Help - My Air Conditioner Won't Keep Up

[patience0830]

jeephammer has the right of things. Home in the dirt is easier to heat AND way easier to cool. When we built the cabin we put a Water Furnace in and I've been very satisfied with the efficiency. Excess heat from the condenser pre-heats the hot water and the coils are always sheltered from the outdoors and the attendant grime and pollutants. Been in the house 25 + years and replaced the first unit at about 16 yrs. Compared to propane/outdoor heat pump, it has paid for itself several times.

 

[maxwelhse]

My parents also like their water furnace a lot. Their house is something like 5500ft^2 and I think the largest electric bill they've ever had is like $220 during the polar vortex. In the summer it's like $100/mo.

It's mind boggling to me how that's even possible. Plus basically unlimited hot water.

 

[gregkl]

Hit me up. Might be able to help.

Will do! Thanks.

 

[Cameramonkey]

I have thought about that but like Mr. Coffee, lol says, I'm concerned about adding too much weight. But that would work. I have plenty of room from the edge of the rafter to the boards.



That could work. It is fairly hot near the top, but running the fan has helped. When I don't run the fan, even my 6' height can feel the heat radiating down. With the fan, I can't. The basement is so cool, I need to think of a way to blow some of that air upstairs. I am standing by the open stairway when I took that pic.

a veneer glued to the foam? (think paneling thickness) That cant add TOO much weight. How hard would it be to remove the current wood to save weight? Just spitballing.

 

[maxwelhse]

a veneer glued to the foam? (think paneling thickness) That cant add TOO much weight. How hard would it be to remove the current wood to save weight? Just spitballing.

Blasphemy! It's way to pretty to rip out.

Plus... that's all structural to the roof. You'd have to literally take the entire top off the room.

 

[churchmouse]

Mine is set on 72-3 during the day and we go 68 at night. it keeps up okay but it takes about half the night to drop it that 5 degree change. Our HVAC guy said it is supposed to basically run all the time when it is really hot. I wanted to size up a notch but he talked me out of it.

OK lets think about this. Stepping up half a ton is really never an issue unless you have duct work that will not support it. And no, they are not supposed to run all the time when it gets hot. When we moved in to this house I knew it was an issue on a hot day just like gregkl's problem because I bought the house from a friend. It was always a half ton short. Kept up fine until about 85*s and then it lost ground. I installed a new AC condenser and evap and went up half a ton.

94* measured in my yard today not far from the unit. House was set at 73* and the unit was cycling normally. I drop it to 70* at night and it takes about 15/20 minutes to drop the house down and shut off. Depending on the outdoor temp but it does not run on for hours. That is not a properly sized system.

Been doing this a long time.

 

[gregkl]

a veneer glued to the foam? (think paneling thickness) That cant add TOO much weight. How hard would it be to remove the current wood to save weight? Just spitballing.

What folgers said. You are looking at the underside of the actual roof. Those boards provide the same function as plywood decking does on a standard roof.

 

[jkaetz]

OK lets think about this. Stepping up half a ton is really never an issue unless you have duct work that will not support it. And no, they are not supposed to run all the time when it gets hot. When we moved in to this house I knew it was an issue on a hot day just like gregkl's problem because I bought the house from a friend. It was always a half ton short. Kept up fine until about 85*s and then it lost ground. I installed a new AC condenser and evap and went up half a ton.

94* measured in my yard today not far from the unit. House was set at 73* and the unit was cycling normally. I drop it to 70* at night and it takes about 15/20 minutes to drop the house down and shut off. Depending on the outdoor temp but it does not run on for hours. That is not a properly sized system.

Been doing this a long time.

Sadly, "it should run all day at design temperature" is something that I've heard over and over from other HVAC people. That and most houses are built with woefully undersized duct systems.

 

[maxwelhse]

Sadly, "it should run all day at design temperature" is something that I've heard over and over from other HVAC people. That and most houses are built with woefully undersized duct systems.

Coming from a tangential end of the industry, it SHOULD "run all day at the design temperature". That means, at least when I say it from my end of things, that it's been designed for 100% duty cycle to maintain X performance. That does not mean that it is some way beneficial for it to do so.

Sounds like maybe in the HVAC world there is some weirdo disconnect between the engineers, general contractors, and the boots on the ground. From a top down perspective, wouldn't you want to sell people a more expensive unit that performs better and meets their expectations?

I'd expect this conversation to happen in the exact reverse of how it sounds it does. As in, "If that's your budget, this guy will work at design spec and run 100% of the time. However... This is what you SHOULD do if you have a little more budget."

Maybe this is all just a byproduct of the general contractors being cheap and the AC sales guys swinging at bottom dollar to make the deal? It all sounds goofy to me...

 

[jkaetz]

Coming from a tangential end of the industry, it SHOULD "run all day at the design temperature". That means, at least when I say it from my end of things, that it's been designed for 100% duty cycle to maintain X performance. That does not mean that it is some way beneficial for it to do so.

Sounds like maybe in the HVAC world there is some weirdo disconnect between the engineers, general contractors, and the boots on the ground. From a top down perspective, wouldn't you want to sell people a more expensive unit that performs better and meets their expectations?

I'd expect this conversation to happen in the exact reverse of how it sounds it does. As in, "If that's your budget, this guy will work at design spec and run 100% of the time. However... This is what you SHOULD do if you have a little more budget."

Maybe this is all just a byproduct of the general contractors being cheap and the AC sales guys swinging at bottom dollar to make the deal? It all sounds goofy to me...

