Help - My Air Conditioner Won't Keep Up

[BiscuitsandGravy]

We had a monthly group call this morning and someone was late to the meeting. He had had a hvac svc co out for a suspect freon leak and ended up buying a new system. Yowza! Get you f-ing wallet out baby, this is going to sting.

 

[churchmouse]

Indeed.

Happened to my unit a couple years ago. Couldn’t find any dual run caps at the time so I just used two separate caps taped together.

Bingo.

 

[Ingomike]

They push those techs to sell. It’s a sliding scale on their pay rate. I get it. But man.

Gotta pay for fancy graphics vans and radio and TV commercials…

 

[femurphy77]

The outfit that is going to replace our system told us that Trane would pay for the service call for them to come out and get us up and running again since it's going to be late July before they can provide the new system. we were able to finagle a charge on it last week but here I am at 1 a.m. and the unit has been running since I got home at 4 p.m. without it cooling off the house. The A coil isn't frozen, the line at the condenser is ice cold and everything is running, and all the filters are clean. That's my repertoire of hvac experience, I guess we'll take trane up on their paid service call offer.

 

[Nazgul]

We had to upgrade the A/C unit 3 years ago after 20 years. Yes, it was a cheap unit the builder installed. The new one has better than 1 1/2 times the capacity of the original. It works well.

We camped at Friendship for 4 days so I could shoot. The thermo goes into ECO mode and lets the house get a little warm. I turned it own about an hour before we got home and it took 5 hours for the mass of everything in the house to get cooled. Fine after that.

Don

 

[Brandon]

We had a monthly group call this morning and someone was late to the meeting. He had had a hvac svc co out for a suspect freon leak and ended up buying a new system. Yowza! Get you f-ing wallet out baby, this is going to sting.

I work in a big name shop. I know our prices are... well... they match the name.

I know some brothers, a man, and a couple other outfits that typically come in higher.

We are usually within a few dollars of another company either over or under.

Glad I got into the trade.

 

[jkaetz]

Well, no it is not OK. It should cycle so the electric meter gets a rest. And no it is not normal for the temps to go up at high noon full sun exposure.
When you put your family in a neighborhood built by low bid sub-contractors you get exactly what you pay for. The silly crap we have found when upgrading the original units is just nuts.
Those installers get "X" amount per house to install units that are marginally sized at best and all too often at least a half ton short on delivery. They get the bare minimum. It's all about the money.
Every one of those homes (unless done by a very reputable builder and even then ???) has increased in comfort levels after we get done. Its very common to hear the house would loose ground on a 90* plus day and the unit never shuts off.
Thats just a waste of energy and costs so much more to condition the home.
The old adage that too big is not good holds true. Yes, you can over size the system. But it's not rocket science.
Also upgrading to a modern T-stat is a huge plus.

This is the truth, I've owned two modern houses this far. The first was built in 2006. During the 2012 heatwave we had the setpoints at 76 during the day and 73 at night. The tiny unit the builder installed (1.5 Ton) in the 2006 house ran continuously from 10 AM -> Midnight or later all while loosing ground until the sun went down. I discovered the ductwork design plans after this and found that they weren't even followed leading to an undersized unit and lack of CFM for the spaces. CM replaced the AC side of the unit a slightly larger capacity and I added two more supply runs to the large great room and master bedroom. No more lost ground during 90+ days.

Fast forward 12 years with two newborns and much better income we moved to a larger and much nicer house built in 2012 ~3400 SqFt + finished basement. Given the size and cost of this house we were surprised when we discovered that again on 90+ degree days the system wouldn't be able to hold our setpoint of 76 during the day. Additionally this house has a full bank of northwest facing windows providing great lighting but also adding a lot of solar load after ~1 - 2 PM. I spent some time swearing at the builder once again and I already knew what the solution was. After speaking with a few of the INGO HVAC experts I contracted a new two stage furnace paired with a 5 ton inverter drive condenser to replace the 3 ton single stage system. I then spent the next month or so making strategic holes in the basement ceiling adding two more supply runs, upsizing three others, and adding an inline fan to the run that was the longest and makes a U turn after coming off the trunk. Don't know who thought that would ever work. Lots of work and expense that I shouldn't have needed to spend on a 7 year old system but the results were worth it. The system typically gets to run in low stage until early afternoon or later when the solar load picks up before switching to high stage to keep things comfy and bring the temp down for night time. Electricity use is roughly similar or slightly less than having the single stage unit run all day. Our electricity use during the summer is ~1700 - 2200 KWh including three fish tanks and a larger IT infrastructure than most people. May was only 1380. IPL/AES also put us on a slightly lower rate after the install because we're technically using the system as heat pump. Though I have it switch over to NG after the temp drops below 35 ish degrees. I see no need to burn electricity after that when NG is available.

