Does a new 2 stage HVAC unit need fancy Aprilaire?
We have rec'd quotes on Lennox, Bryant, American Standard, and lastly, Amana HVAC units to replace 30 y/0 Lennox 150,000 BTU (yes, that's right, 150,000) gas furnace and 10 y/o Tempstar 8(?) SEER 5 ton unit for our 2700 sf+ house in North Central Florida.* Are getting quotes for functional 15 SEER units -- for the Lennox, that means a XC21 to deliver 16.3 SEER , Bryant is the Evolution , .** AS dealer encouraging us to get the 14 SEER as he doesn't feel increasing to the 18 really gives a bang for the buck -- about .* Haven't gotten a written quote for Amana, but he estimated a 16 SEER 2-stage at about $.* We are getting local utility rebates so the price of all except the 14 SEER AS would be about $ less than quoted price ( have to have minimal 15 SEER -2 stage for rebate).* All companies have been around area long period of time.* Have used the Lennox company in past for previous house.The Lennox price initially looked good.* However, included in the price is an Aprilaire 4200, surge Kit at breaker box or at AC unit, and a UV light at the coil.* He states that Aprilaire is needed to keep computer board clean for functioning (stated that it only cost $ more), and UV lights to keep mold from growing on coils, since this system would remove so much more moisture from house that there would be an increased growth of mold.* I don't know if he is blowing smoke up the stack with that info.* Other 3 companies said that the Aprilaire, or simular unit would be good, but not necessary.* Also suggested that the UV light was a way to make $$$$$.** Also includes 1 year planned service agreement -- basically 2 visits.* Wonder if he's adding unnecessary accessories?* Lennox also wants to replace 3/8 inch copper in slab to larger 1 1/2 and 1/2 inch thru attic and down exterior wall.* AS and Amana said this isn't needed, but I've read on other sites that there is no effective way to flush R-22 out thru lines in slab when replacing with R410A -- that the mineral oil will get trapped in the dips in the line.I guess I have*3 questions -- do we need a fancy air cleaner to protect the unit (I'm not concerned with air quality in house); are UV lights needed for the coils, and should the current lines in the slab with R-22 be replaced?Thanks -- long post, i realize.
EDIT: NO PRICING
Last edited by Dad; 06-28-2008 at 03:34 AM.
Indoor Air Quality (IAQ) is a prefrence. However, It is never a bad choice to have any of that if you can afford it. The "standard" 1" disposeable filters do little of nothing. If you have asthma or allergies then you will appreciate it. It prevents problems from occuring in the future such as dirty blower wheel and coil. I know some people feel that it is a waste but i have an air cleaner and a UV system in my own home. You would be surprised how well they actually work. The lennox HC 16 is the best expandable filter. You should look in to that one.
In the lightning capitol of the nation, Florida, a surge kit seems like money very well spent on a new system, assuming they mean electrical surge. I have a lightning protection system on my roof with surge arrestors on my home in Maryland. I've taken a direct hit to the system and the home didn't burn and the electronics inside was not damaged. There are protectors available for the mains and for the thermostat wiring. Get both installed. Have one installed at the meter socket as well. These lighting strikes travel great distances through power lines in Florida, because there is no conductivity to earth (sand). You can ask for this addition from any of your proposing contractors. The meter arrestor may be an item from your utility that might include some insurance coverage.
Pipe at 1/2" and 1-1/2" seems excessive for five tons. You could have trouble with oil return by oversizing the lines, even for just a portion of the run. The oil needs some velocity so it returns to the compressor to lubricate it. An oversized suction line will leave oil pooling. Look for direction and approval from the factory rather than "rules of thumb". You don't want oil trapped so it cannot return to the compressor.
I wouldn't run a new R410 system through old R22 pipes. If the original R22 system burnt down, I wouldn't run even a new R22 ystem through the original etched pipes. If the current system is R22 and still working, that would make the choices harder. I replaced pipes here where there was a burnout, but the other systems will be running R22 through existing old pipes. I wouldn't run R410 through pipes used for years on R22 through a slab, though many claim they are successful with that change. You understand the oils are different and don't mix well. How will you get the wrong oil out? You would need to circulate a solvent through with a pump, not just blow a can or two of magic stuff to rid the old oil.
You are buying new equipment. Do you want to run it through unknown old copper tubes inside the slab? This can be acid etched from the inside or etched from the concrete on the outside. If they are not insulated where they pass through the slab, you can get liquid slugging from the cool slab. There are special concerns for tubing that passes through slabs. Has the factory been consulted? Add in concern about flushing and change-over to R410, I don't think this is the place to save money.
You have 150,000 btu/hr furnace in Florida? It must come on for two minutes and shut off with the home overheated.
Review your utility bills to chose if better efficiancy has a payback period. Fifteen percent saved from $is different than 15% saved from $. Where you are, latent heat removal will be important, and the high SEER numbers may not make you the most comfortable.
Look into variable speed ECM blowers so you can adjust latent heat removal.
Last edited by Dad; 06-28-2008 at 03:35 AM.
A. edit out your prices, its not allowed on this site, its in the rules, Thank you.
B. Surge protection is nice, not 100% required, if you have good insurance.
C. A good air filter is a plus for you also, but not required.
D. UV lights can do as much harm as they do good.
What about a ERV I thought those were manditory in Florida ??? Does your home not have any insualtion to need a 150k BTU's, that' alot I would have the house checked for insulation, check your windows, doors and other penitration thru out the home before you have new equipment sized and installed would be my advice. A VS blower using a ECM motor will be beneifical to you and your pocket book for the life of the equipment and you will be glad you did after the fact. Ask to have both Manual D & J done to get the optimal size equipment and keep operating cost at a minimum and get several estimates, and as the pro's say here it's all about the install not nesscessarily the equipment, sounds worng but very true !!!
in response to 150,000 BTU furnace
Furnace is original to house being built in 1978, we bought the house 3 years ago. We have had an energy efficiency study done and have more than adequate insulation. There are several other features of the house that were "overdone" -- it wasn't just the furnace! Had the windows replaced last fall as the breeze that went thru the house on a drafty winter day was significant -- however, we still are using 1726 KWH with the house in June with therm at 78 during day, 83 when we leave house. We are hoping to get a reduction in KWH use during summer -- that's the significant change I am seeking, although I know that with proper furnace sizing and an improvement in AFUE we should see some change in the gas bill in winter.
Thanks for the posts regarding the lines and reusing them for 410A after being used for R22 -- I think we'll be having some bids refigured --