Self Installed - Insulation/Duct Test Question

[aclockworkoi]

I just had a 95% furnace installed after recently having my old asbestos-wrapped sheet metal ducts removed. It would have cost around $ more to have the HVAC company install new ducting so I elected to do it myself. I used R6 flex ducting , pulled tight, as straight as possible, and with no 90 degree turns; all the stuff I read. I zip tied the flex duct to each joint, wrapped it in SureTape, and did the same with the insulation. I used un-insulated PH2 boots at each existing register hole. I flashed the boots to the subfloor from the inside of the house using foil tape. They haven't done the duct testing... apparently in Sonoma I need to rate under 6%. The guy was out to install the condensation pump today and talked to my wife. Apparently when he was under the house to run the drain line he said I did a great job and was surprised it was my first time(It was the hardest thing I've done to the house down in the muddy adobe crawlspace - recently installed a sump pump), though I did pay a guy for assistance that seemed to be familiar with ducting. The guy told my wife I needed to insulate and better seal my register boots to pass the test. Should I use the spray foam from the hardware store (I would have to use one can per boot(7)) and spray around each boot up to the subfloor? Wow, long explanation for a short question.

[Peztoy]

How much flex duct?

[aclockworkoi]

There are 7 registers(The hardware store that had my size boot only had boots with 6" attachments so I have the following:

2 registers with 8" flex going to 6" reducers into the boot(one has a 35-40' run, the other is about 10') that are both fed by about 4' of 10" from the plenum into a Y.

2 registers with about 15' each of 6" fed by about 3' of 8" from the plenum.

1 register with a straight shot of about 4' of 6" from the plenum

2 registers fed by about 6' of 6" connected to the plenum by about 3' of 8" from the plenum.


Sorry if that was confusing.

[hvacvegas]

What size equitment...?

[aclockworkoi]

not sure.....I can get the model number when I get home....It's a new Lennox variable speed furnace.

[Gunnery Sergeant Hartman]

Post some pics!

[beenthere]

Using 6" supplies cause thats the only size the hardware store had. Could get you in a bind.

[aclockworkoi]

I realize my bathrooms might be a little overheated, especially the one with the straight short shot from the plenum without a damper....I just assumed I would close the registers in there and let that be my damper. I was also told that the reducers at the boots from 8-6" would not pose much of a problem and would just increase the velocity of the air coming out of the registers in the two large rooms.

[beenthere]

Might also just make your system sound like you live in a wind tunnel.
May also not have enough air flow and cause your furnace to cycle on its high limit.

post model number of furnace as soon as possible.

[hvacvegas]

Might also just make your system sound like you live in a wind tunnel.
May also not have enough air flow and cause your furnace to cycle on its high limit.

post model number of furnace as soon as possible.

You forgot the part:
Cycling on high limit drastically shortens the life of the furnace.

And will screw you on air conditioning.

Don't be surpised if your all sizes are going to have to be changed.

[btuhack]

Checkout the California Energy Commission website. They post lots of "do this, do that" stuff for the job to meet the leakage rates.

You didn't mention 181 sealent/mud, so get some. The CEC will instruct you on it's purpose and application. Messy but effective, and water soluble.

[aclockworkoi]

The model is a G61MPV-36B-071. The intake PVC from the roof whistles a little. I used duct sealant on the plenum connections and on the Y joints. I used UL rated 181 Shurtape with the special adhesive or whatever combined with long zip-ties applied with a tensioner/cutter tool. How can I tell what my furnace is cycling at? Is there a special way I should program my thermostat? I have a Honeywell PRO8000 that they installed

[Roadhouse]

All of this is fine and dandy EXCEPT for R-6 insulated flex is NOT up to code any longer, at least here it is no longer allowed. Everything is R-8, mimimum. Not certain nationwide but if so..

[aclockworkoi]

R6 is fine here :) we don't have the temp ranges you do :)

[beenthere]

Your furnace probably hasn't gotten out of first stage yet.

Set your stat 5 to 10 degrees above room temp, and see how your system sounds in second stage.

[aclockworkoi]

Your furnace probably hasn't gotten out of first stage yet.

Set your stat 5 to 10 degrees above room temp, and see how your system sounds in second stage.

The return duct got louder(they installed that) and I can now hear the air coming out of the living room instead of it being completely silent but nothing loud or unexpected.

[Roadhouse]

R6 is fine here :) we don't have the temp ranges you do :)

That's good because you would have set the perfect example of why not to DIY.

"Hey guys, I got me brand new high efficiency variable speed heating cooling system but I installed the last decade's R-6 flex duct that takes it back down to 10 seer." :)

[aclockworkoi]

:worthless:
That's good because you would have set the perfect example of why not to DIY.

"Hey guys, I got me brand new high efficiency variable speed heating cooling system but I installed the last decade's R-6 flex duct that takes it back down to 10 seer." :)

All the HVAC companies quoted R6

[Roadhouse]

Not for long. :D

[bigbird]

How do you know NOT FOR LONG???

[Roadhouse]

I'm assuming because as systems become more and more (higher) in efficiency that everything else directly related to keeping systems at their designed efficiency rating will also go up.

Codes to not degress.

He said crawl space UNDER the house, right, in the mud? If so, that is more open to ambient temperatures, moreso than attics which are enclosed and already R-8.

It's only a matter of time.

[keeplearnin]

Hey aclockworkoi I used to live in Sonoma ca. Iwent to Altimira middle school.

[bigbird]

I drained alot of wine bottles in sonoma.

[aclockworkoi]

Ill get down there and get some pics...I live in Petaluma, CA :)

[bigbird]

I used to deliver beef to santa rosa & petaluma, A long ,long time ago.
I see your in climate zone 2 where r-6 duct insulation is required.
Is it also required to have the duct leak tested by a HERS rater??

[aclockworkoi]

Indeed it is. Need to rate under 6%

[aclockworkoi]

I just now saw that this forum says no DIY stuff - whoops :/

[bigbird]

I`m in zone 4 & so far not required here.(san jose)
It`s a lot of fun changing ducts in the crawl space"NO"
I`m still doing it & i`m 69 years old.

[aclockworkoi]

worst. job. ever. :)

[aclockworkoi]

May also not have enough air flow and cause your furnace to cycle on its high limit.


When the guy put in the filter with it running it sucked it up into the return - he said that meant I had pretty good airflow.

[skibme]

When is the inspection ?

[aclockworkoi]

When I call them.

[beenthere]

When the guy put in the filter with it running it sucked it up into the return - he said that meant I had pretty good airflow.

Thats not what it means.

Could actually be showing you that you have a very under sized return.

[bigbird]

Have the installing contractor come out & do a static pressure test on ducts.

[aclockworkoi]

Maybe I'm not sure how this works. The people that installed the furnace will be charging me to run the test. They then send it out to the county or whatever for finalization. I guess 1 in 7 of those are retested by the county.

[aclockworkoi]

Thats not what it means.

Could actually be showing you that you have a very under sized return.
It's big and was installed with the furnace. They increased it in size from my last one.

[beenthere]

Ok. What size is the filter grille, and what size is the duct that is attached to it. And how far does that duct run(in length, don't just say all the way to the furnace, :LOL: )?

[bigbird]

No, static presuure test is different than the duct leak test.
The SP test on the ducts will determine If the duct system is designed to move the correct amount of air that your furnace is delivering.
The test is then compared to the manufacture`s installation instructions to determine the cfm at a static pressure,
I hope i explained that correct.

[bigbird]

ALL THE WAY TO THE FURNACE.....Thats good:deadhorse: