Weird question about central air (1 Viewer)

[Superfly]

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.

 

[Josie]

When I was purchasing my house, I was told by the inspector that I had the most insulation in a house that he's ever seen. And my electricity bill is usually under $100 (except for a month or so in the summer and winter).

I don't know what's causing your issues, but 75* seems a tish high for sleeping. I like to snuggle, though.

 

[Slyfox696]

I'm far from an expert on A/C, but I've had my fair share of problems. Please keep in mind these are only things I have picked up on as I've dealt with my problems, and I cannot vouch for the accuracy of my comments.

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.

It could make sense, actually. When you wake up hot and sweaty, is the A/C running? One of the things the A/C does to cool the air is remove humidity from the air. When you are asleep at night, and the temperature falls outside, the inside is no longer increasing in temperature, but rather staying roughly the same temperature as the outside. This means your A/C may not be kicking on often (or even at all) and thus the moisture stays in the air leading you to feel more miserable.

While 75 degrees is 75 degrees, the humidity might be different, leading one to feel cooler than another.

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.

This doesn't make any sense. Either you got hosed on the A/C unit or you have cool air rapidly escaping the system/house (which could be occurring in multiple ways). I'd also assume your A/C runs constantly and never stops?

I had a similar problem (my house never really cooled), and the problem I had was my A/C coil was covered with pet hair, meaning the air running through my house was not cooling very much at all. Is the air coming out of your vents cool/cold? Or is it kind of warm? Do you have strong air flow from your vents?

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.

It really does sound as if you have a part with a problem. It might be a leak from where the lines run from your fan into the house, either a leak in the hose or at the connection.

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?

Yes, to both questions.

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.

I'd call an established name in A/C repair and see what he/she says. Because something obviously does not sound right.

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.

If your A/C is running all the time anyways, I cannot imagine your bill going much higher. You might also check and make sure it's your A/C causing the high bill. Have you tried turning off your A/C and checking to see how fast your electric meter is spinning, and then turning the A/C back on and checking again?

 

[Lutherf]

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.

The first thing is always to check the filters. If your filters are dirty (especially if you have pets) that will mess everything up. The other thing you might want to have someone check is the valves that regulate the flow of Freon. It's possible for a tiny piece of crud to get in there and clog the valve so that the Freon doesn't flow correctly. That will make the system act like it's low on charge when it's actually overcharged.

 

[radioman]

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.

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.

----------------------------
It's not the heat it's the humidity....really.
I'd say get a de-humidifier except for the frozen wires incident.
Probable Freon leak.
You probably do need a *something-or-other* part.

EDIT: Listen to Slyfox696....he seems very knowledgeable.

 

[Superfly]

When I was purchasing my house, I was told by the inspector that I had the most insulation in a house that he's ever seen. And my electricity bill is usually under $100 (except for a month or so in the summer and winter).

I don't know what's causing your issues, but 75* seems a tish high for sleeping. I like to snuggle, though.

It's very high to me. When I lived in upstate New York, I'd sleep with windows cracked in the dead of winter. I like a very cold bedroom when I sleep. I'm just afraid to go below 75. $400+ is scary enough.

 

[Threegoofs]

I'm betting you live in an area with high humidity.


Simply put, the AC isn't working at night because of low temperatures, but what you hate is the humidity. Add a dehumidifier in your bedroom at night, and you'll solve your problem.

 

[Superfly]

I'm far from an expert on A/C, but I've had my fair share of problems. Please keep in mind these are only things I have picked up on as I've dealt with my problems, and I cannot vouch for the accuracy of my comments.

It could make sense, actually. When you wake up hot and sweaty, is the A/C running? One of the things the A/C does to cool the air is remove humidity from the air. When you are asleep at night, and the temperature falls outside, the inside is no longer increasing in temperature, but rather staying roughly the same temperature as the outside. This means your A/C may not be kicking on often (or even at all) and thus the moisture stays in the air leading you to feel more miserable.

The air kicks on from time to time at night. It's not constantly running, though.

This doesn't make any sense. Either you got hosed on the A/C unit or you have cool air rapidly escaping the system/house (which could be occurring in multiple ways). I'd also assume your A/C runs constantly and never stops?

No, it doesn't really run constantly. The AC unit is supposed to be brand new, as the house is brand new. We don't know where to check for an air leak. The attic is explosively hot, and I'd think if there was a leak in the ductwork up there, we'd notice a change in the temp. It's hotter than the surface of the sun up there.

