Weird question about central air

[Superfly]

Thanks, RM. I've been told we're OK with insulation in the attic, but of course, I'd like to have more if it would help. I think we do have a heat pump. And I think our unit is the right size -- I checked this morning, and it's a 3 ton which is average for 2,200sf.

They are replacing the coil - I wonder how much that would have to do with problems with the bill. It's only a year and a half old.

 

[Removable Mind]

Thanks, RM. I've been told we're OK with insulation in the attic, but of course, I'd like to have more if it would help. I think we do have a heat pump. And I think our unit is the right size -- I checked this morning, and it's a 3 ton which is average for 2,200sf.

They are replacing the coil - I wonder how much that would have to do with problems with the bill. It's only a year and a half old.

Our places are about the same size. And the heat pump is a 3 ton.

If they are replacing the coil...is that the condenser coil outside....or the evaporator coil inside?

 

[Superfly]

outside. Everything is outside, I guess.

 

[Removable Mind]

outside. Everything is outside, I guess.

That can be a problem too. That is where the coolant is actually cooled down and recirculated back to the evaporator coil. If the coil is too small or leaking...then it won't lower the temp of the coolant.

 

[ttwtt78640]

OK I have a weird question. I try to keep my thermostat set on 75. Our electric bill is really high (around $400+ a month, during the summer) so I tried to keep it on 78 but it was just too hot, and my husband has COPD and emphysema, so he can't breathe when he gets too hot. Anyway. So during the hottest part of the day, when it's around 90 to 95 outside, the house is quite comfortable at 75. However, at night, when the temps drop to 70 to 75, the house is just awful. It's so hot. Last night, I went to bed about 3am, and my tee shirt was stuck to my back from all the sweat. Now does that make sense to you?

I'd think, logically, that it'd be hotter in the house during the day than during the night, but the night is often unbearable. Also, logic would dictate that 75 is 75, no matter what the temp is outside.

Also, let me reiterate - I run an extremely high electric bill. It's at least double, if not triple, of everyone else's here in the neighborhood. Now this is a brand new house, only about a year old. Last Sunday, we woke up and the house was really hot. We went outside to see if the unit was running, and it was, but along all the wires leading into the house, they were frozen solid. We turned off the AC and turned the unit strictly on fan, and left it on until the ice melted. Once the ice melted, the air started working again. We had the HVAC guy come out and he had to put in a couple of pounds of Freon and said he thinks we have a bad *something-or-other* part.

Would that have anything to do with us sweltering at night? Would it have anything to do with our electric bill being so much higher than everyone elses? I don't want to depend on this guy to tell me the truth, because of course he's going to say that everything's fine and I'm worried over nothing. My husband and my daughters both said that it's unbearably hot at night, but I don't dare turn the thermostat down below 75. I couldn't imagine what the bill would be.

You seem to have two problems:

1) Your A/C is running too much, either due to faulty A/C system (duct leaks/blockage, clogged filters or low freon) or a severe lack of insulation.

2) your nighttime problem is probably when you close the bedroom doors the air circulation is greatly reduced, allowing the bedroom(s) to get warmer and more humid. Most central A/C (and heating) systems have outlets in each room and a single return on each floor, thus closing off a room leaves no "draw" from the outlet to the return - effectively removing that room from the system. Check to ensure that at least one inch of clearance exists under the bedroom door(s).

 

[Superfly]

You seem to have two problems:

1) Your A/C is running too much, either due to faulty A/C system (duct leaks/blockage, clogged filters or low freon) or a severe lack of insulation.

2) your nighttime problem is probably when you close the bedroom doors the air circulation is greatly reduced, allowing the bedroom(s) to get warmer and more humid. Most central A/C (and heating) systems have outlets in each room and a single return on each floor, thus closing off a room leaves no "draw" from the outlet to the return - effectively removing that room from the system. Check to ensure that at least one inch of clearance exists under the bedroom door(s).

