HVAC: What type of system?
I’m installing a HVAC system in my townhouse. The building is 20×65 on four floors and is approximately 5,000 square feet. It’s a single family dwelling. I’ve received various quotes from contractors – all roughly in line, e.g., 33-37k. I’m looking at 3 Zone, 10 Ton, R410A/SEER 13 heating and cooling systems. I was told…
I’m installing a HVAC system in my townhouse. The building is 20×65 on four floors and is approximately 5,000 square feet. It’s a single family dwelling. I’ve received various quotes from contractors – all roughly in line, e.g., 33-37k. I’m looking at 3 Zone, 10 Ton, R410A/SEER 13 heating and cooling systems. I was told to stay away from R22/SEER 10 systems. Due to global warming, recent federal legislation phases out R22 refrigerants by 2010. Furthermore, in 2006 the gov’t adopted a minimum standard of 13 SEER for all central air systems. I was told to avoid HVAC contractors looking to clear their inventory of soon to be antiquated SEER 10/R22 systems. From what I understand, these systems will have to be retrofitted after 2010 and replacement parts and repairs may prove difficult to obtain. I’m pretty much sure of the specs that I want (R410A/SEER 13) but I’m confused on the type of unit. I’m deciding between a traditional “split” system and a “packaged” product system. Which system is better and for what reasons? What are some of the advantages and disadvantages to both?
I used http://www.hvac-talk.com‘s Residential HVAC forum to gather pre-purchasing information. Ditto what cmu posted about the Manual J calculation – it’s a small mark in his/her favor if a contractor will use this without prompting/begging.
What did your hvac contractor do, multiply 5000(sqft) by 24(btu/sqft) to get 10 tons? Demand a true Manual J calculation, it will surely come in about half that unless you have a couple commercial kitchens on the premises.
Most hvac systems (see web citations) are oversized and therefore wasteful of capital and running costs. COntractors do this because 1) easier than calculating load and 2) safety in high numbers. If as you say you have any concerns for global warming, use the smallest system you need.
Also interested in those quotes, who are you talking to?
Those are great quotes – does it include all the ductwork as well?
Split means the condenser and air handler are seperate… usually better because you don’t need ducts running from the roof (or yard unit) to the floors you are cooling. Mine in 3 zones, 2 of the zones are split system, and one is a package. If you got a place to tuck all 3 air handlers, I’d say keep them inside the house (ie. split). You should really have an architect go over the HVAC plans.. especially considering this is big bucks you are looking to spend.