High Velocity Central Air Systems

[LPM911]

Anybody have experience with high velocity central air? House shopping and thinking about purchasing an older home (early 1900s) with no existing duct work. Spacepak and Unico are the main brands I've heard of but I've really got no experience with HVAC at all and could use any info to arm myself what it comes time to chat with the contractor. From reading the internet, it sounds like these systems need to be very well designed to function properly and duct locations are very key to success.

Traditional HVAC is an option too but rumor is that it means I will lose all the closet space for the duct work, and given the house age, closet space is already at a premium. Although, I'm sure I'll get a quote for both options.

Thanks in advance!

[cmartin]

Considered a mini split heat pump? If my project ever gets underway it looks like I'm going with ceiling mount cassettes or a wall mounted unit.

http://www.greenspirationhome.com/wp-content/uploads/2013/10/cassette.jpg

[nikedog]

I live in a 1860s house. There was no AC when I bought it. I put the Unico system in and it is great! The installation was fast(less then 5 days total) That was 13 years ago...
No issues. Just make sure you get a good installer that has experience with the Unico installations. That is key.

[LPM911]

Considered a mini split heat pump? If my project ever gets underway it looks like I'm going with ceiling mount cassettes or a wall mounted unit.

http://www.greenspirationhome.com/wp-content/uploads/2013/10/cassette.jpg

Considered but looking for other options.

We have mini splits in the place I'm in right now and it works relatively well. But, we've had some issues with long term support. The HVAC guy had a very difficult time finding a replacement remote the only one we had failed. The one we have now only does C. We have the same unit in two areas and one of them has recently had trouble, despite being "repaired" by the HVAC guy.

I'd use them in a heart beat for a screened in porch, a workshop, or even the garage. They seem to work much better in open spaces.

[cmartin]

Sorry for the hijack, but thanks for the info. They arent exactly cheap but seem very affordable. I have the choice to modify my existing spaghetti ductwork, rip it out or add in a mini split. Seems I could use one outdoor unit and one each in the house and garage.

Please let us know how it works out.

[Dr K]

HV systems can be pulled through walls for much older houses. Have a friend who restores old homes, lives in the old (very very old) Governor of Georgetown's summer place near Poolesville, and has one.

[Lupin..the..3rd]

Is exposed ductwork an option? Would make installation easier/cheaper. Obviously it would have to fit with the style and decor of the place.

[Vicegrip]

house that old the HVAC is only one issue of many.....

[Lupin..the..3rd]

house that old the HVAC is only one issue of many.....
No kidding. I have a buddy who bought a 1930's house a few years ago, and had no idea what he was stepping into. He had the pleasure of learning the hard way, all about knob and tube wiring, rusty steel water pipes, asbestos flooring, and precisely how many kilobucks it takes to replace a roof.

[Fritz]

house that old the HVAC is only one issue of many.....

X2!

Our 1850 house throws challenges at us every month. You should be looking at buying an old house because you want the character of an old house and are willing to pay for that "pleasure". Some HVAC systems can be retrofitted into the exterior walls because the studs are often true 2x6 and there is nothing close to resembling insulation to get in the way. Ours were run in the corners of the rooms and a little bump out was dry walled in. It's mostly not noticeable. AC and Heat are often oversized to deal with the drafts and aforementioned lack of insulation. And historic districts can make you jump through hoops depending on state/local codes. On the other hand, you get craftsmanship that can't be easily matched and history (both good and bad) to discover and uncover.

[N Fotouhi]

thinking about purchasing an older home (early 1900s) with no existing duct work. Thanks in advance!

Run Forrest, Run. If you are looking at the early 1900 house, sell the 964 now, cause you will never have time to drive it, and you'll need the money to put into that money pit.

We looked at old houses in MA in early 90's and gain in early 00s hen we moved to NJ from FL. We love old houses, but after looking at a few, including a 100+ YO house that was sagged in the middle, we came to our senses in both instances. I only would have one when I can afford to have the "this old house" guys to gut it and refurbish to 2020 standards.

You are welcomed in advance. :D

[Jazzbass]

To me, buying an old house is like buying an old car but x100. Only do it if you like a big project and it's not your primary car/house. Trying to living in an old house while renovating it is like trying to DD a 40 yr old unrestored car - hell. When I was a teenager my father bought an 80 yr old house - but he got it cheap enough (western PA - $30k for the house) that we didn't have to sell our old house at the time. So he spent 6 mos gutting it, rewiring, replumbing, new HVAC, etc. Fixed everything without having to worry about living in it at the same time, then sold the old house and we moved in. It was a very good way to do it.

