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Where are you/your dad located Airborne? Locations like Ft. Drum or Ft. Bragg have different temp/humidity considerations, but with the questions you asked, you sound educated on it a bit. I too was Airborne for 17 years, Ft. Bragg and Germany for all of 22 years. For those unfamiliar or non-Airborne qualified as a paratrooper, “what holds up a chickens a__”? Good luck and hoo-aah!
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Where are you/your dad located Airborne? Locations like Ft. Drum or Ft. Bragg have different temp/humidity considerations, but with the questions you asked, you sound educated on it a bit. I too was Airborne for 17 years, Ft. Bragg and Germany for all of 22 years. For those unfamiliar or non-Airborne qualified as a paratrooper, "what holds up a chickens a__"? Good luck and hoo-aah!
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My preference for these situations, and we do it all the time (of course, budget permitting) is to use two systems for a 'top-down, bottom-up' approach - one air handler in the attic (blowing down) and one in the basement (blowing up).
You'll probably hear quite a bit on pros and cons of the high-velocity system. It can work well but I prefer the above approach, if the house is large enough to justify two systems and the duct runs are workable.
Also, buy the highest SEER you can afford - minimum 13 and 14 is better. Higher initial cost but lower over time. The new Trane variable speed units are outstanding, IMO.
*Here are a few starting points for you:Hi-V, look under PRODUCTS, then HI VELOCITY SOFT-AIRE FAN COILS, they've got a design/installation manual in there that may answer some of your questions on design and installation of these systems.SpacepakUnico, 800-527-0896This last one had some Unico manuals buried in the pages.Run a search using the three keywords. I've seen Unico and Spacepak product, but there isn't a Hi-V distributor in my area. Hi-V is actually trying to break in with the Unico supplier in my area. I'm going to see the Unico supply rep next week, he'll have seen the Hi-V product by then, I'll ask his opinion.Unico branched off from Spacepak a few years back. Theory is the same, products are fairly similar, slight modifications from one to the other.
*Everyone thanks for the start.Mongo, Thanks especially for the links. And now the research begins. If you see your rep my dad’s house is in Baltimore. Though Humidity is incredibly high in the summer it is quite notoriously low in the winter. That is why I thought of the humidifier. Right now the air is so dry in winter your skin will dry out. The house itself is two floors at about 500 sq.ft. top and 750 sq.ft. bottom. Attic and basement are unfinished and the house is balloon framed so when we add new siding this Aug. I have no problems creating a chase that would be 14-1/2" x 4". Or multiple chases if need be. Not that far of a run in any direction. 30' for anywhere on the first floor(going up from the basement) and 40' to go all the way up into the attic and to any room upstairs. Those distances are from were the inside air handler would sit.Thanks Dave
*How 'bout an Aprilaire humidifier for the winter? Piggybacks on the ductwork, seasonal bypass damper, humidistat. I grew up in No. Va. suburbs so I know what you mean by oppressive summers.
*We have one available! See the innumerable crticisms of humidifiers, which I have come to believe -- consider the unattractiveness of pumping gallons of water into the air and squeezing it out through the cold winter sheathing (where else can it go, except to condense on and rot out the windows?). If your house is REALLY leaky (like our sieve) it is not a problem, but as you begin to seal it in a modern way the destination of the moisture can bring many hidden problems.
*Dave, I'd recommend holding off on the humidifier for at least another year. I'd venture that since you're improving the house's envelope with new insul and siding, you'll most certainly reduce the number of air changes that the envelope is now experiencing.Fewer air changes should mean less dry, chilly, outside air being drawn into his house, resulting in the living space retaining more moisture, thus increasing humidity. Your Dad may find that simply tightening up the house will solve the dryness problem, saving the possible (read: probable) headaches associated with a humidifier.Also, encourage your Dad to take more showers, or, if he's anything like his son, encourage him to start taking showers. Or eat more pasta (boiling water).For those contacts I listed earlier, I'd recommend phoning them. Most of the time I've emailed them (corporate email vs specific person email) I've had a tough time getting responses to my questions.
