Posted: 5/2/2026 10:53:30 AM EDT
|
Out HVAC can't keep up. House has older metal air ducts. Over the years, rats were in the attic and chewed open the insulation along the bottom of the ducts. Since we have bought he house I have done my best to clean the choked up coils, close up small leaks I found in the duct work and patch the open insulation. Also added exhaust fans to the attic. Though improved, my ac struggles. Is there any easy and simple way to add insulation over the to the existing duct work? I'm tempted to go buy a bunch of polyester blankets and just throw them over the ducting. Not looking to do anything major or hard. Just want to ride it out until the AC needs to be replaced. |
|
Here's an option that maybe others can comment on. I've never tried one of these, but the principle is sound. (There are other kits on Amazon. This is "the original") It would be easy to cobble something together to see if it would help. A lot will depend on your outdoor humidity. Cool-n-Save AC Misting Kit https://coolnsave.com/products/the-original-patented-cool-n-save-ac-misting-kit  Savings start with 5 easy steps | Cool-n-Save Another option is an indoor dehumidifier. A lot of the work your AC does is removing humidity. When the water condenses out of the air, it releases latent heat, which your AC also has to remove. Having a dehumidifier can make a big difference in cooling your house. |
9 lives - 9 pellets... Coincidence?
|
I’d check the ducts closely for leaks. Are there any rooms that are warmer than others (or cooler than others in the winter)? What type of heat system? |
"It behooves every man to remember that the work of the critic is of altogether secondary importance, and that, in the end, progress is accomplished by the man who does things."
Theodore Roosevelt
Theodore Roosevelt
|
When is the last time the pressure was tested [on both high and low sides] along with the output temp of the conditioned side? No matter what else you do, if your refrigerant is low or your fins on the condenser are clogged, you are fighting a losing fight. What refrigerant does your system use? |
Liberals are a curious mix of communism and fascism, they want to destroy you but want to use your own money to do it.
I'm getting down to the last box, the others have all been destroyed...
I'm getting down to the last box, the others have all been destroyed...
Veteran of the Third Battle of Tannhauser Gate.
Joined:
Dec 2005
Posts:
86854
EE: 100% (6)
ID, USA
| Are you sure that your HVAC system is fully charged? Maybe it just needs some coolant. |
87% of the time, any question starting with "Why..." is answered with "Money."
I am so tempted to lay down the melancholy burden of sanity...
"...and if you can't wait for dawn you can always light a fire."
I am so tempted to lay down the melancholy burden of sanity...
"...and if you can't wait for dawn you can always light a fire."
| The neighbor had his house windows tinted with infrared heat rejection tint. It made a very noticeable difference in reducing the solar gain thru the glass and the AC performance. You could do a reflective tint on south or west facing glass and a less noticeable tint on the other windows. The tint also helps retain heat in the winter. |
|
Originally Posted By urbanredneck: It has an electric coil box in the handler. How well does the heat work in the winter? Is it a heat pump or just an electric furnace? |
"It behooves every man to remember that the work of the critic is of altogether secondary importance, and that, in the end, progress is accomplished by the man who does things."
Theodore Roosevelt
Theodore Roosevelt
|
Impossible to tell why it won’t keep up or trying to diagnose it over the internet. I suggest you get someone qualified to check it out. |
What is a democrat? Someone who wants everything you have, except for your job.
Politicians should wear uniforms like NASCAR drivers so we could see their corporate sponsors.
