Author Topic: Off Grid (Read 44120 times)

Volvo farmer · « **Reply #33 on:** March 17, 2010, 05:02:47 AM »

You just wire it into the inverter and the inverter does the rest. My Outback switches from Generator/charging/pass-through to batteries with nary a hiccup. Nifty stuff. Go download the Outback manual and have a read.

ghurd · « **Reply #34 on:** March 17, 2010, 05:30:57 AM »

That 300 gallons may not be so bad.

Most of the plumbed bush cabins I stay in have 100 gallons, gravity pressurized. Seems like plenty of water for 4 people for a day, except for showers.

Only takes once to remember to run the (gas Honda) pump before a shower!

http://www.fieldlines.com/images/scimages/2050/ImpWater.jpg

If the solar is minimal just for maintenance, the generator will be run regularly. Fill the tank then.

The pump won't factor into the inverter.

Something I keep thinking about is the 12KW generator running long enough to get past bulk, and into float. That takes a while.

Not sure if something like this would be up to the task. It could be economical.

Gas motor, reworked car alternator,

http://www.fieldlines.com/story/2009/6/26/223425/021

That 1200W 600CFM fan still bothers me.

G-

stevend · « **Reply #35 on:** March 17, 2010, 05:57:07 AM »

To further clarify what Volvo Farmer said, the Outback/Magnum/Xantrex off-grid inverters have battery connection, AC output to load connection and AC input from generator or grid connection. When the generator is off, i.e. there's no AC input, the inverter will convert DC from the batteries to AC (called inverting) and send it to the loads via the AC output connection. When the generator is on the inverter will see it on its AC input connection and use some to charge batteries as needed and some it will pass thru unchanged to the loads via the AC output connection. This detecting of AC input is done automatically by the inverter and the switch over from inverting to pass thru and vice versa is done so quickly that the loads don't notice. Here's a link to a single-line diagram:

http://rimstar.org/renewnrg/sptypes/sptypes_offgrid.jpg

-Steve

http://rimstar.org/renewnrg

Airstream · « **Reply #36 on:** March 17, 2010, 08:12:04 AM »

I think twice during my membership here I've gotten eMail updates.

redoverfarm · « **Reply #37 on:** March 17, 2010, 12:25:11 PM »

Stevend

Thanks for the link. I may decide to go with a very minimal PV panel later for nothing else but to keep the batteries charged and lessen the run time on the genset. Now I am totally over my head as if I wasn't before. What would be the basic panel and approximate cost?

I wasn't sure if the inverter would actually charge the batteries or whether I would have to go with a stand-alone charger.

stevend · « **Reply #38 on:** March 18, 2010, 12:26:15 PM »

Here are the numbers you gave above:

27055.6 Correcrted Watt hrs per week of AC load

1127.317 Amp Hrs per week

10.42 Amp hrs per week DC load

1,137.73 Amp Hrs per week of AC/DC totals

162.53 Daily Amp Hrs Used

702.14 Amp Hr capacity per Batteries.

Do you have a link to where you found this? Or you could upload the spreadsheet you filled in by clicking on your username and going to your Files section. Then we can all look at it. One thing that's missing is your largest power use at any one time. That's a factor in selecting an inverter.

It looks like you gave it both AC and DC loads.

It looks like your total weekly usage is 27055.6 watts of AC loads and a system voltage of 24 volts. 27055.6 watts / 24V = 1127.316 Amp Hrs per week for the AC loads.

It looks like you gave it 10.42 Amp Hrs of DC loads, which when added to the above 1127.316 Amp Hrs gives 1137.73 Amp Hrs per week of combined AC and DC loads. 1137.73 Amp Hrs per week / 7 days per week gives 162.53 Amp Hrs per day.

I'm not sure what how the 702.14 Amp Hr capacity per batteries was calculated but I'm guessing it was something like the following...

You told it that you wanted 2 days of battery storage.

162.53 Amp Hrs x 2 = 325.06 Amp Hrs.

You don't want to discharge your battery bank past 50% of its capacity. Doing so shortens the life of the batteries. The less you discharge them the better. But this means you need twice the capacity (for a maximum 50% discharge.)