[roundel]

My house is from 1961 and it has a retrofitted AC system. Other than replacing filters, I have been lucky with it. It is a Trane and is huge taking up a large percentage of my attic and there is ducting found in all sorts of weird places. The solutions are not perfect, but the location of the house is so I was not upset by that trade-off.

In a perfect world, I would have bought a house in a similar location that was brick or stone on the entire exterior. It would have access to natural gas and radiant heat but still be on a well. And obviously there either needs to be a high ceiling garage or room in the budget to build one. :D

[Fritz]

...Trying to living in an old house while renovating it is like trying to DD a 40 yr old unrestored car...

X2 on this too. If you are going to buy a historic house, or any house that needs extensive work for that matter, do the major renovations before moving in. We had contractors do work for the first four months of ownership to get it to a state where it is livable. We still have a bathroom to address and just had the boiler replaced, but those are very localized tasks so 90%+ of the house has been usable. Living around a full scale demolition zone is unhealthy for your body and your marriage. :)

[LPM911]

Appreciate all the comments, but really still looking for insight from folks with experience with high velocity central air systems and whether they are worth it not. And any good info on what to hassle an HVAC contractor about should I choose to talk to someone about getting a quote.

For reference, this house is not in a state of disrepair at all. Currently it is inhabited, modern electric, modern plumbing, fully functional, and liveable as is. Current owners are satisfied with window units and have been for 20+ years. I'm just speculating about replacing the window units as they are not my preference and was looking at the unico and spacepak systems as an alternative to installing traditional duct work.

[LPM911]

I live in a 1860s house. There was no AC when I bought it. I put the Unico system in and it is great! The installation was fast(less then 5 days total) That was 13 years ago...
No issues. Just make sure you get a good installer that has experience with the Unico installations. That is key.

Any lessons learned from your experience having it installed? Internet says if you don't get the right stuff, the system will cycle too often and there are some complaints of wind noise. Also that the location of the vents and returns are critical to the system working right. Of course, all of that is quite logical and not terribly useful as there is usually no explanation of how/where they should be located and sized for it to work well (outside of the manufacturer documentation I've read).

[BlackTalon]

Lane, I highly recommend contacting the technical department for one of those manufacturers and getting their input on the correct system components, etc. I would be hesitant to leave it solely in the hands of an Installer to 'design', no matter how experienced they may be. Also, the manufacturer may be able to give you names of contractors who install their systems, or at least direct you to local distributors who can give you some names. Of course the big issue for you right now is getting ballpark costs, I'm sure, and that is tough to do without a system design and some idea of what needs to be torn into in the house.

[LPM911]

Of course the big issue for you right now is getting ballpark costs, I'm sure, and that is tough to do without a system design and some idea of what needs to be torn into in the house.

Bingo gringo. Mostly, I'm trying to figure out if these systems do a good job at controlling temp and if they are costly to operate and then I want to know what to pester the contractor giving me a quote to make sure he's knowledgeable enough to do it well. From the HVAC guy, I will be able to get my estimate on cost but others are welcome to chime in so I could rough out a ballpark and see if that works with my numbers.

However, this may all be a temporarily moot point as it appears the listing has been removed. I had been trying to schedule a time to take a contractor to the house with my real estate agent but it sounds like the place may be off the market. Maybe they realized that it'd sell better with AC and will have it installed so I can buy it completed. :)

[nikedog]

Any lessons learned from your experience having it installed?

Lane - I did call Unico directly. Also talked to the local rep for names. I got references and actually went and visited some of the installs. Home work up front seemed to pay off. The system is very efficient to removing humidity. Less humidity makes you fell cooler. System does not need to run as much as regular systems.

It is important to have the systems designed correctly. Quantity of and length of runs makes difference.

I was amazed how they were able to snake the runs in the walls etc. I lost only 8" by 14" of one closet for the entire install of a 4000 sf house.

The system did cost about 20-30% more installed(In 2001) than the standard forced air system. However there was no framing, drywall or painting needed. Returns are in the ceilings. It was a no brainer for me.

I would recommend my contractor but they were long ago bought/swallowed up by some large contractor. Can't remember who it is now.

Is your heating hot water radiators? I kept my radiators for heat(glad I did) and the Unico is only AC. You can add a heat pump to do light duty heating before the furnace turns on.

[Don Wohlfarth]

Sorry I'm a little late to the party. Over 50 years I've installed several Unico systems. They work well when properly designed. Contractor MUST do room to room load sheet not whole house. Find experienced contractor and talk to a couple of people where he has installed their system. 20-30% more is about right.

[BobNovas]

Don Wohlfarth! you're alive!