*Mongo, Thanks for the hint about phoning.As for the showers I didn't notice it but then again I am on the ground, with the breeze blowing, doing the real work. I am quit sure that is why the AF put you in A-10's. No one would be your backseater. As for the house it leaks like an open window. My thought was to use 3-1/2" fiberglass in the stud bays, the old sheathing is coming off because of dry rot at the corners and windows. Then with new ply installed I was going to use Tyvek then Fanfold followed by the siding. As much as I hate to do it is going to be vinyl. He wants to stop getting up on ladders to paint.Any way that is why I don't see a problem adding ductwork. Thanks all. Dave
*Dave, I spent about 3 (long) hours with the rep today. I asked him a few questions regarding your setup, in terms of looking for an in-line humidifier. A couple of tidbits, hopefully helpful ones:*You can do it.*Unico doesn't provide humidifiers, but they have surveyed manufacturers and have a list of humidifiers that are "Unico compatable."*Since the ductwork will most likely be in an un-conditioned (possibly even sub-freezing, though doubtful in your area?) part of the house, using just the blower with an in-line humidifier in cold temps could present problems.*Circulating cold "winter" air in the ducts (cold and stagnant from unheated attic exposure?), and adding water to it could present condensation problems, so they recommend either running on CAC (continuous air circulation) or adding a small heating module, 5kW or so, to take the edge off.*With the system beging used infrequently in the winter, there are also concerns of warm air getting into the duct and having water vapor condense out. To prevent, they provide "winter shut-off caps" to cover duct openings.*There are myriad ways to to this, heat/cool vs cool-only units, duct in conditioned/unconditioned space, using a heated pan, steam, power, or atomizing humidifier, so...I recommend either sending out for "Technote 109/June 1999, Humidification for Unico Heating Systems" or searching for it on-line.Best of luck to you, and here's to making your Dad more comfortable...Mongo
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SSG David Rosendale
I am a air conditioning contractor in Florida. If you have natural gas available in your area you might want to go with a natural gas forced air furnace and AC unit. I would not think it economical to install a forced air system and keep a hydronic system functioning in the house. A humidifier could be easily installed in a gas furnace. If you have to ask questions on how to do ductsizing you should hire some one to do the work. I am saying this for your benefit. Sizing ducts is not a easy thing to do for the novice. I spent a grueling three weeks learning the basics and another two in a advanced class. I use Air Conditioning Contractors of America manual "J" for heating load calculations and Manual "D" for duct sizing of residential homes. I recommend strongly that you get a professional to do the work.
PM
*I hope I'm not too late to give you some very succinct advise... DO NOT EVEN Think about dropping the hydronic system and do not do anything with the humidity till after at least one full year with all the new siding and insulation. The people telling you about the trouble with moisture at the cold shell are right !!!! Also, forget about the idea of running ducts up/down any outside walls -- that is an absolute no-no. too much loss of effeciency be cause it outside the comfort space and you cannot afford to have uninsulated cavities -- thats where ice dams on the eaves come from!!!! Now -- what you DO want to do--- put the airhandler in the attic over the second floor and do not under any circumstances use the little high velocity ducts -- you will not be able to sleep under them. use large ceiling diffusers and large return air grills to keep velocity very low but move at least fifty percent more air than the upstairs cubic requires. Also put a huge diffuser at the top of the stairs. If there are downstairs room(s) without reasonable flow path to the stairwell -- then look for second floor interior partition walls to drop down to ceiling or high on the wall grills for those first floor spaces. Remember -- you don't have to really cool the down as much as the up -- heat rises in both summer and winter and cold goes down in both seasons. Also basic physics: moisture moves from place to place in the house very easily -- so if you dehumidify the upstairs thoroughly you WILL also very effectively dehumidify the downstairs too and that is the real comfort solution. You have a very small house to work with == two systems is way too much capacity. best bet for equipment is the Bryant scroll type 12+ seer rating compressor/condenser -- your neighbors will also really thank you as it on of the quietest units on the market. I've done this in 10+ houses -- it really works very well!!
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Charles - Given the size of the house, now posted after my first post, I would totally agree that 2 systems are overkill.
