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JoelC707
Premium Member
join:2002-07-09
Lanett, AL

JoelC707

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[HVAC] Air Conditioner ideas, re: large power bill

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So after getting our largest power bill ever for a single month last month ($650, over 5000 kWh) I'm thinking we need to investigate WHY. Yes, there are a LOT of people here (10-11, sometimes 12) and there is a camper on the property with it's own AC and WH and everything running, and all the appliances are electric so I expect the power bill will be high, but come on, 5000 kWh in a month? Our smallest power bill was ~$350 (winter and we used propane for primary heat instead of electric) and our average bill over a 12 month period is about $450 a month (we pay about 11-12c/kWh so that puts it about 4000 kWh average).

I'm starting to wonder if the AC is undersized for the space it's trying to cool (if they did any kind of calculation, I'm sure it didn't expect this many people). I keep the AC in the house set at 78, the AC in the camper is set about 75 or so. During the night I'll bump the AC in the house down to 75 usually because it'll sit at about 76/77 and never kick on all night if left at 78 and it gets quite humid in the house.

Two people stay in the camper and sometimes there is another person here that stayed in another camper last time she was here but is currently not here (that's why the body count fluctuates). Basically there are only 8 people in the house, which is what I would use for any calculations.

I do not know how to perform a manual J calculation or anything like that but I did use my Google-fu and found a sqft calculator. Here's some specs on the house: it's a double wide mobile home, approximately 76x28, I don't know about insulation in outside walls (I know there is none in the inside walls) but I suspect it's minimal if any, there are an average number of windows I'd assume (all the rooms generally have at least one window, there are a total of 13 windows and one sliding glass door and all have blinds/curtains over them). Oh and the worst part of it all? NO SHADE over the house at all. That hurts the most I'm sure.

OK, so here's the results of the sqft calculator I used:
R7 insulation, average windows: 6.14 tons
R7 insulation, many windows: 6.92 tons
No insulation, average windows: 10.04 tons
No insulation, many windows: 11.31 tons

The calculator doesn't take into account people, which calculate out at 400 BTU per person I think? Which based on the 8 in the house that's 3200 BTU or an additional quarter ton if my math is right? So basically I should have a 6-7 ton unit and possibly one as high as 10-11 tons? My current unit is a Carrier comfort series that ranges from 1.5 to 5 tons from what I can find. Based on the model number of 24abb348a0031010 and some more Goolge-fu, it's a 13 SEER 4 ton unit which means it appears to be undersized. During the morning and late evening the unit actually cycles on and off but there are times during the middle of the day that it runs non-stop which I believe also points to it being undersized.

Would this cause the high power bills like this or am I barking up the wrong tree?

chamberc
Premium Member
join:2008-08-05
Addison, TX

chamberc

Premium Member

[HVAC] Re: Air Conditioner ideas, re: large power bill

That's pretty normal. We have 4400 sq ft home, 2 adults, 2 kids, a pool (4 pumps) and 3- 3 ton 12 year old units. Last month, here in Dallas we had a very normal summer, and we used 5600 kwh. Normally leave the thermostats on 74.

guppy_fish
Premium Member
join:2003-12-09
Palm Harbor, FL

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That many people means lots of doors being opened and closed, lots of hot water for showers and cooking, how many TV's, cable boxes, video games, computer ect running and the RV is probably 1/3rd the usage as they have almost no insulation.

50 bucks a person seems like a deal ...

You can get a power meter and measure what the RV is pulling, it will be eye-popping for sure the Kwh its using

Having a bigger AC won't lower your bill, if your all hot, it might make it more comfortable, but will use more electricity to do it as you list no insulation

In the south you should have R40 in the attic and R8 in the walls as code minimum ( house )

ImpldConsent
Scouts Out
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join:2001-03-04
North Port, FL
·Comcast XFINITY

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said by JoelC707:

I'm starting to wonder if the AC is undersized for the space it's trying to cool (if they did any kind of calculation, I'm sure it didn't expect this many people). I keep the AC in the house set at 78, the AC in the camper is set about 75 or so. During the night I'll bump the AC in the house down to 75 usually because it'll sit at about 76/77 and never kick on all night if left at 78 and it gets quite humid in the house.

