For more videos like this on how you can get the best HVAC for your home and avoid common mistakes, make sure you’re subscribed to the channel here youtube.com/@TheHVACDopeShow?sub_confirmation=1
Really helpful! I just turned my fan onto On instead of AUTO, hoping that makes a difference. One end of my home is warmer than the other. I also have my thermostat in a hallway, I’ll need to move it to the living room. Thanks again 😊
@@USCG.Brennan It depends on your geographic location. Generally if you are in a high humidity area like southern U.S than that is a very bad idea. if your air handler/furnace blower is running continuously independent of A/C setpoint you will be drawing in hot, humid air through doors ,windows etc. without it being conditioned. As in you are bringing in unfavorable air when your A/C condenser is not operating so introducing higher load than designed for and will cause many issues. TLDR: Leave fan on auto
@@serlalonde8420 I'm in Western Oregon (near Salem) and our humidity is far less than down South (where I was stationed). I've been leaving it set on Auto and we're OK with that. Thanks for the info though.
@@serlalonde8420 Are you saying that the AC is blowing conditioned air outside? Because that’s the only way I can see it creating a vacuum that sucks air through cracks around windows and doors.
I learn something every time. As a kid, my parents would have me close different vents and open others in summer and winter. I have always believed and even recommended to friends to do the same. Who knew... a professional I guess!
I always wondered what was "wrong" with my AC, since we keep it set at 68, but in the middle of summer, it'll frequently creep up to 70-74 if it's REALLY hot outside. I guess the system was probably designed to that 70-74 range you mentioned. I haven't heard of this before from any of the other hundreds of AC videos I've seen, so thank you for spreading the info! :)
For sure! Thanks for watching… When we retrofit a system and do a quote we always ask what temp they like to set things at because I’ve had people say 65 and when we hear that we almost always look at adding a ductless somewhere or VRV unit so that it keeps up!
I wish you had a branch in Miami...no one here wants to take the time to conduct such a comprehensive analysis, and/or they simply aren't sufficiently knowledgeable to do it. I had a "reputable" Trane authorized company come out to give me an estimate on installing a new, additional, split system to my house as the two existing 5 ton systems are unable to keep the temperature from rising during severe temp days in the summer... and they told me that I had to hire a GC to do a load calculation to determine the size of the new system...I mean, shouldn't a good AC company be able to do that? Certainly sounds like your company can...
I had the opposite, an undersized system. I figured when it was in the mid 90s to 100s outside, not getting below 78 indoors was normal. My unit was close to 16 years old so I wanted to replace it before it died on a hot Texas day so I did early this year. Lo and behold, all bids I received told me my 3.5 ton was way too small for my sq ft. of 2699. They did some duct mods and now it cools nicely.
I have the same problem. The house was added onto and when the central AC was replaced, it was replaced with the same size and not upsized. Went from like 1700 sq ft to 2300. Still a 3.5 ton unit. The air flow is also messed up. Shut air off going to addition, put a window unit in there. Had to put in dampers to balance the rest. Had a ton of air dumping into one bedroom. Still have a lot of work to do. Poor airflow to two back bedrooms. Duct is coming off the back of the plenum. Someone told me that will cause poor airflow. Need to add a vent going to middle bathroom. Gets hot in there. Lol old houses.
From 8:04 to 8:50 is priceless info for those of us living in certain parts of Texas where our units run all the time during the summer months. Kudos for a great video!
I live in Houston, TX and my ac doesn't run all the time during the peek summer 72at night and 74 during the day. Now I do have to mention my attic has spray foam insulation. So it's only about 10-15 degrees warmer up there. That means my ac isn't fighting the heat in the attic to cool the house.
There is another consideration in system sizing in very humid areas: If a system is sized too big, it will bring down the temperature before it has reduced the humidity in the house, resulting in the homeowners feeling cool and clammy.
