Hi efficiency HVAC

[Tom Tee]

Want to do a retro HVAC for my new digs. Last house had twin American Standard two speed variable speed 14 seer HVAC units installed in 2000.

Whats the best thing going today? Know of a JB quality site for info?

Also need to do a insulation upgrade. Want to foam in the hollow between the plaster and block. Ideas? Websites?

tt

[Sponsored Links]

[sandbagger]

a word of caution - the high-efficiency furnaces are generally quite noisy. Make sure you're not installing one near your bedroom.

[bamadave]

Tom, check out www.waterfurnace.com for one of the best geo-thermal systems on the market. Like most items that are considered the best, they are also the priciest. I had the system installed in our new house in 2002, it cost about 50% more than the conventional heat pump system and have already been paid back the difference in utility savings. Alabama Power told me in 2002 that with a heat pump the utility cost would exceed 700.00 a month. ($350.00 x 12= $4200.00 x 5 =21,000 savings in 5 years) My house is 7000sqft and levelized billing is 350.00 a month. Also a 10 year parts and labor warranty is part of the deal.
The bonus of this system is it can also preheat much of your hot water further decreasing your utility cost.
My insulation package consists of sprayed foam in the attic (no fiberglass) and sprayed cellulose in walls. This package of course is complementing the hvac system in making the house more comfortable.
If I ever build another house (which I doubt), The first thing I would do is plan on installing another Water Furnace System, and no they aren't paying me for this endorsement. I have better things to spend my money on other than giving it to the utility companies. You can pay now or more later, the choice is always ours to make


Dave

[Tom Tee]

Sandbagger,

The noise issue must be subjective.

After I first had my American Standard 94% units installed I called the contractor as soon as I turned them on. I told him they were not working, I did not hear them kick on.

He instructed me to stand over a floor register. I did, I was embarrased.

I have a third hi efficiency unit in another part of the home. Armstrong. That one is a contractor grade and it is noisey.

Dave,

Gotta look into the waterfurnace. Just got my first gas & electric bill. $394.00!!. Seems that Delaware just left 10 years of price control and they are making up for lost time. These new prices will make paybeak of any unit a quick payback.

Thanks guys.

tt

[LGB]

I'll second the geothermal systems. We had a Florida heat pump (http://www.fhp-mfg.com/) system installed in our new home 3 years ago and couldn't be happier. We also get a good amount of our hot water from it.

[cx]

Sandbagger,

The noise issue must be subjective. Gotta agree with Tom on that one, Art. Not sure what kind of equipment you're familiar with, but Ruud and Trane high-efficiency (14SEER&up) equipment is remarkably quiet in my experience.

I'd be looking into one of the brands that uses the double compressors in their condenser units, Tom. You can watch your 'lectric meter and swear those are not running, too. :D

I've actually pewt my current meter on one new one we installed in a remodel and called my AC guy to axe him if there was something wrong. Reading was just too low for that size unit in my experience. "Nay, nay," quoth he, "that's normal."

I've been pretty impressed with what's come out in just the last five years or so. Amazing just how much more efficient the new ones are. And they've made some great strides in the filtering systems, too, if you have anyone in the house who suffers from airborne "stuff." Don't think I'd ever pay for some of it, but I have customers who are absolutely in love with my AC contractor. :)

[sandbagger]

I think we're confusing apples & oranges here. or cool vs heat. shoulda figured as much from Texans. ;)

I'm referring to the high-efficiency furnaces, cx. The 90+ Heil we had in Michigan was noticeably noisier than our older "mid-efficieny" Heil it replaced. Our contractor actually warned us to expect more noise. I'm sure some models and even types of installations can have significant impact, and that was almost 10 yrs ago.

That said, I'll second the Trane recommendation. The first thing we did when we bought our house in AZ was to rip out the entire OEM (30-yr old) system and put in a new Trane. We opted for the dual-compresser AC system coupled to a mid-efficiency furnace. The 2-speed blower runs on low most of the time and is very quiet. You do notice when it kicks up to high on occasion, but not much. It usually drops back to low fairly quickly. My first electric bill with the old AC was August in AZ and over $270. :sick: The highest since then was a little over $150. :clap2:

[Tom Tee]

Art,

For absolute clarity, what exactly are you refering to when you say furnace? I am thinking natural gas hot air heater.