The second par to of the argument I frequently hear is that if you size it for the extreams (95+ in Indiana) it won't run long enough to dehumidify well in the more common 80 degree days and thus will make you uncomfortable during more of the time.

This of course all assumes a single stage system. It is one of the reasons I went with a variable capacity system. It can take care of the 80 degree days just fine on the lower speed yet doesn't struggle with the outliers either. Downsides are of course higher up front cost and potentially higher cost repairs on a more complex system but the extra comfort was worth it in our evaluation.

 

[maxwelhse]

The second par to of the argument I frequently hear is that if you size it for the extreams (95+ in Indiana) it won't run long enough to dehumidify well in the more common 80 degree days and thus will make you uncomfortable during more of the time.

This of course all assumes a single stage system. It is one of the reasons I went with a variable capacity system. It can take care of the 80 degree days just fine on the lower speed yet doesn't struggle with the outliers either. Downsides are of course higher up front cost and potentially higher cost repairs on a more complex system but the extra comfort was worth it in our evaluation.

I would have assumed that all but the most bargain basement modern units would have variable speed compressors exactly for the situation you're describing. It's becoming a thing in the appliance word to have variable speed linear compressors for absolute efficiency and because they're almost dead silent. Not sure where the AC stuff is by comparison.

Especially given our climate, a "monster" sized variable speed unit seems like the go-to choice. I could see why builders would cheap out and not do that, but I think most home owners would like it.

 

[BiscuitsandGravy]

Its that time of year again... Forecast hot as a mofo this week...

Take a few minutes to clean out your outdoor AC unit and trim the grass around it for unobstructed air flow.

Its going to be working extra hard for the next few days. You don't want a hot-and-bothered partner upset when the AC stops working.


From one of your local moronic news stations...

 

[gregkl]

Its that time of year again... Forecast hot as a mofo this week...

Take a few minutes to clean out your outdoor AC unit and trim the grass around it for unobstructed air flow.

Its going to be working extra hard for the next few days. You don't want a hot-and-bothered partner upset when the AC stops working.


From one of your local moronic news stations...
View attachment 205703

Yeah, it will be getting hot in our house. Good thing we have a nice finished basement that stays at 70 year round.

 

[femurphy77]

Yeah, ours hit us for the bi-annual top of the freon in our system due to a slow leak about 2 weeks ago. They quoted $800 for the 3 pound fill. We have a guy that will do it for the cost of the freon but he was in a pretty bad accident recently so we didn't bother him. Upon hearing $800 we decided this is the year we upgrade the whole system. Of course supply chain issues mean it'll be the end of July before they can do the install.

 

[Brandon]

Yeah, ours hit us for the bi-annual top of the freon in our system due to a slow leak about 2 weeks ago. They quoted $800 for the 3 pound fill. We have a guy that will do it for the cost of the freon but he was in a pretty bad accident recently so we didn't bother him. Upon hearing $800 we decided this is the year we upgrade the whole system. Of course supply chain issues mean it'll be the end of July before they can do the install.

Youch.
That quote covers the whole jug and maybe lunch.

Our warehouse was filled with equipment in the spring time to get ahead of the shortages.

 

[churchmouse]

Yeah, ours hit us for the bi-annual top of the freon in our system due to a slow leak about 2 weeks ago. They quoted $800 for the 3 pound fill. We have a guy that will do it for the cost of the freon but he was in a pretty bad accident recently so we didn't bother him. Upon hearing $800 we decided this is the year we upgrade the whole system. Of course supply chain issues mean it'll be the end of July before they can do the install.

I have some gas if you need it.

 

[KG1]

Yeah, it will be getting hot in our house. Good thing we have a nice finished basement that stays at 70 year round.

Our finished basement stays cool as well. The ground supplies the insulation from extreme heat.

 

[KG1]

Youch.
That quote covers the whole jug and maybe lunch.

Our warehouse was filled with equipment in the spring time to get ahead of the shortages.

Our local HVAC dealer that we use did the same. Asked them if they had a shortage of inventory and they said they were well stocked on units and inventory. We are lucky in that our 30+ year old Carrier unit is still working well. Just had them check it out and they said there is no reason to upgrade. It may not be the most efficient but as long as it's getting the job done there is no reason to mess with it.

 

[KG1]

Received this email from a local HVAC dealer about extreme heat and how an AC works. They say it's normal for your AC to run continuously in extreme heat and it won't damage your unit. Now if your AC runs continuously to try and reach your set temperature at normal summer temps then that is obviously a problem.

URGENT: Extreme Heat & Your Air Conditioner​

Air Conditioners are designed to keep your home up to 20 degrees cooler than the outside temperature and are sized based on regional summer temperatures. The extreme heat will cause your air conditioner to run continuously. This will not damage your unit. Your unit was designed and sized for the average regional temperatures we experience 98% of the time. Turning down your thermostat will not make it blow colder air. Set the thermostat to the temperature you want to achieve and leave it set there. When outside temps reach near or over 90 degrees, it is normal for the temps to go up in your home during the hottest part of the day. Check your vents. If the unit is blowing cold air, the A/C is working as best as it can during the extreme heat. Once temperatures cool back down to normal summer temps, your air conditioner will catch up and resume it’s normal run cycle.

 

[HoughMade]

I'm sure everyone has their A/C on by now, but remember to look at the forecast and turn it on before the house gets hot. Keeping the house cool is many times easier for it than making it cool.