325.06 Amps Hrs x 2 = 650.12 Amp Hrs

Then they probably added an extra 10% or so for inefficiencies to get 702.14 Amp Hrs.

I would have just added 25% off the top to your needs instead of counting individual inefficiencies - a pretty standard industry practice - but that's fine.

Volvo Farmer had recommended Eight T105s (8 T105 Trojan Plus batteries, I'm guessing it's the Plus version). They are 6V each and 225 Amp Hrs capacity. For a 24V system voltage you'd need 4 in series to get to 24V, but that would be only 24V and 225 Amp Hrs. Series means connecting positive to negative and that voltage adds but Amp Hrs stays the same. So to increase the Amp Hrs to what you need, you'd need to connect 3 of these series strings in parallel (positives to positives, negatives to negatives.) When connecting in parallel the voltage stays the same but the Amp Hrs add. So 3 x 225 Amp Hrs = 675 Amp Hrs. So for 2 days of storage your battery bank would consist of 12 batteries (4 x 3) giving a total size of 24V, 675 Amp Hrs. That's a little less than 702 Amp Hrs but this is all pretty abritrary since you have a 12kW generator always at hand.

You can shop online for the price of T105 Trojan Plus batteries to get an idea of cost. Alternatively you could go for fewer larger batteries.

So you'll arrive at your cottage and turn on your generator first thing. You'll then turn on the pump to get some water. The inverter will see the generator power and pass through power to whatever loads need it. At the same time the inverter will start charging the batteries. They will be partly discharged from the previous weekend and have lost some charge during the week (about 2% per day at room temperature, more if colder.) Remember, we sized the batteries according to your needs to use up 50% during 2 days. The inverter will Bulk charge for a while, then go into Absorb charging for an hour or two. This gets your batteries up to about 80% state of charge (80% x 675 = 540 Amp Hrs.) As batteries get more and more charged, the less current can be pushed into them. So the inverter will go into Float charge mode where it is using a tiny fraction of the generator's output to charge up that last 20%. Depending on how discharged the batteries were this whole process could take as long as 6 hours. With the Outback you tell it how long to stay in Absorb mode and how long to stay in Float mode. I don't remember for Magnum.

Another consideration is that a discharged battery in below freezing temperatures will crack as the water turns to ice. A fully charge battery will not freeze. So what will you do during the winter? Without a solar system to keep the batteries topped up all winter, you'll have to take the batteries home. An alternative is to install an Automatic Generator Starter (there's one built into the Outback, but there are others, Magnum has one and there are standalone ones) where the AGS will start the generator as needed to keep the batteries charged. I wouldn't trust it to work all winter though.

-Steve

http://rimstar.org/renewnrg

PS. Sitting here getting over a cold. Oddly enough, writing all this works well so I kept going. :-)

redoverfarm · « **Reply #39 on:** March 18, 2010, 01:30:53 PM »

Steve

I appreciate your time and effort. As I stated in the beginning this is completely over my head. Give me a saw, nail, hammer or stone anyday and I am fine. Anyway to address some things you brought up.

First off this is what I used. I found a "PV System Calculator V2.1.1.xls Microsoft Spreadsheet". I am not even sure I did it correctly but it was the best I could do. I didn't save it and in fact when I printed it only half of it printed and I had to go back and hand write some of the figures.

The DC load was on the surflow pump if that makes the difference. I guess I could use it under 110/120 but thought it would be more efficent in DC.

What you are asking concerning what my use of the power will be. Honestly I have no idea as it will just be a weekend retreat for family or friends. I was just trying to guesstimate what might be used and how much. If anyone knows there way around these spreadsheets I could supply the information needed ( I think?).

Where I am situated is in gods country so to speak so the availability of these components including batteries would probably have to be shipped in. The closest Walmart is 45 min drive and that is about it unless I drive 2 hours. I did check with a repair shop that I deal with and this is what he can get regarding batteries. I can check on the Trojans and see if he can get them.