Also, heat pumps and geothermal, are they more favorable in warmer states? Financially advantageous in colder north east locals?

My early experience with heat pumps in Pa was not comfortable. Circa 1985.

Thanks folks,

tt

[Tom Tee]

OK, after reading the interesting web site I have a question, actual initial cost or price range.

My ranch is 2000+ sq ft main floor w/ fully used basement.

Looks like the grass takes a serious hit.

tt

[cx]

I try to get folks to use gas (LP) furnaces here, too, Tom, but many want only heat pumps with electric heating strip backup. I sure wouldn't want a heat pump up yonder in Yankee Land where it gets really cold for long periods. I remember growing up in Pennsylvania, totally without AC, and with wood/coal for heat and I remember never having enough of that heat part. :D

But either one is exceeding quiet, Art. At least as quiet as the AC portion. And it should be, since both are using the same air handler for distribution.

Y'all's furnaces a completely separate unit from the AC? :scratch:

[sandbagger]

interesting to see how regional differences in climate and HVAC affects this discussion.

"furnace" = gas-fired forced-air heat system. Usually a gas burner in the same box as the blower (aka, air-handler). In a "central-air" system the AC coils are in the same box, with the main compressor outside the house.

In a heat pump system there's no gas burner - you use the same coils for both heat and cool. The most common heat pump is basically an AC compressor that reverses the refrigerant flow to get heat in cool weather. you never want to use this type of heat pump in the northern climates. On the other hand, high-efficiency forced-air gas furnaces (aka, "90+") are much less common in the warmer South. At least as quiet as the AC portion. And it should be, since both are using the same air handler for distribution. yes, and no. On the system I had the air handler ran at a higher speed on the heat cycle than it did on cool. Mind you this was almost 10 yrs ago and it was a "single stage" system that couldn't adjust the fan. More money buys you the 2-stage systems that are much quieter.

[cx]

Naa, we're onna same page here, Art.

A whole lotta the noise problem in a forced air system is the result of the ducting and vents not being properly sized for the anticipated air flow. Sounds like the noisy one you had may have been designed for the lower air flow of the AC operation. Proper ducting can make a world of difference in the noise levels, no matter how efficient the components of the system are.

And some of the components are gettin' eye-watering efficient. A fella changes out an "antique" 8SEER (maybe) unit for one of the available (but still grossly expensive) 18SEER units and he's likely to think he won the lottery come electric bill time. Unfortunately, only guy I actually know who has one is the guy who owns my AC subcontractin' company. :)

[sandbagger]

A whole lotta the noise problem in a forced air system is the result of the ducting and vents not being properly sized ...wellllll,, you're prolly onto something there, cx - the house was built in 1958. Original furnace was oil-fired and there was NO consideration for AC.

bottom line is it prolly doesn't make a lot of sense to try to translate experience with retrofits in old construction with new construction where you get the opportunity to design the entire system from ground up. Not that there aren't plenty of opportunities for a creative builder to mess things up.... :rolleyes:

The only reason I don't have one of those 18-ers you mention is cuz they weren't available when I bought mine 5 yrs ago. I think mine's about 16-ish. But when you run the AC pretty solid for at least 6 months it can be worth it. I figure I've saved at least $2500 in 5 yrs over that old system. :yeah:

[cx]

Not that there aren't plenty of opportunities for a creative builder to mess things up....Spoken fluently here. :)But when you run the AC pretty solid for at least 6 months it can be worth it.Part of a rather extensive remodel I did two years ago involved changing out three HVAC systems. My AC guy did talk the customer into a good bit of bells and whistles, but the base package was 14SEER Trane heatpumps to the tune of about $27,000 as I recall. They showed us verifiable numbers, based upon his past five years' electric bills and such, and he recoups the total cost of the upgrades in something less than seven years. I spent a lot of time with the paperwork and not only couldn't prove it wouldn't work, I was convinced the estimate might be a little conservative. To date, said customer is still very happy with what he got, 'specially at 'lectric bill time. It's impressive what they can do that they couldn't even do five years ago. :)

[ITO]

http://trane.com

Trane is top of the line and can back up what they say.

