Determining Ideal Balance Points for VisionPro IAQ

[beenthere]

They must follow the instructions on the 16i outdoor unit for wiring.

[motoguy128]

I'll make that suggestion. I'm looking at the 16i wiring diagram and I think there could be some some confusion from the notes. I think W2 and W3 need to be jumpered ad they need to determine if they have or need the ODT sensors that stage the heating for defrost. THey are shown as optional, but they seem fairly useful.

These types of issues are common in the industrial conttrol world where you have OEM controllers that you're trying to integrate with a central process control system. If the mfg doesn;t clearly explain what the system is doing or why it's doing something and all you have are wiring diagrams, it can be difficult to everything to work together properly.

[badtlc]

Well...I came home and guess what? Wiring problems!
I think he might be getting mixed up because W1 on the IAQ is the O/B terminal when using a Heat Pump.

He says he's having trouble with the defrost board wiring. The IAQ was set to "fossil fuel KIT installed" which is incorrect. Y2 is not connected on the Furnace control board. W1 and W2 are jumpered together.... so the furnace is doing all the staging for tonight. They had the Comfort R mode turned off. The IAQ looks pretty but right now isn't doing anything my previous Honeywell RTH7000 series couldn't do.

The good news is the ductwork is done and I have heat. The returns are silent and the furnace is silent. The supplys are quite a bit quieter, but i haven't seen full fan speed yet.

The bad news is no heat pump control yet, no humidifier instlled yet and there's a few installation items I'm not excited about. My air balane is only marginally improved after replacing 2/3'rds of my main trunk. I think the mian supply plenum right off the furnace must still be a little small. I might ask to have dampers installed in 3 of the ducts to better balance everything. Balancing at the register seems a little sloppy. I suspect overall my static pressure is pretty low, but I doubt I'll get a measurement out of them.

I'm a little disapointed so far. I really thought my air balance would be much better than this.

That was almost the exact same problem I had. They confused the terminal labels and went with the "conventional" labels instead of following the "heat pump" labels.

I ended up reconnecting everything myself and charged them $100 for getting the t-stat rewired. They were very honest about the situation and paid it readily. That is the main reason I still use them for all my maintenance items.

[motoguy128]

It's a small town so I don't want to piss them off. The next nearest Trane dealers are 30 and 40 miles away.

I don't think they are making the same mistake as you, but I don't think they do many dual fuel set-ups.

I'ts funny, Trane advertises dual fuel, BUT, big BUT, they want you to buy their top of the line furnace and XL900... which in a small home is a waste of money, there's no payback on a 95% furnace, especailly if it only runs 20% of the time.

I'm glad I didn't use the 803 thermostat. The furnace staging is poor. It wasted 10 minutes of low stage while recovering from a 5 degree setback.

[beenthere]

I'll make that suggestion. I'm looking at the 16i wiring diagram and I think there could be some some confusion from the notes. I think W2 and W3 need to be jumpered ad they need to determine if they have or need the ODT sensors that stage the heating for defrost. THey are shown as optional, but they seem fairly useful.

These types of issues are common in the industrial conttrol world where you have OEM controllers that you're trying to integrate with a central process control system. If the mfg doesn;t clearly explain what the system is doing or why it's doing something and all you have are wiring diagrams, it can be difficult to everything to work together properly.

If they jumper W2 and W3, it eliminates the IAQ's ability to stage the gas furnace. And makes the IAQ work more like the 8320.

It needs the outdoor sensor, to do dual fuel HP and furnace lock outs.

[motoguy128]

If they jumper W2 and W3, it eliminates the IAQ's ability to stage the gas furnace. And makes the IAQ work more like the 8320.

It needs the outdoor sensor, to do dual fuel HP and furnace lock outs.

I was refering to the optional outdoor temperature switches (sorry they aren't sensors) on the heat pump itself that are used to stage auxillary heat during defrost.

I thought with a 2 stage furnace, W1 and W2 are the 1st and 2nd stage respectively and W3 is unused. The XL16i wiring diagram assumes you may have 3 stages of electric resistive heat.

This is a PITA. The Infinity has all these issues covered. It even allows for a time delay for the furnace to ramp-up.

I think they'll get it eventually.

[beenthere]

IAQ W2 and W3 are needed to control 2 stage furnacce in dual fuel set ups.

[motoguy128]

Alright...I think we have everything sorted out. The Sales person/shop foreman (he might also be an owner) was there when I went home for lunch. The service tech sorted out the HP wiring on his own and the owner told him how to wire the 2 stages seperately. He just had ot remove the jumper and connect W2 and W3 off the IAQ as shown in the drawings. I tired to tell him that, but I guess it needed to come from the boss not a HO.

They added dampers to the 2 supply branches on the plenum. It helped a little bit and he suggested I try that for a few days to see if it helps. The alternative was to run a new 8"x10" branch to supply those seperately. I'll humor him for 3 days and call him on Monday and have that done. I have a feeling I'll prefer them silent at 6AM when the HP ramps up to second stage. I'm hoping it's as quiet as advertised being located outside our bedroom wall.

Basically if I can stand in either bedroom and hear the furnace out of the vent, it's too loud. Moving their supply downstream 4' from the furnace will fix that. He even said they almost relocated them, but decided just to leave them there. He said it's normally "taboo" to install any supplies within 3' of the plenum. That sounds like a good policy.

I'll take some pictures tonight and get some overall opinions. They went heavy on the shiny slicone caulk (no foil tape...wohoo!) so I think the ductwork is sealed pretty well.

[motoguy128]

I have a heat loss question. If you have X% of excess capacity, how quickly can you expect the temperature to rise. So if my heat pump is at 50% duty cycle, how quickly should I anticipate it raising the temperature. Of more accurately, if my heat loss rate is 15k BTU/hr and my heat pump is genrating 25k BTU/hr, roughly how long will it take to raise the temp 4 degrees assuming a typcial RH of 35-40%. Can that be calculated by knowing my air change rate and take the % of heat rise not used to match the heat loss?

[beenthere]

Not really.

The furniture and walls, will absorb some of that heat, and make it take longer then if it was just warming up air.

On paper, it would come to 36 minutes.
In reality, it can be closer to an hour.