Higher humidity in the home will be the result of an oversized system, especially in the South. A larger than needed system that is short cycling simply isn’t running for the time needed to remove excess moisture from the home.
Interesting. My problem with my A/C is the second floor works great, but the first floor doesn't feel like it is getting much air. The ducts are open on the first floor yet it doesn't feel like any air is coming through them while upstairs it most certainly is. The air isn't naturally trickling down either so while I have the upstairs set to 70, the first floor is 74-75, and the basement is even warmer at 75-77. I don't have central heating but heat rises just fine in the house. I also have electric baseboards to compensate so this isn't an issue I am seeing. I feel like something is jammed in the ducts or something.
This is very strange I’ve never heard of a basement being warmer than the rest of the house when the AC is running. I would look at ducting. Sounds like an issue with airflow balancing or maybe runs being disconnected, I’ve never ran into this lol for what that’s worth… sounds like ducts aren’t connected or dampers are shut or something is off with the design
thanks! it ended up being i tried using too high a quality of a filter than my AC could pull though. I switched it back down to a lower quality and the thermostat started to drop almost right away
Correct. Some filters like 3m make very thick filters and can cause a restriction. I always recommend 11 or 13 Merv filters, unless you have a very high efficiency unit where it was made to take the media filters that are about 6 inches thick
I remember a few years ago it hit 108 degrees here in Portland, Oregon and my system was not keeping up. i called the A/C people and asked about it. Their answer is simply that they don't design systems in Portland for such abnormal heats. When I later had to replace my 15 year old condenser, I asked them to increase the size from 30K to 36k BTU. Good thing to, as a couple years later we hit a staggering 116 all time record heat and my house stayed reasonably comfortable.
Yeah that sounds right the design temps vary by region but if your ductwork could handle the increase in sizing (which it sounds like it can because it’s not icing) then it sounds like it was a good move 😁
Thank you for this information, I was panicking about why my ac unit outside was constantly running the past 3 days almost nonstop since we got 90° to 103° days and staying at 74° to 76° for the inside temperature while the set point is 73°f, so I now know my ac unit is in an efficient mode to save on the life of the AC unit and energy cost.
our crazy utility company had a program where you could have a shutoff installed on your outside condenser unit so when they had peak demand they would just turn off some customers for a few minutes each hour and let your indoor unit still circulate cool air but it was all a total lie the first hot day they turned off system for 25 minutes then on for 5 minutes which had our house over 80 degrees in no time since our system is the right size and needs to run to keep house cool apparently they scrapped that whole system so many people had them take it out after 1 hot day they claimed that when I called and complained they could not change the settings and it would be a couple days till they could take it off my unit. I had to disconnect it myself to keep my pets from dying so never sign up for stupid energy saver programs.
Xcel energy has this too they call them savers switches and customers regularly ask us to remove them because they cause service calls when they wonder why their AC isn’t keeping up
I keep mine at 75.. it turns on 2-3 times an hour during 95+ weather. We've insulated attic added a gable fan, i installed new windows and covered air leaks in the attic. All recommendations from hvac guys.. last guy told me that turning on 2-3 times an hour is normal.. is this true?
Honestly sounds like a little bit of short cycling but if it was sized for the home before insulation and then you insulated this can happen. 75 is a moderate temp for 95 degree weather, so it might be slightly oversized based on how often it runs but you can also adjust the deadband settings so it turns on at 76 and off at 74 when set to 75 so that it cycles less if you find it annoying. If your bill is still reasonable thought it might be fine. Normally we size our installs to have long run times and change the temp 1-2 degrees per hour on the hottest day of the year. This typically means in the afternoon / peak usage the system will run nonstop for a couple hours normally. So if you get home at 5pm and drop it from 82 to 75 we like to see the temp come down in 4-5 hours, if it’s a lot quicker than that it might be a little oversized but if it doesn’t ice up (outside lineset gets covered in frost) then you’re probably ok 😁
@TheHVACDopeShow thank you for that info. No it doesn't ice up at all. Is there any brand thermostat you would recommend so it doesn't short cycle? I don't have a c wire.
