Duct Sealing... (Houston, Austin: how much, new home, heat pump)

[janejanejanejanejane]

Is duct sealing and pressure testing a gimmick? We just got a quote for over $900 for this. They said it will reduce bills by 20%.
I can't stomach it. Thoughts?

[CptnRn]

Duct leakage can result in significant losses in an older home, but its not likely in a newer home, and there is no way anyone can tell you that sealing the ducts will save you 20% without first determining if you actually have any leaks.

https://www.city-data.com/blogs/blog3...ac-system.html

Typical duct leakage is 25% in an older home. That is 25% of your energy and dollars being lost to duct leaks.

The typical grey flexible ducts installed in the 1970's is now becoming brittle and easy to crack, resulting in significant leakage in those homes.

Edit to Add: Since you have said in other threads that you have already replaced your HVAC and your heating bills are still significantly higher then other similar houses in your area, you very well could have duct leaks or insufficient insulation or incredibly leaky windows and doors.

How old is your home? I thought you bought a new home recently but that can't be if you have already had to replace the HVAC.

[CptnRn]

Ohh I see in your other thread you wrote:

Originally Posted by janejanejanejanejane

Something is wrong with our house. Our house is consistenly using more energy to heat and cool than pretty much any house exactly like it or similar. It's a 2005. We cannot, I mean, cannot heat our house past 66 in the winter or we are hit with huge propane bills, 500+ to keep it semi-warm. Something is very wrong.
It could be the furnace and ac unit, but I dunno...
There are no leaks in our furnace, etc. We have them checked by propane often. The elec co won't come out to check the meter, but I doubt its the meter anyway.
Our fireplace vent was open for 2 years and we just realized it, closed it and it made zero difference.
I need our house checked thouroughly. We had it inspected when we moved in and were told nothing bad. We put in solar screens and a new ac unit last year.

What gives?! Who can we call- what kind of company?

OK House was built in 2005...

"We have them checked by propane often" What does that mean? Propane company? Furnace company? Who checked it?

So you put in a new AC unit last year, did you replace the heating element (propane furnace) also?

You have " huge propane bills, 500+" I assume that is $500+ how much propane does that represent? I'm not that familiar with propane consumption, have you looked at some of the other treads that discuss that? I believe I saw that you had participated in some of them.

And how big is your house?

Basically it comes down to two things;
1. Either the furnace and or heat delivery system (ducts) is inefficient or leaking, so heat is not getting delivered as well as it should, or;
2. House is leaking heat due to poor insulation, leaky windows, doors, etc. Which should also result in poor energy performance during the air conditioning season.

[austin-steve]

All HVAC systems have leakage. 13% is average. Over 20% leakage means there is a repairable leak somewhere.

My house failed the mandated City of Austin ECAD Audit when I bought it. I haven't spent the money to improve anything because the electricity-only portion of my utility bill, and my gas bills, are extremely low nonetheless. So I don't see a payback near-term. When the old system craters, I'll do it all then.

If you have a high bill and therefore savings to capture, it might be worth it. You can get an ECDA Audit person to come test your ducts and tell you the amount of leakage you have. Insulation, weather stripping and solar screen are the other 3 of the 4 things that almost every ECAD Audit says could be done to the typical home.

Steve

[centralaustinite]

My house is a three star, green built in 2001. When they came to do the pressure test, they said they had never seen a house with the ducts so tight! (My GO was a totally sticker about that kind of stuff with the subs). Anyway, both my bills and energy consumptions are very low. We spent less to cool and heat a 2400 sq foot house then we did to cool and heat our old 900 sq feet house.

Are you so far outside the CoA that you don't qualify for any rebates, subsidies, etc?

[janejanejanejanejane]

[quote=CptnRn;32484630]Ohh I see in your other thread you wrote:



OK House was built in 2005...

"We have them checked by propane often" What does that mean? Propane company? Furnace company? Who checked it?

Propane company checked it and a company checked it yesterday, third party.