I was having similar bills prior to 2012, when I replaced my 11yr old 3-ton Goodmans with a couple of 2-ton Trane's. I'm not saying Trane is the way to go, but I think having a qualified installer come out and size systems correctly is the ticket. They spent a couple of days coming up with an efficient design - adding returns/registers for efficiency.

Even with the pool running 12hrs a day, AC set at 75, my largest bill (not on budget billing) was 198.00. Really, it used to be 600-700.

Corehhi
join:2002-01-28
Bluffton, SC

Corehhi to JoelC707

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Think you need to look at the basics first.

Hot water for that many people will cost a good amount. Check into a gas fired on demand water heater and heat pump water heaters.

I would certainly look over the insulation in the attic and how well your house is sealed. Many utilities will do a home energy audit for free if yours does I would do that first. Attic vent fan may help a lot too.

You didn't say sq ft of the house so I'm not sure if you are under sized. If your AC holds the temperature down enough to be comfortable I wouldn't worry about that. A bigger AC unit will use more electricity. Have you had the AC to make sure it isn't low on Freon or Puron???

You have a bunch of stuff to check. If the house leaks air and it's not very well insulated I would start there. Next hot water. After that if you have like 4 computers running and TV's everywhere with cable boxes that will drive your bill up as well.
JoelC707
Premium Member
join:2002-07-09
Lanett, AL

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Yeah, I can agree that the RV is a large portion of the usage. Even if that weren't in the picture though, I could still see our power bills being around 300-400 at peak which still seems like a lot.

I realize this is also an issue of double wide vs house in that the double wide is not built for high efficiency (they've gotten better sure but it's still built using the smallest walls and cheapest materials). I know the underside is well insulated with several inches (probably around R19 or so) but I don't know about the ceiling or outside walls. What I have seen of the outside walls indicates 2x4 construction (inside are 2x3 at best) so that means R7/R11 for the outside walls at best
JoelC707

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said by Corehhi:

Hot water for that many people will cost a good amount. Check into a gas fired on demand water heater and heat pump water heaters.

True on the hot water. This thing came with a single element 40 gal hot water heater and one person could wax that thing with a single shower (not even a long one), two people back to back had better make them QUICK showers. We happened to have a dual element 50 gallon water heater and swapped that in and now we have all the hot water we want. I'm sure we could empty it if we tried but all the cold showers and such stopped the same day we swapped it. I know people will say that caused the power bill to go up but honestly I don't see it. The power bill fluctuates month to month and aside from this past month it hasn't really been a noticeable jump. In other words, if it affected the power bill it was minor.

A gas heater is not an option. It sits on an outside wall so we could vent it easily but our only gas option is propane. We currently have a 100 gallon cylinder that I want to upgrade to a 250 - 500 (somewhere in that range) but we burned close to 500 gallons (my estimation) of propane in heat last winter which wasn't cheap (cheaper than using electric most likely) so adding a gas water heater seems like it would just shift the cost from one bill to another.
said by Corehhi:

I would certainly look over the insulation in the attic and how well your house is sealed. Many utilities will do a home energy audit for free if yours does I would do that first. Attic vent fan may help a lot too.

There's no attic access that I've seen but I believe there is insulation in there as I noticed some when swapping basic light fixtures for ceiling fans. It's probably no more than R7/R11 as it's probably nothing more than 2x4 construction there too. Alabama power did mention having the AC system checked (filters are changed every 30 days or sooner if it is really bad looking) but didn't mention anything about a free audit.
said by Corehhi:

You didn't say sq ft of the house so I'm not sure if you are under sized. If your AC holds the temperature down enough to be comfortable I wouldn't worry about that. A bigger AC unit will use more electricity. Have you had the AC to make sure it isn't low on Freon or Puron???

I gave the dimensions of the house (76 x 28 approx) so I figured most would guesstimate off that. I do have a Visio drawing I did of the place when we first looked at it so I could get slightly more accurate sq ft numbers but a rough estimate should be 2100.