*Thanks, As I reaserch I am leaning toward the High Velocity units running from basement to second floor thru a supply duct next to the chimney chase.Still reaserching though.AE
*Dave, One design recommendation...tough to give since I don't know the house layout, but guessing the majority of the cooling is to occur on the first floor, with less on the second?Consider the air handler and main plenum in the basement, with ducts running off that plenum to the first floor. Outlets can come through the floor. It took me (in some ways I'm still trying to get over the bias) some time to accept cooling outlets in the floor, but they do work. Then, branch your plenum with the branch going up the chase to the attic. This would reduce duct length and the associated flow loss of many 2" ducts going up the chimney chase vs a main plenum with the shorter ducts branching off once in the attic. Run your second floor outlets to come through the second floor ceiling. There are strict comfort guidelines to outlet placement (NOT over bed, as previous poster wrote), as well as the numbers of outlets on a branched plenum.You could also completely reverse the layout, top to bottom.Just another idea. May or may not be appropriate.
*Mongo,You must be Psycic.I talked to a Soft-Air Rep on the phone and he said the same thing for the most part. He even gave me a tool manufacturer for a hole saw and extensions for the outside diameter and said if I could be sure there were no wires or plumming in a stud cavity I could run up an inside wall with the saw. That adds alot of flexibility. He said I could drop the outlets into the wall and save the extra run off going up and over into ceilings. With the inside walls I know were the wires run, etc and only have to go thru plates. No blocking in this old house.Thanks,Dave
*Dave, Glad to see you were able to get info from the reps.One word of caution...I infer you're considering bringing the duct up through the wall cavity, then turning it 90 degrees and having the outlet on the wall?If so, be very careful regarding the min duct bending radius. A tight turn inside a wall cavity (2-4" radius bend) is almost a guarantee for a noisy system, too much air turbulence right at the outlet.Some manufacturers have something they call "air chambers" or something like that, where the duct, coming up from the basement, empties into the bottom of this small hollow "chamber". There is an outlet on the face that comes through the wall and into your room. I've never seen them installed, so not too familiar with them.One other option is what they refer to as a "toe kick" outlet. You got it, it's designed to take the airflow from the 2" duct, it dumps it into a small chamber, which then bends the airflow 90 degrees and the "show" (outflow) side of the outlet is a small opening, about 1" high by 8" or 9" or so wide...sized to provide flow through cabinet toe kicks, though some installers use them everywhere. Pricey, though, I think $70-80 a copy? That's just for the outlet. Yikes.Let me know what you think of the Soft-Aire products when you see them. Sounds like your plan is coming together...here's to a cool summer.
*Here is to the last cool summer with no views and the TV cranked to drowned out the window units.Have a good weekend my friend.DaveI just caught a glimps of this one on the other board an hope I post it OK. For any reading by others. Chuck Turi "Hi Velocity AC" 5/18/00 10:59am
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Good Afternoon All,
My Dad just stumped me. He wants to add a Central Air unit to his home.
He is tired of the window units, in and out every year.
Here is the overall situation. The house has Hot Water baseboard heat and is very efficient. He is quite fond of this system and does not want to remove it. He would like to add an A/C unit that uses those small round vents that are good for retrofitting old plaster. I would like him to consider also using the system to provide heat and a little humidity so as to stop the total dry feeling that winter brings.
My question is were do I find them and some flow charts for their size so I can accurately calculate air flow?
My second question is what type of unit would I need?
Knowledge is everything and that is were I am at right now.
By the way, new siding and insulation going on/in this August.
Getting rid of the old Asbestos Shingles and Blowing in insulation from the outside before new siding over fanfold goes up.
Dave
*dave.. keep the heating system.. look at some of the split systems, like Sanyo & Mitsubishi.. they don't use any duct..the sytems you are talkng about are Space-pak..and Unico..Mongo likes those....i wouldn't add the heat capability, nor the humidity,not without real ductwork..and that is expensive, especially if it's done right...but you could add a 5 gal capacity humidifier, sears makes a couple of nice ones.. with our solar hot air heat.. we need a lot of humidity.. i use about 5 gallons a day during the real cold weather....(about 2000 sf)