials. I would get something for under the unit but concrete is one of the best dampening materials for any noise or vibration transferred to it. That said you will get more noise from the unit itself so you might want "stick on" dampening material on the metal enclosure. The company linked below sells that type materials. Check out the testing results

What Is The Best Sound Deadening Material? - Independent Testing Data – ResoNix Sound Solutions

Looking for the best sound deadening material to use in your car? Well, now you can ignore all of the marketing and look at the data.

resonixsoundsolutions.com

 

[toplessHO]

I have geo unit sitting on a regular condenser pad. It appears to be similar to the Polarpad version.

I've run geo for awhile and used the same pad with different units. Noise and vibration from standing base aren't really and issue with these units. The main noise is compressor related.
I had an early version that was a two stage piston pump. Case insulation on that thing was an afterthought. It made plenty of racket, but it wasn't from sitting on a pad. In fact, I raised it up and put cork - rubber anti damping under the unit hoping to quiet it down. That didn't change sound levels that I could verify.

With that old clanger banger unit, I ended up doing a light frame around the thing that I lined with unfaced insulation batts. That little trick helped cut down noise levels considerably.
My newer units have been pretty quiet. They are mounted on the same HVAC pad setup used on the clanger-banger.

Speaking from experience. I would mount on a pad just get the unit off the floor. I had a water heater pop in the mechanical room. It was adjacent to the geo unit. The water heater blowout ran full bore for awhile before my wife got the water shut down. She says the water was only an inch deep before running into the drain. Water stains on the wall say otherwise. Either way, the geo unit was not damaged sitting a couple inches up on the pad.
Put it on a pad just for the extra insurance.

the first geothermal I had in this location was in the 80s and it was a FloridaHeatPump,made right in this town.
The second was a Bard,I think built in Wisconsin.
That one has a scroll compressor,the FHP one was reciprocating.
The Bard must operate on a different harmonics,as it will resonate and of all places I hear it is on 2nd fl master bath.
So the sound is traveling thru the all concrete basement,thru the concrete floor of the 1st fl. Im guessing its using the
drain pipes in bathtub as a conduit. Dont get me wrong its not that bad but might as well try and improve it.
The manufacturer of the one Im having built,has a sound/insulation upgrade option for $100,
which I chose but imagine its just a blanket over the compressor.
I would like to find a 1 inch rubber pad,24x24 or 24x26.Been thinking of those horse stall pads they sell at Tractor Supply
but way over kill on size. Making the wrong choice here will be a big PITA to replace if this pad falls apart later.
Im going to call Amazon Rubber here locally. They arent related to Bezos and have had that name for hundreds of years.

 

[toplessHO]

If sound/vibration is an issue the company linked below has good sound dampening materials. I would get something for under the unit but concrete is one of the best dampening materials for any noise or vibration transferred to it. That said you will get more noise from the unit itself so you might want "stick on" dampening material on the metal enclosure. The company linked below sells that type materials. Check out the testing results

What Is The Best Sound Deadening Material? - Independent Testing Data – ResoNix Sound Solutions

Looking for the best sound deadening material to use in your car? Well, now you can ignore all of the marketing and look at the data.

resonixsoundsolutions.com

My biggest fear is to place something under this almost 400#vibrating equipment thats not up to task of compressionability (if thats even a word)

 

[gmcgeo]

PolarPad is typically for outdoor use and may be overkill. It’s often made of foam or rubber crumb, which is okay but not ideal for concrete basement installations.


The best option is a 1 inch thick dense rubber pad made of neoprene or EPDM. These materials are good at absorbing vibration on rigid floors like concrete.


Better options

DiversiTech EVA pads
Mason Super W or RPS pads
Kinetics KIP pads

You can use a full 24 by 24 pad or place smaller 6 by 6 inch pads under each foot of the unit. This helps with leveling and isolation.


Avoid using thick pads like the PolarPad unless the weight and vibration are much higher.


For best results, use four rubber pads under each corner. You can also add a thin cork layer for extra noise control.

 

[Fav Onefour]

the first geothermal I had in this location was in the 80s and it was a FloridaHeatPump,made right in this town.
The second was a Bard,I think built in Wisconsin.
That one has a scroll compressor,the FHP one was reciprocating.
The Bard must operate on a different harmonics,as it will resonate and of all places I hear it is on 2nd fl master bath.
So the sound is traveling thru the all concrete basement,thru the concrete floor of the 1st fl. Im guessing its using the
drain pipes in bathtub as a conduit. Dont get me wrong its not that bad but might as well try and improve it.
The manufacturer of the one Im having built,has a sound/insulation upgrade option for $100,
which I chose but imagine its just a blanket over the compressor.
I would like to find a 1 inch rubber pad,24x24 or 24x26.Been thinking of those horse stall pads they sell at Tractor Supply
but way over kill on size. Making the wrong choice here will be a big PITA to replace if this pad falls apart later.
Im going to call Amazon Rubber here locally. They arent related to Bezos and have had that name for hundreds of years.

It might be worth digging around to make sure none of the heat pump components or line sets are touching plumbing runs. I found a couple areas of light contact and the slight vibration was definitely traveling through the plumbing. In most cases the plumbing supply and drain lines have a little room to move. With a little vibration and the right harmonics the sound will keep going through the piping.

Rubber pad idea is probably not bad. The one advantage of using a thick compressor pad is the flat - sturdy surface. Heat pumps just sit on the base. Concrete in mechanical areas is generally a little wonky if they are tight rooms. The compressor pad gives your pump a flat base.
How about a compressor pad with thinner rubber isolation?