We've only been in here a little over a year and it has not been checked in that time. I suppose it could be checked and I could ask the service person if they think it's undersized but I figured it wouldn't need service just yet since it was brand new at the time.

I figured a bigger AC would use more electricity but I also assumed if it actually cycles during the day instead of running constantly (or nearly constant), that it would be better on the bill. Of course there's a point where that's a wash and I may be in that since it does cycle most of the time (and you don't want to go too big because then it short cycles and doesn't properly remove humidity and such).
said by Corehhi:

You have a bunch of stuff to check. If the house leaks air and it's not very well insulated I would start there. Next hot water. After that if you have like 4 computers running and TV's everywhere with cable boxes that will drive your bill up as well.

Of the three doors in the house, they do seem to be well insulated and not leaking air. I'm sure I could improve upon it but as mentioned earlier, with all these people and all the in/out traffic that's a hindrance as well. Seems like a damned if you do, damned if you don't situation.

We do have several computers in the house (a total of 7) but only a couple stay on all the time, the rest stay off until someone uses it and they either shut it down when they are done or the power settings kill it after a short period of time. There's also 5 TVs in the house (like the computers, only on when in use) which means 5 cable boxes (those do stay on all the time, power usage is relatively low but heat generation obviously isn't). I do want to switch to a network CableCard tuner for various reasons (none of them power related lol) which means the cable boxes would go away but the TV and computer usage would be the same or possibly slightly increase.

DKS
Damn Kidney Stones

join:2001-03-22
Owen Sound, ON

DKS to JoelC707

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Do you use the programmable thermostat? That has been a big saver of hydro for us. And switching to LED bulbs.
averagedude
join:2002-01-30
San Diego, CA

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Suggestions:

1. Clean the coil on that condensing unit. All that dust acts like an insulator and lowers the efficiency of the AC unit. Use a garden hose and wash off dirt. Do NOT use a nozzle as the high pressure stream of water WILL damage the coil.
2. Do NOT use HEPA type pleated filters on your AC. Please use the 50 cent cheap throw away type that only block stick twigs and branches. The restriction of air flow from pleated style filters will have a large impact on the efficiency or the AC unit.
3. Have a NATE certified AC tech check the house AC to make sure it is "performing" and not just "working". Have the tech clean the inside evaporator coil. »www.natex.org/
4. Change all the shower heads to 1.5 GPM heads. That is a huge savings of water, especially from an electric water heater. Less gallons of hot water used equals less KW used. I have cheap 1.5 GPM shower heads from home depot and they work just fine, even the girls with long hair have no issues.
5. Check with your electric utility provider to see if "Level Pay" is available in your area. Level Pay averages your electric bill for the entire year and helps with balancing your budget. Be aware that if Level Pay is available it usually has a short open widow for applications and will not help you now, but it will help next summer....again if it is available in your area.
JoelC707
Premium Member
join:2002-07-09
Lanett, AL

JoelC707 to DKS

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to DKS
said by DKS:

Do you use the programmable thermostat?

I do not but I want to get one. There have been a few occasions where I/we forget to bump the thermostat back up to 78 from 75 at night.
JoelC707

JoelC707 to averagedude

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to averagedude
said by averagedude:

1. Clean the coil on that condensing unit. All that dust acts like an insulator and lowers the efficiency of the AC unit. Use a garden hose and wash off dirt. Do NOT use a nozzle as the high pressure stream of water WILL damage the coil.

It didn't seem that bad to me but looking back at the picture I do see dust and dirt on it. I'll get to that asap.
said by averagedude:

2. Do NOT use HEPA type pleated filters on your AC. Please use the 50 cent cheap throw away type that only block stick twigs and branches. The restriction of air flow from pleated style filters will have a large impact on the efficiency or the AC unit.

I don't, I bought an entire box of the cheap filters for it. It does take two filters that are annoyingly different sizes. One is 16x20, the other is 20x20. I also vacuum off the door and such and try to keep that entire area as clean as possible in a (likely futile) effort to keep the filter clean longer.
said by averagedude:

3. Have a NATE certified AC tech check the house AC to make sure it is "performing" and not just "working". Have the tech clean the inside evaporator coil. »www.natex.org/

Thanks, I was wondering who would be a good person to call to have it checked out.
said by averagedude:

4. Change all the shower heads to 1.5 GPM heads. That is a huge savings of water, especially from an electric water heater. Less gallons of hot water used equals less KW used. I have cheap 1.5 GPM shower heads from home depot and they work just fine, even the girls with long hair have no issues.

Existing shower heads are 2.5 GPM (just looked), specifically it's the Peerless Intuition (I think) 2-in-1 shower head. I'd prefer to keep it but if they have a low flow version that could be considered.
said by averagedude:

5. Check with your electric utility provider to see if "Level Pay" is available in your area.

Alabama Power calls it Budget Billing and we just got on it this month. It's leveled out our power bill to $466 a month which at least we can plan for and expect each month instead of expecting something in the 400 to 500 range and getting hit with $650.

Corehhi
join:2002-01-28
Bluffton, SC

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The more I think about it the more I think you are stuck with those power bills.

On the water heater they do make propane fired water heaters that are instant on. Advantages are higher efficiency then electric tank WH, endless hot water, small box that can be mounted outside. All 8 of you could shower one after another then run laundry, wash dishes etc. and never run out. Would that save you enough money quickly enough to be worth it? I'm not sure. I did put in an heat pump water heater but I got a list of rebates that made that make sense, no rebates and I wouldn't have done it. Family of 4 and the heat pump water saves about $20 a month tops.

You can get an idea of how much the A/C is costing this fall when we hit a month that's cool and your A/C doesn't run much or at all. I know my cheapest power bill is in October/April around $180. I spike to around $300 in the dead of summer and dead of winter, I have a heat pump so all electric. Running full blast heat and A/C cost me about $120.

Do you have any attic space or is it just roof with a sloped ceiling on the inside??? If there is a space it might be well worth it to put in a gable fan to keep air circulating through the space. Depends if you actually have space.

I've changed out a few appliances which some have had in effect on my electric bill. I bought last years floor model of a high efficiency washer for $400 and that was noticeable on my power bill. I assume you do a lot of laundry with 8 people??? Swapped an old tube TV for a LCD and I think that actually lowered my bill. If you have old tube TV's in use I would probably be swapping them out for cheap LCD TV's.

Make sure you clean out the air handler along with the outside unit on your A/C. The coils on the inside very well may have a lot of crap on them. Grease from cooking etc. I use stuff they sell at HVAC supply houses, spray foam that you just spray and then spray a little water on cleans those right up.
JoelC707
Premium Member
join:2002-07-09
Lanett, AL

JoelC707

Premium Member

Yeah, when you consider how many are here, it's really not THAT bad, but still. I was just hoping there was some magic fix for it and thought that the AC might have been undersized (it may yet be, but if it is, I suspect it's not terribly so).

I know they make propane water heaters but if I have currently only a 100 gallon cylinder (looking to move to a 250-500) and have used 500 gallons just in heating last year, I can't see adding a large demand appliance like that being beneficial. Sure the on-demand part is really nice and so is endless hot water but in that case I'd have a $300+ a month gas bill to go along with my roughly $300 a month power bill (in short, its a wash bill wise).

We have an old attic fan that we mounted in a frame and install in place of the utility room door to act as a whole house fan and use that instead of the AC in the spring/fall. It doesn't work so well in summer because when the outside temp is 90+ it's doing good if it gets it into the low 80s inside.

There should be attic space because we don't have sloped ceilings yet there is a sloped roof. That said, I have not seen any kind of attic space access anywhere so I can't really say for sure what's up there or anything. We do have those mushroom vent things on the roof IIRC (not the spinny ones) but I'm sure attic ventilation could be improved, just not sure how to do it with no access.

No tube TVs in use anymore but we did have two plasma TVs that have since been replaced with LCD. Not for their power savings but because they got taken out my lightning/surges and an LCD was chosen for their replacements. The doublewide came with new kitchen appliances (energy star supposedly) and we retained our old fridge (running both as we need that much space, plus a chest freezer). The washer and dryer were retained but we did just recently replace them due to the old ones no longer operating at peak efficiency (after several repairs it's time to replace). The current ones aren't new but they are more efficient, washer is a front loader so that helped with the water bill for sure. You're right though, we do a LOT of laundry (and hang clothes out to dry as much as possible) given the number of people here.

tschmidt
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Milford, NH
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tschmidt to JoelC707

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You are probably not going to find there is a single magic bullet to reduce cost. Here in NH Propane is not cheap compared to electric hot water. Since a well insulated electric water heater has negligible standby loss may even be cheaper the Propane.

1) See if your utility offers a home energy audit.
2) Attic fan may be more effective then your realize in reducing temperature. 90F is better then 120 and over night "stores up" cooler air.
3) Plant shade trees to reduce attic heating (but will take years for them to grow).
4) Reshingle with light reflecting shingles
5) More roof/wall insulation.
6) Better windows or overhangs.
7) New HVAC.
8) Solar or Heat-pump hot water.
9) Does utility offer a lower rate for hot water? We have two meters one for normal electricity and a reduced rate meter for hot water.
10) Replace incandescent and old T12 florescent lights.
11) Fewer people.

/tom
fixed typos

guppy_fish
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join:2003-12-09
Palm Harbor, FL

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There is no fix that doesn't involve more money. You can have lower BTU loads by improving the structure, such as a secondary roof over with a foot of insulation, you could rigid foam panel the exterior walls and then put siding on that any you might cut your AC load by 1/3rd, figure thats about 10K or a payback of 6-8 years

Solar hot water might save 50-75 month, costs 1500
Heatpump hotwater tank, 500 bucks might pay for itself in two years ect

Bottom line is you have allot of people which all adds up to your usage. The only thing that you can do for free to lower you bill is hand out the hat or send some of the "guests" packing ...
averagedude
join:2002-01-30
San Diego, CA

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After reading your post, I thought of one more item.

You might want to keep track of how much you're using the electric stove top and electric oven. Those two items can burn lots of KW.

Every KW of electric heat produced because of the stove/oven is a double whammy because then the AC has to turn around and reject that heat to the outside. Basically, you're paying to twice to cook your food.

The same goes for TV, cable boxes, anything that produces heat as a byproduct. Where possible, try to unplug any device not directly needing to be on at the moment.

We switched to using the microwave and counter top oven as much as possible.

cowboyro
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join:2000-10-11
CT

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An undersized unit will not cause large bills - it runs longer, but uses less energy. If it manages to cycle once in a while during the hottest days then it's properly sized.
Running the unit with the thermostat at 78 vs 75 at night doesn't save much unless it is a very hot and humid night. Your largest expense is by far during the day.
JoelC707
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join:2002-07-09
Lanett, AL

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That's true on the stove/oven. I have a toaster oven that I try to use if the item can fit as it doesn't dump out the heat of the big oven. I do have a couple of those inductive cook tops but I sometimes have 3-4 eyes on cooking dinner so I would still need an eye or two on the stove. I also have an electric skillet that gets used too so theoretically I could possibly do all the work without the main stove/oven depending on the meal. The downside to that is there's only two circuits in the kitchen and the bulk of the counter space has just one of those circuits and it has been known to trip when multiple things are on at the same time. I also like putting stuff in the crock pot and letting it cook all day (also helps with the rush of cooking as half/all of it is done during the day lol).

DKS
Damn Kidney Stones

join:2001-03-22
Owen Sound, ON

DKS to averagedude

to averagedude
said by averagedude:

You might want to keep track of how much you're using the electric stove top and electric oven. Those two items can burn lots of KW.

Every KW of electric heat produced because of the stove/oven is a double whammy because then the AC has to turn around and reject that heat to the outside. Basically, you're paying to twice to cook your food.

This is why God invented barbeque.
JoelC707
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Lanett, AL

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said by guppy_fish:

Bottom line is you have allot of people which all adds up to your usage. The only thing that you can do for free to lower you bill is hand out the hat or send some of the "guests" packing ...

Oh yeah, I figured all the people here would add to that. If the people in the camper went, so would two inside the house. That would mean we'd be down to just 6, maybe 7 people here. I'd be surprised if the bill didn't cut in half with that kind of drop in load. And trust me, the hat gets passed around for contributions to the household bills (they all live here, they can all contribute).

The downside is there's only two of the people here that have a decent paying job and it takes everything they both have (and then some) to cover all the bills. And if push comes to shove, my fiance and I (we're one of the two with the good paying job) are technically considered "guests" so it's beneficial for all parties to stay put (that's not to say we don't want out on our own, its just not in the cards right now).
JoelC707

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I do that too when possible LOL

nunya
LXI 483
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join:2000-12-23
O Fallon, MO
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I have to agree that one of the "biggest losers" would be an attached camper / rv. They aren't very efficient. Especially for full time use.

2nd, a big problem I notice with doublewide trailers is leaking ductwork. If you can get underneath, you might want to follow the ductwork and feel for leaks.

As far as insulation goes, trailers are usually insulated as much as they can be. There's not much you can change except maybe the underside (probably the least benefit).

All that said, with that many people in your household, I think you are pretty much screwed. Your usage doesn't seem all that outrageous when you consider that factor alone.

To save money, turn up the thermostat and kick some people out. Start charging lot rent to campers / rvs.

Doctor Olds
I Need A Remedy For What's Ailing Me.
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join:2001-04-19
1970 442 W30

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Re: [HVAC] Air Conditioner ideas, re: large power bill

Look into this as a possibility.

»www.comfortcover.org/htm ··· _us.html
tomupnorth
join:2005-01-14
UpperMidwest

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said by JoelC707:

I keep the AC in the house set at 78, the AC in the camper is set about 75 or so. During the night I'll bump the AC in the house down to 75 usually because it'll sit at about 76/77 and never kick on all night if left at 78 and it gets quite humid in the house.

Your power bills are absolutely to be expected; no doubt about it IMO. If you can't-or-won't throw anybody out, your best bet is to insist on 80 during the day and 78 at night (for sleeping) and that should go for the camper also which (like your doublewide) has completely inadequate insulation--I'll bet their AC runs all the time.

Ten people, 7 computers and 5 TVs-with-cable-boxes. Are you kidding? In a doublewide? You're not kidding....

No hope, no hope at all. Sorry.
JoelC707
Premium Member
join:2002-07-09
Lanett, AL

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JoelC707

Premium Member

No, I wish I were kidding LOL.

Without getting into too many unnecessary details, I'm essentially a "guest" here as well because the place isn't in my name. There's no way I'd get thrown out because I (well my fiance, and she would go with me) brings in half or more of the household's income. It's the others with low paying jobs that want to mostly focus on themselves and not the household bills that should go IMO but that's neither here nor there as there's nothing I can do about it.

The camper's AC does cycle but I'm sure not much. I guess since this is SOP with this many people there's not much I can do about it then. Especially since I can't easily do much to combat the insulation issues with either of them. Although Doc's link is pretty interesting. The roof will likely need to be replaced and we were leaning towards tin (a light color to help reflect) and we could easily put down those insulation sheets between the existing asphalt roof and the tin. It's an idea for sure but I have no idea when we will get to it.

TheTechGuru
join:2004-03-25
TEXAS

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Re: [HVAC] Re: Air Conditioner ideas, re: large power bill

said by chamberc:

That's pretty normal. We have 4400 sq ft home, 2 adults, 2 kids, a pool (4 pumps) and 3- 3 ton 12 year old units. Last month, here in Dallas we had a very normal summer, and we used 5600 kwh. Normally leave the thermostats on 74.

Too bad the OP can't get TXU Free Night's where he lives. You probably can though.
TheTechGuru

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said by JoelC707:

said by averagedude:

2. Do NOT use HEPA type pleated filters on your AC. Please use the 50 cent cheap throw away type that only block stick twigs and branches. The restriction of air flow from pleated style filters will have a large impact on the efficiency or the AC unit.

