Hey all-

Hoping to get some straight answers here. I live in the D.C. area, and we are adding a 1000 sq ft addition. This area needs conditioning, so we are discussing a heat pump right now; I inquired about a furnace, but the plumber indicated our gas line could not supply the BTUs required, as we already have an existing furnace and gas water heater.

Does this check out? I had preferred a gas furnace but the BTU supply threw me for a loop. In general I am aware that heat pumps will cost me a little more in electricity and they aren’t great in the winter. So not the best choice if it gets cold below 30 degrees...

It does occasionally get pretty cold here; I'm being told by the HVAC guy that the heat pump is sufficient for heating in the winter here. But what I understand about heat pumps is that unless you have a super mild winter, the thing is not going to cut it. My issue is that we're just doing this for the addition, and one of those rooms is our bedroom. If it's not gonna be warm enough, my wife's not going to be too happy. We don't have a backup furnace (I mean, we DO, but it's not connected to the same space,all new ductwork is going in for the new space only)

Further, I'm concerned about our electric bill, which is already like $300/month (the house isn't that big). I definitely don't want to double it or anything crazy, and if the heat isn't going to be enough, AND I have a much higher bill, that's not acceptable.

Thank you so much for the response! Our "emergency heat" (HVAC guy's term) is set to cut over at 25-30 degrees, and is unfortunately not propane, but electric strips. I'm not loving that; those are basically resistance coils that get energized and air is blown over them, which heats up and is blown into the space. But that shouldn't be terribly often - and plus, the rest of the house is heated by a second zone with a regular, but incredibly inefficient, gas furnace.

I double-checked my electric bill - and I was WAY off. It's more like $220 or so/month. I expect it to go up obviously, but not by double.

He definitely said "emergency heat," but described it closer to what you're calling "auxiliary heat". Still, the gas two-stage sounds like the way to go. Thanks very much again - this has cleared up in a few minutes of 'real world' that reading on the internet for a week was not making obvious.

Fantastic - looks like ours is a Carrier; I'll look into whether it's a 2-stage or not. Upgrade's an option in the future, I suppose. Funny you mention the oil tank - I had ours removed a few years ago, as it was taking up valuable pinball space in the basement!

You've got a deal to meet up somewhere in the area after this dies down. Seafood? Well, you just said the magic word. We (used to) visit the Annapolis area quite often, Reynolds' Tavern is a favorite!

Supposedly our rates are $0.11 / kwh which isn't bad. Gas is $40-50 on average (in winter it goes way up). Guess I need to stop complaining. I appreciate all the input guys