L-16 216 Amp Hrs $228

U-24 Golf Cart 154 Amp Hrs $146

Another Golf Cart with 109Amp Hrs which was not recommended for $128.

I am somewhat familar with the price of Batteries today as I had to get one for my truck. Ouch!! $134 for one. I replaced the other last year.

I am sorry if I made it sound like I would just vacate the cabin for the winter months. In fact I can make it to the cabin if I plowed the road. I did it 7 times this year and made it up everyday. But with the type of heat that I have I would be worried about it freezing during the winter months thus just drain it and wait til spring. Unless there would be a break in the weather for a week or so. Didn't happen this year as we got over 210" of natural snowfall. So maintenance would not be a problem periodically during the winter to run the generator and charge the batteries.

Thanks for your time and

Hope you get over the bug.

John

wpowokal · « **Reply #40 on:** March 18, 2010, 05:00:18 PM »

Steve 2&/day self discharge seems a bit excessive?

allan

stevend · « **Reply #41 on:** March 18, 2010, 08:13:54 PM »

Allan, 2% is what I was told by a fellow who ran a local Interstate battery place for over 15 years and solar for around 15. Maybe I remembered it wrong? Anyone have a different number?

-Steve

http://rimstar.org/renewnrg

ghurd · « **Reply #42 on:** March 19, 2010, 05:28:52 AM »

I recall 2% being a standard number for calculations, though I believe the real self discharge is a lot less.

If it is figured at 2%, then they certainly will stay fully charged without use.

Of course that is around a 50~60W PV for each pair of T105s.

Sam's Club or Costco has T105 equivalent batteries for around $70 each.

Interstate is considerably cheaper than Trojan, but a lot more expensive than Sam's or Costco.

I have not had any trouble with the Sam's batteries (never tried Costco, none local).

Considering a 48V system takes 8 6V batteries, a Sunday drive to Sam's could save $600.

Might want to call ahead. Sometimes they don't have 8 in stock.

Check the date stickers and terminal voltages.

G-

stevend · « **Reply #43 on:** March 19, 2010, 07:50:58 AM »

G, Volvo,

What are you guys using for battery bank capacity if you are suggesting a 48V bank with 8 6V batteries? My understanding is if the batteries are 225AHr each then that's a 225AHr battery bank - all 8 have to be in series to get 48V from 6V batteries.

But starting with 27055.6 watts/week AC, 27055.6/48V=563, 563+10.42=574, 574/7=82AHr per day, 82*2 days*2=328AHr, 48V battery bank size needed, not taking into account inefficencies. Or do you think his needs are actually less?

John, in case the different AHr confuses you, G and Volvo are talking about a 48V system and your spreadsheet used 24V. 48V*328AHr=15744 watt hours and 24V*700AHr=16800 watt hours, which is about the same. The former doesn't have inefficencies included.

I calculate about the same amount of PV to make up for self-discharge. I used 4 hours of sunlight per day average but that is a guess since I don't know where his cottage is.

-Steve

http://rimstar.org/renewnrg

ghurd · « **Reply #44 on:** March 19, 2010, 08:32:44 AM »

I figure it's in WV.

I considered the peak loads.

The 1200W microwave and 1200W vent fan.

At 24V, that's pulling close to 100A out of 190~225AH batteries. I have a feeling the inverter could go LVD well before it should with that kind of high %.

At 48V, it's only about 45~50A, which I could live with even if I didn't like it.

Also, many US-based guys with large 24V systems wish they would have went with 48V at the start.

Could stay 24V with larger batteries, or PITA parallel, but 'bang for the buck' goes to 48V and T105s IMHO.

John- The quote for "L16 216AH $228" is considerably off track somewhere, and sounds like T105s.

L16 is 325AH or 370AH.

T105 is about 200-220AH, which is the type Sam's sells for $72.

