Need help: Noisy air flow with new heat pump system

[toolman4]

I just got rid of the old fuel oil furnace for heatpump with electric backup. The noise and draft from the extra air movement was unexpected and now I'm wishing I would have kept the old system. Would I have been better off to go with propane or back to fuel oil? Is there something I can do to correct this? With my old system I couldn't even here it run. I have a 4 ton goodman system with vairiable speed motors.

[BigJon3475]

You can't get the company that installed it to come back?

[beenthere]

Call the contractor back, to come and check it out.
If the ducts are too small, then he needs to tell you what it will take to fix the duct system.
Was a load calc done, or did they just size it off the sq ft of your house.

[dash]

What size A/C system did you have before??

Sonuds like the ducts are undersized or the fan is set to high.

[toolman4]

He came out and looked at my ductwork before I ordered . My house is 1500sq ft not including a full finished basement. My old cooling sytem was rated at 3000btu. I'll have to have him come back out. With most new systems now, do they move more air because the heat doesn't get as hot? With my old system I couldn't even hear when it turned on for cooling or heating. Should it be that way with the new system? Thanks for the replies.

[beenthere]

Do you mean 30,000 BTU's for the A/C?

Sounds grossly oversized for 1500 sq ft.

How many estimates did you get for this replacement.

[toolman4]

It is a 10 seer rheem for cooling but the coil in the old furnace said 3000btu. When figuring my sqft do you include the basement so instead of 1500 it would be 3000. He said I had to go with a 4ton because it wouldn't be enough heat for here in Minnesota. It would be on the backup heat too often. I can't find anything for size on the old air conditioning unit but I think the heat pump was sized more for heat. I had three bids for the project, 2 bid 4 ton, 1 bid 3 ton.

[BigJon3475]

...

[Airmechanical]

Do you mean 30,000 BTU's, Sounds grossly oversized for 1500 sq ft..


nah, but they probably replaced the 2-1/2 with a bigger system!



.

[badboyheel]

i would have the co. who put it in come back and check duct sizes and also blower speed. as for the heat pump i'm assuming where you live in minnesota it gets very cold, i'm n ot a fan of heat pumps in extremely cold temps even with electric heat.

[BaldLoonie]

Gasp! 4 ton for 1500 sq ft, no wonder it is noisy. Going from 2.5 to 4 ton on the same duct system? No wonder it is noisy. What brand is it? Oh yea...

Sorry, you have a real mess on your hands.

[RyanHughes]

Ask the contractor who sold you the system to do a load calc. to prove his sizing technique, if he stands behind his work.

Is the basement actually conditioned (heated/cooled)?

Heat pumps are typically sized for cooling, not heating.

[jrbenny]

Me thinks his installer doesn't understand air flow and duct sizing.

[Avery123]

I really appreciate this site - good for person like me who has little knowledge to have folks to get input from. I wrote in another post that I am considering the hybrid infinity heat pump/furnace but am concerned about the noise level. This is new territory for me. House was built in 1949 and expanded since - kinda rambling open style country house - maybe 3000 square feet. Does anyone have any experience with noise level of infinity? Thanks for any hel p or input to aid me in making the decision to go for something new. I certainly love my prius car hybrid. Thanks

[beenthere]

Can you post the model numbers of the furnace and Hp that they installed.
Also, could you post the size of the duct that is attached to the furnace for the return and supply.






To avery123. Your Infinity will make all kinds of noise if installed wrong.

[skippedover]

Well the horse is out of the barn now. I've attached a document with my standard recommendations on how not to get screwed having HVAC equipment replaced. It's most likely that the contractor you hired was smart enough to know you need a very large HP to do the job in your climate but never connected the dots between the size of the existing system, which was a high temperature heating system and the new HP, which is a lower temp heating system. The result is the need for a larger HP than you would need for strictly cooling purposes. The error is that the duct system has to support that larger unit. He also should have made provisions for you to get proper cooling in the summer. If it's a single stage HP, then he needs to have put in some sort of by-pass or dump system to get rid of roughly 50% of the cool air. Otherwise you'll feel like a trout. Cold and wet all summer. As you can see, I'm not sure you've truly seen all the negatives of what's been done to you. I'd recommend one of two things that needs to happen. First and foremost, if you're going to use a HP to heat the place (maybe not the best decision in your climate for the coldest weather but good for the milder days/nights) then you will probably need to upgrade the distribution system (ducts) to handle the increased airflow. Second, I'd highly recommend a 2-stage HP so you get a cooling system for the summer that's closer to what you need. Otherwise the HP will be too big for your home and you'll be very, very, uncomfortable. I think the simplest way out is to go back to a fossil fuel system but have a HP 1/2 the size of what you've got now. Use the heat pump as a dual fuel system on the milder days and the fossil fuel system on during the colder weather. That's where you'll get the best economy and most comfort. This is a sad but all to frequent result of the homeowner getting thrown under the bus when dealing with less than completely competent companies. Let us know how you make out.

[toolman4]

The contractor is supposed to show up this week. I will report back what we find and also see if he can do a load calc on the house. The basement gets heat from the system but I close the ducts in the summer because I don't need any cooling there. Is it possible to just program the fan not to blow as much air since it is variable speed? I questioned him on the size before I bought. He has a reputable business in the area and has a heat pump for his house so I figured he knew what he was talking about. I'll see if I can get the model numbers. I can get electricity at 4.5 cents per kilowatt so it was cheaper to go the all electric route. Thanks for the replies.

[beenthere]

Depends how much air is needed over the coil to keep the system from freezing.