I had a similar problem (my house never really cooled), and the problem I had was my A/C coil was covered with pet hair, meaning the air running through my house was not cooling very much at all. Is the air coming out of your vents cool/cold? Or is it kind of warm? Do you have strong air flow from your vents?

Sometimes (rarely) the house gets very cold. It's almost like it doesn't know when to turn on and when to turn off. There are times when it's on 75 and it's so effing cold in the house that I am looking for a blanket, and other times, like right now, at 105 in the morning, that I hear the air running from the vents, and my tee shirt is stuck to my back with sweat and the thermostat is still on 75. Freezing one minute, sweating the next? Makes no sense.

If your A/C is running all the time anyways, I cannot imagine your bill going much higher. You might also check and make sure it's your A/C causing the high bill. Have you tried turning off your A/C and checking to see how fast your electric meter is spinning, and then turning the A/C back on and checking again?

Yeah, we did all that last year when our bill skyrocketed. We had the AC guy come out and check everything over, and he said it was all fine. I think you're right, though, that I should get an independent AC guy to come out and look at it. Obviously, there's something wrong.

Thanks for all the info.

 

[PirateMk1]

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.

If your bill is triple I would have the electric company come out and track down where the draws are. You might have a short somewhere. If you have a new house the AC should be under warranty. I would check to make sure all the ducts are sealed. My mom had a duct that was open into the attic and she had high electric bills as she was cooling the attic. Check the evaporator coils on the ac unit and make sure they are clean and the airflow is unrestricted though them. AS your unit was said to be low on refrigerant then there is a leak that needs to be corrected. Coils freezing up is generally due to low Freon, restricted airflow, and bad drainage for the condensate water. As far as nighttime temps set your thermostat to just below the average nighttime temp for the season and the ac will dry the air, reducing the humidity.

 

[Superfly]

The first thing is always to check the filters. If your filters are dirty (especially if you have pets) that will mess everything up. The other thing you might want to have someone check is the valves that regulate the flow of Freon. It's possible for a tiny piece of crud to get in there and clog the valve so that the Freon doesn't flow correctly. That will make the system act like it's low on charge when it's actually overcharged.

We buy filters in bulk, and change them every 30 days. With our light bill being so high, we know that a dirty filter can make a big difference in our bill. And our Freon was low - he had to put some in (like a pound or two) because it was leaking from somewhere.

 

[Superfly]

----------------------------
It's not the heat it's the humidity....really.
I'd say get a de-humidifier except for the frozen wires incident.
Probable Freon leak.
You probably do need a *something-or-other* part.

EDIT: Listen to Slyfox696....he seems very knowledgeable.

:lol: Thanks.

 

[Superfly]

If your bill is triple I would have the electric company come out and track down where the draws are. You might have a short somewhere. If you have a new house the AC should be under warranty. I would check to make sure all the ducts are sealed. My mom had a duct that was open into the attic and she had high electric bills as she was cooling the attic. Check the evaporator coils on the ac unit and make sure they are clean and the airflow is unrestricted though them. AS your unit was said to be low on refrigerant then there is a leak that needs to be corrected. Coils freezing up is generally due to low Freon, restricted airflow, and bad drainage for the condensate water. As far as nighttime temps set your thermostat to just below the average nighttime temp for the season and the ac will dry the air, reducing the humidity.

We have had people come out and look at everything, Pirate, and no one can tell us anything. There's a problem with our pot lights (they are using as much electricity as our AC unit, believe it or not, with 40amp bulbs) but no one will fix it. Our builder is a giant dick and every time we tell him there's a problem, he says it's all in our heads.

The AC guy did say something about a bad evaporator something or other, and it's on order. Could that have anything to do with our electric bill? The unit is still under warranty.

 

[Superfly]

I'm betting you live in an area with high humidity.


Simply put, the AC isn't working at night because of low temperatures, but what you hate is the humidity. Add a dehumidifier in your bedroom at night, and you'll solve your problem.

I do, three goofs. I live in extreme southeast Georgia, almost right on the coast. The humidity here is unbearable. Will look into a dehumidifier. Thanks! And thanks to everyone else who mentioned a dehumidifier, as well.

 

[APACHERAT]

OK I have a weird question.

It's not a weird question but there are so many things it could be. Dirty filters, insufficient insulation in the attic and walls. A/C unit not large enough to handle the sq. ft. of your home. Electrician not running the proper gauge wiring to the unit. And voltage drop would cause your compressor to over work and ice up.

