Please help - New zoned system problems!

[mparkes]

I hope someone here can give me some advice, I am not an installer, just a poor schmuck who hired what I thought was a reputable compant to install a zoned system in our home we just built here south of Spokane - and we are having lots of problems with it.

Rheem 4 ton, 3 zoned system, 2800 SF home (9ft ceilings first flr, 8 ft second) 2 zones down, 1 up. We had problems with the cooling on it back in the warmer months (system could not cool the house down, would run non-stop and then cycle off I guess to prevent freezing the unit up?) - we noticed that zone 1 on first floor, you could barely feel any air flow coming from the registers.. well they finally fixed that and the house cooled down okay without the unit running non-stop.

But now, we are having a similiar problem with the HEAT in that we were noticing that there was very little air flow from zone 1 registers in heating call, and the system would run for about 30 minutes and was unable to raise the temp 3 deg (from 66 to 69) and then the AUXILARY heat would cut in (heat strips I guess, we sould see a little light turn on on the thermostats to indicate the AUX heat cutting in)... it still would run non-stop and we just gave up and turned the heating down to 66 so as to not run up the elec bill with those dang heat strips. So they came out and adjusted something under the house (the unit is in our crawl space) and replaced the thermoststs! (From invensys to Honeywells).. not sure why they replaced the thermoststs, that didn't make sense to me. Anyway, the system seemed to run a little better, until this morning with an outsie air temp of 34 deg, this system came on at 3AM, and NEVER SHUT OFF until 6:30 and then only for about a min. We have the house set to 68 deg. Is that NORMAL??? Air flow from the registers seems to vary quite a bit, I guess this is because of how many zones are making calls at the same time?

My wife is starting to freak out, thinking that this thing is going to burn up its running so much. Any advice is appreciated!

[dash]

Can't tell much from here,what does the installing contrctor say??


Posting pictures of the unit and dampers ,would help,might see something.

Zoning is often poorly designed ,hope that's not your case.You may need to find another contractor with more zoning knowledge.

[dan sw fl]

Originally posted by mparkes
we just built here south of Spokane - and we are having lots of problems with it.

Rheem 4 ton, 3 zoned system, 2800 SF home (9ft ceilings first flr, 8 ft second) 2 zones down, 1 up.

But now, we are having a similiar problem with the HEAT in that we were noticing that there was very little air flow from zone 1 registers in heating call, and the system would run for about 30 minutes and was unable to raise the temp 3 deg (from 66 to 69) and then the AUXILARY heat would cut in (heat strips

... it still would run non-stop and we just gave up and turned the heating down to 66 so as to not run up the elec bill with those dang heat strips.

So they came out and adjusted something under the house (the unit is in our crawl space) and replaced the thermoststs!

Anyway, the system seemed to run a little better, until this morning with an outside air temp of 34 deg, this system came on at 3AM, and NEVER SHUT OFF until 6:30 and then only for about a min. We have the house set to 68 deg. Is that NORMAL???

Air flow from the registers seems to vary quite a bit, I guess this is because of how many zones are making calls at the same time?

Note that the Heat pump capacity is significantly reduced at < 40'F.

No RHEEM equipment model numbers, heat strip rating
( __ 15Kw ?) nor Manual J info has been provided.

Heating at least two zones to 72'F should not be a challenge for a Properly designed system at the Design Temperature.

Air balancing for different zone calls needs to be THOROUGHLY investigated by an experienced, third-party, certified balancer.

[mparkes]

Thanks for the replies -
I will take some photos of the system and post here later - should I be able to get the manual J numbers from the installer? What other intelligent questions should I ask him, rather than just griping? I'd like to be able to approach a third party to come in and analyze the system and see whats wrong, do I just ask them if they are a "certified balancer"? thanks

[bornriding]

What seer rating is yur equipment - 4 tons on 2800 sg ft is pushing the limit - by rule of thumb - and if yu have variable speed blower, yur problems may be mutiplied. If you have high seer, then you don't have 4 tons anyway, so yur 'short' even more.
Can't give you an answer to yur problem as I am not there,
but I am sure that you paid a premium for that system & you deserve to have it right
Sue the installers !! ( just kidding ) - but you do need attention by the installing company.