[toolman4]

model # on heat pump is ssz16041ab,
model # on air exchanger top part capfa860d6ba
model # on air exchanger bottom part mbe2000aa-1ba
duct work on exhaust side is 8" X 12" going west and a run 8" x 15" going east and a very short run of a 5" tube going south exiting in the basement
intake side they built a 15.5" X 16" duct work to feed the exchanger No air filter came with the air exchanger so they have to build one in that 15.5 by 16 duct. Is that normal? Somebody told me Amana is the better line from goodman?

[jrbenny]

Two. Maybe 2.5 tons of air through the supply.

They put the ductulator on 0.1 for the return duct. :eek:

The equipment isn't the problem. It's the duct to which it is connected.

[hvaclover]

Like the man said you size heat pumps for the cooling needs of the house.

Your home on the face of it needs (just a ball park with out doing load calc) not more than 2.5 tons of cooling. That would give you an effective heating capacity of 30,000 btus. But two things come into play here concerning the heat.
One is that the amount of heat from the hp is never enough by itself so you back up heat.

Two is the fact the HP is only good down to about 30* (you guys correct me if I am off on that) and the colder it gets the less heat it can produce and the more electricy you use.

Minnesota is way too cold for a HP. I live below you in Mi and the people who had HPs pulled them and just stuck with a furnace.

Your contractor tried to get around rule number one and two.

If your house has been added on too since contruction in '49 the duct work could be a hodge podge of under sized trunks and connections.

One thing is certain, the 4 ton is way over sized for your home and the duct work. The installer did not do you any favors by installer a HP or by over sizing it.

There is no real fix unless you want the ducting resized to accomadate the 4 ton.

I am not a believer in hps for the Mi and Northern mid west. Just gets too darn cold.

If I had to do over again I would go with a 95% two stage furnace with a varible speed blower.

[beenthere]

As JR, pointed out on the first page. The installer gave no thought to the air flow.

The 4 tons is too big for cooling, and the duct isn't sized for it either.
It might not be too late to have him take out that over sized 4 ton, and put the right size in.

[beenthere]

Because you said that he came out and checked your duct work before you odered the HP.
Did you buy this HP yourself online, and just had him install it?

[toolman4]

I ordered the heat pump through my dealer. They spent a lot of time fabbing the new exchanger in. Is mine a 2 stage with the variable speed exchanger? How much less airflow is the 3 ton vs the 4 ton? I did a little research online and the seem to be putting the heatpump in colder and colder areas and making them work. The dealer has had one for a while now but his is geothermal. Since he is the dealer, how do I tell him that it is oversized after that is what he reccomended?

[beenthere]

No, its single stage, Amana has a 2 stage in the 16 SEER.

Before you go having another unit installed by guessing on the size.
Go to this link, pay the fee, and find out what size you need. http://hvaccomputer.com/talkref.asp

[buford]

sounds like ductwork issues,seems like the start up and charging charts should have showed this.along with temp rise,amp draw,static pressures!

[toolman4]

I finally got time to do the hvac calc and I came up with 2.5 tons. So, one size bigger is 3 ton. How do I know what cfm and size of ducts I should have. With the sizes I have given I figured 232 sq in. out and 248sq in. coming in. How do you figure the ductilater to get .1? He has to add the filter yet, so I assume that will make it worse?My blower operates 1200 to 2000 cfm. My contractor hasn't come out yet but said the blower could be turned down for winter but not probably summer. He has to come back out to some plumbing in for the shower and would talk over things then. I assume there is a way to measure the speed of the air entering the rooms through the ducts to relate it to comfort right?

[RyanHughes]

So you came out to 2.5 tons and had a 2.5-ton unit before (30,000 BTU/H, correct?), but the contractor put in a 4-ton unit? The unit sounds grossly oversized and it is apparent with the duct noise, btu that's just my speculation. I would show your load calc. to the contractor. Is the contractor a plumber?

[hvaclover]

So you came out to 2.5 tons and had a 2.5-ton unit before (30,000 BTU/H, correct?), but the contractor put in a 4-ton unit? The unit sounds grossly oversized and it is apparent with the duct noise, btu that's just my speculation. I would show your load calc. to the contractor. Is the contractor a plumber?

We the heck does everybody pick on plumbers?

Some of the best HVAC guys here are plumbers too.

Sheesh!

[RyanHughes]

That's understood. But do some of the best plumbers belong doing HVAC work, too? Plumbers do get some beating here. I just asked if he was a plumber since the OP mentioned someone coming back to do the shower plumbing! :D

[acmanhoney]

some plumbers are hvac guys and some are just plumbers who do hvac....

[beenthere]

With manual D, you can figure out the FR, and then use a ductulator to figure the required size for the ducts.

[toolman4]

Thanks for the replies. Yes, he does plumbing and refridgeration also. I believe my old system was 2.5 tons. Where is this manual D? I looked in the hvac 4.0 program but couldn't find it. I assume turning my fan down kills efficiency in both seasons. Should he have a tool to measure my speed coming out of my registers? What speed is comfortable without being too drafty?

[allan38]

The largest part of my experience is with Goodman/Amana equipment.
Most of their heat pump air handlers can be used for a wide range of heat pumps.
For example 1.5 - 3 ton or 4 -5 ton.
Many air handlers I've seen were factory set for the largest capacity.
Thus the installer needs to set the air handler's speed to match the heat pump.
This may part of the problem.
It's a slight field adjustment that may fix the problem.
I've seen a 4 ton heat pump with a 5 ton air handler. It was really noisy for 5 years (until I was the tech doing the annual maintenance).
At the 6 year point I heard the system operate and set the fan speed for 4 tons and it quieted right down.

[toolman4]

Good to know. I think mine is a 4ton matched with a 4 ton. What is the fr and where is the manual D?

[beenthere]

Try your local library for Manual D.
It will explain FR.