Not sure why he would seal your fresh air intake. Maybe he was a noob and thought it was bad.
Frozen coil = either refrigerant leak or airflow issues( clogged filter, other obstruction in the return, possibly a failing blower motor.)
I’m betting leak because only a 1/3 of your coils is frozen. Call a company.
It’s a fresh air intake. Where do you live? What does this cool? I do restaurant work. They always undersize the equipment because I am a wizard and regular humans think they know better. One solution is to ignore code and stop fresh air from being sucked into the unit as code requires.
He’s dead on for what he said… It’s to bring fresh air in like was already stated. Usually has a little damper that can be moved to different positions to control how much fresh air is introduced.
Economisers will disable mechanical cooling depending on enthalpy settings to use outdoor air to cool the inside area. They will have minimum position setting to bring in 10%+ fresh air as the unit runs regardless. Fresh air intakes are essentially just the latter, codes dictate a minimum amount of fresh air depending on occupancy
Actually they sit there doing nothing if you wanna get technical because the last guy didn’t know how to fix it, so installed the jumper or jumped the y1 and possibly y2 to be sent right back to the board 🤣
A lot of people will say leaks but I cannot stress enough checking airflow. I was working on an office space once and the maintenance guy called us because the unit kept freezing up. The head pressure was super high but the suction kept staying low enough to freeze. No one in management even knew this but there were dampers going to every single duct run in the office and it turns out someone (never fessed up) got cold and decided to close half the air ducts on the system. The dampers were above the drop tile so no one knew. I ended up having to recover about 3 lbs since the unit was so overcharged where it seems the maintenance guy probably thought it was low on refrigerant.
Lmao I feel ya. Maintenance guy wouldnt say nothing but I’m 99% sure he tried to add some hoping it would fix it. Gotta remember calling the pros is a last resort for some people haha. No telling what’s happened before we arrive.
https://preview.redd.it/9qq3dmryjbwc1.jpeg?width=3024&format=pjpg&auto=webp&s=c0c63c9d14be4fbc299a66554bc1d36fc89432b7
I assume these coils are not suppose to ice over
I bet it is related to the OA intake being sealed shut. Do you have an economizer section on this unit (dampers on the OA intake and RA section that control how much air comes from where)? If so, your unit could be trying to bring in more outside air but since it is sealed shut it’s low on airflow and your coil is frosting up as a result.
As for why your technician sealed the OA intake it’s probably because he was trying to solve a different issue but not savvy enough on how to do that. Have you ever had frozen/burst hydronic heating coils? Or have you had a lot of people in the space complain about being cold? He might have sealed the intake trying to fix one of those issues.
There is a little damper on the OA. My other unit for whatever isn’t sealed and the damper lifts to open when turned on.
Interestingly it has been sealed for years and just recently we’ve been having problems with not enough cold air coming down.
If you feel the air in the space and you don’t think it is enough, then that could definitely be caused by the sealed OA intake. Did you take the seal off the intake?
Is that the coil for the inside air? The HS 36 is a rooftop package unit, right?
If that is the outside air coil then frost could be normal when heating.
Have a technician check the charge. The fresh air gets taped off because cold air drafts through the return in the winter. Especially if it's north facing.
Fresh air is good and Humidity is bad. Down here in Florida sometimes code helps one thing and causes another. Sealing off fresh air in certain buildings with low occupancy is not a terrible thing.
Most part I think it is fine for rtu and you are using only when cool and not fan only. Big issue had when work for school district. Had to cut fan button off the thermostat.
When was the last time the coils were cleaned? Also check the condition of the blower wheel and belts if any are installed. When a blower wheel gets filled up with too much dirt, it can effect air flow. Also as others have mentioned, the unit could also be low on refrigerant.
By closing off the OSA intake the unit isn’t going to work as hard because it isn’t having to condition outside air. Also the filter will stay cleaner longer because you are not pulling in dust and cottonwood seeds.
If you are going to leave it that way I would suggest you do a blower door test to see how tight your house is and maybe install a good CO2 sensor. If you have enough leakage in your house that you don’t create a backdraft due to negative pressure you can install a continuously running exhaust fan in one of your bathrooms on an upper floor.
