www.hvactechgroup.com - forums

Our house is a year and a half old.  It's a two story on a slab.  The upper story covers only a portion of the lower floor so there are basically two attics – an upper and a lower.  The HVAC is a single unit installed in a mechanical room on the upper floor.  There are two thermostats (up and down) and two zones.  The zones are controlled by normally open dampers and a Honeywell HZ432 controller.    A single feed goes to a distribution box in the upper attic and then is distributed to the registers on the upper floor.  The lower floor is fed by zone one thru two main feed ducts.  One feed goes to a distribution box at the rear of the house and one to the front half of the house.  The front half of the lower floor is the problem.  It's fed by a distribution box (call it Box A) in the lower attic and has 9 ducts out of it to registers in the ceiling of the downstairs.  Three of those 9 go back to the upper attic, down thru the mechanical room and then to registers on the back side of the house.  They did it this way to get around a the stairs.


The duct work is insulated (R-8) flexible foil covered and is basically hanging wherever they could find room.  There is no other insulation covering the ducts.  The distribution box is sheet metal and has some kind of insulation on the inside of it – maybe a couple inches thick.


Now to the problem.  During cold weather, it appears that warm air is going up the stairwell and into the registers and duct work in the upper attic then getting forced (or pulled) back thru the furnace plenum and back up to the attic and fed to Box A.  By the time the air gets back to Box A the air is cold and a significant amount of cold air comes out several of the registers coming out of Box A.  Also, when we're using the fireplace air also gets sucked back up those ducts from Box A that go up to the mechanical room before dropping back to the first floor.

I used a smoke pencil to follow the air flows as I described so I'm pretty sure this is what's going on.  The HVAC installer has checked all kinds of things.  He has verified that there is cold air coming out of the lower floor registers but seems to be at a loss as to how to address this.  Any and all ideas would be greatly appreciated.

its in Malton and build before 2000. 90,000 input to 82,ooo btu out

Hi,

I'm doing HVAC Installation and repair and I was thinking of partnering with an Insulation Company or Air Duct service provider through referral. Have you had experiences partnering with these kinds of services and how does it go for you?

-Dean

Where is the house located and how old is it?  And what is the input/output of the existing furnace?

Without a heat loss calculation it won't be scientific but I can probably get you in the right ballpark.

how to size a high efficiency 2 stage furnace replacing a single stage 90,000 BTUs natural draft furnace. How many btus needed for new high efficiency furnace

thanks

Quote from: kristi8640 on September 10, 2023, 11:21:41 AMHi
I recently approved by SKILLED TRADES ONTARIO to challenge 313A exam.
I am looking someone to provide study material so that I can pass exam.
I WOULD BE REALLY GRATEFUL FOR HELP.

bidichev1.slava@gmail.com

Hi Kristi8640

Just checking if you managed to get some prep exam questions for the 313A exam,l am also looking for prep questions
Thanks

The attached Goodman Bulletin SR-021 is from 2008 but may apply to your problem.

2023 Goodman heat pump. Loud whine from the condenser. You can hear it as soon as you step out of the van. Ran unit for a few seconds without the compressor, fan runs fine. Only makes the sound in heat mode. AC mode runs quiet.

Sadly no dry contact setting on my ERV model. Might look into switchbot and Home Assistant. Thank you.

Ah yes need to set the ERV to 'DRY' mode and select speed...thanks!