So the questions are, where do you live ? What's the outside humidity ? Is your home custom built of a tract home ? If it's a tact home are any of your neighbors experiencing the same thing ? The HVAC contractor could have cut corners just to save a buck and undersized your AC. So need to know how many tons is your AC and how many sq. ft. is your home ?

Not uncommon for homes to heat up at night during hot weather after the sun goes down. This is caused from insufficient insulation in the attic. If you have a flat roof with no attic, you got problems. Only solution run sprinklers on the roof in the afternoon and evenings.

If the home is only a year old, it should still be under a warranty.

Call your local HVAC dude and make sure his name isn't bubba.

But I would start with the filters, washing the compressor with a hose and using a multi meter and reading the voltage and how many amps the unit is drawing and seeing if the wiring is properly sized. If the wiring isn't properly sized, the unit is going to over work itself and ice up or burn up.

 

[radioman]

We have had people come out and look at everything, Pirate, and no one can tell us anything. There's a problem with our pot lights (they are using as much electricity as our AC unit, believe it or not, with 40amp bulbs) but no one will fix it. Our builder is a giant dick and every time we tell him there's a problem, he says it's all in our heads.

The AC guy did say something about a bad evaporator something or other, and it's on order. Could that have anything to do with our electric bill? The unit is still under warranty.

--------------
Hmmm...the pot thickens....ooops.....I mean the plot thickens.
40amp bulbs translate to 4400 watt bulbs.
Those are really big bulbs.
Are you sure about your bulb size?

 

[Fisher]

The fact that your house is new doesn't mean anything unless you have warranties. The builder could easily have cut corners, or his subcontractors could have as well. It sounds like you have resolved your AC leak issue. If it was a spec house that you just bought when it was done, odds are they put in a crappy unit to begin with.

That said, try a fan at night and see if that helps before you go drop $300.00 on a dehumidifier. I know I can sleep with a fan on me when it is 105 as well as I can with AC when it is 75. During the hot part of the year we usually keep the upstairs about 65 at night and 73 during the day (we have two units--a smaller one for the upstairs bedrooms and the big one for the main floor/basement. There are other options that might help cut your bill, but it might require more effort and expense than you are willing to try--like a window unit just in your bedroom or a portable AC. I think I have seen those for about the same price at places like Lowe's for about the same price as a dehumidifier. If you are not there all day, you could try a programmable thermostat.

 

[APACHERAT]

We buy filters in bulk, and change them every 30 days. QUOTE]

Where do you live, in the dust bowl ? Most of todays filters you just wash them with a garden hose and let them dry out and put them back in. Usually twice a year is the norm.

If you had to recharge the refrigerant (freon is no longer PC and illegal in most states) and the AC unit is only a year old, sounds like a micro leak. Usually if there's a leak it all goes real quick. But that doesn't sound right having to recharge the refrigerant on a AC unit only a year old.

 

[PirateMk1]

We have had people come out and look at everything, Pirate, and no one can tell us anything. There's a problem with our pot lights (they are using as much electricity as our AC unit, believe it or not, with 40amp bulbs) but no one will fix it. Our builder is a giant dick and every time we tell him there's a problem, he says it's all in our heads.

The AC guy did say something about a bad evaporator something or other, and it's on order. Could that have anything to do with our electric bill? The unit is still under warranty.

If pot lights are using that much energy they are most likely defective installed wrong, or you need to change the type bulbs they are using. I presume you meant 40 watt bulbs. For lighting I would start switching over to LED lights when possible they use much less electricity and are much cooler. Other then a electric oven or dryer unit your ac should be the top consumer of electricity by far.

 

[APACHERAT]

--------------
Hmmm...the pot thickens....ooops.....I mean the plot thickens.
40amp bulbs translate to 4400 watt bulbs.
Those are really big bulbs.
Are you sure about your bulb size?

HID lighting probably, metal halide , high pressure sodium, etc.

40 amp bulb should be sufficent to help light up a football field.

There are some old time electrical contractors who still use HID lighting outdoors for highlighting gardens and trees at night.

 

[Fisher]

I use Equiv. to 100W ottlite natural light bulbs in my recessed lights and I don't see a noticeable different in electric bills than when I use lower wattage bulbs.

