How to adjust airflow and make hvac magic?
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Getting 12-16 degrees temp differential at the vents isn’t bad. When you’re delta T is too high, not enough air is getting throughout the house due to low fan speed. Good chance the customer will complain the ac won’t keep up on hot days. Still fairly new in the trade so I’m enjoying the educational side of the videos but in the field, this has been my experience.
Most techs or installers don't do this. Also true Delta t requires humidity reading. The higher the humidity the less the split will be. So you might b be at 17° split then when humidty drops it might read 20°. Good work like watching you.
you are right, most Real Techs actually do it right, lol
Check the static pressure bro! This will simplify your process! .5-.7 on most models. Then go level the vents. Nice video.
thanks 👍 😊
Excellent...you did a great job....I never ever had an a/c tech do what you did....never ever once was the subcool or superheat checked or balancing the the air flow.
Thanks 👍
If I only had a dollar for every time I had to adjust air handler fan from it's absolute maximum cfm { usually the factory setting} down to the cfm that matches the size of condensing unit. Well, I guess you could say I've earned thousands of dollars doing exactly that.
You're the man
Don't own a house, but I am excited about hvac! Great job, will remember the 20 degrees differentiation and that variable fans can run too fast and loud.
Awesome i'm glad you learn something my friend
But they slow to a whisper to maintain temp. I got one.
I wish we had basement/crawl spaces for ducts to go here in Texas. So much cooling lost with ducts in the attic.
ALL FINE AND DANDY BUT ID LOVE TO SEE SOME STATIC PSI READINGS
Beautiful job, I hate it when the returns are sucking hard, and the vents are roaring. Man! that looks nice.
Thank you brother
Those Accurite thermometer/hygrometers are okay but you need to test the accuracy of the humidity with a salt test as they are usually off. Get a small container (maybe 2 ounces) and fill it with a damp paste of table salt (not super saturated). Put that in a zip lock freezer bag along with the Accurite and leave it in a room around 70 - 72 degrees for 24 hours. The humidity should be 75%. If not, just mark the device how many points its off either way and you'll have an accurate unit. (The temps are usually all good on these). I have over 15 of these with most of them in coolers used as cigar humidors with several placed around the house and the outdoor shed.
I had same problem when I moved into my new mobile home. The system was not commissioned. Installers left fan setting on highest setting and I had great delta T but humidity was off the chart. Very uncomfortable. Changed fan settings to lowest speed and now it’s very comfortable.
Glad to hear my friend
Careful with those cheap temp/hygrometer. I have 3 of them that all read wildly different values sitting next to each other. I have checked their calibration and 1 of 3 was with 3% RH at 50%, others were 7 and 8% off.
I got a similar york unit. Its capable of dehumming also.
So far like the unit.
Not a fan of the flex in my attic though. I am foamed in the attic.
I hate hearing the vents also. Had a tech come by and want to turn up the fans.
Need more like you.
All air conditioning dehumidifies. Some better than others
@@racegrubb2152 yes a product of creating cold air. However some have a specific mode to dehum.
One recommendation: your temp clamp should be placed 6” from test port and on the top of the line set so oils don’t mess with temp
I think you are reaching here a bit
@@j727100 hey, if you want to be a good tech and not a great tech then that’s your prerogative. The only thing stopping you is yourself.
@chrismunoz7156 well how can you argue with that
I will test this out. I'm going to place my clamp thermistor on the service brass portion of the valve and then 6" away. Then I'll switch postion from the top to the bottom. Record my readings to see if there is any difference in temp.
@@j727100 you’ll have to do it with every unit to see the correlation, it won’t happen every time. I was a proctor for TEP and they were very strict on how readings were taken. They’ll also teach you this in trade school
Great video, unfortunately, from house owning experience, not all duct system is done well. Current house on a dual zone system, and struggled for a year to get it better, and it will never be correct, unless I want to rip apart a finished basement and fix all the ducting. But I have learned a ton the last 4 years becaue of this house
I just had my 5 ton American standard 2002 serviced by my cousin. I called an air conditioning company who informed me that I have R 22. Which is so expensive at $275 a pound, i might be better of changing my units (i have 2.5 magic aire in the basement).
So I went online and bought 30 pounds of R22 for $924 for just in case.
My cousin found the leak slow leak in the attic. Added 10 pounds of R22. Fixed the motor in the basement unit. Spent 7 hours doing the job and charged me $500.
My units are running like brand new. Because I gutted my house before I bought it and had both units put in. 20 years and counting very little problems so why change them.