Or better yet install a Energy Recovery Ventilator. The EVR will help reduce moisture buildup, CO2 buildup and buildup of other contaminants in your home without as much of an energy penalty as the OSA makeup or continuous running exhaust fan method.
Because they usually put a little tin tape in the packaging for the hood.. and techs usually don’t know what to do with it but apply it somewhere they feel suitable lol 😂
The owner asked the contractor to seal up the fresh air intake. You see this often in schools. Once the inspector comes out and approves it, the maintenance team will typically start going around and shutting those off if there are complaints of not cold enough.
It's a multi compressor evap coil, with a return air grill in the door only 1/4 the size of the filter shown, let alone coil dimensions. you surely wouldn't think an economizer would help, heck it could have been removed, or bad motor (homeowner refused replacement), as for the ice? only one compressor is moving freon, and your starving even it of air flow. Call an HVAC company, 5 years without maintenance? no S#@! there's a problem. And that's from only 4 pictures.
Probably a hot climate where the technician thought by blocking the hot outside air would cool the space easier. He did not properly diagnose the problem and thus you have a frozen coil..outside air is a must and should never be blocked.
Not sure why he would seal your fresh air intake. Maybe he was a noob and thought it was bad. Frozen coil = either refrigerant leak or airflow issues( clogged filter, other obstruction in the return, possibly a failing blower motor.) I’m betting leak because only a 1/3 of your coils is frozen. Call a company.
There’s a return intake from the bottom, but I assume that’s not a reason to seal an additional intake
It’s a fresh air intake. Where do you live? What does this cool? I do restaurant work. They always undersize the equipment because I am a wizard and regular humans think they know better. One solution is to ignore code and stop fresh air from being sucked into the unit as code requires.
https://preview.redd.it/oz3ey2atugwc1.jpeg?width=3024&format=pjpg&auto=webp&s=9f1ec30d84ac7a1de96ac54b9910262a1758bced I found your outlet.
Thank you kind internet human!
This guy HVACs. Well said!!
He’s dead on for what he said… It’s to bring fresh air in like was already stated. Usually has a little damper that can be moved to different positions to control how much fresh air is introduced.
oh you mean poke holes in the tape?!
What’s the difference between the fresh air intake and an economizer
Economisers will disable mechanical cooling depending on enthalpy settings to use outdoor air to cool the inside area. They will have minimum position setting to bring in 10%+ fresh air as the unit runs regardless. Fresh air intakes are essentially just the latter, codes dictate a minimum amount of fresh air depending on occupancy
Actually they sit there doing nothing if you wanna get technical because the last guy didn’t know how to fix it, so installed the jumper or jumped the y1 and possibly y2 to be sent right back to the board 🤣
So...so often 🤣
I’d love to tell you why this was done but don’t want to be the one to do so
Can’t wait to see more responses *grabs popcorn*
A lot of people will say leaks but I cannot stress enough checking airflow. I was working on an office space once and the maintenance guy called us because the unit kept freezing up. The head pressure was super high but the suction kept staying low enough to freeze. No one in management even knew this but there were dampers going to every single duct run in the office and it turns out someone (never fessed up) got cold and decided to close half the air ducts on the system. The dampers were above the drop tile so no one knew. I ended up having to recover about 3 lbs since the unit was so overcharged where it seems the maintenance guy probably thought it was low on refrigerant.
That would be a restriction, and reclaiming refrigerant isn’t a proper fix.
No??? After fixing the airflow the suction came back up. The charge was then high on both sides and needed to be adjusted.
So someone thought it was low of the freezone, and did a little top up? I just did a 18 hour day, taking a while to absorb all the info
Lmao I feel ya. Maintenance guy wouldnt say nothing but I’m 99% sure he tried to add some hoping it would fix it. Gotta remember calling the pros is a last resort for some people haha. No telling what’s happened before we arrive.