Not disputing any of this. Like I said in another post my 30+ years old Carrier unit may not be the most efficient but it's still been getting the job done just like when we first bought it. It's been a solid unit and I don't see any reason to upgrade while it is still doing so. Now it may be due to that it could be sized right to perform like it has. That's a real possibility for it's longevity and performance. My electric bill during peak summer months has been running less than $300 a month on a 3600 sq. ft house. That's not bad in my estimation.

That's a big electric bill. Know what the actual KWh usage is? Whenever you do replace it, you will very likely drop your usage quite a bit.

They marked the parts up. $50 would have bought them at the supply house.

$475.
Buddy’s spouse flipped the hell out. She should have waited.

This extends far beyond HVAC and is the place we've landed since we have companies withholding service documentation/parts and telling us we can't work on our own equipment. What happened to the days of service manuals and helpful people who would actually teach those willing to learn how to maintain their own stuff. Even cars are moving in the direction of "Do not open, no user serviceable parts inside.". We're going to have 100k electric vehicles that need to be thrown out because they need 50k of work that only a dealer can perform.

 

[churchmouse]

This is the truth, I've owned two modern houses this far. The first was built in 2006. During the 2012 heatwave we had the setpoints at 76 during the day and 73 at night. The tiny unit the builder installed (1.5 Ton) in the 2006 house ran continuously from 10 AM -> Midnight or later all while loosing ground until the sun went down. I discovered the ductwork design plans after this and found that they weren't even followed leading to an undersized unit and lack of CFM for the spaces. CM replaced the AC side of the unit a slightly larger capacity and I added two more supply runs to the large great room and master bedroom. No more lost ground during 90+ days.

Fast forward 12 years with two newborns and much better income we moved to a larger and much nicer house built in 2012 ~3400 SqFt + finished basement. Given the size and cost of this house we were surprised when we discovered that again on 90+ degree days the system wouldn't be able to hold our setpoint of 76 during the day. Additionally this house has a full bank of northwest facing windows providing great lighting but also adding a lot of solar load after ~1 - 2 PM. I spent some time swearing at the builder once again and I already knew what the solution was. After speaking with a few of the INGO HVAC experts I contracted a new two stage furnace paired with a 5 ton inverter drive condenser to replace the 3 ton single stage system. I then spent the next month or so making strategic holes in the basement ceiling adding two more supply runs, upsizing three others, and adding an inline fan to the run that was the longest and makes a U turn after coming off the trunk. Don't know who thought that would ever work. Lots of work and expense that I shouldn't have needed to spend on a 7 year old system but the results were worth it. The system typically gets to run in low stage until early afternoon or later when the solar load picks up before switching to high stage to keep things comfy and bring the temp down for night time. Electricity use is roughly similar or slightly less than having the single stage unit run all day. Our electricity use during the summer is ~1700 - 2200 KWh including three fish tanks and a larger IT infrastructure than most people. May was only 1380. IPL/AES also put us on a slightly lower rate after the install because we're technically using the system as heat pump. Though I have it switch over to NG after the temp drops below 35 ish degrees. I see no need to burn electricity after that when NG is available.


That's a big electric bill. Know what the actual KWh usage is? Whenever you do replace it, you will very likely drop your usage quite a bit.

