[stevehull]

The month of January will have sufficient numbers of heating degree days to do a good estimate. What heating system do you have now?

The reason I ask, is that you need to get a reading say on January 1 and then another on Feb 1. Then you need the number of units you use for heating over that time period. If you have natural gas, then this is simple as you can just read the meter on those dates.

You can get the degree days for that period (or whole year) from your local NWS (National Weather Service) office.

Propane is harder as the gauge on the tank is not quite precise enough to get a good reading.

Electricity is easy as you can read your meter, but it is confounded by lighting, baking, cooking, washing machine/dryer etc.

I would encourage you to look at your basal electricity use in October (often November bill) as this will reflect minimal heating/cooling, other stuff and this month often reflects basal electricity use.

Again, you don't need an exact 30 day period, but you do need to be able to get the number of units of fuel on the start and stop dates. I like January and February to use as performance data as the Christmas holidays screw up data with all the comings and goings.

And yes 4 tons would likely do it, but I bet with some good insulation and minimization of infiltration, you could easily get to 2.5 tons. By FAR, the best savings are with buttoning up and tightening up.

Anyone who holds out their thumb and says "4 tons" without performance data or a very strict manual J calculation should not be hired (IMHO).

Lastly, the winter usage data should be available from the utility for the last few years. Can you get that?

Steve








Steve