High Velcoity Air Conditioning
69STINGRAY
| Posted in Energy, Heating & Insulation on
Couple quick questions.
1. Does anyone have any experience with High Velocity Air Conditioning systems?
2. Do they work as well as Reg. air conditioning? (I am assuming they work better 🙂 ) Are they more efficient?
3. How do you tie it into a air exchanger?
4. Any preferred manufactures?
5. What is the delta in cost between the installation of a traditional duct system and a High Velocity system?
Thanks in advance. I am planning my 2000 sq. ft Colonial with ICF foundation and SIP walls. I have looked on some web sites and love the idea of High Velocity systems.
Replies
Why would you assume they work better?
Cost is similar to higher. Efficiency is similar or worse.
I can see a single benefit, assuming they work 'as well as', the ability to retrofit in to structures with limited access. I sell Unico, brand. I also sell Coleman, York and Goodman. Not many folks interested in the Unico.
I am assuming they are more efficient because they do not have leaky ducts, the air does not loss as much temperature due to insulation, rooms stay cooler and have less "cold" spots because it mixes better the conventional floor registers. I am assuming the vents are installed in the ceiling.
Am I wrong? Anyone have these type of units in their houses?
Well, we looked at forced air and high velocity. I think both systems are great for different situations.
In our situation (1914 home, no soffits, retrofit, plaster walls, wanted to keep the steam heat)...quality forced air was actually MORE expense than the high velocity. They need to first floor closets to run central ducts and we would have had to create a few soffits. It was a very difficult plan to execute.
The high velocity system was a better match for a retrofit. We had a high quality outfit install and we were very active in solving the problems in running the ducts and placing the exhausts. They welcomed this interactivity and we ran through a few different solutions for some tough problems before choosing.
Tonight, I'm sitting in a house that is cool for the first time in years. The mustiness factor has gone down substantially. Unico air handler was chained to the attic ceiling (pretty amazing install considering the space they were working in.) Because we were lucky enough to have the 2nd floor walls and ceiling open, we could really see what they were doing. How carefully they taped the ducts, sound proofed them...very nice. The exhausts are extremely low profile. The supply and drain lines took a space about 4" x 4" down the corner of one of the closets to the basement and then out the wall to the air conditioning unit.
It wasn't cheap (definitely more expensive than a hack job...these guys have to really pay their dues before they get to do install....longer term employees). But it was cheaper and less disruptive than forced air...for us. We're living in while this is going on. (I know...shoot me now.)
Drawbacks so far...they've got to come back and do a little more soundproofing in one room that is below a walk-in attic. We have to creatively figure out how to insulate around the air handler to dampen the noise when we close up the ceiling. And I wish we had gone in for an external air conditioner that runs at 69 dB versus 75 dB. Otherwise, it is very easy to forget the air when it is on. In some of the external rooms there are a lot more windows and a few more ducts. In those two rooms, you hear a little "whoosh". But then we love our steam heat too...so no problem for us. They did balance the exhausts noise and air-wise when they installed. But ducts cannot be "shut" like they can be for forced air. (Never having HAD any air, I'm not sure why that is a very big deal, so it doesn't bother me.) And there is one cold air return at the top of the house in our plan so we need to keep the staircase door open (which is no problem....we'd like to open that stair up someday.)
And that's all I have hear...reporting for the Insomnia Club...
jm
My experience is similar to yours. We air conditioned our 200 YO stone house 2 years ago. Went with conventional system and amazingly strong flex ducts. They seem to be wire reinforced cordura and foil. Lost a little floor space to two vertical chases, but saved about 40% on the euipment.
Air handler is behind a knee wall in an attic bedroom. You can hear it, but it is not noisy. VERY IMPORTANT: Be sure you get a spill pan under the air handler. And run 2 drains - One for the air handler and one for the pan. Don't let the installer talk you into one line! (Learned that the hard way shortly after we started up the system.)
We put high velocity in out home about 5 years ago. 1919 consruction with excellent steam heat system. Standard ducting would have cost about twice the $12 price tag...most of the additional costs in significant structural modifications to accommmodate standard size ducts.
The system is OK. It cools three floors (blower in in attic space on third floor), and is very nearly silent except for air noise coming through some ducts. I can live with that. They tout the system's efficiency at removing humidity, and it does a fine job at that. Our problem is getting the first floor to a comfortable temp...my wife likes COLD...68-70 degrees. We easily get that on the second and third floors, but not the first. Since I work at home now, and have a much more active shop in the basement (custom cabinets), we wanted to try to get the first floor "fixed".
The installer came back and checked out the system. Found a few leaky ducts in the attic that needed re-taping. Ran another duct to the kitchen (remodeled last year). Will (soon, I hope) install a return to the first floor. Current return is on the third floor in the central stair that goes from first to third floors. Fortunately we can use a stud wall as a return (I know, that's supposedly bad, but I'm not worried about leakage in the center of the house).
Even though it's been five years since the original install, the company is doing all this work at no cost to me. This I did not expect!!! Great outfit...not cheap, but very good.
Oh. The basement. I had a small air conditioning window unit down there to off-set the heat generated by the summer/winter heating system. My wife gets mad when I shut the furnace down and forget to turn it back on. She doesn't like cold showers in the morning. The little AC unit didn't do a great job, although it keeps the humidity down. So a few weeks ago I went to Sears and bought a 12,000 btu winddow unit for $260. This has made a huge difference in the first floor temp, and my shop is way more comfortable this time of year. I'm in the Philadelphia area, BTW.
Your HVAC guy is aces!
I am not too far from Philly, and am in the Phila. Electric Co. service area. My home was already set up for their off peak service when we bought. You might want to look into it if you don't have it.
The electric for my AC and water heater is $0.018 per KWH, versus $0.0605 for the rest of my supply. We adapted very easily to the shut off hours. That may have been easier because we're empty nesters.