advise on a a/c unit new instalations

johnnyge

ok, this is the deal. I am a homeowner. I already have my one pipe steam heat running the ways its suppose to be(silence) no more hissing or water hammer. Thanks to all the advise on this site and Dans Books, and also Steamhead advise. At one point I was going to change the system with a force air furnace and also do the central air aircondition, but now I am going to keep my boiler(only 3 years old) and will like to do the central air conditioning in the house. which units are the best, efficiency, and price, Its going to be AC only. My house is around 1400 square feet living space Its a 2 story colonial built around 1930's. means walls are plaster. basemenent still unfinish, esay access to the joists. I have read about the UNICO system which doesn't require mayor duct work, use some kind of pipes. but i haven't seen one install or hear anything about it except the advertise in the old house magazzine. any imput in this matter any brand that will be easy to install in this old house. thank you.

tom_49

Johny,

We have had great success w/ the Unico system. It can be installed in homes that cant have "standard" duct systems.
It uses a 7,9,or 10' main duct, depends on the size or the system, as opposed to 14" . The branch ducts are 2" alum insulated flex. There are several ways to lay it out depending on the house lay out.

It is easier to install than standard a/c systems. You can even zone it using mech. dampers. For zoning, We have been using Unicos variable speed air handlers w/ 2-speed condensers, they are quieter than the standard ones.

For condensers I like Carrier. They have the broadest line of units. We use mostly units w/ R410a refrigerant.

When running the 2" flex lines, make sure all 12' of the sound intenuators are used, anyhing shorter may get loud.

Are you going to install this or are you going to use an experienced HVAC Co?

The Unico euipt. is top quality. You will be happy with it, as long if its installed properly.

Good luck , Tom

hvacfreak

how and why

I don't have much experience with this high velocity stuff...how and why is it any better ? I mean...you still need the return air 600 fpm if I remember. Your paying someone to install the supply duct...is it that much more to install a rectangular register that would do well for ...a heat pump ? And if you went with a heat pump system , you could do an outdoor t stat to change-over to your 1 pipe steam ( here in the Washington DC area , we have day after day weather patterns ).

I see no advantage for this " high velocity " stuff , unless you like the noise . 600 fpm return , 1.0 static supply is what were taught for heat pump...your paying for the install any way...why not just do it ?

tom_49

hvacfreak,

I didnt say it was "better" than a conventional system. We do 50 conventionals to 1 Unico. What I did say, was that it will go where conventional wont. It all depends on the house. Some jobs we literally cannot install rectangle duct. No room.

You should try it sometime. Dont knock it if you dont have much experience with it.

hvacfreak

yeah

Yeah , I wasn't being ' combative " ...I guess I just don't understand the benefits at all....but if your restricted to a space I can understand.....my argument is....increase the available space. And I have had that discussion many times too ( like every day ). I like comming here and talking , it reminds me of why my business fails ( personal ) ...I will only install a system on my terms , and who the hell wants that..lol.

tom_49

No offense taken.

Sometimes, you just dont have enough space for the ducts. Most people dont want to sacrifice space for something like a/c, but it were granite counter tops.....

I find the Unico stuff to be a great solution to some houses, not all.

I also like the Carrier "Infinity" system alot. Thats conventional.

johnnyge

how a heat pump work with the ac it is reliable? I havent hear much about how it works