G-

Volvo farmer · « **Reply #45 on:** March 19, 2010, 09:37:52 AM »

I gave him the advice based on my own experience, his stated loads, and the seat of my pants. I think his calculations came out to over double what he might actually use. I have an electric refrigerator, small chest freezer, 40" television, satellite receiver, washer/(gas) dryer, EVDO wireless router, 3 laptops and the wife uses a hair dryer most mornings. We don't usually use more than 5KWhr/day including inefficiencies.

I'm rarely more than 1/4 discharged into my eight L16s with daily recharge. I think the OP could get by on a set of golf cart batteries and be less than 50% daily discharged. He might have to run that generator every single day for a few hours, but if he buys Sams batteries like Ghurd suggests, he'll only be $600 into batteries, and that is a good thing, since he's likely to be pretty hard on them IMHO.

redoverfarm · « **Reply #46 on:** March 19, 2010, 04:30:54 PM »

OK Everyone now that you have gotten me completely confused. What is the advantage/disadvantage of either 24V/48V. I want to minimize the generator as much as possible. When entering into the equation parallel/series when used with either of the above.

I will double check on the batteries. Not real sure of the manufacturer I was just getting a ball park figure. I do have access to Interstate but in IMO I really don't care for them although that is what is available to me locally. Yes I sometimes go approximately 2 hrs to a Sam's Club so the batteries would not be a problem if I can't get something locally that is comparable.

I do have a South/southeast facing cabin which appears to get a good bit of sunlight after 10:00 AM to about 4-5:00 PM. My original idea was to mount solar panels up onto the front roof until I found out how costly they were and the fact that I really didn't want to take away from the asthetics of the cabin that way. Another concern is the high snow volume. There is a retaining wall which was in the photographs just west of the original cabin which would be suitable to mount at least one and not do that much in the way of how they appeared.

GHRUD

I really wouldn't concern myself too much with the microwave and the fan. Both of which will be used very little. BTW how much power is used to heat a cup of coffee for 60 seconds. No real stainable use by either appliance.

VOLVO (BTW Nice car I have had one since 2004)

As far as the spreadsheet like I said before I am not confident that the information was accurately placed in the apprioate catagory but being unfamilar with certain catagories and whether they apply or not I am not certain. If anyone wants to take a stab at it based on my info then let me know.

I have learned a great deal from the discussions and am learning daily. Maybe when it comes time to "get r done" I may have at least mastered the basics. Hope this clarifies some things.

Thanks again.

ghurd · « **Reply #47 on:** March 20, 2010, 11:51:28 AM »

Watts is Amps x Volts.

A 24V system uses twice the amps for the same watts of load.

With that 2400W, simplified but close enough,

A 12V system must supply about 200A.

A 24V system must supply about 100A.

A 48V system must supply about 50A.

The 'amps per battery' can be reduced by paralleling more batteries, or seriesing more batteries for a higher voltage.

(disclosure of prejudice- I am anti-24V in the US and Can.)

If the peak load that was a lot less, I would go 12V and parallel more batteries.

With a regularly occurring load like 1500W or 2400W, I would skip 24V and go straight to 48V.

Need to consider the peak load.

I realize the worksheets do not usually mention that.

Poor example, but the best I can think of.

My wife's 4-cyl car's starter uses about 40~50A. For about 1/2 a second.

That's 45A x 12V / 120 = 4.5 watt-hours.

A 9V Energizer alkaline "smoke alarm / transistor radio" battery can supply 10ma (0.01A) for 60 hours.

That is 5.4 watt-hours.

A generic chart, if twisted the right way or incorrectly interpreted, insinuates a 9V battery will start a car with power to spare.

I could argue 24V is fine with larger batteries, like L16 or L16HC. But that's a lot of battery to start with.

VF, You run 24V? Do you wish you went with 48V?

TomW, You run 24V? Do you wish you went with 48V?

G-

TomW · « **Reply #48 on:** March 20, 2010, 02:30:59 PM »

TomW, You run 24V? Do you wish you went with 48V?

YES

The inverters were kind of rare when I upgraded from 12 volts.

Starting at 12 volts was the dumbest waste of effort and resources IMHO.

Just my opinion.