 

[fitter30]

Vibration pads are a hit and miss. Have to large of a pad/ pads can be worse than direct contact McMaster Carr has a good selection.of rubber and cork pads. Compressor is internally sprung blower motor is on rubber mounts. Duct work should have canvas connections both supply and return.

 

[toplessHO]

It might be worth digging around to make sure none of the heat pump components or line sets are touching plumbing runs. I found a couple areas of light contact and the slight vibration was definitely traveling through the plumbing. In most cases the plumbing supply and drain lines have a little room to move. With a little vibration and the right harmonics the sound will keep going through the piping.

Rubber pad idea is probably not bad. The one advantage of using a thick compressor pad is the flat - sturdy surface. Heat pumps just sit on the base. Concrete in mechanical areas is generally a little wonky if they are tight rooms. The compressor pad gives your pump a flat base.
How about a compressor pad with thinner rubber isolation?

just called Amazon Hose and Rubber.
$200 for a 2 ft piece 1 inch thick of neoprene,which was all they had in that thickness, 60 durometer

 

[toplessHO]

this is the stuff I want in a 24x24 or 24x26 one piece pad
The test was pretty sketchy but I guess new vs old wins out here.

 

[pcmeiners]

My biggest fear is to place something under this almost 400#vibrating equipment thats not up to task of compressionability (if thats even a word)

Not suggesting placement for the base. The stuff I was referring to was for the walls of the unit if needed. $200 for a piece neoprene is a absolute total rip off, any dense rubber mat or floor runner will do, any rubber material will not stop all sound or vibration. Most of noise/vibration will be transmitted from the steel enclosure and duct work.

Compressibility that is the word your looking for.

 

[toplessHO]

Ive got a call in to Diversitechs tech dept,they sell an 18x18x7/8 sandwich pad.
Hoping they will sell a bigger piece.
This stuff is made 35 miles away,pretty cool.

 

[yatg]

horse mat? cut up to size and stack pieces.

https://www.tractorsupply.com/tsc/product/4-ft-x-6-ft-x-3-4-in-thick-rubber-stall-mat-2219003

 

[rlitman]

this is the stuff I want in a 24x24 or 24x26 one piece pad...

Why so big? Even if the machine's outline is that large, there's no way it evenly loads such a large area. It's got to be sitting on some feet, or perhaps sides or part of the perimeter. What is the real ground contact? That's where you need your isolation.

 

[toplessHO]

unit is fully enclosed
Heres one similar,pretty sure is a label swap

 

[toplessHO]

horse mat? cut up to size and stack pieces.

https://www.tractorsupply.com/tsc/product/4-ft-x-6-ft-x-3-4-in-thick-rubber-stall-mat-2219003

see post 6

 

[toplessHO]

A tech from DiversiTech called back.
Product is made in VietNam so cant custom order it.

Looks like I will buy 2 of the 18x18 and section, unless I can find another source

 

[yatg]

see post 6

if you set the unit on a mat, you won't have to clean the dead space under the unit

 

[rlitman]

unit is fully enclosed
Heres one similar,pretty sure is a label swap

And? If you poke the sheet metal in the middle, does it push in? Enclosed is fine (maybe it's made for multiple orientations...), but that doesn't mean it has an even weight distribution.

The problem with any vibration isolation material is it needs to be matched to the pressure that's resting on it. If you put a soft pad under something like that, the support points will sink into the pad, leading to the bottom sheet metal doming up where it's unsupported. If that's where your drain pan sits, that could be an issue. If you use a sufficiently hard pad across the whole bottom that negligibly compresses under the support points, it will be so hard that it does nothing to help with the vibration.

This Amazon image illustrates my issue:

It shows an 18x18 pad being used where only four squares (out of 81) even do anything. The Amazon listing states 60 PSI max, and with the squares being 2"x2", you could put 240lbs on EACH square, so with solid washers under the compressor feet, two pads would do a better job, which also means that this stuff is probably too hard for the compressor they show on it. Real world example: I use four squares of something like this on each corner of a 3000 lb piece of industrial equipment sitting on a steel frame, and it's vibration isolation is at best so-so.

If this were in my basement, the first thing I'd do is figure out how to get it up off the floor on a curb in the event of a flood. Just a couple of inches makes a big difference. Thinking this through, I'd want a hard and solid base to place under the unit, and a few small quality vibration damping feet that compress visibly under the weight of the unit. 3/4" plywood would work, but I'm thinking a 24" outdoor porcelain paver might work even better (one of those really heavy tiles can easily support over 2000 lbs when mounted on pedestals for rooftop patios). 5 blocks of inch thick EVA under that (one in each corner and one in the middle; notched side down on the concrete), with strips of waterproof UHB tape holding the smooth side of the foam to the tile to keep them from shifting. Maybe some more UHB tape between the equipment and the tile.

 

[toplessHO]

not full height in area the AC is at so cant increase the height
Unless I can find another solution Im going to buy a box of those 6x6 sandwich
pads with the blue stuff in middle and stitch them together.

https://www.supplyhouse.com/Bluefin-VPE-600-E-V-A-Anti-Vibration-Pad-6-x-6-x-7-8

 

[rlitman]

not full height in area the AC is at so cant increase the height
Unless I can find another solution Im going to buy a box of those 6x6 sandwich
pads with the blue stuff in middle and stitch them together.

https://www.supplyhouse.com/Bluefin-VPE-600-E-V-A-Anti-Vibration-Pad-6-x-6-x-7-8

That's an option. Spacing them in a grid is still going to work better than filling out the space completely. i.e. 3x3=9 is better than 4x4=16.