Any recommendations on a replacement system in Las Vegas? Currently have two 25 year old Carrier furnaces a 17 year old york single stage condenser and an 11 year old goodman condenser single stage. When the time comes to replace does it make sense to replace with single stage? I’ve seen your videos about the Daikin Fit and also seen video about Bosch ids 2.0. Not sure how heat pumps would work in the desert tho. Thanks for the advice.
They work great but I would check with a local contractor on the Daikin fit and in Vegas get a higher efficient inverter system you’ll be much happier you did… your AC runs constantly there the savings will definitely pay off over time. I’ve heard the Daikin fits do well but in high ambient above 110/115 there can be issues with humidity during monsoon season (in phoenix) above 3.5 ton systems only. So just check with a local contractor that sells Daikin because they’ll have the inside scoop on local systems, but an inverter system is definitely worth it in vegas and will keep up fine in the winter too.
If you only have 1 return air duct in a house it's a Red Flag! Make sure you have a HVAC tech check your static pressure! If the total static is over 0.50 you need to fix the size of your ductwork! In my area over half the homes only have a single undersized return air duct. This is often giving you half the airflow that your system is designed to move.
So, if your system is running all day and keeping things set to where it's designed, then I take it to mean that just like a car with cruise control engaged, it runs smoothly. If it's running like it's driving in New York City, well, stop & go driving is no fun. Thanks for a good video. I'm gonna share it with a few folks so they check their systems against the points you mentioned.
What do you mean doesn’t have a return? That’s not possible the system will just ice and not run and not be able to circulate air. You definitely need enough return air otherwise it won’t circulate air without a return… did a fix and flipper cover them up or something ?
It just kills me that I pay natural gas surge prices in Colorado when Texas is falling apart because the utilities don’t cold proof their gas pipelines and generators. I’m with you on heat pumps to free me from Texas’ energy failures.
Systems used to be oversized more than they are now, and they thought is for both comfort and efficiency longer runtimes (especially during the hottest part of the day) is perfectly normal and most comfortable. Glad you enjoyed it!
The caveat is making sure it’s satisfying design temp which varies by region, but normally is between 72-80F with the hotter temps being design temps in places like Phoenix Arizona where they get extreme highs
Hi, I really appreciated this content and extensive explanation on why my HVAC system may not be keeping up. Let me start off by apologizing from the start as this may be a bit too lengthy. I currently have a Daikin fit inverter unit that was installed 2 yrs ago, this is my 3rd unit in 7 yrs a little background info. • I live in the Tampa, FL area, we have very hot spring and fall season with even hotter & humid summer conditions. So, my biggest complaint to the HVAC companies was that my HVAC sys not only couldn’t maintain set point temp(5-7degrees) but if I used my stove/oven it was even worst8-12degrees). • My home was built in 2006 • My Square footage is 1919sq ‘ • I’ve owned this home since it was 6 months old • The original homeowners had it built themselves, they paid the builder for a copy of his blueprint, took them to an engineer & architect and cut the square footage down from 3,000 sq’ to 1,919sq’ • My home is a 3bdrm 2 bath cinder block construction • I have crappy builder grade single pane windows • I have a lot of sun exposure • I have more than the usual amount of windows per square foot of wall space • The minimum ceiling height is 10’ (mainly in the bedrooms only, approx. 600sq’) • The main living area ceiling height is 14’(approx. 1319sq’) • We would like to maintain 70 degrees during day and 68 degrees at bedtime • Outside temp is usually mid to upper 90’s during day and upper 80’s to lower 90’s at night in summertime So, I started with my first unit in 2017 with a York inverter system, I called several HVAC companies to discuss why my current 10 seer straight cool single stage system couldn’t maintain set point temp or come close within 1-2 degrees, matter of fact it would climb above as much as 5-12 degrees above set point temp depending on if we were cooking in the house or not. None of the 5 companies I had come out to give me an evaluation inspected my current system or duct work, they all seem to agree that because I had these issues I needed a new system. They looked to see that my original system was a 4-ton unit and each one