Return duct and filter box

[homeownerjim]

New construction is very "cut throat" especially in a tract home situation. Every corner is cut to keep costs low because the builder tries to keep costs low, ductwork usually suffers to keep costs low as well as inexperienced installers to keep labor cost low. If it was a custom built home then the hvac sub should have met with you and the builder and given you options and gotten input from you about how important certain things such as IAQ, humidity etc is to you and your family. A good duct system installed per manual D would have balancing dampers at each branch line on the trunk line that would be balanced and set when installed to match the heat gain/loss calculated by manual J of the room.

This is not a tract home, it's a close to seven-figure semi-custom.

I was required to work directly with the HVAC contractor, although he didn't work FOR me--he worked for the builder. In the end I could specify the equipment I wanted, for which, as I've said, I paid a massive markup. My other option was to take the standard package from the builder and rip it all out the day after settlement.

In hindsight, that would have been a better choice. The HVAC contractor (HAC contractor really, I don't think he knows a thing about ventilation) refused to do anything I wanted with the ductwork. To be perfectly honest, after my first meeting with him, I wanted someone else, but by then I was stuck by the terms of my contract.

This is all water under the bridge at this point. The question is where I go from here to get closer to having the system I wanted to begin with?

Clearly, replacement of all of the accessible panned joist ductboard with real sheet metal ducts is going to be required. Possible replacement of other incorrectly sized ductwork too, and probably the brand new XC16-048 as well. It's entirely possible that walls have to be pulled apart as well. Obviously, relocating the zone 2 thermostat to the master bedroom, where I requested it be installed in the first place too. (I only mention that because it would have taken 5 minutes during construction, and now it's going to be a pain in the rear end). These things may well have to be handled in phases as my family has to live here.

First steps for me are an energy audit and manual J, S, and D calculations. Hopefully that will tell me what the extent of the losses are, and how much of the ductwork has to be replace due to sizing issues. The return air drop (the subject of this conversation) will be replaced along in there somewhere.

Thanks for the thoughts. I appreciate any other comments or recommendations.

[pauls heating &]

you could use mastic to seal the supply ducts and joist panning and electrical penetrations thru it, i did that in my 50's vintage house

[Cooked]

.........I know what you're thinking, what does some PE with a fancy calculator know about airflow in the real world.........

.......I'm not an engineer but I think I have a basic understanding of fluid flow........

I thought you were.

Wow, close to a million bucks and you have to put up with that kind of horse manure?

Other than the shooting, how was the play Mrs. Lincoln?

Just a couple of comments;

The floor boots looked pathetic.

To me the return air duct looks odd with the filter where it is and they should've made it larger.

Building cavities can be used for return chases if they are sealed properly but it's a last resort and not a best practice.

Contract or not, I would have been on that builders a$$ like stink on a fresh turd. Totally unacceptable.

If you can physically get to the ducts Aeroseal is a decent option.

The insulation on the suction line is primarily to prevent sweating but the installers attitude says all, especially in front of a homeowner. Complete lack of professionalism. I'd bet a dollar he was young.

Wireless thermostats are an option these days.

Good luck Jim, keep us posted.

[homeownerjim]

Wow, close to a million bucks and you have to put up with that kind of horse manure?.

Before you all think I'm some kind of schnook, there was a lot that went right with this deal for me and my family. The HVAC system just wasn't one of those things. I was also very pressed for time during construction due to moving and so on; I just couldn't watch construction on a daily basis. The worst part, as I've already mentioned, was that the arrangement meant that the subs didn't directly answer to me. As I found out, in the end I simply couldn't just tell them to do something, or fire them. The HVAC installer I was forced to use wouldn't have gotten a foot on the property, if it had been up to me.

The floor boots looked pathetic.

Indeed. Fortunately those are easily accessible and easy enough to seal, if time-consuming.

To me the return air duct looks odd with the filter where it is and they should've made it larger.

Thanks, me too. We'll get that addressed, once I repair the return ducts sufficiently to ensure that most of the return air actually enters through the return registers.

The insulation on the suction line is primarily to prevent sweating but the installers attitude says all, especially in front of a homeowner. Complete lack of professionalism. I'd bet a dollar he was young.

No, he wasn't young. I should have been more specific: I'm talking about the suction line from the condenser to the house, not inside the house. This part of the line bakes in its southwest exposure. If this line is sweating (or even if it isn't) heat is transferring into the refrigerant, no? I thought leaving the job with a dollar's worth of insulation hanging off this pipe was "wall of shame" sloppy. Just my opinion.

Wireless thermostats are an option these days.

Speaking of sloppy, I can't get over mounting the zone 2 thermostat in the hallway. Apparently it was his effort to balance the temperature from one end of the house to the other: one end would be above the setpoint, the other below, maybe the homeowner won't notice. Just to add insult to injury, he mounted the thermostat so as to cover a 4 inch square hole in the sheetrock, leading to who knows where. I'm going to have to be in the attic anyway, so I'll pull the wire over to the master bedroom and get it properly located.

[homeownerjim]

I want to thank everyone who's replied on this thread. Just putting my issues down in writing has actually helped.

I'm focused on fixing the system so it works the way I wanted from the start.

To begin with, I'll get a PE to do the manual J, S, and D calculations and a duct test to see exactly how bad the leakage is. Then I'll see what can be reasonably done to improve the situation. There are a lot of panned joists in the basement, for example, that are still accessible for replacement, before I start ripping open walls.

Somewhere along the way I'll address the ventilation issue also. Unfortunately I probably won't get the HRV I wanted with its own supply and return ducting, but we'll do something to ensure adequate air changes and control where the fresh air is coming in.

Other thoughts, please let me know. Thanks again.

[homeownerjim]

An update on the ductwork.

I hired a P.E. who does not do HVAC work to evaluate the condition of the ducts. Bottom line is that the ductwork in this new house is worse than I thought. There is gross duct leakage into unconditioned space on the order of 300-400 CFM at a fairly low pressure differential. Clearly there's either a one big hole or a whole bunch of small ones.

The likeliest spot is the attic. I suspect that they cut a hole in the supply trunk, didn't use it for some reason, and then just wrapped insulation over it. I won't even bore you with my disgust. Clearly doesn't come anywhere close to meeting code which means no duct test was done, or the inspector was asleep, or both.

So I'll be looking for someone who can do quality retrofit work to crawl around up there. There's related work in the attic as the ductwork for four bath fans needs to be replaced with insulated and supported ductwork, and wires need to be pulled to relocate the thermostat to the master bedroom where it belonged in the first place. I'll also probably want to relocate a bathroom supply register somewhere other than directly over the bathtub. Don't get me started on that piece of foolishness.

Probably I'll try to find someone on a time and materials basis because no one can predict what we'll actually find up there. And have the engineer back on-site before wrapping up to confirm the leaks have all been found and fixed. Just need to find a detail oriented person or company that doesn't mind cleaning up someone else's mess. Once this is done, I can get to replacing the A/C condenser and coil and adding the ERV, but no point till the ducts are tight.

Appreciate the comments. Again, this is on a house that was new in August 2012. This is beyond a mistake or oversight--this leak is of the magnitude that someone obviously knew about it and just couldn't bring himself to care.