Tom

stevend · « **Reply #49 on:** March 20, 2010, 05:18:59 PM »

G,

Funny you should say that an L16 is a lot of battery. I usually work with Surrette S-460 (460AHr), S-530 and larger and a minimum of 4 but usually 8. The only time I've worked with smaller was a recent job with Trojan T105 Pluses (225AHr). I agree, pulling 100A out of a 225AHr battery, or even two, is too fast.

-Steve

http://rimstar.org/renewnrg

Volvo farmer · « **Reply #50 on:** March 20, 2010, 06:29:15 PM »

VF, You run 24V? Do you wish you went with 48V?

Yes. I run 24V and also wish I went 48V. Once I gave up the DC loads pipe dream, the whole concept of 24V became silly. It works just fine, just is harder to upgrade and add panels/batteries etc because of bumping up against current limits on equipment. A single string of batteries would equalize better too.

redoverfarm · « **Reply #51 on:** March 22, 2010, 09:48:04 AM »

Alright from what I am reading the preferred is 48 volt. Wired in parrallel or series?

Now the preferred battery 6 volt. I take it that 6 volt would be better suited for the continual charging cycles as well as the draw down. So in essence a T105 at Sams is approx $70. I would need 8 total for a 48 volt system.

OK given the information that is available to you and the premise that I will go with a 48 volt system what would be the recommended inverter size. 2500-3000Watt or higher? Now I am going to ask which is best or what you recommend brand wise, price, ease of use, reliability. I know it is sort of like asking which is the best Ford or Chevy? Give it your best shot. You have to understand that I am simply dumbfounded in this area so bare with me. Any recommendations are just that. The ultimate decision will be mine. Just from what I have gathered in this group and outside it appears that Outback, Xantrex and Magnum are the preferred brands.

Thanks again

ghurd · « **Reply #52 on:** March 22, 2010, 10:53:50 AM »

"Wired in parallel or series?"

You lost me on that. I figure the answer is in series.

Do not underestimate the power 8 T105s can store, if properly charged.

Can feel it quantity of power in the lower back as the last one is loaded in the truck.

The size of my 'inverter' is a pretty personal question! (sorry, couldn't resist)

I'd recommend something bigger than the first thought, simply because when you see how well it works and expand the RE (you will), the wife/kids/friends/yourself will add more loads.

A bit of experience watching the volt meter and use-it-when-you-got-it mentality will let you run the pump for a few minutes every so often, with minimal impact to the battery charging.

Once you are playing with the big boys, a few more watts is usually not a big jump in cost (I did not check current prices).

My vote on Ford/Chevy debate is indecisive, except to semi rule out newer Xantrex in favor of either Outback or Magnum.

Seems like once you make it to this size class, any of the 3 are good solid units.

Just make sure it has a genuine brand name on it (as opposed to some generic wonder product on ebay), and a UL sticker always makes me feel better.

Seems like I recall someone having issues with one and it's internal charger having issues with a generator, and someone mentioning certain chargers are not completely compatible with input from some generators.

Very interesting thread.

G-

ghurd · « **Reply #53 on:** March 22, 2010, 11:29:56 AM »

Another twisted opinion from me, because I usually work with much smaller systems.

For now, Minimal RE in John's system will require the gennie to run everyday, mostly.

Which arguably takes the 2 day required capacity down to 1 day, or an un-good 12 hours.

The intermittent microwave drawing for 45 seconds is OK, but the 1200W fan will be more than a minute (that fan has to go!).

Cost on the 'Sams batteries' is about $600. Say those are toast in 2 or 3 years...

Cost on 2 parallel sets or replacements is $1200.

Total is $1800.

Which the total cost is Still about $600 less than a set of L16s.

And 2 pairs of Sams 6V is more capacity than a set of L16HCs.

Seems like a winning proposition. Especially for a 1st set of learning batteries, and a 2nd set of double capacity parallel replacement batteries.