of them provided me with a 3 tier option (Good, Better, Best). They all said because I had a 4-ton unit and my home was only 1919 sq’, I only needed another 4 ton unit. So, I ended up going with the 2nd to highest estimate with a new to market York Inverter technology system 21 seer unit. It was installed in mid-summer of 2017 and right off the bat I knew this wasn’t going to be the solution to my old system. They finished installing my system around 6pm and I didn’t feel the house cool down until almost 12-18 hours later. Fast forward 3-4 years, the system kept having issues, throwing fault codes, shutoff when it shouldn’t have run constantly (as inverters are designed to do) and my electric bill remained the same if not even higher than my old 10 seer straight cool unit. After multiple trouble shooting appointments (40-50 appointments & 3yrs later) between the HVAC dealer and Youk technical support on site, it was determined that they needed to install a new unit. After 2nd unit was installed the same problems and poor performance repeated itself, so then they decided they needed to upgrade my duct work to accommodate the more highly advance system than what I had originally, still no improvement as I still couldn’t maintain set point temp (4-7d above) and extremely high electric bills. Set point temp wouldn’t be achieved until 6-7a next morning, and once the sun came up and mid to late morning would hit the temp just kept rising above the setpoint temp. I had the 2nd York unit for about 2 yrs. The nice thing about York was they had a money back satisfaction guarantee and gave me my money back. So, my HVAC dealer steered my to the Daikin fit, I love its compact design and foot print but sadly its performing the same exact way as the last two York units. This leaves me to question a few things: 1. Is my HVAC properly sized, tonnage wise? It runs constantly but doesn’t achieve set point until 6a 2. Is my duct size correct? 3. Do I need more attic ventilation? Everyone I had in my attic says it is adequate The main problem I seem to have is finding a knowledgeable and reputable company in my are such as yourselves that knows what they’re talking about. Everyone I call out either wants to try to experiment because they have no clue or tells me the whole system is wrong and wants me to pay thousands and thousands of dollars more with no guarantee they will achieve my desired indoor/outside door temp range. So my question is, what is your recommendation of what my next steps should be or try? Or am I asking too much of any system in Florida?
First off thank you for the info, I read most of it lol but got the general idea of what your issues are… basically I see 2 things that are my hunches. 1. System is undersized, the high ceilings are a dead giveaway on this because a house with 8’ ceilings is different than a house with 14’ for sure and the fact that brand new systems aren’t keeping up. This can also be ductwork but if the system is not throwing a B3 error code for airflow on a Daikin fit at least, then it’s not an airflow issue and is a sizing issue. 2. Insulation is poor or just isn’t adequate, you might be able to insulate the attic and / or roof, double pane windows are a pricey upgrade but might be worth it just to get the home comfortable. My hunch of a solution (without seeing it and sizing your ductwork) would be to a 5 ton system and honestly potentially a supplemental mini split to cover the load since you’re trying to achieve such a low design temperature for the Florida climate. But before throwing in a 5 ton system, you could look at renting a portable 2 or 3 ton unit for one day to see if that plus your current system running is enough to cool down your home and if it is - you likely have a load issue and need larger system or supplemental system like a mini split in the bedroom or living room to take off the edge. I would also consider insulation or siding however possible in Florida in order to get a better envelope for your home to keep things more comfortable. We have a guarantee to hit design temps but I will say 74/75 design temp is typical in Florida so I would consider adding a supplementary mini split ductless system and also insulating however possible to tighten up the house. I feel your frustration and if you’d like I can try to ask around for a referral of someone that can potentially help. But for me a portable AC rental for a day to verify the load, and also check the ductwork to confirm it’s not pulling in outside air or attic air via a disconnected duct in the attic (it’s probably just undersized but either way wanted to mention this)
We leave ours at 77-79 normally. at the lowest its on 75 for maybe 10 minutes. It's so hot here it's pointless to keep it below 77 for a long period of time. It just runs constantly.
