I live in Southern California and I'm about to replace the existing HVAC in my home. The home is 15 years old and still has the original system installed by the builder. A 3.5 ton Condenser (Carrier off-brand) and a 4 ton Carrier Weathermaster Furnace. We've been in the house for 3 1/2 years now and the HVAC has given us problems the last 2 years ... everyone that has serviced the unit has said that it is undersized. The house has a very open floorplan with the main living room being open to the second floor with lots of windows. It is 2000 square feet with around 750-800 of it on the second floor.
Now, I've been lurking on this forum for about 3 months now as I've been researching systems and what to look for in installers. The first thing I've read time and time again is that all good installers do a heat load calc to size the system .. I've had 9 estimates ... only 1 guy did the calculation (Sears) everyone else has ballparked it ... of course while letting me know how long they've been doing this .... Ironically half have suggested a 4 ton and the other half a 5 ton.
I've also had conflicting opinions regarding zoning the system .. a couple of guys swear by it and others say that the floorplan of the house will negate any benefit. Some have blamed poor ductwork while others have no problem with it ... to make a long story short ... I'm pretty confused.
Well, the last guy to give me a bid finally convinced me .. even though he did not do a heat load calc he seemed to be on the ball with regards to everything else. I won't go into prices here as I understand it is not allowed but his quote was somewhere in the middle ... His company is the Home Depot installer of choice in this area and that's where I found him.
His quote seems to cover all of the bases. Upgrading electrical panel, Installing dampers in the ductwork, Hanging the furnace to code using metal rods and a metal base, new pad for condenser, installing a new copper line to handle the bigger condenser, enlarging the return and even changing the registers (the builder used stamped everywhere).
His quote is for Lennox equipment ... a XC14 and a G61V furnace .. the upgraded furnace is there so that I can qualify for the $1500 Federal tax credit ..
We are planning on staying in the house for a good long time .. I'd even like to add a room in the future ... 250 - 300 square feet max.
I've really tried to do as much research as I can but as you probably know a little knowledge is a dangerous thing .... I'd love to hear any feedback with regards to my situation .. my biggest question is the actual size of the system .. his explanation was that the open floor plan, while not actual square footage, still requires cooling for the air .... makes sense to me ... as opposed to the zoning idea which left me scratching my head .. how do you control the upstairs when it is so open.
Sorry for the long post and thanks to everyone on this forum ... I really learned more than I'd ever wanted to regarding HVAC systems.
All the best,