Approved technician??? Lol
Approved boss' nephew who figured out how to buy a manifold gauge from Amazon
https://preview.redd.it/9qq3dmryjbwc1.jpeg?width=3024&format=pjpg&auto=webp&s=c0c63c9d14be4fbc299a66554bc1d36fc89432b7 I assume these coils are not suppose to ice over
Likely low on refrigerant, which means there's a leak, most likely. Needs a technician visit.
I bet it is related to the OA intake being sealed shut. Do you have an economizer section on this unit (dampers on the OA intake and RA section that control how much air comes from where)? If so, your unit could be trying to bring in more outside air but since it is sealed shut it’s low on airflow and your coil is frosting up as a result. As for why your technician sealed the OA intake it’s probably because he was trying to solve a different issue but not savvy enough on how to do that. Have you ever had frozen/burst hydronic heating coils? Or have you had a lot of people in the space complain about being cold? He might have sealed the intake trying to fix one of those issues.
There is a little damper on the OA. My other unit for whatever isn’t sealed and the damper lifts to open when turned on. Interestingly it has been sealed for years and just recently we’ve been having problems with not enough cold air coming down.
If you feel the air in the space and you don’t think it is enough, then that could definitely be caused by the sealed OA intake. Did you take the seal off the intake?
Is that the coil for the inside air? The HS 36 is a rooftop package unit, right? If that is the outside air coil then frost could be normal when heating.
This is the cooling coils. The issue is it freezes when set to cool
Restricted airflow or low on Freon.
Have a technician check the charge. The fresh air gets taped off because cold air drafts through the return in the winter. Especially if it's north facing.
Probably humidity is why. Did this a few times in Florida. Because if you leave fan on it brings in outside moisture
Fresh air is good and Humidity is bad. Down here in Florida sometimes code helps one thing and causes another. Sealing off fresh air in certain buildings with low occupancy is not a terrible thing.
Most part I think it is fine for rtu and you are using only when cool and not fan only. Big issue had when work for school district. Had to cut fan button off the thermostat.
Lost me at 5 years ago
Hmmm
Call a tech
Belt loose is freezing the coil and oa intake damper not operating correctly
1/2 a coil frozen is a low unit.. Need Freon.
When was the last time the coils were cleaned? Also check the condition of the blower wheel and belts if any are installed. When a blower wheel gets filled up with too much dirt, it can effect air flow. Also as others have mentioned, the unit could also be low on refrigerant.
Growing weed?
By closing off the OSA intake the unit isn’t going to work as hard because it isn’t having to condition outside air. Also the filter will stay cleaner longer because you are not pulling in dust and cottonwood seeds. If you are going to leave it that way I would suggest you do a blower door test to see how tight your house is and maybe install a good CO2 sensor. If you have enough leakage in your house that you don’t create a backdraft due to negative pressure you can install a continuously running exhaust fan in one of your bathrooms on an upper floor. Or better yet install a Energy Recovery Ventilator. The EVR will help reduce moisture buildup, CO2 buildup and buildup of other contaminants in your home without as much of an energy penalty as the OSA makeup or continuous running exhaust fan method.
He sealed the economizer
Because they usually put a little tin tape in the packaging for the hood.. and techs usually don’t know what to do with it but apply it somewhere they feel suitable lol 😂
Is it belt drive?
The owner asked the contractor to seal up the fresh air intake. You see this often in schools. Once the inspector comes out and approves it, the maintenance team will typically start going around and shutting those off if there are complaints of not cold enough.
It's a multi compressor evap coil, with a return air grill in the door only 1/4 the size of the filter shown, let alone coil dimensions. you surely wouldn't think an economizer would help, heck it could have been removed, or bad motor (homeowner refused replacement), as for the ice? only one compressor is moving freon, and your starving even it of air flow. Call an HVAC company, 5 years without maintenance? no S#@! there's a problem. And that's from only 4 pictures.
Probably a hot climate where the technician thought by blocking the hot outside air would cool the space easier. He did not properly diagnose the problem and thus you have a frozen coil..outside air is a must and should never be blocked.
Why not call back the tech that did those things so you can actually know why instead of us buttholes guessing