Replies

1. 
   junkhound | Jan 02, 2003 04:19pm | #1

   My own house has a 4T Rheem package unit. I literally built a 'shed' (complete with a 3-tab roof) over it with R-19 insulation and 3/4 plywood walls. Built a simple venturi from sheet metal to duct the evaporator fan.

   I'll post a picture of it later today when I get back home.

1. 
   edwardh1 | Jan 02, 2003 05:02pm | #2

   that will never work - too simple.

   thanks. would like to see the pix.

   I have a 3.5 t rheem - very old.

   pretty quiet but would like it even quieter.

1. 
   junkhound | Jan 03, 2003 04:30am | #4

   Here are 3 pix of the 'doghouse' for the HP.

   1. Overview is obvious,

   2. 2D venturi keeps cold air from side of house, improves flow (fan actually draws about 10% lower current at higher power factor with venturi)

   3. Big advantage to a packaged HP unit vs. split system (I have an EPA freon license so could have installed either) is that it is inherently more thermodynamically efficient due to shorter piping runs, etc, but there are additional losses due to the warm condensor being outdoors - superinsulating the condensor section eliminates these losses, the accordian doors are needed for access to the filters, etc.

   The dual pane window above  the HP is right next to my computer desk, no louder than a normal gas furnace duct being close.

   Good luck with your efforts, Wain.  A few years ago the aircraft surplus store here sold surplus lead filled insulation batts used on the aircraft which were great for both insulation and noise suppression, but the lead liability aspect now puts that good stuff into hazardous waste disposal I hear.

   edit PS: the inteior of this Rheem uit uses a fiberglass/Al foil sandwich for insualtion and noise supression (only 1" thick"), and the data sheet lists it as only down to 82 dB as is.  

   Edited 1/2/2003 8:33:24 PM ET by JUNKHOUND

1. 
   edwardh1 | Jan 03, 2003 05:32am | #5

   cool.

   actually too cool to work. (?!)

   I like stuff like that.

   82 db is common for some package units. semi loud.

   I pulled off my interior window trim and foamed the gap in the wall - that helped some - you could really tell it.

   manufacturers do not seem to give package units much noise reduction material.

   another advantage to me to a package unit is that it is factory assembled.

   thanks for posting these pix.

   I may try something sompler like a "blabket' to sit over the top (less fan of course).

   Thanks again.

1. 
   junkhound | Jan 03, 2003 07:42am | #6

   Good luck with your noise reduction, I once even considered building an acoustic amp/speaker combo (like aircraft headphone) to mount outside next to the packaged unit, but the box/shed  does the double purpose of noise reduction and thermal insulation.

   Art B.

2. 
   edwardh1 | Jan 03, 2003 03:26pm | #7

   I am leaning toward some noise reduction material foam/lead

   about 2 1/2 feet x 5 ft long maybe under a piece of Hardie plank soffit type material to just lay on top the unit.

   Or i may take your advice and try to do just the compressor area.

   My 1983 Rheems have given great service, and are relatively quiet compared to some carriers and Yorks but in my area the distributers are always changing - (seem to be plumbing supply houses) - even the Rheem dealers complain about they (dist) like to sell new units but not parts.

   The Rheem web page lists no dealers in my area, even tho there are 5 in the yellow pages.

   I think Rheem is good but they have some distribution problems.

   Edited 1/3/2003 7:44:36 AM ET by wain

2. 
   TLRice | Jan 03, 2003 05:06pm | #8

   Junkhound, you said:

   "Big advantage to a packaged HP unit vs. split system is that it is inherently more thermodynamically efficient due to shorter piping runs, etc,.."

   I don't understand this statement. Could you explain it to me. I understand a little about thermodynamics and refrigeration cycles, but I've never heard this claim before.

   BTW, when a fan motor draws less current it is because it is moving less air and doing less work, not because of any improvement in air flow.

   Tim

2. 
   booch | Jan 02, 2003 05:28pm | #3

   If you want to get really serious, line the interior with some industrial product that has foam sandwiching a metal septum. The metal floats between the foam sheets and isolates - supresses the sound.

3. 
   lancer7540 | Jan 03, 2003 07:54pm | #9

   Chances are that the noise you are trying to reduce is caused by the compressor, especially if it is a reciprocating type (has pistons) versus the newer quieter scroll compressors, usually a high pitch whine that can be very irritating.  Many compressor manufacturer's have a sound blanket that fits their compressors,basically a jacket made out of 2" insulation with a weatherproof covering. The three big manufacturer's are Copeland, Tecumseh and Bristol and I know that all of them offer these for their reciprocating compressors.  Call your local distributor of the brand of unit and usually they will know what you are talking about, most times the installing contracter does not know about these.  The distributor or manufacturer usually has these as an option for cases like your own.  Hope this helps.

4. 
   nigelUsa | Jan 04, 2003 01:11am | #10

   At long last the nextdoors York heatpump failed and could not be fixed. It sounded like an old truck with a bad exhaust. The replacement is near noiseless. So glad to be rid of the york!!