Poor HVAC Install - Help with DIY

[nissanK]

Home is less than 4 years old and with the recent cold snaps, I'm noticing serious temperature variations from room to room. I've closed all but 2 basement heat vents to push more heat up to the main floor (split level with vaulted ceilings) but I'm still finding the main floor and bedrooms are colder than ideal.

All cold air returns(floor) and heat vents are open/not blocked.

Basement is unfinished so I was able to take a look at all the exposed HVAC and here's what I found:

https://imgur.com/a/ntpkH

So here are my questions:

1. Should the cold air returns be fully sealed?
2. Should I just replace with the same product for cold air returns? (the cardboard product) Or source something else/better? (Rigid foam insulation)
3. All the heat pipes are galvanized steel, should I wrap it all with insulation? (Reflectix)

I might consider having an HVAC tech come and do an assessment of the system to see where all the leaks and inefficiencies are.

I haven't got a clue where to start but based on my research I definitely need to do something to improve the efficiency of the system. I'm not opposed to doing some of the work myself.

Any and all help appreciated.

[macman64]

I had similar issues in my new place (2 years old). I found two things have helped. Buy some ductwork silver tape and seal everything you can find that leaks in the basement. Secondly I installed an ecobee thermostat. I have it set to run the furnace fan 15 minutes per hour. I also set up some automation to turn on the fan if the upstairs temp and main floor differ by more than 4 degrees. My old programable thermostat could only do fan on or off. This has worked great!

[suntan]

Sealing cold air return ducting really isn't all that important.

Like macman64 said, seal heating ducts with foil tape. If you want to use duct mastic that's even better. Make sure to seal all the leaks on the assembly on top of your furnace unit. Make sure to check the large ducts that feed to upstairs.

Do you have a bonus room? Often the ducting to that room gets disconnected.

[speedog]

Curious nissanK, does your home have an open concept on the main floor or/and an open concept stairwell between the various floors?

[nissanK]

Good to know that maybe circulating the air in the house helps. I may be able to program that into my existing thermostat.

No bonus room and I've confirmed there are no disconnects in the system. Looking at the system, it looks like they did a piss poor taping job of the leaks and gaps also so I'll definitely start there. Should I at least attempt to seal the cold air returns better?

Yes, open concept main area that opens into the stairwell down to the garage man door and basement. I'm looking into sealing the garage man door as well.

[BokCh0y]

Some guy named mintay at the place I work at talks hvac stuff all the time, he plans hvac with the IT guys. I'll get him to respond to this thread, he's a pro.

[superflychief]

Check that your cold air returns are actually working by putting a piece of toilet paper on em. If it holds you are good. Some of mine weren't closed off properly when our place was built. They had to close em off but it improved things dramatically. Tougher if the runs are in finished areas. May have to pull carpet to fix for example.

[suntan]

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Good to know that maybe circulating the air in the house helps. I may be able to program that into my existing thermostat.

No bonus room and I've confirmed there are no disconnects in the system. Looking at the system, it looks like they did a piss poor taping job of the leaks and gaps also so I'll definitely start there. Should I at least attempt to seal the cold air returns better?

I would focus on the heating ducts first, but hey sure if they're readily accessible work on the cold air returns.

Let me put it to you this way: How the hell is the "cold air" supposed to return if there's no warm air to push it?

[spike98]

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Sealing cold air return ducting really isn't all that important.

Like macman64 said, seal heating ducts with foil tape. If you want to use duct mastic that's even better. Make sure to seal all the leaks on the assembly on top of your furnace unit. Make sure to check the large ducts that feed to upstairs.

Do you have a bonus room? Often the ducting to that room gets disconnected.

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I would focus on the heating ducts first, but hey sure if they're readily accessible work on the cold air returns.

Let me put it to you this way: How the hell is the "cold air" supposed to return if there's no warm air to push it?

I disagree entirely. I'ts not about cold air per say, its about pressure. You can see this effect when you leave a bedroom door closed and it gets cold. If old air can't escape, new air cannot be forced into the room. If your cold air return is not drawing air from tight spaces you will get uneven temperatures.

[nissanK]

I can access the cold air returns since the basement isn't finished. I'll look at sealing them better than they are now.

Did the toilet paper test on a few of the vents and they stuck BUUUUUT as spikers said, all the doors were open when I tested. We keep the doors closed during the day and that's when we notice the temperature variations are the worst. (Rooms are cold when we go in later) So that tells me that the pressure from the cold air returns are not enough to circulate the warm air when the doors are closed.

Just trying to source duct mastic right now. Looks like I have to go to an HVAC supplier.

[jeffh]

Get a can of pro-seal(blue lid ice cream bucket) from Brimark. Also get a couple 1”-2” wide brushes for applying it into the joints. Rip off any duct tape on the joints. Apply the sealer everywhere you can think of. Especially, around the supply plenum, ductwork, end caps, and takeoffs. The pipe joints are less of a priority. Also apply foil tape to larger holes on the return ductwork, and patch any larger openings.

[suntan]

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I disagree entirely. I'ts not about cold air per say, its about pressure. You can see this effect when you leave a bedroom door closed and it gets cold. If old air can't escape, new air cannot be forced into the room. If your cold air return is not drawing air from tight spaces you will get uneven temperatures.

Cold air gets moved all the time. That's the thing. It's not like your house is starved for cold air in a region like Calgary's.

[nissanK]

Based on my research it's not the cold air itself, it's creating the negative air pressure in the rooms/spaces by sucking out the colder air to allow the warm air to circulate better.

Jeffh, I assume this is what you're referring to: http://ductmate.com/product.aspx?id=23

[jeffh]

Yes, that’s the stuff. Great product.