John- Don't take them below about 12.2V for more than a few minutes, and they will give great service. Pretty sure a set at the shop is about 7 years old and still OK, and horribly abused for 3 months in the winter. They are paralleled with some newer batteries so their actual capacity is not quite clear.

Imagine how well they would work if NOT horribly abused!

G-

redoverfarm · « **Reply #54 on:** March 22, 2010, 01:27:41 PM »

Ghurd

Thanks for the reply. I was wondering which particular model would best suit my needs. It seems like in Chevy & Ford (couldn't resist)there is multiple models to choose from. The outback and Magnum has what they refer to a vented, sealed, grid tied and mobil.

I noticed that some offer either pure sine or modified. If it is my understanding some appliances will not operate properly off of modified. But then again the pure sine is considerably higher in price.

Specifics would be nice to narrow the field and make the search less a PIA and ultimately eliminate alot more posting and replies. Shoot if you even want a disclaimer that's permissable. Ha.

Thanks again

Volvo farmer · « **Reply #55 on:** March 22, 2010, 05:19:58 PM »

If you're ready to spend, I'd call a few places that sell the stuff and start fishing around for recommendations. When I bought my system, I found a guy with lots of experience that was willing to spend 40 minutes on the phone coaching me because I was spending six grand with him.

redoverfarm · « **Reply #56 on:** March 22, 2010, 07:36:42 PM »

VF that is actually what I was trying to avoid. Without some imput from experienced people as yourself. I don't like to approach this empty handed. I would never take a knife to a gunfight. Yes haggle for a price I can do but depending on a salesman who's ultimate goal is to sell his product to tell me this is what I need. Is it really or can I get by on something else that he fails to mention.

BTW is it the way I am "replying to this post" causing it to appear elongated. I thought that if I posted it as a "parent" post it would move it up under my original and take it out of sequence.

stevend · « **Reply #57 on:** March 23, 2010, 08:02:52 AM »

I've already stated I don't know the Xantrex inverters well. Of the Outback and Magnum, I've already recommended the Outback and said why. Of the Outbacks, Sealed is for if the inverter is outdoors though it can be used indoors too, Mobile is for a motorhome or boat, Gridtied is if you're on the grid, so that leaves the Vented versions, VFX, which is what I usually install in cottages.

The first step in selecting an inverter is how many watts it must put out. For that you need to figure out what time of day you use the most power. Add up all the loads you'd have on plus add anything that might spontaneously turn on (you're cooking and you turn on the tap which may cause the pump to come on) plus phantom loads (things that are always on) such as a clock on a microwave, a TV which uses power for quick start up when you turn it "on", ...

Then you realize you can't afford such a big inverter and you change all your incadescent lightbulbs to compact flourescent lightbulbs.

1100 watts of lighting. That is a total but only a portion will be used at one time.

9.8 amp 110/120 well pump

1100 watt Microwave

2- exhaust fans. One is a bathroom exhaust and the other a 600CFM kitchen fan

1- Sure flow DC pump

3- ceiling fans

So of the above, let's guess that when you're cooking is the time you're using the most power. At one time you might have:

1176 watt well pump (9.8 x 120)
the 1100 watt microwave or 1200 watt exhaust fan but not both
445 watts from your 7-65 watt kitchen incadescent lightbulbs
130 watts from 2 other lights elsewhere
20 watts for the inverter

Total: 2971 watts

This also assumes you won't turn on the ceiling fans or the bathroom exhaust fan while cooking.

Since you're going with a 48V battery bank, of the Outbacks there's the sealed FX3048 and the vented VFX3648. If you change your lightbulbs to compact flourescent, say 20 watts each then you can chop off 405 watts ((65-20)*9 bulbs)

and you're into the FX3048.

-Steve

http://rimstar.org/renewnrg

PS. I clicked on "Post a Comment" at the bottom of the page.

TomW · « **Reply #58 on:** March 23, 2010, 08:43:46 AM »

Just in case folks missed this bit:

With a Mate and a Hub Outback units can be stacked, either for more parallel power or more voltage like powering a deep well 240AC pump.

This means you can buy a smaller unit initially and stack another if / as you need it.