I don't, I bought an entire box of the cheap filters for it. It does take two filters that are annoyingly different sizes. One is 16x20, the other is 20x20. I also vacuum off the door and such and try to keep that entire area as clean as possible in a (likely futile) effort to keep the filter clean longer.

If this is what you have been doing then your coils are probably clogged. Spun fiberglass filters do not filter enough to keep the coils clean. (After having your coils professionally cleaned) I suggest using the cheapest pleated filter you can find, no need for the fancy ones that do actually block airflow.

You have a total of 720 square inches of filter surface area, if that is not enough for your a/c unit with a pleated filter then you just need to increase the size of the intake to allow for even bigger filters or add another intake and filter.

Corehhi
join:2002-01-28
Bluffton, SC

1 recommendation

Corehhi to JoelC707

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Re: [HVAC] Air Conditioner ideas, re: large power bill

I'm thinking a good clean of the AC inside and outside along with checking if it's charged up might be well worth it. Also as someone else said I would look at all the duct work and make sure it's sealed. Easy DYI.

Had a neighbor whose bills were threw the roof and the first problem was his system leaked at just about every joint. Easy fix with mastic. He added another intake in his living room which dramatically made a change in the air temps in that room. He was turning down his thermostat too make up for the living room being full of people every night, to make it cool enough. The intake that was added made a large difference in the air circulation in that room allowing him to turn up the thermostat. He also put thermo tint on two skylights and added an attic fan. In the end he dropped his power bills during the summer by about a quarter. Well worth the money he spent, almost an instant return.
JoelC707
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join:2002-07-09
Lanett, AL

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Re: [HVAC] Re: Air Conditioner ideas, re: large power bill

said by TheTechGuru:

If this is what you have been doing then your coils are probably clogged. Spun fiberglass filters do not filter enough to keep the coils clean. (After having your coils professionally cleaned) I suggest using the cheapest pleated filter you can find, no need for the fancy ones that do actually block airflow.

You have a total of 720 square inches of filter surface area, if that is not enough for your a/c unit with a pleated filter then you just need to increase the size of the intake to allow for even bigger filters or add another intake and filter.

I'll have a look at them shortly and take a pic to let you guys see. I don't think they are clogged but it could be something I have missed honestly.
JoelC707

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Re: [HVAC] Air Conditioner ideas, re: large power bill

said by Corehhi:

Also as someone else said I would look at all the duct work and make sure it's sealed. Easy DYI.

Had a neighbor whose bills were threw the roof and the first problem was his system leaked at just about every joint.

Most of my duct work is up inside the floor joists behind the fiberglass and plastic barrier underneath so I can't check that. What I can check is the crossover from one side to the other, I have seen where that can leak (this is one reason why I do NOT want a trailer for my house no matter what, no access to anything and it's all built with the cheapest materials possible).
said by Corehhi:

He added another intake in his living room which dramatically made a change in the air temps in that room. He was turning down his thermostat too make up for the living room being full of people every night, to make it cool enough. The intake that was added made a large difference in the air circulation in that room allowing him to turn up the thermostat.

Most of the larger spaces have two exit vents but the bedrooms (except for the master because of it's size) have only one vent. The downside is there is no ducted return. I know this means we have to leave the doors open to actually get circulation and if we do "close" the doors, there is generally a shoe or something propping it open so it isn't closed all the way.

I did close off the damper on one vent in the living room. This vent is right against the wall just a few feet from the thermostat. I closed it off so the thermostat didn't pick up the localized cold air and turn off prematurely.
said by Corehhi:

He also put thermo tint on two skylights

While I don't have skylghts, with the lack of shade on the house, I've given serious consideration to tint or foil or some other kind of heat resistant barrier in the windows. I'd prefer tint as we do like to use the windows for natural light during the day instead of turning on the electric lights. I did have someone give me a single "room darkening" blind, the dark brown kind instead of the white one. Yeah that thing SUCKED, it literally melted the next day and you could smell it melting every day.