 

[Superfly]

It's not a weird question but there are so many things it could be. Dirty filters, insufficient insulation in the attic and walls. A/C unit not large enough to handle the sq. ft. of your home. Electrician not running the proper gauge wiring to the unit. And voltage drop would cause your compressor to over work and ice up.

So the questions are, where do you live ?

Extreme Southeast Georgia, in Brunswick.

What's the outside humidity ?

Right now it is 97% and I am sweating inside my home.

Is your home custom built of a tract home ?

Well, sort of both. I am in a subdivision where the houses look similar, but we made a lot of changes to the plans to make it fit us better.

If it's a tact home are any of your neighbors experiencing the same thing ?

No. The average utility bill in the summer here is under $150. Our average bill in the summer is $400.

The HVAC contractor could have cut corners just to save a buck and undersized your AC. So need to know how many tons is your AC and how many sq. ft. is your home ?

I don't know how many tons it is but I can find out for you tomorrow. This is the 2nd summer we've complained about the electric bills, and some of our neighbors said that our unit was the biggest in the neighborhood, save one other person's, and our houses are the biggest in the neighborhood. The heated SF is around 2,200 downstairs, and another 500sf upstairs in the bonus room, but we don't count the bonus room in the heated SF because it's on a different unit - a small thing, not like a window unit, but a built-in, separate unit. Hard to explain. But it never runs because we rarely use the bonus room, so that wouldn't affect our utility bill.

Not uncommon for homes to heat up at night during hot weather after the sun goes down. This is caused from insufficient insulation in the attic. If you have a flat roof with no attic, you got problems. Only solution run sprinklers on the roof in the afternoon and evenings.

Could have a third party look at the insulation as well, but the roof is pitched, and not flat.

If the home is only a year old, it should still be under a warranty.

Well, a year and 4 months. Out of warranty.

But I would start with the filters, washing the compressor with a hose and using a multi meter and reading the voltage and how many amps the unit is drawing and seeing if the wiring is properly sized. If the wiring isn't properly sized, the unit is going to over work itself and ice up or burn up.

And that's something an electrician could tell us, no? Because we've thought about hiring an independent electrician to come out and look at the house and tell us if there's an issue. Obviously there's something going on.

Thanks for the info.

 

[Superfly]

--------------
Hmmm...the pot thickens....ooops.....I mean the plot thickens.
40amp bulbs translate to 4400 watt bulbs.
Those are really big bulbs.
Are you sure about your bulb size?

No, I'm not. I'm sorry LOL. I meant 40 watt. I had Georgia Power on the phone asking them about the bulbs. We took one out of the pot light, and it said something like 120V bulb and she said that was the equivalent of a 40 watt bulb.

 

[Superfly]

That said, try a fan at night and see if that helps before you go drop $300.00 on a dehumidifier. I know I can sleep with a fan on me when it is 105 as well as I can with AC when it is 75. During the hot part of the year we usually keep the upstairs about 65 at night and 73 during the day (we have two units--a smaller one for the upstairs bedrooms and the big one for the main floor/basement. There are other options that might help cut your bill, but it might require more effort and expense than you are willing to try--like a window unit just in your bedroom or a portable AC. I think I have seen those for about the same price at places like Lowe's for about the same price as a dehumidifier. If you are not there all day, you could try a programmable thermostat.

We are both home, all day long. And we do use fans. We have ceiling fans in every room, plus we sleep under 2 fans at night, and the girls sleep under a fan also. I would honestly be terrified to run my AC at 65/73.

 

[Superfly]

We buy filters in bulk, and change them every 30 days.

Where do you live, in the dust bowl ? Most of todays filters you just wash them with a garden hose and let them dry out and put them back in. Usually twice a year is the norm.

If you had to recharge the refrigerant (freon is no longer PC and illegal in most states) and the AC unit is only a year old, sounds like a micro leak. Usually if there's a leak it all goes real quick. But that doesn't sound right having to recharge the refrigerant on a AC unit only a year old.

The warranty on our unit says that the filters have to be changed out every 30 days.

 

[radioman]

No, I'm not. I'm sorry LOL. I meant 40 watt. I had Georgia Power on the phone asking them about the bulbs. We took one out of the pot light, and it said something like 120V bulb and she said that was the equivalent of a 40 watt bulb.

-------------

40 watt is more reasonable.
No way 40 watt bulbs would use as much power as your AC.....unless you have a hundred of them.
I think you've gotten a few good leads on this thread.
Good luck, my friend and goodnight.