Their gear is built like the proverbial brick outhouse. I know people personally who have had excellent warranty service even from failures that could have been considered "Acts of God" more than equipment failure.

Others may do this as well but I only have Outback equipment myself.

Just FYI.

Tom

redoverfarm · « **Reply #59 on:** March 26, 2010, 04:59:46 AM »

Thanks to everyone who posted to my thread. I plan to actively gather all my components the 2nd week of April. Let the fun begin.

Steve BTW I will only have about 102 watts in the kitchen lighting as they are all tube lighting. I will try to change what lighting I can to CFL's where possible. Some of the fixtures uses the smaller candleabra bulbs and there is not sufficent room for the cfl's.

I am sure that I haven't covered all the bases and things will come up that I hadn't anticipated but I will work through them.

I am sure that I may re-visit to seek a little more guidance or let you know how I am getting things going.

Again Thanks.

John

DamonHD · « **Reply #60 on:** March 26, 2010, 08:22:35 AM »

I have a couple of low-power (LED and CFL) 'candle' bulbs with a 14mm ES fitting, if that's what you mean.

Rgds

Damon

REdiculous · « **Reply #61 on:** March 26, 2010, 11:10:13 AM »

The 1200w 600cfm fan bothers me too...

My brother's got a 130w, 12v DC squirrel cage blower that moves 250cfm. With 1200w we could run 9 of these blowers. Nine! That's 2250cfm...or roughly 3.75 times more air w/ the same power.

Besides that, I suspect that you could over-volt the blower and get even better results...if you don't plan to run the blower for extended periods of time that is.

Seriously...that fan is terrible.

REdiculous · « **Reply #62 on:** March 26, 2010, 11:26:42 AM »

Damon, where'd you get those? We've got incandescent bulbs in our chandelier because I can't find cfls to fit. It would be nice to use the chandelier more often. tia

ghurd · « **Reply #63 on:** March 26, 2010, 11:59:36 AM »

It is Worse than terrible!

Not exactly Apples to Apples, but 1HP = 746W.

Who knows where they get the 1HP rating on some items. Either the shaft output, the power input, locked rotor input, etc.

Anyway. 1HP (746W input?), 48" dia, 20,679CFM. 40% less power, over 34X the CFM.

http://www.northerntool.com/shop/tools/product_200226074_200226074

A newer cheapie 20" box fan is around 150W now, and around 2,000CFM.

The old ones were around 400W.

I am wondering if the blower motor is an old 6-coil 1100RPM multi-speed type.

A newer, more efficient, fan would pay for itself in short order. Maybe instantly (in inverter cost).

Or how about a Comair Rotron Diplomat #039870? 625CFM, 24VDC, 83.5W. ($250!)

Not exactly what I would buy given the cost of both, and other/better options.

It only shows efficiency matters.

CFLs are available with candelabra bases. I bought some at a Big Box store a few years ago. 5 and 7W? They were junk. CFLs have come a long way in the last few years. Maybe the new ones are better.

If not, there are 'adapters'!

G-

REdiculous · « **Reply #64 on:** March 26, 2010, 01:18:05 PM »

Your first example is a bit expensive, no? $1800...wow. But it does prove the point.

I'm not sure cheap box fans are really comparable to blowers though. Cheap fans might move 2000cfm but only when there's zero back-pressure. The box fans in our windows slow down considerably whenever the wind blows through them, for instance.

I guess I haven't looked for cfls w/ a candelabra base in years. Adapters won't work..standard bulbs are just too big for our chandelier.

DamonHD · « **Reply #65 on:** March 26, 2010, 01:30:37 PM »

Hi,

Both are Philips bought some years apart at our local John Lewis department store in Kingston as it happens (8W CFL at least 2 years ago and a 2W LED recently), eg see in this selection:

http://www.johnlewis.com/Electricals/Lighting/Lighting+Accessories/Light+Bulbs/3758/ProductCategory.
aspx

and do a show all to see both ES14 LED and CFL bulbs.

Does that help at all?

Rgds

Damon

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