Now if I'd got the same job done by the original company I'd would of spent $2700 just on Freon R22. I doubt he'd do such a fantastic job as my cousin. Because he took his time to figure out what was wrong with my unit which was iceing up outside and not cooling the house once it got above 85 outside
very cool bro glad to here that you did not get ripped off
@@TaddyDigest thanks you. I love your channel especially after this summer.. I'm glad the first guy scared me with the price of R22. Because even my cousin was shocked 😦 by me buying it for 924 for 30 pounds online. He said his company normally charges customers 150 to 200 a pound 🤔. Well I have 20 pounds left. With my slow leak found in the attic that should last me for awhile 🤔
I feel so antiquated with my 2004 Trane Heat Pump....everything is so fancy now
They don’t last no more than 15 years lol
I live in a manufactured home and the original heat setup was forced air with electric heating elements and AC, but I had them change it to AC with reverse heat pump, but the fan was so loud.. So I slowed it down some, but I don’t really know how to get it actually correct, obviously slower flow will make less air go through, so it will be colder but at some point it has to be, not pulling enough heat away. It’s a piston also, not an TXV, and on top of that, ever since I had the outdoor unit moved, there’s been a small leak that we haven’t been able to locate, it’s been taking like maybe 1 pound per year. The tag inside doesn’t provide as much information as I would have liked, but even if it does show a target superheat, seems like that would be when the air flow is correct, and I don’t know what that is so I’m chasing my tail a bit.
In college (mid '80s) I got fed up with our apartment's system always blowing like a hurricane. Who thought that made sense? I took off the cover and discovered the fan had 3 speeds, adjustable by putting the wire on a different terminal. Went from max to min, the place was far quieter and cooled at least as well.
Today I'm wondering if my upstairs air handler has a similar secret to tell.
It will cool the same, the BTU exchange does not change with fan speed. Faster fan makes the room seem to get cool quicker.
That duct system is nice! I’ve never been a fan of York but you how the whole brand thing goes. Great work again bro.
I do lots of auto ac repairs, replaced an evaporator in my truck recently, thinking of doing this as a job :lol: It is similar. There is no subcool on a truck though :lol:. Once the truck moves everything changes. It is charged strictly by weight.
Great work fella 👍🏾
Well factory charge is 15ft on that York. Then there is a chart to add after that. Off top of my head its .6 oz per ft after. I would add extra charge befprw opening valves. Dip switches should have been set before turning on power. Rwmember long flex lines past 5' add static and drop cfm/pascal. When in doubt pipe it out. Flex should ONLY be use to minimize vibration.
You may have lower temperature now but are not providing enough airflow to properly cool the space. Adjust the fan speed can cause higher electricity also. I’m more concerned that unit may not be the proper tonnage for the space.
This is a foam insulated house 🏠
Works great 👍
You just got yourself a call back because the customer can’t feel the air coming out of the vent.
As a side bonus humidity will be much better controlled.
It's nice when the basement is open and you can access everything but when you have a finished basement and very little access to the ductwork there's little that can be done in way of balancing ductwork and adjusting blower speed. If I went into someone's home and told then, Hey if you let me tear apart your basement ceiling I can optimize and balance your system by changing your ductwork/fan speed for a more efficient system. They would point me to the door and tell me to leave.
You also have to consider the customer's budget. It's not cheap to redo all the ductwork in a house and 90% of people will tell you NO.
It's a great install and it looks nice.
I am concerned when I hear that the units superheat is only at 5 degrees. If your superheat is to low or nonexistent you run the risk of liquid refrigerant coming back to the compressor and causing damage or it washes the oil out of the compressor which would also cause it to burn up and fail. I normally try to set my superheat at 10-15 degrees.
I still liked your attention to detail and I hope to learn a couple things from you in the future. Thanks for the content.
260 Psi high temperature pressure gauge (red). 20 cell per division.
One of the most commonly overlooked A/C issues here in Florida is the air distribution. Overuse of flex duct is the devil.
It's all in the attic, block construction.
Over time k-type connecters where it plugs into your meter. Those flat blade types. They usually don't have a good strain relief and you can take it apart. Cut back to fresh wire and re-attached to the two screw heads. I see those ones are not-re-buildable. Get generic k-type ends that are field wire capable.
