Manual J: Are we doing things backwards?

[54regcab]

Instead of sizing the A/C and heat to the house how about designing the house to work with the HVAC? How about a building code that limits HVAC units to a certain size per sq ft and have the builder/insulator design/fix the house so that it will cool properly? Let the builder decide if they would rather get rid of the black roof, huge west windows, or insulate more/seal properly. This also would force the units to be installed properly instead of oversizing to cover up installation problems. For the heat side the furnace will almost always be oversized just to get the blower capacity needed. I've never seen a situation where the the house cooled fine but the furnace couldn't handle the heating load.

In our area the limit could be something like this:
New construction: 1,000 sqft per ton (this isn't unreasonable in our area for properly insulated/sealed house)
Existing homes built after 1990: 800sqft per ton
Homes built 1970 - 1990: 650 sq ft per ton
Homes pre-1970: 500sq ft per ton.

Lets start fixing houses and correcting installation issues instead of just sticking in a bigger A/C to cool things off.

[mark beiser]

Been hitting the sauce a bit today eh?

[Southern Mech]

My neck of the woods they are pushing blower door tests on every new house with a % leak allowed, duct blast minimum on remo and c/o

[AccurateHT]

Instead of sizing the A/C and heat to the house how about designing the house to work with the HVAC?

At this point you would have to get involved with a "green" builder to go in that direction.

Maybe now that the upper middle class has had their collective ass handed to them the tide will turn away from McMansions toward more sensible homes.

[Saturatedpsi]

Because some people want black roofs and huge west windows?

[kls-ccc]

Why not require the HVAC conractor & building contractor make the system work with the house. In other words the building contractor has to provide enoough room to get properly sized duct to all areas of the house after the HVAC contractor has designed a duct system that will actually work.

[tipsrfine]

I think it's a great idea. Look at refrigeration as an example. You get a service call on a refrigerator that has cooling problems, condensate, won't stop running etc...., you don't recommend they replace the condenser, compressor & evap coil with larger ones; you replace the door gaskets! Also, some of the most cost effective ways to deliver comfort to a home is to air seal & resolve insulation issues. There are some companies out there that have sucessfully changed their business model to include this "whole house" approach to comfort & energy use, and some of those pro's are members of this site.

[jtrammel]

That is a great idea, but this is for the time being at lest America a free country! If you want lots of glass you can have it, if you don't mind paying the power company every month go for it. Same goes if I want a 68 Chevelle that gets 4 miles to a gallon I can and that is why I love America. What would help more than regulations is to have craftsman in the trade and get rid of HACKS!