This extends far beyond HVAC and is the place we've landed since we have companies withholding service documentation/parts and telling us we can't work on our own equipment. What happened to the days of service manuals and helpful people who would actually teach those willing to learn how to maintain their own stuff. Even cars are moving in the direction of "Do not open, no user serviceable parts inside.". We're going to have 100k electric vehicles that need to be thrown out because they need 50k of work that only a dealer can perform.

In truth there are ever increasing numbers of mouth breathing jock straps that would but should not attempt to service these units. This is as much an issue of warranty as anything

 

[jkaetz]

In truth there are ever increasing numbers of mouth breathing jock straps that would but should not attempt to service these units. This is as much an issue of warranty as anything

Oh for sure. There are plenty of people who shouldn't be doing a brake job or an oil change either but we don't withhold the information from them and penalize everyone else in the name of "safety and security".

 

[firecadet613]

This is the truth, I've owned two modern houses this far. The first was built in 2006. During the 2012 heatwave we had the setpoints at 76 during the day and 73 at night. The tiny unit the builder installed (1.5 Ton) in the 2006 house ran continuously from 10 AM -> Midnight or later all while loosing ground until the sun went down. I discovered the ductwork design plans after this and found that they weren't even followed leading to an undersized unit and lack of CFM for the spaces. CM replaced the AC side of the unit a slightly larger capacity and I added two more supply runs to the large great room and master bedroom. No more lost ground during 90+ days.

Fast forward 12 years with two newborns and much better income we moved to a larger and much nicer house built in 2012 ~3400 SqFt + finished basement. Given the size and cost of this house we were surprised when we discovered that again on 90+ degree days the system wouldn't be able to hold our setpoint of 76 during the day. Additionally this house has a full bank of northwest facing windows providing great lighting but also adding a lot of solar load after ~1 - 2 PM. I spent some time swearing at the builder once again and I already knew what the solution was. After speaking with a few of the INGO HVAC experts I contracted a new two stage furnace paired with a 5 ton inverter drive condenser to replace the 3 ton single stage system. I then spent the next month or so making strategic holes in the basement ceiling adding two more supply runs, upsizing three others, and adding an inline fan to the run that was the longest and makes a U turn after coming off the trunk. Don't know who thought that would ever work. Lots of work and expense that I shouldn't have needed to spend on a 7 year old system but the results were worth it. The system typically gets to run in low stage until early afternoon or later when the solar load picks up before switching to high stage to keep things comfy and bring the temp down for night time. Electricity use is roughly similar or slightly less than having the single stage unit run all day. Our electricity use during the summer is ~1700 - 2200 KWh including three fish tanks and a larger IT infrastructure than most people. May was only 1380. IPL/AES also put us on a slightly lower rate after the install because we're technically using the system as heat pump. Though I have it switch over to NG after the temp drops below 35 ish degrees. I see no need to burn electricity after that when NG is available.


That's a big electric bill. Know what the actual KWh usage is? Whenever you do replace it, you will very likely drop your usage quite a bit.

This extends far beyond HVAC and is the place we've landed since we have companies withholding service documentation/parts and telling us we can't work on our own equipment. What happened to the days of service manuals and helpful people who would actually teach those willing to learn how to maintain their own stuff. Even cars are moving in the direction of "Do not open, no user serviceable parts inside.". We're going to have 100k electric vehicles that need to be thrown out because they need 50k of work that only a dealer can perform.

Lower your set point. I'm in a 3000sq ft big builder home with an undersized 20yr old system. I keep it at 68, dropped it to 67 before this heat wave hit. The air runs all day, only got up to 69-70 yesterday but back to 67 by the time I'm up.

Just checked my ecobee app and somehow it's only at 68 right now, to my surprise.

 

[jkaetz]

Lower your set point. I'm in a 3000sq ft big builder home with an undersized 20yr old system. I keep it at 68, dropped it to 67 before this heat wave hit. The air runs all day, only got up to 69-70 yesterday but back to 67 by the time I'm up.

Just checked my ecobee app and somehow it's only at 68 right now, to my surprise.

Tried that in both houses, ~72 in the morning and would still be 78 late into the evening as it tried to cool off all the furniture, walls, etc... Yours sounds like it's sized pretty well if it only looses a couple degrees during these extremes. It should give good humidity comfort for the more mild days.