You don't adjust airflow to delta T to be 20 degree, you adjust airflow to system manufacturer's requirements, (you design your ducts to that requirements). If everything is done correctly usually you will get delta T of 20 deg or slightly higher. If ducts are done correctly they are not noisy. It is like trying to meet fuel economy standards by driving your car no more then 25 mph. Thanks for posting your video!
Thank You !!! system airflow chart and Man J not Delta T !!!
Great video Taddy !! Wish I could find someone like you. Thanks 👍🏽👍🏽
You're welcome thank you so much for watching
1st video I’ve watched if your an internet definitely subscribed now! Good information man. Wish all Hvac techs had the same passion to make things best as possible. Bought new home couple years ago and it has good trane and Honeywell equipment but install and set up was awful! This helped
Thanks for the sub!
actually appears to be doing Start Up of a New Install. most Real Techs don't hack at it, they actaully check the blower speed chart and make adjustments without doing a you Tube video so you never see what we do.,
@@craigkennedy9968 that’s good to hear . I’m just stating in my case it was less than ideal or average . The company was t.a. Kaiser and they were definitely sub par . There wasn’t much I could do at the time . I do industrial hvac , work through a union so I have some higher expectations I suppose but if you seen the install brother you would be ashamed for them . I respect the good ones . Appreciate the feedback
Can you show us how to take a static pressure reading and explain to us what it means
yes of course I will get that on video soon
@@TaddyDigest Will be watching!
Anyone notice that not one of them floor joist have a hangar on it attaching to the beam? Is a nice HVAC system though!!
Looks nice on a, from what I can tell, a fairly new house and duct system. What about a 30-year-old one?
Most HVAC people I've seen, install, turn on and you never see them again. Never knew these details before. Want to install a system in California?!
Yeah people don't really commission anymore it's sad.
I'm pretty far away from california l o l
I prefer to take static pressure and set air flow to 350-400 CFH per ton of cooling. With your second probe it will compute TEET.
very good practice I like that 👍
Without design conditions(manual j) , how are you achieving proper SHR from the equipment?
That's one way to do it, just not the right or most accurate way. You should have measured static pressure and compared to blower performance chart and started by adjusting the blower speed based on static pressure. Also all your ducts shouldn't have the same amount of airflow or velocity either. Depends on the manual J load calculation and the design of the home, and register location...
Now here's the magic of physics... No matter the fan speed the BTU's applied to the room are the same.
A lower fan speed will simply dehumidify the room quicker.
A faster fan speed will give the perception of the room getting cooler quicker.
You need to add joist hangers where joist meet header beam.
Last I checked, this isn’t a carpentry video.
Good catch.
Something to think about. 12 to 16 degrees superheat. Do u follow the charge chart or apply the 12 to 16 degrees principle?
Thank you for the tip you are the best
I wish I had someone to come to Chester County and check my like that I can trust.
Chester south Carolina?
PA?
Same
Thanks man.
Happy to help
Good stuff as always from the hvac boss
Nice looking job!!!! Getting that evapor coil as cold as possible slowing dowing the fan speed, Question what was the total static pressure on the duct system? looked good no vent ducts on the end looked well balanced, keep up the great work bro 👏
NiCE VIDEO! What would cause the air coming out of the vents to pulsate. Even with the AC turned off and just the Fan on it still pulsates. it blow out strong then soft every few seconds. Thanks!
I just found a new favorite hvac channel 👍🏽
Excellent
I love my fast hard blowing ac.. my house stays freezing cold..
Daddy is the man!
wish my upstairs room blew 1000 ft/min. its bakin even with the downstairs dampers and thermostat at 70
So the real question to ask is…. What does the thermostat control the temperature of? The answer is… The thermostat! Everything else is an assumption. You have to have air flow to control temperatures in the house!
What do you do for a single stage? Here on the Gulf Coast, the humidity is so high and temps have been so hot lately.
He don't know he is a hacker
What happened to the super heat when you turned down fan speed? What happen to coil temp? What happen to delta?
I thought that was all in the video I will do a video that next time
I’m not a technician just a home owner. Had new system installed (Canada). 1.5 ton AC with 2 tone A coil. They didn’t set my fan speed but I do know how to adjust the taps myself.
Currently it’s on 796 cfm should I knock this down to 596. The old system that died was a 2 ton. They said I was over sized. 1300 sqft house.
I did try it briefly but I only saw at the register about a 1 degree drop. So at the lower speed I get 53.7
Is 200 cfm really worth the reduction. I’m seeing the upper floors warmer a tad dripping down the cfm
I would keep it where it's at
try insulating the supply. No radius on the supply plenum elbow??? No turning vains???