I hope you all the best,
Richard

[gate]

Originally posted by mparkes
[snip]
Rheem 4 ton, 3 zoned system, 2800 SF home
4-ton approx equals 1600CFM maximum air-flow, this is too small for 2800 sq.ft.
If it's a heat pump, then it's BTU/h heating capacity is insufficient for the air flow requirements of the structure.

(9ft ceilings first flr, 8 ft second) 2 zones down, 1 up. We had problems with the cooling on it back in the warmer months (system could not cool the house down, would run non-stop and then cycle off I guess to prevent freezing the unit up?) - we noticed that zone 1 on first floor, you could barely feel any air flow coming from the registers.. well they finally fixed that and the house cooled down okay without the unit running non-stop.

But now, we are having a similiar problem with the HEAT in that we were noticing that there was very little air flow from zone 1 registers in heating call, and the system would run for about 30 minutes and was unable to raise the temp 3 deg (from 66 to 69) and then the AUXILARY heat would cut in (heat strips I guess, we sould see a little light turn on on the thermostats to indicate the AUX heat cutting in)... it still would run non-stop and we just gave up and turned the heating down to 66 so as to not run up the elec bill with those dang heat strips. So they came out and adjusted something under the house (the unit is in our crawl space) and replaced the thermoststs! (From invensys to Honeywells).. not sure why they replaced the thermoststs, that didn't make sense to me. Anyway, the system seemed to run a little better, until this morning with an outsie air temp of 34 deg, this system came on at 3AM, and NEVER SHUT OFF until 6:30 and then only for about a min. We have the house set to 68 deg. Is that NORMAL??? Air flow from the registers seems to vary quite a bit, I guess this is because of how many zones are making calls at the same time?

My wife is starting to freak out, thinking that this thing is going to burn up its running so much. Any advice is appreciated!

For zoning systems, a variable speed furnace/air handler should be used along with a 2-speed air conditioner or heat pump. Why? Zone demand.

You haven't given us much info in your lengthy post.
You mentioned a Rheem (http://www.rheemac.com/)... does this product have a model number?
What type of Zone system? Who manufactured it? What model/type of zone product?

How was the duct system designed to seperate the the zones?
Why did you install zones in the first place, why not have two systems: one for the second floor, and one for the first (either or both could then be zoned for more "comfort.")

The more specific information, the better of a response you'll get. Give us homeowner information and not homeMoaner whinning.

Rule of thumb:
You get what you pay for
Go with the cheapest, live with it.

Want to see what Professionals use to zone standard residential equipment? Look here (http://www.arzelzoning.com/).

Want to elimnate your problems? Go here (http://www.residential.carrier.com/).
;)

[airworx]

zoning systems work great, we have had not one problem.
my thinking is maybe the duct design is not adequete. i would hire another contractor.

[gate]

Originally posted by bornriding
... If you have high seer, then you don't have 4 tons anyway, so yur 'short' even more.

What???
What does SEER have to do with Capacity (http://www.google.com/search?q=define%3A+capacity&btnG=Search+the+Web)?

Seasonal Energy Efficiency Ratio (SEER)

The total cooling output of an air conditioner during its normal annual usage period for cooling, in Btu/h (W), divided by the total electric energy input during the same period, in watt-hours, as determined by DOE 10 CFR Part 430, Subpart B, Test Procedures. New equipment ranges from about 10 to 16 SEER. Higher SEER ratings indicate more efficient equipment.

Ummm..
Go here (http://www.energycodes.gov/), and lurk the glossary, and maybe learn a few things ;)

[bornriding]

If you look at the BTU rating of the compressors in the high SEER systems, you should notice that the compressors for a certain size system will be reduced in capacity as the seer rating goes up. At least this is what I am discovering when looking at higher SEER equipment. Don't know how they retain the size rating, but the BTU's are lower. Which is how they can save energy. Even the 10 Seers don't put out full rating BTU's.
Please, inform me if I am incorrect.

