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Phil, Mechanical Engineer
Category: HVAC
Satisfied Customers: 7496
Experience:  Retired HVAC/ Electrical & Boiler contractor. Industrial
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What approx size furnace and A/C will I need for a 3000 sq

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What approx size furnace and A/C will I need for a 3000 sq ft ranch home with a full walk out basement in NW Penna?

Thanks for looking at my profile. I hope I can be of service


Let me get back to you, I need to look up the climate zone there, and the ASHRAE guide 2% weather conditions.


For now, as an wild guess, not knowing how much south and west facing glass you have and of what type, insulated glass or not, home construction details etc.


You will end up in the range of 6 to 12 or more tons of cooling required... lots of variables involved. How much electronics on at one time, and how frugal or not frugal are you?


Would you be willing to have the home get up to 80F on a few hot days a year or not...that can have a huge impact on sizing and operating costs.


Are you interested in an exceptionally green approach or not.


does the 3,000 sq ft include the basement space or is the total space 6,000 sq ft?


What kind of roof does the house have, insulation?


Zoning and back up are issues as well... on a house that size Id use 2 or 3 totally separate systems..that gives you back up, and a way to shut down areas of the home not in use during the day or night... etc.


Fill me in on some of those details and I will estimate your load a bit closer.



Thanks, Phil



Customer: replied 6 years ago.


Thanks for answering! Let's see if I can answersome of your questions. This is a new home and I want to make sure that the builder is putting is a sufficent size HVAC system. The house sits E-W, West facing. The 3000 sqft is only for the main level, doesn't include the w/o basement. It will be well insulated R-15 walls, R-42 ceilings, and Anderson energy efficient windows. We will be using ceiling fans to help circulate the air and would like the system to be 90-95% efficient.


Hope this helps!



How many sq feet of glass facing south and west? Is it solar reflective glass? it probably is..if not high reflective glass, the best you can get, would be a really good idea on the south and west facing glass, but not the East facing or North facing glass...You want solar heating on the east side.



Efficiency is rated in SEER, (Seasonal Energy Efficiency Rating).. for an AC in your area If I owned the home, I'd pay 50% more and get SEER 14.


If you have natural gas..(not propane) I would go with gas furnaces, 90% efficient max, not 95% etc.. the cost of repairs dwarfs the energy savings in my experience.


From what you have said so far, a total of 6 tons for cooling would be a bare minimum. .. 7 would be better... and I recommend splitting that up to 2 each, 3 or 3.5 ton units (14 SEER). and

2 each 90% efficient gas furnaces, (the cooling coils (A coils) above each furnace located in the basement. Furnaces rated 120,000 BTU's each at least in order to handle the air required for cooling.


This estimate is plus or minus 20%.


If i were the home owner, and wanted to keep it below 75F no matter the heat of the day Id be looking, 2ea, 4 ton SEER condensing units with A coils, and 2ea 120,000 bu furnaces (required for air flow during summer).


I'd buy Rheem of I wanted the best for less and ease of maintenance... I don't appreciate the serious complexity the two market leaders provide..costs too much to repair, with scant benefits if any...that would be company names beginning with C and T...those have great promo though.




the contractor may want to provide heat pumps...I don't like them for widely distributed systems.. These get double the wear on compressors as compared to what Ive recommended above.


Package units, heat and cool in the same box,,with ducted distribution is not the best in cold east coast climates. and puts service men outside in the weather, thats expensive.


Costs in your area will range between $1,500 and $2,500 per ton+.. worthwhile add's are Honeywell automatic wash electronic air filters, if anyone has alergies or smokes. .those are expensive.. and high quality humidifiers, stanless steel basin type those will improve the family heath in the winter, buy them oversized, and in stainless steel, dont skim on the east coast, they get a lot of use.







I hope that helps, Phil











Edited by Phil on 3/7/2010 at 10:48 PM EST
Phil, Mechanical Engineer
Category: HVAC
Satisfied Customers: 7496
Experience: Retired HVAC/ Electrical & Boiler contractor. Industrial
Phil and other HVAC Specialists are ready to help you
Customer: replied 6 years ago.


Thanks!!! This is exactly what I needed, I appreciate the detail!

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