Was gonna say looks good if it’s 75 degrees but you beat me to it
In Louisiana it hot heat wave
Proud to be American
Maybe I just missed it, but I don't think you explained why this improves things or how it works. I get that the lower blower pressure is quieter, and you said that it also improves the dehumidifying effect, both of which are nice but is there some significant improvement of cooling effect that results from lowering the blower pressure?
You showed that the air coming out is cooler, but of course it's both the volume of air as well as the temperature difference that determine the total amount of cooling effect. Is there some sort of optimum tradeoff between CFM and temperature?
As for how it works, my guess is that because the air is moving through the plenum more slowly, it has more time to get cooled by the evaporator coil. And, of course, the colder the air is, the more humidity drops out. Is that the whole explanation or is there more to it than that?
You hit the nail on the head with the last sentence
Good deal
You understand
Not only did I increase the capacity of the equipment and correct the c f m across the return grill.
But I provide better comfort and remove more humidity
AND that is how u get another subscriber :)
Sweet
Show more on how to do a temp split Tad. Plz.
Will do my brother
1,2 degrees cooler but little air coming out of the vents this may runs longer to cool the house
@@1Jomarcel If you run slower, the power consumption will be lower so you can run longer with increase your power bill. The advantage of running slower and longer is that dehumidification is better, so you can get your house to the 40%-50% humidity. A lot more comfortable and avoid mold.
I'll have to look at the air flow control on my furnace unit. I feel like my blows to fast as well.
seriously, don't. if you slow it down too much it may not cool well enough or it may freeze up. any airflow adjustments should be immediately followed by checking refrigerant pressures.
My Honeywell pro series & My temperature is not reading room temperature going high temperature by itself & it takes forever my unit or or coil my coil is 20 years old already one of the rooms not blowing enough cold air only things only night time around 10 pm clock it does go down nighttime only Andy daytime my temperature goes up high temperature what to do I think it needs a tune-up check up I hope it's not that was it something else wrong with it AC I like your videos I'm learning how to do it @TaddyDigest
Well done
Thank you
Your all video knowledgebel nice sir
Home owner’$ could learn a lot from this video
Good
Please share the video
@@TaddyDigest I tried to explain this to homeowners myself, but I don’t have the type of equipment that you have. I’m going to invest soon into those.
What would you recommend for my setup? We have a 3 floor townhouse. No basement, first floor is on concrete. Our unit, however, is up on the third floor. Its a reversed system. Upstairs is always dying in the summer and comfortable in the winter while downstairs is cold in the winter and average in the summer.
Hi Taddy,
Love watching your videos! You are very thorough with your work. I have a question regarding air flow. I noticed the return in my second floor is not pulling any air in. When I block the return in the first floor the upstairs return then starts pulling air in. Do you have any ideas on what the issue(s) could be?
Am I understanding this correctly? No matter the size of the room, the supply vents should blow the same amount of CFM? If so, what should that be?
lol, 3-5* superheat, What happens when the filter gets dirty?
Ever since I got my TrueFlow grid for measuring CFM total, my Testo and Fieldpiece airflow, measuring tools, feel neglected in a bandit. The batteries are going to go dead inside them before they ever get used again..
I
Love the video, nice tips. That superheat....blower related? " I'll keep you cool if you let me" I'm going to use that ❤
Copywrited! Tad!
@@dporrasxtremeLS3 even if he did have a copyright doesn't mean you can't use it, you just can't sell for a profit as if you owned the copyright.
That 4 ton was to big for the duct work and probably square footage. If you have to go that low on speed and cant achieve 10-20 superheat. That is probably duct work for a 2.5 ton ac unit.
4 tons for a foam insulation home I hope it’s a 4,000 square foot house give or take if not that air handler will rust out in a year I have a house in south Texas foam insulation 1800 square feet and I’m running a 2 ton 2 stage with the second stage eliminated
The 30% decrease in air flow with the 2 degree change doesn't seem like a "win" to me. If it would be 100 out like it is here that system would never keep up. Why do you feel this is better?
colder air is always a win my friend plus the Feet per minute was way to much according to TVA standards for comfort and efficiency
Need 5000 cfm to 2nd floor and 100 cfm on the 1st floor. Then MAYBE the 2nd floor might actually get cooler.
He is fine for a 1 floor house but not a 2 story.
Need 25 humidity for summer and 75 humidity for winter lol.
Why are there no supply and return vents in the basement?