Respectfully,
Richard

[mparkes]

Okay lets see if I can supply a little more info instead of just whining!

Rheem Model RPPA-049JAZ
14 SEER
8.70 HSPF

Appears to be a Zonex zone controller.

Heat strip appears to be
208V/240VAC
13.2/17.5
Rheem model RBHK 24J18SUE

HahA!!! - there it is - last 4 model letters - SUE!!! I just found the answers to my problems!:)

I'll post some pix later.

We did not go with the low bidder on this project, they were a middle bidder, about $14K for the system

thanks for the replies!

[dash]

Originally posted by bornriding
If you look at the BTU rating of the compressors in the high SEER systems, you should notice that the compressors for a certain size system will be reduced in capacity as the seer rating goes up. At least this is what I am discovering when looking at higher SEER equipment. Don't know how they retain the size rating, but the BTU's are lower. Which is how they can save energy. Even the 10 Seers don't put out full rating BTU's.
Please, inform me if I am incorrect.

Respectfully,
Richard


Yes they may produce less than 12,000 btus per nominal ton,but SEER is based on actual btus(not tons),and energy consumption,so SEER is comparable ,btu to btu.


Now ,be careful if you replace a 47,000 btu ,4 ton,with a 43,500 btu 4 ton.Will it cover the load??

[dan sw fl]

Originally posted by mparkes
Thanks for the replies -

I will take some photos of the system and post here later -should I be able to get the manual J numbers from the installer?

What other intelligent questions should I ask him, rather than just griping?

I'd like to be able to approach a third party to come in and analyze the system and see whats wrong, do I just ask them if they are a "certified balancer"? thanks

Riley Engineering
504 West Thomas Moore Way Street, Spokane, WA 99201
phone: (509) 325-2576

Testing = *$,$$$.$$

Testcomm Llc
801 East 2nd Avenue, Spokane, WA 99202
phone: (509) 533-0498




[Edited by dan sw fl on 10-08-2005 at 12:49 PM]

[dan sw fl]

Originally posted by mparkes
Para phrasing:
Rheem Model RPPA-049JAZ RBHK 24J18SUE
... 14 SEER 8.70 HSPF ... Zonex zone controller.
... Heat strip 208V/240VAC 13.2/17.5 kW
... ~$14K for the system

http://216.122.22.11/FetchDocument.aspx?ID=f0a7209c-da1c-4f5f-ad65-54e1c792b8de

page 6, 3rd line,

47,000 BTUh at 47'F
29,000 BTUh at 17'F
Straight-line averaging
39,000 BTUh at 32'F

Strip heater 17.5Kw
= 59,727. BTUh

[Edited by dan sw fl on 10-08-2005 at 01:07 PM]

[mparkes]

Having the system tested will cost thousands ???


Riley Engineering
504 West Thomas Moore Way Street, Spokane, WA 99201
phone: (509) 325-2576

Testing = *$,$$$.$$

Testcomm Llc
801 East 2nd Avenue, Spokane, WA 99202
phone: (509) 533-0498

[Irascible]

Professional air balancing is a niche market usually reserved for the commercial sector. As a result it is usually pretty expensive for a homeowner to have it done. Alternatively you could hire an NCI certified HVAC contractor. Most of them are not on the same level as a true commercial air balancer. But they are often head and shoulders above a typical residential contractor. Obviously you should give your installing contractor every opportunity to fix the problem before you go to such lengths.

If you're interested in a primer on zoning I wrote this (http://hphaa.com/services/installation/installation.htm#Zone_Systems). It focuses on gas heat with air conditioning. But a heat pump is essentially an air conditioner in reverse. So generally speaking the principles still apply. The focus of what's linked is on airflow. And airflow is even more critical for a heat pump than it is a gas heater or straight air conditioner.