Politicians should wear uniforms like NASCAR drivers so we could see their corporate sponsors.
|
What state? 1 or 2 story house? How old is the house? On a slab, crawlspace, basement? I live in a 126 year old house that didn't have a lick of insulation in it and the 40 year AC units couldn't keep up in the dead of summer. First thing I did was insulate the entire house, that helped tremendously (blown in insulation is a perfect method to retrofit insulation without ripping down the interior to the studs). I still need to replace the single pane weighted windows but thats coming soon. |
The OP either shut it down for the night or is in the bathroom covered in shoe polish from belt to knees trying to get the lighting right -Sierra5
|
Originally Posted By ske714: Here's an option that maybe others can comment on. .......... Cool-n-Save AC Misting Kit The evaporating water will deposit minerals on the condenser and it will corrode until it leaks. The mineral layer that forms will also reduce AC capacity when the coil is dry because it reduces heat transfer to the air. Best thing you can do for the condenser is to ensure it is shaded from direct sunlight when your cooling demand is highest. |
|
Originally Posted By Morgan321: Water cooling on the condenser is a huge boost in cooling capacity, but it will wreck the condenser in short order. The evaporating water will deposit minerals on the condenser and it will corrode until it leaks. The mineral layer that forms will also reduce AC capacity when the coil is dry because it reduces heat transfer to the air. Best thing you can do for the condenser is to ensure it is shaded from direct sunlight when your cooling demand is highest. 
|
What is a democrat? Someone who wants everything you have, except for your job.
Politicians should wear uniforms like NASCAR drivers so we could see their corporate sponsors.
Politicians should wear uniforms like NASCAR drivers so we could see their corporate sponsors.
|
Originally Posted By ZW17: Originally Posted By Morgan321: Water cooling on the condenser is a huge boost in cooling capacity, but it will wreck the condenser in short order. The evaporating water will deposit minerals on the condenser and it will corrode until it leaks. The mineral layer that forms will also reduce AC capacity when the coil is dry because it reduces heat transfer to the air. Best thing you can do for the condenser is to ensure it is shaded from direct sunlight when your cooling demand is highest. https://media0.giphy.com/media/q5VgPxwf8gzxyeUJrz/200.webp?cid=8dc8958cr7cv8v2df3so79etjl02742nm7y79r49v4cjrntf&ep=v1_gifs_search&rid=200.webp&ct=g Best [and easiest] repair I have had [three times over the years] was where the customer covered the condenser outside with something like a cover or tarp and forgot about it and fired it up and the obvious happened. [no cool complaint] Compressor would run for a minute or two, overheat, and the internal breaker would trip. It would cool down, [that usually takes far longer then people think] start again, and re-trip. Only easier repair was when someone had pulled the fuse outside or shut off the breaker and forgot they had done so. Andkeep all you weeds and bushes away from the sides, blocking airflow because you want to ''hide'' the condenser can cost you money and seriously, no one really gives a single damn about your condenser because they have one also. |
Liberals are a curious mix of communism and fascism, they want to destroy you but want to use your own money to do it.
I'm getting down to the last box, the others have all been destroyed...
I'm getting down to the last box, the others have all been destroyed...
|
Originally Posted By Morgan321: Water cooling on the condenser is a huge boost in cooling capacity, but it will wreck the condenser in short order. The evaporating water will deposit minerals on the condenser and it will corrode until it leaks. The mineral layer that forms will also reduce AC capacity when the coil is dry because it reduces heat transfer to the air. Best thing you can do for the condenser is to ensure it is shaded from direct sunlight when your cooling demand is highest. Originally Posted By Morgan321: Originally Posted By ske714: Here's an option that maybe others can comment on. .......... Cool-n-Save AC Misting Kit The evaporating water will deposit minerals on the condenser and it will corrode until it leaks. The mineral layer that forms will also reduce AC capacity when the coil is dry because it reduces heat transfer to the air. Best thing you can do for the condenser is to ensure it is shaded from direct sunlight when your cooling demand is highest. Good point. OP, what is humidity like in your area? If it not Arizona, you could probably really benefit from a dehumidifier. |
9 lives - 9 pellets... Coincidence?