Wow…..have never heard of this!!! Got a new follower bro!
thanks 👍
Need to install a tee after the trap
Nice install. And good video 👍👍
Thank you my brother
I am glad you're here
Hi Taddy, are you going to do another PulseX video after the likely launch this weekend?
Liked your Sacrifice videos. Would be good to hear another video.
I may have to give it a shot
I hope that it really launches
@@TaddyDigest
Great to hear! Yes, Same. We have remained Patient, and all our lives have carried on.
But its all about to get exciting now and the wait would have been worth it. I'm certain of it.
All the best.
How do I find someone in my area who will perform a a detailed test like this?
What is super heat? How does a lower fan speed make the temperature cooler?
Super Heat Can signify how much refrigerant is in the evaporator
Because if you lower the fan speed the air flows slower across a cold coil therefore lowering the temperature.
@@TaddyDigest thanks. My Heil air handler does not have a circuit board on the fan housing, or perhaps it is somewhere inaccessible
What about the filter? Merv on my in laws is like 1 and getting a lot of mud in evaporator drain lines now getting freeze ups . I’m trying to tell him to get something better but he’s worried about losing air flow? I have a 4 inch merv 11 on a standard blower and works great. I need one of those airflow meters!
Nice good job
if i were to hire an alleged HVAC certified tech to do what you show in this video, what questions should i ask of the tech company before hiring?
Drop the fan speed will provide more dehumidification plus decrease my supply 5 degrees, I could use your service in SW Florida. Six visits from my two year newly installed 16 SEER Goodman HP and they still can't get it right.
What is your average indoor relative humidity? what’s your average run cycle time?
Is 700 the best target airflow for pretty much all systems or just this house in particular? Also, I know that if a system doesn't have enough airflow then it can freeze up, so does lowering the fan speed not cause future problems?
In between 400 -700 feet per minute
As long as you monitor the Pressures and adjust the charge properly. You will never have a problem.
What can you do in a 2 levelhouse with Terrible duct work to up stairs?
Good job!
I have a question if you adjust blower speed on a variable speed motor will the blower motor still do the variable speed option?
Yes.
So the thermometer/hygrometer determines if there's too much air or too little cfms?
No a thermometer tells temperature and a Hygrometer tells humidity.
Adding a dehumidifier is just wringing out more moisture right?
yes
Is there such a thing as the return elbow to the furnace as too big ? Mine is 10" x 25" coming down to the elbow.
How does slowing the fan speed down make the air coming out colder?
Lowers the temperature of the refrigerant
At the indoor coil
@@TaddyDigest thanks man
Why is lower fan speed better?
Increase temperature split
So 5 degrees superheat is too low. Not enough air over the evaporator will cause liquid refrigerant to wash out your oil in the compressor making it fail. The superheat was moving all over due to the TXV hunting around. In my opinion you just made a perfect expensive early compressor failure. Always keep superheat at 10 to 20 degrees. Your sub cooling looked good at 10 degrees.
Exactly. Suction temp should never be below 50°. That cold refrigerant will hit the hot scrolls and make some money for the next tech. Unfortunate for the homeowners. Yes they'll be getting better dehumidification now but at the expense of a compressor. If it was me I would have balanced the house opposed to cutting down air flow. That would be the last resort. And on the other hand he should have waited 10mins or so for the refrigerant to make a complete cycle through the system and show the discharge air temp to be lower than after a short walk back up stairs to your velometer. Just my two cents.
Exactly what Ruck said.. 90% of ac installers are bogus...
Yeah 5 is cutting it a little too close for my comfort. Also you shouldn't need a dehumidifier on the main floor or anywhere in the house if the unit is sized properly and set up properly. Maybe one for a sealed crawl space but not the house.
We have a newly constructed house (2 story) foam insulation and the airflow is super inconsistent per vent. 2 rooms stay cold (20 degrees temperature difference on airflow coming out of the vent. House was brand new we moved in July of this year. I opened the door to the attic and he was super hot up there (not a lot of space to move around). Any advice?
the return in our home is the interior of a framed out sheetrock wall its like a 2.5x2.5 chute up into the attic and the top of the shoot is a duct box. There is the backside of drywall, studs, and the concrete slab exposed in this space. Is this correct?
That sounds interesting
I would have to see pictures to be able to tell you if it's right.
Do you wanna click the join button and get my email? I will send it to you and then you can send me pictures.
Tad did you do the duct work? Nice job! Super great video, lots to cover! Details, Details!
yes sir thank you 😊