So you put in a new AC unit last year, did you replace the heating element (propane furnace) also?
Just the a/c unit


You have " huge propane bills, 500+" I assume that is $500+ how much propane does that represent? I'm not that familiar with propane consumption, have you looked at some of the other treads that discuss that? I believe I saw that you had participated in some of them.

100 cubit ft of propane =$7 give or take. Right now, we use about 100-300 cf a day when its very cold out, just to keep the house at 66. If we warmed it more, imagine the cost.


And how big is your house?
4,000 sq ft.I know it's larger, but neighbors with same house and friends with similar sized houses using the same utility companies have bills $50 less typically each month no matter the month.

the third party yesterday said there was 25% duct air leakage, but in the pictures he showed me, it was just the return air that was leaking some. I was not convinced. I do have another company who I trust very much coming out today and they seem to be more reasonable. The guy yesterday said windows are good.
I do think the furnaces are inefficient, but we are not ready to shell out 10k to replace the both with possible heat pumps.

Scared to pull the trigger cause there have been a few times we have spent a grand or more only to see no results- not with the house, but with other things in life. This is one thing- this large bill- we are weary about.

[10scoachrick]

Dang jane...you're gonna give that system a serious test over the next few days. It's one thing to drop in temps at night; but it doesn't look like we get warm again until next week Good luck!

[CptnRn]

Originally Posted by janejanejanejanejane

And how big is your house?
4,000 sq ft.I know it's larger, but neighbors with same house and friends with similar sized houses using the same utility companies have bills $50 less typically each month no matter the month.

the third party yesterday said there was 25% duct air leakage, ...

I do think the furnaces are inefficient, but we are not ready to shell out 10k to replace the both with possible heat pumps.

$50 more a month on a $500 bill is only 10% difference, which could easily be attributed to older inefficient furnaces and a few duct leaks and low insulation values in some roof areas.

In one of your posts you mentioned having high ceilings, if many of those reaching up to the underside of the roof in places, those areas probably don't have much insulation above them, just the thickness of the roof joist. Unfortunately, they may also be difficult or impossible to add insulation in those areas.

Adding insulation and fixing duct leaks are usually the lowest cost, best payback options for saving energy, if it is possible to do in your house.

If it cost you $10,000 to replace both furnaces but were only likely to save $250/year on propane costs during the heating season (5 months x $50/month) it would take you 40 years to break even on the cost of the furnaces. I would not be in any hurry to replace them with that kind of payback.

[janejanejanejanejane]

Originally Posted by CptnRn

$50 more a month on a $500 bill is only 10% difference, which could easily be attributed to older inefficient furnaces and a few duct leaks and low insulation values in some roof areas.

In one of your posts you mentioned having high ceilings, if many of those reaching up to the underside of the roof in places, those areas probably don't have much insulation above them, just the thickness of the roof joist. Unfortunately, they may also be difficult or impossible to add insulation in those areas.

Adding insulation and fixing duct leaks are usually the lowest cost, best payback options for saving energy, if it is possible to do in your house.

If it cost you $10,000 to replace both furnaces but were only likely to save $250/year on propane costs during the heating season (5 months x $50/month) it would take you 40 years to break even on the cost of the furnaces. I would not be in any hurry to replace them with that kind of payback.

You make a great point there.
We are doing insulation and duct fixing from the guy today for about $700. Much better than the 1800 the other guys wanted for both.

[Cleonidas]

Originally Posted by janejanejanejanejane

Is duct sealing and pressure testing a gimmick? We just got a quote for over $900 for this. They said it will reduce bills by 20%.
I can't stomach it. Thoughts?

I think that people in Houston sometimes replace working A/C units when they actually just need their ducts sealed. It makes a big difference (but only if your ducts need sealing). I don't think that "pressure testing" is at all necessary, particularly if you have an older home. That's probably what turns a duct sealing job from a low margin service line into a high margin line.

I would add that if you have attic access, a roll of UL listed duct tape, don't mind being uncomfortable crawling around up there (or down there in a crawlspace) and some smidgen of mechanical aptitude - you can do approximately the same job for pretty close to zero materials and labor cost.

(I just realized that this is actually the Austin forum, not the Houston forum)