Amazing, informative video.. I’m still not sure where our system falls. Thanking you in advance for reading and hopefully you can provide some suggestions. Just bought this house. It’s our second week. Just recently found the filter was inside what we learned to be a “furnace”? Incredibly intimidating, we managed to find the filter door that was painted shut. We dusted it and stuck it back in while the replacements arrived. After cooling house cooled much better. But next day, it wouldn’t cool anymore. After checking we found some splashing near a plastic pipe, initial research suggests pipe clogged but there’s water flowing into some water pump/box thing How do I address this? Secondly we found ice, initial googling suggested run heater for a bit. How can we check if the freezing is caused by dirty filter and not by other factors? Thank you again
This is one of the best overviews on the subject I’ve seen for the potential customer. I’ve learned it’s better to have non-adjustable registers, and put dampers for each branch to keep customers from messing with a tuned system.
I live in south texas and just moved into a house. 1400 sq ft and the outside is a 4 ton and the inside is a 5 ton. I have 8 vents in the house. I have it set at 80 and in the heat of the day it goes up to 83. Is that normal? It takes about 4 hours for it to start dropping down to like 75. Just wondering if this is normal or not?
Depends if it’s icing, does it continue blowing air during the heat of the day or does the airflow stop and it develop ice on the line sets outside? It should be sized to keep up, it could be low on charge but it does sound slightly oversized for the ductwork. You could try adding a few duct runs but I would get a contractor out there to verify because at a glance it sounds oversized and like a 3 ton (outdoor unit) would keep up better. Indoor unit just has to be at least the same size or bigger and the fan speeds can be turned up and down
Our downstairs A/C seems to be a decent size. No it does not run 24/7 but nor does it short-cycle. We have a separate attic system for the 2nd floor. It’s a smaller system. It’ll maintain our set point of 75 until the outside air rises to about 85 and then by 90 it can longer keep up. Putting the air handler and duct work in the attic does it no favors. 83 yr old house and the sun bakes the roof. We have R38 in the attic - not too bad for TN - none of which really matters in summertime. I’m also of the opinion that the return isn’t sufficient and am thinking of perhaps adding an additional return to it if I can.
I keep thinking there’s something wrong with my system, and I think that there must be because I have my setpoint at 77 and by the 3 o’clock hour the machine is running constantly, and the temperature will be upwards of 81. The machine itself sits in direct sunlight for 90% of the day and the outside temperature in the summer months gets to 105+. It seems to me that the machine is not able to keep up, but I don’t understand what the issue is.
Has it ever kept up? I would check the basics like air filter / open all the vents etc… it could be refrigerant charge but I always check airflow and basics first. Especially if it was working at one point and just recently stopped… if it’s never worked properly from day 1 it could be a sizing issue / design issue.
I knew when they were installing my new central air system in my 101 yr old house that it would never actually be comfortable inside. Mainly because they had not even invented insulation when the house was built!!! (Nor was there any indoor plumbing!) This is in a moderate southeastern normal residential neighborhood. We actually set the thermostat on 82 downstairs in hot weather, and a miserable 85 upstairs, because otherwise they would both run day and night and never stop or catch up. It would be impossible to upgrade the entire house to install insulation, because it would be far more cost effective to just bulldoze the house and rebuild... believe it or not. So, other than simple things like checking filters and cleaning condensers, there are no real solutions here. Oh, incidentally, during winter we set the thermostat on a cool 61 for "heat"! Can't raise that to a comfort level for the same reason. One more thing: if I were to blow in insulation, would have to ensure this is not creating a fire hazard around the 100 yr old knob-and-tube wiring! Main lesson: Think twice before buying an OLD house!!!