 

[churchmouse]

Tried that in both houses, ~72 in the morning and would still be 78 late into the evening as it tried to cool off all the furniture, walls, etc... Yours sounds like it's sized pretty well if it only looses a couple degrees during these extremes. It should give good humidity comfort for the more mild days.

That little half ton boost when you upgrade does amazing things on a system this close to good.
Also the dehumidification ability's of a 410-A system is far better than an old R-22 relic.
Say what you will but not addressing this might bite you in the bootie......just saying.

Up date....yesterday a measured 99+ degrees in my back yard. House set ay 73* and it cycled. Not long down times but 99+ is well above the norm.

Just checked and it is a measured 100+ out there now. Its keeping up and cycling just like yesterday.
One thing we do is set the blower to the "On" position as we have a high vaulted ceiling in the living room. Doing this keeps the house pretty even temp wise throughout. Only on 90+ days.

 

[Timjoebillybob]

I love new insulation and windows. Went out of town and wife left the AC off, come home tue night the house was only 83 at the thermostat. Still took forever to get it down to temp but after being closed up on a well over 90 degree 2 day stretch I can't complain.

 

[femurphy77]

I think I finally cracked the secret on our issue; it always "seemed" like the blower moves more air in the winter than it does in the summer. Turns out it does. When heating they're typically designed to move more air so I had to figure out how to make it blow more air in the summer. Enter youtube. I was out in the garage at midnight with the blower opened up and figured out which two wires to swap to increase the cooling fan speed and almost immediately the house pulled down to setpoint and the unit actually cycled off. You don't want to permanently slow down the blower in heat mode as it can cause expensive problems but this solved our cooling problem long enough to get our new system installed and tuned in. Be interesting to see how it handles the temps today.

 

[Brandon]

I think I finally cracked the secret on our issue; it always "seemed" like the blower moves more air in the winter than it does in the summer. Turns out it does. When heating they're typically designed to move more air so I had to figure out how to make it blow more air in the summer. Enter youtube. I was out in the garage at midnight with the blower opened up and figured out which two wires to swap to increase the cooling fan speed and almost immediately the house pulled down to setpoint and the unit actually cycled off. You don't want to permanently slow down the blower in heat mode as it can cause expensive problems but this solved our cooling problem long enough to get our new system installed and tuned in. Be interesting to see how it handles the temps today.

Incorrectly set blower speeds can make the system act poorly.

For cooling, somewhere around 350 to 400 cfm per ton is typical.

 

[femurphy77]

Incorrectly set blower speeds can make the system act poorly.

For cooling, somewhere around 350 to 400 cfm per ton is typical.

A little background, we added 35% more square footage to our house about 6 years ago without touching the hvac. It was already struggling during "record" heat so we only made it worse. We knew that we would have to up our system but were trying to wait it out as long as we could. No idea what the cfm is at this point but the temp dropped to setpoint last night and is maintaining so far today. This should get us thru until the new system is online.

 

[Brandon]

$452.50 for r410 today.

 

[KG1]

That's a big electric bill. Know what the actual KWh usage is? Whenever you do replace it, you will very likely drop your usage quite a bit.

Sorry I missed this post that was addressed to me. I screwed up on my electric bill monthly cost during peak summer months. I went back and ran the 2021 four-month peak summer averages (June thru Sept.)

Average usage was 1054 kwh. Average monthly cost was $155.30 for a 3400 sq ft home.

Don't know what I was thinking when I said they were less than $300 a month. Maybe it was gas and electric. Who knows. But those are the actual 4 month average electric bill numbers from 2021.

 

[DocIndy]

$452.50 for r410 today.

And how much was a jug of R22?

Funny thing was when I started in the trade R22 could be bought by the skid at $75-80/ jug. R410 was like that 3 years ago and look at it now. Thanks Joe. FJB

 

[Brandon]

And how much was a jug of R22?

Funny thing was when I started in the trade R22 could be bought by the skid at $75-80/ jug. R410 was like that 3 years ago and look at it now. Thanks Joe. FJB

We stopped buying 22 last year. I've heard its beyond up there.