We have an 1887 house that we want to retrofit with central air. We’ve decided on the high-velocity type system, but are unsure of whether to use Unico or Spacepak.
Do any of you have experience with these systems and can you offer an opinion as to which is better, both in terms of the product and the company?
Thanks!
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Replies
Not very familiar with Spacepak but I have found Unico in a number of historic buildings in the Mid-Atlantic. So I took the plunge last year and had it installed in my early 1700's home. The compressor is whatever brand you want or what your contractor recommends. The Unico air handlers are modular so that individual components can be swapped out quickly for repairs.
While the brand is important, the installation contractor is crtitical. Regardless of the brand, the folks putting in your system must know/understand and have compassion for old buildings. My guys spent almost 2 weeks making sure the system did not disrupt anything that is historical in nature.
The system is great - after one season, it provided a very comfortable environment and was very energy efficient.
I installed my own Unico system three years ago. I have a three-story Victorian home, and used one unit for the second (bedroom) floor, and one for the third floor. The first floor never needs cooling beyond what casccades down the front stairs. The air handlers I just managed to squeeze into the attic (un-conditioned space).
I did the heat load calcs, got a local distributor to sell to me, and got a pro to install the refrigerant and to silver-solder the feed lines from the compressor.
It works like a champ: no complaints at all. And we installed it without any substantial alteration to the house (I was re-habbing the third flloor, so had lots of options as to how to run the air hoses from the plenum, which went all around the attic in a loop.)
Bob Chapman
Not what you asked but...
I installed my own high velocity system, about six years ago, from Energy Saving Products based in Canada. I'm very, very happy with the way the system cools and dehumidifies. It's also quiet and fairly easy to install, but where this product really shines is in the company and people behind it. Their salesmen, customer service and tech support were great, especially tech support. They were very helpful in design and installation even helping with the layout using my floor plans. As an added bonus they were (at the time at least) considerably cheaper than the big guys. Back then, the big guys didn't even want to talk to me. (HVAC can be a pretty tight group). Here's a couple of links to get started:
http://www.hi-velocity.com/en/brochures/ESP%20110.04%20HE%20Features%20&%20Benefits%20Brochure_EN.pdf
http://www.hi-velocity.com/en/index.html
Good Luck,
Jerry
PS: I have no connection to the company. It just seems so rare to be so well treated these days, that when it happens, you want to tell someone. :-)
"the big guys didn't even want to talk to me. (HVAC can be a pretty tight group)."Not to hijack the thread, but I know what you mean. The cutoff in these parts for HVAC installs seems to be $5K. Any system under that price and they are "booked" until December. I've always been curious about these high velocity systems - is there any noise where the air flow makes a 90-degree turn? What was the hardest part of the install process?
The Hi-V systems are marketed as being less noisy than conventional systems. I don't have enough experience with either to say if that's true. It seems to me that I've been in homes with regular systems that were noisier and homes that were quieter than mine. My guess is that it may have more to do with the design and installation than the type of system. My system is quiet - I just followed the instructions. The 90* turn is not a problem as long as you follow the minimum duct length recommendations.The hardest part of my install was installing and properly sealing and insulating the main trunk line in a filthy, cramped, 140* attic. (If it has to go in the attic - don't do it in the summer!!) The rest wasn't bad at all.Jerry
So these manufacturers will sell to someone who is not a certified installer? I am a GC building small energy efficient houses and I can wait for a long time for the HVAC guys to find the time to install the relatively smaller systems that our houses use. If I could install them myself it would be a huge time saver. How do you go about designing the system to ensure that you get enough airflow to each room and balanced dehumidification etc...?
Energy Saving Products (the company I linked to in my other post) will sell to contractors and homeowners. They are also very helpful with the layout and design as well. Give them a call; very pleasant to deal with.I used this program for both my heating and A/C calculations:http://www.hvaccomputer.comI highly recommend it.Jerry
Great info. I will check it out. Thanks.
I concur with Jerry. ESP's Hi-V systems are great and the company backs up installers. I put my own in 10 years ago. I made a few mistakes (warned by company) but overall it works well. Since then 3 friends have installed the same system.
Unico is very good also.
With any high velocity systems - the ducts and accessories are expensive. I recomemnd running your own spiral duct or rectangular duct from air handler as far as you can. Then use the flex ducts to ports. Be sure to use the recomemended lengths of flex ducts as this is the 'balancing' system for air delivery.
"With any high velocity systems - the ducts and accessories are expensive. I recomemnd running your own spiral duct or rectangular duct from air handler as far as you can. Then use the flex ducts to ports. Be sure to use the recomemended lengths of flex ducts as this is the 'balancing' system for air delivery."*************************************************************************Mike gives great advice - I just thought I might add some of my experience in that area.I ran regular snaplock round duct in a loop around my attic. I would have preferred to use spiral duct but, couldn't find it locally. Add shipping to the fact that spiral duct is already expensive and I couldn't justify the cost. OTOH, I spent a lot of time carefully sealing the duct I used; that would have been unnecessary with spiral. I found that leftover 2" central vac tubing and fittings fit perfectly with their 2" flex ducts. They were easy to run, especially in floor to floor drops and saved a lot of money. Just be sure to follow their design requirements for minimum lengths of flex or you'll have a noisier system.Jerry