Austin Energy Audits finding lots of leaky ducts (house, to buy)

[CptnRn]

It is not that hard to evaluate how much air is being lost, they do use a flow-meter at each duct outlet and can calculate how much is being lost by comparing it to the CFM of the supply fan. It is a relatively simple engineering calculation.

As an architect I have always been interested in energy efficiency, passive solar design and conservation issues such as this. It just makes sense to reduce our energy consumption and expenses whenever we can.

Just about any HVAC company in town can perform these tests for you, as part of a complete energy evaluation of your house. The City originally implemented these kind of whole house evaluations years ago as a requirement for getting energy rebates from the City. I don't think it has anything to do with any particular companies being tied to council members so much as it has always been something promoted by those interested in energy efficiency and conservation.

They have been doing these evaluations since at least 1996, as it was part of the City of Austin rebate program back then, when I had one performed on my first house when I replaced the 15 year old HVAC system. The rebates that are available from the City alone makes it worth doing if you are going to stay in the house. It reduces your cost for the new system and saves you money operating it. The only recent change has been council requiring this to be done withing 10 years prior to selling a house.

I provided some similar information about duct leakage issues in this in this thread https://www.city-data.com/forum/austi...ac-system.html

But to recap a few of the relevant points:

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.

I have also observed that in the past it was common practice to attach the flex duct to an HVAC register boot/vent without sealing the connection or the boot. Most of the boots have slots and openings along the joints that leak if not sealed up. Now they cover the whole thing with mastic to seal it.

[tibbar]

My daughter is living in a rental duplex community and she is trying to get them to replace her AC. The unit runs all the time when set at 80+degrees. They come check the unit and tell her it is full of coolant. I am sure her ducts are messed up and finally someone is supposed to look into it on Monday. Her electric bill is almost 3 times mine for a place less than half as big.

[austin-steve]

They come check the unit and tell her it is full of coolant.

That sounds like an unsatisfactory answer.

I'd want to know what the "splits" are. That is, the air temp being sucked into the filter versus the air temp being blown out of the grills. Should be a differential of 16-20 degrees. Also, you want to know the tonnage of the unit to see if it's sized right for the amount of square footage. And a visual inspection of the plenum and ducts will most likely reveal if any leaks exists.

A $70 A/C evaluation from most any reputable HVAC company can determine these things. Just because a unit is "full of freon" doesn't mean it's functioning as designed and cooling properly.

If your daughter is not doing so already, she should start documenting all communication with the landlord in writing. Also, the free Austin Tenant's Council can assist and advise with these type of issues.

Steve

[Exiled Texan]

Do you think as a renter we have a right to ask that the land lord check our home for this? Our darn AC runs 24/7 and can't break 80. 1950s ranch with casement windows.

[Exiled Texan]

Anyone know of an HVAC company that would come out and do an assessment for a de minimus fee?

[tibbar]

Thanks for the advice Steve. I am passing your words on to my daughter.

13 years ago a woman from our Bunco group in Westcreek said her AC was running all the time and when the AC guy went into the attic all her ducting was SPLIT OPEN and pumping cool air into the attic. When we had a new unit put in 10 years ago we had new ducting installed since the insulation on ours was split and falling off.

[austin-steve]

Originally Posted by Exiled Texan

Do you think as a renter we have a right to ask that the land lord check our home for this? Our darn AC runs 24/7 and can't break 80. 1950s ranch with casement windows.

Well, you can ask whatever you want, but renters and landlords are all individuals with different personalities so the outcomes will vary. I can only tell you how I would handle it.

First, all homes in Texas are rented as-is. A tenant can't rent a 1950s ranch house and expect the electric bills to be as low or the air conditioner to be as efficient as in a newer home. So the questions would be:

1) Is the electric bill "high" for that type and age of home?
2) Is the high bill being caused by a/c deficiencies that the landlord is responsible for curing, or is it a lifestyle reason, such as a tenant who runs the a/c at 72 degrees all day long?

There would be a lot of grey area there. With outside temps above 100, many hvac systems will struggle to cool an older home, even without problems.

Since I personally have my a/c units evaluated annually, I would discover and cure anything obviously wrong with the system before a tenant moves in. Nevertheless, if a tenant called and said "our electric bills are over $300 ever month and we think it's because the a/c system isn't operating properly", I'd let them know that I can send someone out to check it, but I'll bill back the service call to the tenant if no problems are found. If problems are found, I'd fix it and not charge the tenant. I think that's fair, and that's the offer you could make.

But if you asked 10 landlords, you'd probably get 10 different answers.

Steve

[CptnRn]

I pretty much agree with what austin-steve wrote above. The only qualification that I will add is that if the tenant rented a home with air conditioning in it, then the tenant is entitled to expect the air conditioning to work. The problem comes in trying to define what qualifies as "working". The difficulty here is there are so many variables.

The good AC unit in a 1950s ranch with casement windows is probably not going to perform well in this heat unless the entire house has undergone energy conservation upgrades such as adding insulation and sealing all ducts, windows and doors.

If the AC is running 24/7, non-stop as alleged and can't get the temperature down below 80 even at night then its not working or there are some other serious problems with the house. I personally could not live in a house like this so I would not expect my tenant to either, and I probably would not own or rent out a house that had these kind of problems.

If the AC is running non-stop only during the hottest few hours of the day and can only get the temperature at that time down to into the low 80's, then it is probably doing the best it can in an unimproved 1950s ranch with casement windows.

I have only seen this happen once with the 15 year old HVAC unit in my 1981 rental house. It was when the coils iced over from all the humidity collecting on them. The tenant had left the patio door open for most of the morning and the unit iced up because it was running constantly. Shutting it off for about 4 hours was sufficient to give the ice time to melt and it has worked fine every since. The only reason I didn't charge the tenant for that service call is because the repair man did not charge me since I had an annual service agreement with him and he didn't actually have to repair anything. I have them check the heating components in the fall and the air conditioning components in the spring, to try and prevent problems.

[CptnRn]

Originally Posted by Exiled Texan

Anyone know of an HVAC company that would come out and do an assessment for a de minimus fee?

Jason Krieg, Alamo Austin Air is very reasonable.
alamoaustinair"at"yahoo.com
replace the "at" with a @

[johng2431]

Strand Brothers Index is in tight with the city, and then the other guys that seem to do a lot of work in this area are Green Collar - Free Energy Audits - Make Your Home Energy Efficient in Austin, Texas

Strand has been around for a long time. I suspect they are more tied in w. someone at ciity council. Their price quote was also double what keith at Green Collar charged me - but strand is larger and Green Collar has only been doing this for about 3 years and looks to be a younger more up and coming company. Not sure if those guys have someone they know at city hall....