The cooling coil of a heat pump in summer becomes the heating coil in winter. You could call it the radiator for the compressor. If you severely reduce airflow you'll cause the compressor to quickly overheat and shut down. With just one zone calling it's extraordinarily unlikely that you're maintaining proper airflow. Even with two out of three zones calling you may have the same problem. If the compressor is shutting down on its safeties then that would explain why it's taking so long to heat up.

[docholiday]

Dan you are confused, there is no significant loss in capacity at 40 degrees. There may be a loss but insignificant. The balance point is where the loss of the structure equals the capacity of the machine. This is a fiarly large system and if sized properly he has a 18kw heater (This should be sized for full heat loss). 17.5kw equals 59,727 btuh total load for the coldest of nights.

Any one who works on heat pumps would come to the conclusion that this heat pump will perform well into the low 30's in this home maybe even the high 20's. He doesnt need the 60k of heat until its 0 out. at 30 degrees outside his heat loss may only be 25k. But we dont know what his load calcs said.

If he really wants to know where the problem is, he should open the zone dampers, close any bypass and run the system. If the system performs, then he's got a zoning issue. The implication is that zoning is just as good as multiple units and it isnt, its a lesser expensive way to zone a home.

[dan sw fl]

Originally posted by docholiday
Dan,
You are confused, there is no significant loss in capacity at 40 degrees. There may be a loss but insignificant.

The balance point is where the loss of the structure equals the capacity of the machine. This is a fiarly large system and if sized properly he has a 18kw heater (This should be sized for full heat loss). 17.5kw equals 59,727 btuh total load for the coldest of nights.

Any one who works on heat pumps would come to the conclusion that this heat pump will perform well into the low 30's in this home maybe even the high 20's.

He doesnt need the (Full ..added) 60k of heat until its 0 out. At 30 degrees outside his heat loss may only be 25k.
But we dont know what his load calcs said.

http://216.122.22.11/FetchDocument.aspx?ID=f0a7209c-da1c-4f5f-ad65-54e1c792b8de
page 6, 3rd line,
47,000 BTUh at 47'F
29,000 BTUh at 17'F

Additional ARI rating: 35,000 BTUh at 35'F ...
__ 25% reduction (perhaps Significant % to most people for 12'F decrease in Outside temp) in Heat Pump capacity
when Outdoor Temp drops from 47'F to 35'F.

Heat loss is very likely > 35,000 BTUh at ~35'F
(70-35= dT= 35'F = Inside - Outside Temp)
based on my Manual J calc for a typical 2,800 SF house in WA.

Heat Loss for 63'F dT ( 7' F Design Temp for Spokane)
is >_ 60,000 BTUh.

Balance Point should be 36'F +/-
for this 2,800 Sq.Ft. residence,
Rheem RPPB049JAZ/RBHK24J18 4-Ton heat pump and
2,500 foot elevation in Spokane (48' N).

If the heat pump is not running quite At Design conditions, the Balance Point could be a little higher.

Owner may determine the balance point based
on his actual observations in the coming weeks.

Dan

[Edited by dan sw fl on 10-09-2005 at 09:59 AM]

[mparkes]

So you're suggesting we were at (or below) balance point yesterday morning? If this is the case, shouldn't the system have activated the supplemental heat, or is this normal for these units to run non-stop for hours WITHOUT aux heat?

"...with an outside air temp of 34 deg, this system came on at 3AM, and NEVER SHUT OFF until 6:30 and then only for about a min...."

[dash]

If below the balance point,a typical system will cycle the strip heat on and off,to maintain the indoor temp near the setpoint ,while letting the heat pump run continuously.You can tell if this is the case,by hotter supply air ,when strips are on,followed by cooler,when they are off.

Some mfrs. have better control systems that bring on say 3Kw of strip heat as needed,maintaining a more even supply air temp.,but the heat pump still runs all the time below the balance point