The only question now is: How much money do you want to spend?

[Tom Tee]

Great infdo guys,

I understand Trane and American Standard are by the same mfg. Any real preferance?

Also, what kind of cost for geothermal systems?


tt

[sgrandjean]

I believe that American Standard might be considered the entry level units in Trane's heirarchy...slumlord replaced a 30 year-old compressor with a 13 SEER American Standard in September. Looked like a decent unit...but I don't really think it's a Trane.

My parents have four Trane compressors at their house...five years old and going strong...plus they still look like new.

Cheers.

[bamadave]

Tom, geo systems are pricey, but the only system that will save big bucks in the long run. Call and get quotes, they're free. The news today said Ingersol-Rand just paid 10.5 billion for Trane.

[Tom Tee]

This months (Dec) gas electric bill is $458. 310 for gas balance for electric.

Just got back from the Philly home show.

Three different dealers;

New 18 seer 100.000btu natural gas heater / 3 ton AC Amana replacement installed w/ existing ducts $4,500 Projected annual energy savings was $1500.

twin 15 seer 50,000 Amana w/two 2 ton AC units $7300 (Long ranch with two distinctive living areas).

Geothermol unit installed using three 250' deep well holes, $18,000. Estimated annual electric expense to run the geothermal $400.oo

Leaning to the geothermal.

Do the numbers seem in line?

tt

[Brad Denny]

Hiya Tom,
I know a guy in commercial real estate who just built his own house. He's good with numbers, knows the building trade pretty well, and is good runnin' down info on the net. I can't remember the figures, but I believe he figured 5 years to get even with a gas/electric with a geothermal.

[cx]

I don't know diddly about the geothermal systems, but just using rough math it sounds like Brad's estimate works out pretty close for you compared to that 18SEER system. Spent about the same overall at the five year point.

That 18SEER bid sounds very low to moi, though.

[bamadave]

Tom, whose geo unit were they pitching. The price of the geo looks about right, don't know about others.

[Tom Tee]

CX, Agreed! That is more like the components price only in my understanding.

Dave, WaterFurnace waterfurnace.com


Sitting here going thru the info. They push aux back-up ELECTRIC heat in case of failure. Plus use an additional heat pump system for boost in the dead of winter in it's design, they say that the cost of a large enough system to do the coldest of winters by it's self is so expensive that it pushes off investment recovery.

Sounds like it's one of those cases where the little print takes away what the big print gives you.

In my ignorance I'm getting a little chilled w/ geo.

Delware is now going thru three tiers of substantial electic rate increases. The first one was 40%.

Pennsylvania to follow suit in 2011.

Utility strategy will only get more important as time rolls on.

tt

[LGB]

Tom, our geo system was around $8500 3 years ago when we built. We have an open loop system though so we didn't need any additional wells other than 1 for water supply. Our well produces 30gpm so we had more than enough to run the system. I'd say 18k is a good price if it includes the drilling. Remember you can get a substantial amount of your hot water heating from it too with a superdeheater. We've never had the auxillary coil kick on.

[bamadave]

Tom, as mentioned before, Water Furnace is the one I had installed. Before you give up on geo, have the company give you a customer list of satisfied customers. Call them and see how others in the area like it and cost associated with it. I have 2 50 gal. hot water heaters and when Alabama Power came to the house to to an analysis on it, they claimed my hot water heaters would only cost around $100.00 year to heat because of the superheater. The system maintains + or - 1 degree in a 7000 sf house. If I had to do it over, I'd make the same decision. And no, water furnace isn't paying me to say this, lol. Oh, because of the geo, it typically doesn't require as many tons of btu to do the same as conventional systems, thus saving you more.

[Tom Tee]

Dave,

Yup, that scared me a bit. They said I would only need a 50,000 btu for my 2000 sf not so efficiently laid out ranch?????

So your suggesting maybe thats OK? Hafta get a geo guy in here.

Thanx,

tt

[cx]

Oh, because of the geo, it typically doesn't require as many tons of btu to do the same as conventional systems, thus saving you more.Gotta take issue with that, Dave.

If your house requires X BTUs to raise the temperature inside one degree, it matters not if you've got an efficient conventional system, an inefficient conventional system, a geothermal system, or if you set the couch on far, it's still gonna require the addition of X BTUs of heat to get that one degree rise.

Now, if your geothermal salesman is telling you his system can produce X BTUs of heat while consuming less energy to do it, I can accept his claim if he can demonstrate its validity in a test against the conventional heating system, which he may well be able to do. Same holds true for a comparison of cooling capability and the removal of heat, of course.

But if he claims he can raise the temperature while actually adding less heat, I'll not be able to wait long enough for his demonstration, I fear. :shades:

My opinion; worth price charged.

[Tom Tee]

CX,

That line sounds a little like the line my ISO foam sprayers used.

ISO yields an initial 7.+ r per inch of depth settling in around 6.9 W/ 5 1/2" bays I figured I'd go for the max and get 38 r with a full cavity.

The guy says ISO r value is much more than fibergalass r value. Somptin bout how air can not low through foam. HUH???

R value is r value ain't it? After some more of his gobbligook I still got 5.5" of foam sprayed.

Just do not get some sales lines.

Guess it's my ignorance.

tt

[bamadave]

Here's what I'm saying, Water Furnace claims their unit is The Most Efficient hvac system on the market. Check out their website www.waterfurnace.com
Lower Operating Cost
A WaterFurnace geothermal system operates more efficiently than ordinary heating and air conditioning systems because it can deliver an astounding five units of energy for every one unit of electrical energy used. By combining stored earth energy with safe electric power, many WaterFurnace owners realize savings up to 70% for heating, cooling and hot water.

I don't know of to many people that have a 7000sf house with power bills of 350.00/month. This is on levelized billing. With standard heat pumps, Alabama Power estimated closer to 700.

[cx]

Here's what I'm saying, Water Furnace claims their unit is The Most Efficient hvac system on the market.That, on the other hand, is a reasonable thing for them to claim.

Don't know that it's true, mind ya, but it's at least reasonable claim that your system is more efficient. The other claim would have required their system to be magic, eh? :)

[bamadave]

Well CX, it's is almost magic. Because one of the greatest benefits of the Water Furnace unit is the superdeheater hooked up to my 2 50gal water heaters, Water furnace claims that it provides 93% of the heat to the heaters. Don't know about you CX, but it's almost magic the way water heaters work without working.
CX, how much are you paying to heat your hot water? According to Alabama Power, they said my hot water should be somewhere around $25.00 - 50.00 a year. According to the stickers on the tanks, it should be closer to 480 each per year. Alot of difference between 960 and 50. An extra 910 a year to buy more power tools, whoooohoooo.

[cx]

I heat my water with LP gas, Dave, and the $50 a year would likely be in range for me if I could break it down.

'Course I don't heat but 6 gallons at a time, unlike all you wealthy folks who think a hunnert gallon shower is far too short. :D

[kate42]

'Course I don't heat but 6 gallons at a time, unlike all you wealthy folks who think a hunnert gallon shower is far too short

:x: :yeah:

[MudMaker]

tt,
I had a Lennox HSXA19 Signature Series 2 stage w/R-410A installed 2 years ago and it hardly makes any noise at'all..
Very happy with it.. I oversized the A - coil and used GM61PV series inside unit - also oversizing it..
I have a problem that way..
The DC blower starts up slow and revs to high. Shutting down the same way. No all-on starts or stops. Overall really happy with the system..

[Tom Tee]

Over size? Hummmmm, I was warned by several to have my job calculated very closely so as to maximize efficiency.

My present 80% 20 y.o. unit is way too big and short cycles.

???????


tt

[cx]

Oversizing the air conditioning portion of a HVAC system is a bad idea, not just from the efficiency standpoint Tom suggests, but the "short cycling" doesn't allow the system to remove moisture from the air as it's designed to do.

If you were gonna make a mistake in your calculated load, I think you'd be better off undersizing the AC slightly than making it too large.

My opinion; worth price charged.

[bamadave]

Tom, one more thing I like about the Water Furnace system is that the unit maintains the humidity level so well that you can adjust the thermostat up a few degrees and is as comfortable as if would be if it were set 3 or 4 degrees cooler.
And on the magic note, because of the efficiency of the unit, I got by with 3 1/2 tons where if I had gone with a standard unit, the house would have required 6 tons. I'm not driving as much equipment. Also, there is no outdoor equipment to make noise and be exposed to the elements. I can be on my deck and hear only my neighbors systems cycling.

[MudMaker]

Can't help it cx, it's in ma blud..
I run the DC fan all the time in the Summer and keep the air pretty well distributed. Have dehumidifier in the basement keeping the humidity levels low there too.
I'm well aware of the industry's reasoning with just undersizing but I like the big guns when ya need em.
The unit outside is a two stage scroll compressor and really does an excellent job. I always like underworking stuff rather than overworkin em... :shades:

[cx]

I always like underworking stuff rather than overworkin em... In this case that's a lot like driving your car around town all day because you don't wanna take it out onna highway and work it too hard.

Doesn't help your air conditioner, either. :shades:

My opinion; worth price charged.

[MudMaker]

Au Contraire my friend...... ;)
The two-Stage Scroll Compressor – Runs at low speed 80% of the time, which means less expensive to operate and more consistent comfort.. :shades:
The second stage only kicks in when it needs to haul A$$ :D
The oversized A-Coil helps too in that whilst I'm runnin the DC blower (slower speed and lower cost to run) the moisture collects on the coil further pullin the moisture outta the air..
Plus, ya really don't want the air to be too dry, that's why ya run your humidifier in the winter to make sure ya don't dry out all your high cost finished woods... :)

[cx]

Just mark that down as one more thing we don't agree on, Frank. :)

[MudMaker]

Hey.. It's gettin to be a pretty dang long list cx.. :D
If I ever write a book you can write the Preface or introduction... :)

[Brian in San Diego]

I'm coming to the party a little late but the primary benefit of A/C is dehumidification. Now, we're not talking suck the moisture right outta the furniture dry, but comfort to the human body kind of dry. That dehumidification only has a chance to occur when the the A/C system is properly sized and runs for appropriate lengths of time. Time necessary to wring moisture from the air. Most A/C systems are designed for "design degree" days (planning for the hottest days of the year in the particular locale) and by using that method most systems are already oversized. To further oversize a system is a waste of money and perhaps comfort. The problem with an oversized system running at the first stage is that the coil is not getting the same amount of refrigerant it would when running both stages. This results in a higher than design superheat and decreases the ability of the coil to remove moisture from the air. Generally what happens is the owners of such systems have to run the temperature lower than one properly sized or a little undersized. To feel comfortable with higher than design humidity the air temperature has to be colder. When I put A/C in my own house I undersized it . I used a 30,000 btu coil with a 24,000 btu condenser (for a 1750 sqft 2 story house). I found that on the days when I need to turn the system on the temperature of the house drops 1* per hour. Once the system is on for a couple of hours the house is comfortable. I can maintain my house at 77-78* and everyone who comes in remarks how cool it is. Cool and dry is far more comfortable than cold and clammy. If you don't believe that go into a house with a "swamp" or evaporative cooler on a humid day. The primary consideration for sizing an A/C system is and should be dehumidification. Also a properly sized system consumes less power than it's oversized counterpart. In my opinion, it doesn't make sense from either a comfort or energy standpoint to further oversize a system.

Brian

[MudMaker]

I contacted a Lennox rep and axed him the same question about this particular unit that I installed in my house.. :deadhorse
His reply:
Mr. Black,
Oversizing HVAC equipment is typically more common in commercial applications due to ventilation air requirements. In defense of the decision you made for your home, both the furnace and A/C units are 2 stage products, meaning that the furnace is running at 2/3 capacity (normally 95% of the time or more) and the 4 ton condensing unit is operating at 2 1/2 ton capacity, unless the space demands the higher speed. The VAV fan system (DC current, variable speed), adjusts for the proper CFM volume accordingly. If I were to say what advantage you have over a smaller system, it would be that on the most extreme weather days (winter or summer), you would have enough capacity to maintain temperatures that would not be possible with a smaller system. Our normal design conditions for Dayton are 4 degrees - winter, and 90 degrees - summer.

[cx]

Dunno, Frank. Seems like somebody woulda run a load calculation on that house before you installed that system and determined the correct size for the unit. If you're running on a 2 1/2 ton AC compressor 95% of the time with a 4 ton unit allegedly sized for the house, you might have actually needed only a 3 1/2 ton unit to begin with, which would likely have a 2 ton for the other compressor running most of the time.

At any rate, after a lengthy discussion with my AC sub on the issue moments ago, It's still my considered opinion that you size the units, both heat and cooling, for the house according to actual load calculations (Manual J ?) and you still never intentionally oversize the AC units, not even the newer dual-compressor systems.

My opinion; worth price charged.

[Tom Tee]

cx,

Considering it is 2008, are certain of what your talking about? :rolleyes: :rolleyes: :rolleyes: :rolleyes:

tt

[cx]

My most current information is barely an hour old, Tom, and I'm stickin' by it. :)

[pitterpat]

CX does your HVAC guy agree with running the fan allaof the time?

[MudMaker]

Yea... but how old is your source?? :stick:

Hey Pitter - don't humor him.. :shades:

[pitterpat]

Frank I wasn't humoring him...that was an honest question! Honest. Personally I agree with CX, all of the HVAC people I knnow say to properly size the units and not to oversize them.

[Tom Tee]

I am leaning toward cx but when we have awfull nasty hot humid Delaware Valley days I think I could see a use of second stage oversizing.

Got stats for 24/7/365 two stage variable fan use. It costs way less than popular conventional fans cycling on only for temperature delivery.

The world is a changing.

tt

[MudMaker]

Frank I wasn't humoring him...that was an honest question! Honest.
OOOOooooKKay then... :) :)
I'm kinda gettin into these font changes.. :D
Yea Pat,
In most cases you don't, but when you have a variable speed DC motor, ya can.. It moves air a little slower than when it comes on to heat or cool. Just enough to even out the temperatures in all the rooms. It uses less Kilo's and is $$ friendly.. I use it when Fredia's cookin and when I want some of that real cool basement air upstairs. I don't do it all of the time - just when I want.

All said and done cx is proly technically right

[cx]

Haven't had that particular discussion for many years, Pat, but the old wisdom was that if that's what it required to make you feel comfortable, run the fan.
But even then it was usually thought to be more cost-effective to run ceiling fans in the occupied rooms instead.

And even with the technological advances we are now seeing, I don't know how that thinking would likely change. Air movement still makes skin feel cooler and would be of benefit to the comfort level, which is what it's all about, eh?



Now, which of y'all AC geniuses knows the most efficient method of charging AC systems these days? That is, the actually adding of freon (or other cooling medium) to the system. I learnt something about that there this very day that I'd never heard before. :shades:

[MudMaker]

OK.. I'll bite.. Evacuate, pull a vacuum and recharge.. :D

[cx]

Yeah, of course you still gotta make it empty and dry and then fill'er up, Frank.

The magic is in how to determine when you have pewt exactly the correct amount inna system.

[Tom Tee]

Don't know anything about this 'ceptin that my auto guys filll the chilly stuff till their temperture thermoniter thingie sittin' in an a/c vent reads an desired amount. When I questioned the guy 'bout the specifics he says ya gets to feel the right amount??? Donno. Kinda too iffie for me.

tt

[pitterpat]

CX, Frank, TT,
I run the fan on my HVAC system all the time. My HVAC guy said to and I trust him.

All this other gibberish I know nothing about and when I get my next system I'll worry about it.

[cx]

They (at least Trane) have a system now that knows when it's full, Tom. The "technician" just hooks up a hose to his freon can, turns it upside down, and waits 'till the system says it's full, disconnects from the system and wanders back to the truck. Manufacturer says it will be within a tenth of a pound.

AC business is having the same concerns with finding good help that alla other business are having. And proper filling of the newer systems is getting more critical alla time with precise freon level having a large effect on the advertised efficiency level. So the manufacturers are tryin' to make it easier to do it right (read dumb it down).

I was impressed. Hell, now I could fill a system correctly, again. Without even havin' my antique gauges calibrated. :)