Yeah, my husband said that about the doors being closed. During the day, the doors stay open, and at night when the girls go to bed, the doors get closed until we go to bed.

 

[Superfly]

I was wrong. They are replacing an evaporator coil, and it's upstairs in the attic. Does that make sense?

 

[mike2810]

I was wrong. They are replacing an evaporator coil, and it's upstairs in the attic. Does that make sense?

many a/c units have the evap coil in the attic.
I did'nt read the whole thread, why are they replacing the evap coil?
It is rare for the coil to be plugged internally. The finds can become plugged with dirt and dust over time if air filters are not changed.

Just a note. Since your coil in the attic. There should be a coil pan that catches the condensation from the coil when the a/c runs during humid weather. Make sure they don't crack it. Make sure the drain line is reinstalled properly. Also your unit should have an emergency overflow pan to catch the condensation in case the coil pan ever overflows. Make sure its drain is also properly installed to drain the water to the outside.

Reason I posted this about the pans. We had a bad pan on a house we bought. When the a/c people fixed it, they did not install the drains properly, resulting in water leaking onto our kitchen ceiling.

have a good one.

We replace a 18 year old unit with a new one seer 16. Cut our bill by 40%.

 

[Superfly]

Well I have an extremely high electric bill, and have had issue with the AC unit. They said the evaporator coil went bad because last week we had our hoses outside freeze up - the ones that go into the house.

 

[Thrilla]

I was wrong. They are replacing an evaporator coil, and it's upstairs in the attic. Does that make sense?

yup, sure does...

the evap is where the refrigerant is "cold" ( low pressure).. the air moves across the coils( thereby removing the heat from the air passing over it) and off to your vents.

for it to be "bad" means it's internally blocked by particulates, or it has a hole in it.

 

[Superfly]

yup, sure does...

the evap is where the refrigerant is "cold" ( low pressure).. the air moves across the coils( thereby removing the heat from the air passing over it) and off to your vents.

for it to be "bad" means it's internally blocked by particulates, or it has a hole in it.

OK - if the evaporator is in the attic, where it's always hot - would that not mean that it has to work harder to cool the air?

 

[Thrilla]

Yeah, my husband said that about the doors being closed. During the day, the doors stay open, and at night when the girls go to bed, the doors get closed until we go to bed.

airflow is key when it comes to AC's... if you have a vent going into a room, you need a way to get air out of that room and returned to the system... if the door is closed, you'll prevent air from getting back into the return vents and it will create a kind of " logjam" of air in that room.

our last house in Vegas had a couple of room that would get stupid hot at night... so I took the doors off, cut 2 inches of the bottom of the doors, and reinstalled em'.

worked perfectly...we had good circulation after that...and we didn't have to add any return vents or leave doors open.

 

[Thrilla]

OK - if the evaporator is in the attic, where it's always hot - would that not mean that it has to work harder to cool the air?

nah.. it's closed off from the attic heat....

picture a straight duct .. just a big pipe with air running through it.... now picture adding a coil that look like a car radiator that is cold to the touch right in the middle of that pipe... the air is pushed/pulled across the coils by a fan and comes out on the other side colder than it was goin' in.... in a nutshell, that's what is happening in your attic.

water is the natural byproduct of that cooling process ( condensation occurs when warm humid air meets cold coils)... which is why evap need drains... and also why they turn into big blocks of ice if something goes wrong :lol:

 

[Superfly]

alright hon, thanks

 

[Thrilla]

in the interim , tell hubby to get out the palm fronds and grapes...have an Egyptian Princess themed role playing night




....just leave out the part where eunuchs traditionally did the fanning and feeding of grapes to the exotic princess :lol:

 

[Superfly]

in the interim , tell hubby to get out the palm fronds and grapes...have an Egyptian Princess themed role playing night




....just leave out the part where eunuchs traditionally did the fanning and feeding of grapes to the exotic princess :lol:

:lol: I'll be sure to leave that part out!!