I would verify its sized properly for the load and ductwork. A simple “cheap” insulation is blow in… you can get the machine rental at Home Depot for free if you buy enough insulation, it’s like maybe $500 to insulate a 1200’ attic space and that will usually make a huge difference if you have no insulation whatsoever
@@TheHVACDopeShow Thank you for the reply. I have attic landing insulation, that's not really the problem. It is a large old house with plaster on lath walls downstairs, and wood drafty beadboard walls upstairs, no insulation. By creating countless DOZENS of holes in these walls to blow in insulation, it could help some, but would then create a virtual nightmare to repair all those plaster and beadboard holes throughout 11 large rooms. Plus, the old style construction used angled members some places behind the walls, which would prevent blown in insulation from filling the voids. The house would be absurdly impossible with holes every 16 inches in 11 large rooms, just about impossible to properly repair. Not easy like drywall is.
I just had a new unit put in(3ton) in a 1200 sqft house same as the old one but it blows way harder. I have so much positive pressure its blowing the pet door going into the garage open Now. I added weight to the door, made sure all vents were open, and even remove the filter to make sure it wasn't too restricted. It still has too much pressure. Any ideas?
It will run constantly to reach setpoint in the summer… if it’s 5 degrees warmer than design temp (varies by region, 72-78F are typical design temps depending on your region for cooling) then it could be undersized if the system is working properly and there’s not another hidden issue… I’ve seen everything from returns disconnected in attics sucking in hot air to systems that just won’t keep up because they were low on charge, but if everything is dialed in then it can often times come down to the load being greater than the home can handle.
@@TheHVACDopeShow Unless I am missing something ( quite possible) the unit should cycle off when the set point is reached. Short cycling means that it is reached too quickly. and things ice up. I have read that an AC unit cycling off 2 to 3 times an hour is optimal.
Hi, Great video and I watched it more than once and I have a question; After a power failure during a thunderstor, the AC kicked back on and all was good untill we noticed that it is colder in the house than usual while the thermostat was set to 74 degrees, i eventually cranked it up to 77 wich is still cold but 78 is not comfortable. I tried resetting the thermostat to factory settings and still doign the same thing. I downloaded two apps on my phone to read room tempreture and they both read lower by 3 to 4 degrees. My thermostat is Honeywell pro. Hopefully i can get some help,
Maybe the t-stat temp. sensor is bad. If you have a Honeywell, you could try switching to a Honeywell T4 thermostat, they are very reliable and not crazy expensive, unless you have a 2-stage unit then I would try a Honeywell T6
@@Goodfella0982 Thank you , I looked at the T4 pro online and look like the same backplate connections, so I can just plug it in and program it without wiring or rewiring?
I switched the T6 witha T4 and set it up correctly and I am still experiencing the same thing. Is ther anything else that could be bad, up in the attic or in the outside unit?
Have you adjusted the calibration in the stat? If the temp is off you can just adjust the calibration so the temp on the screen reads the same as the temps on the phone
If the condenser is dirty u will never have a iced up evap coil I'm sorry to inform but that is not possible dirty condenser coil raises the refrigerate pressure an temp
Honestly, I've never seen a dirty condenser ice up an evap coil. It will definitely cause high head pressure, and your capacitor might have to be replaced and down the road eventually your compressor will fail
Lol thanks I catch them but honestly don’t have the energy to send it back to the editor so as long as it’s nothing crazy I let it slide. You’re paying attention, good eye!!
Right on if it’s not icing then it’s probably fine… It still restricts total airflow so if you have too many vents shut to the point it ices us and doesn’t keep up it will actually be counterproductive. We advise people to keep as many vents open as possible. In systems with undersized ductwork even 1 or 2 closed vents out of 10 or 12 can make a difference to cause things to ice.