|
Our upstairs unit can't keep up during the hottest months of the year. I stumbled across this and it sounds good but our attic is enormous so I just punted on digging into it more. If it works half as good as claimed it should make a tremendous difference. I have to wonder if it makes the shingles so insanely hot that it decreases the life of the roof though. https://www.atticfoil.com/ |
|
Originally Posted By Blackbird_Pilot: Our upstairs unit can't keep up during the hottest months of the year. I stumbled across this and it sounds good but our attic is enormous so I just punted on digging into it more. I out the aluminized bubble wrap on the underside of our west facing roof because the attic is like 150f in the late summer afternoons. It cooled the attic temps a bit, but as I found out the exterior walls with no insulation were the bigger problem. In the winter you can see the roof frost where the bubble foil insulation is, and thaw where there is none of it. It definitely works, but tough to know beforehand if it will solve your problem. 
|
|
Originally Posted By urbanredneck: Out HVAC can't keep up. House has older metal air ducts. Over the years, rats were in the attic and chewed open the insulation along the bottom of the ducts. Since we have bought he house I have done my best to clean the choked up coils, close up small leaks I found in the duct work and patch the open insulation. Also added exhaust fans to the attic. Though improved, my ac struggles. Is there any easy and simple way to add insulation over the to the existing duct work? I'm tempted to go buy a bunch of polyester blankets and just throw them over the ducting. Not looking to do anything major or hard. Just want to ride it out until the AC needs to be replaced. 2010 or so at our old house, we replaced the hvac. Our peak summer and winter power bills dropped over $300 per month. All electric house. The entire house stayed cool as well. We should have replaced the entire system years before. Lesson learned. |
z - Deplorable Neanderthal Garbage per liberal media.
|
OP needs to provide basic info like how old is the unit and it's condition, we know the ductwork itself is in rough shape. Two years ago I ripped out all of the ductwork (in my crawlspace) for the package unit serving the first floor. I had a ME friend design the new duct system and I fabbed it up and installed it myself. Huge improvement in terms of sound, air distribution & energy. This ductwork dated back to 1975 and was held together with tape - no screws other than the ones at the unit where the supply and return square to round adapters are attached to the unit itself. The whole system was poorly designed to begin with and the insulation was shot. You could actually stick a finger into gaps along the trunk line at the takeoffs, I was losing a bunch of air at these locations. This is the crap I replaced:   One pic of the new stuff, I was not finished insulating the return:  I guess what I'm trying to say is that it might be time for a total duct replacement job instead of trying to patch up the system. Edit: for clarity & spelling. 
|
|
Attic insulation, wall insulation, windows, and air leaks are the biggest places to start. If you can buy, borrow, or rent a thermal camera, that can help figure out which is the first priority. If it's wall insulation, you can add rigid panels to the outside, then put siding over them, it's super common here where we have some beastly sun. Replacing your AC with a bigger one will get expensive because you'll probably need bigger ducts as well, insulation is a great place to start, and gives you returns for decades to come. |
|
Originally Posted By GlutealCleft: Attic insulation, wall insulation, windows, and air leaks are the biggest places to start. If you can buy, borrow, or rent a thermal camera, that can help figure out which is the first priority. If it's wall insulation, you can add rigid panels to the outside, then put siding over them, it's super common here where we have some beastly sun. Replacing your AC with a bigger one will get expensive because you'll probably need bigger ducts as well, insulation is a great place to start, and gives you returns for decades to come. Windows and doors account for approximately 75% of the heat loss and heat gain in your average structure. Insulation makes up a good percentage of the rest. Always start with the windows, then doors, then insulation. |
What is a democrat? Someone who wants everything you have, except for your job.
Politicians should wear uniforms like NASCAR drivers so we could see their corporate sponsors.
Politicians should wear uniforms like NASCAR drivers so we could see their corporate sponsors.
Joined:
Jan 2023
Posts:
3703
EE: 0% (0)
OK, USA
|
Check your attic for cool spots coming up through from a/c below. Add insulation in attic. idk on houses nowadays, but in Oklahoma houses had two or three whirlybirds on the roof to vent out hot & humid air from attics. Bit off op's question, Before a/c was/had installed lots of older houses had exhaust house fans too that vented hot & humid air out of house into attic in evening time when you got home from work, just open windows & flip on for 5 to 15minutes to cool house down. Course back then everybody here had swamp coolers hanging in the living room window too. |