 

[Thrilla]

a Chamois cloth makes a great period loincloth for the "slave" to wear.


... or so i'm told..... or read in a book.... or something.



:angel?:

 

[Superfly]

a Chamois cloth makes a great period loincloth for the "slave" to wear.


... or so i'm told..... or read in a book.... or something.



:angel?:

:lol: That's AWESOME. But of course, pics or GTFO. I'll be waiting.

 

[Phoenix]

+1 for making sure the filers are clean / replaced. Iced over lines are a symptom of dirty filters
Not knowing where you are or what the outside temp you have there, it sounds like something isn't working correctly.
We also do not know what size house but will assume it's about the size as the others in the neighborhood.
I can't imagine any modern built house of modest size having a power bill that high. If the filters are clean I would have someone check the installation of the heat pump units. They may be improperly installed. Some of the vents my be bent or kinked. Any reduction in airflow causes the unit to work extra hard.

 

[Superfly]

+1 for making sure the filers are clean / replaced. Iced over lines are a symptom of dirty filters
Not knowing where you are or what the outside temp you have there, it sounds like something isn't working correctly.
We also do not know what size house but will assume it's about the size as the others in the neighborhood.
I can't imagine any modern built house of modest size having a power bill that high. If the filters are clean I would have someone check the installation of the heat pump units. They may be improperly installed. Some of the vents my be bent or kinked. Any reduction in airflow causes the unit to work extra hard.

Thanks, Phoenix.

Are there other filters to check, other than the return filter inside the house? We change that about every 30 days. I am in South Georgia, so its mid-90s all summer long, and high humidity. The area of the hosue that is being cooled is 2,200sf (about 200sf bigger than the rest of the houses in the neighborhood). The upstairs bonus room is on a different system. The HVAC guys were here this morning, changing out the evaporator coil. They said everything looked perfect.

 

[Phoenix]

Thanks, Phoenix.

Are there other filters to check, other than the return filter inside the house? We change that about every 30 days. I am in South Georgia, so its mid-90s all summer long, and high humidity. The area of the hosue that is being cooled is 2,200sf (about 200sf bigger than the rest of the houses in the neighborhood). The upstairs bonus room is on a different system. The HVAC guys were here this morning, changing out the evaporator coil. They said everything looked perfect.

Hopefully for you the evap coil will cure your problem. Those are the only filters I know of.

 

[Superfly]

yeah I hope so too :lol:. A $400 a month electric bill when everybody else is paying under $150 is getting old.

 

[Lutherf]

Thanks, Phoenix.

Are there other filters to check, other than the return filter inside the house? We change that about every 30 days. I am in South Georgia, so its mid-90s all summer long, and high humidity. The area of the hosue that is being cooled is 2,200sf (about 200sf bigger than the rest of the houses in the neighborhood). The upstairs bonus room is on a different system. The HVAC guys were here this morning, changing out the evaporator coil. They said everything looked perfect.

They changed out the coil but didn't know whether it was bad or not? There's a fluorescent dye they can pump into the line and a light they can use to see if it's leaking. There is also an ion detector wand thingy available to check for leaks. If they didn't try those things before replacing the coil I'd be concerned that they're messing with you.

 

[Superfly]

They changed out the coil but didn't know whether it was bad or not? There's a fluorescent dye they can pump into the line and a light they can use to see if it's leaking. There is also an ion detector wand thingy available to check for leaks. If they didn't try those things before replacing the coil I'd be concerned that they're messing with you.

They said they believed there was a leak. It was the only thing that would explain the pipes freezing over in a brand new unit. I did see them walk in with this huge part today - half as big as the guy installing it.

 

[radioman]

They said they believed there was a leak. It was the only thing that would explain the pipes freezing over in a brand new unit. I did see them walk in with this huge part today - half as big as the guy installing it.

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Hmmm.....given your earlier posts with thrilla, I think this thread has deviated--so to speak--into erotica.
On a serious note--really!!--I hope your AC problems are cured.eace