Heat Pump and Insullation

[Pat Jax]

I have added a 1000 square foot expansion to my house and it is Haeted and Cooled by a Lennox 2.5 ton heat pump. I seem to be having trouble getting the room to heat.

I have not yet had my insulation installed (so the new room only has the ceiling dry wall). I understand that this has an impact on the efficiency of the HVAC system. How much of an impact does this have on the houses ability to warm. Furthermore, due to some unfinished work there is an area that is about 1/2" by 6" near the air return (in the ceiling) that does not have dry wall covering it and is exposed. This is a source of cool air that comes in from the roof vents. It was 38 degrees last night and the heat pump has had to use aux heat most of the time to maintain 64 inside.

[Ed Imeduc]

How much of an impact does this have on the houses ability to warm.

I dont think you can warm the whole outdoors with that 2.5 pump. Also if you have a poly V/B there on the ceiling under the drywall get insulation up there now or the drywall ceiling will cup down on you. Been there done that.
You have to close that add on up.

ED :eek:

[Pat Jax]

I live in Florida and don't think I need a V/B in my ceiling; I though the soffitt vents and the roof vents took care of the moisture? Any Comments?

Are Lennox units good units ?

From you other post, I gather that insulattion makes a SIGNIFICANT impact on the heat pump's ability to warm my addition. I have a contractor scheduled to come look at blowing enough to make R30 later this week. thanks for your help and any comments are appreciated.

[Ed Imeduc]

You dont say where you are down here. Im by west palm beach. Now here we dont use a V/B. Dont use a heat pump it dont pay. Put the money in the bank and use strip heaters when we need heat like right now. Had 48o last night. Make sure you use the foam rafter vents in the attic so the air can get from the over hang to the attlc. Most here go for a R 38 insulation in the ceiling make sure you have good roof vents near the ridge . A power roof fan on a tstat pays for itself here for sure. You also want a time delay on the compressor there cause the electric power is so bad here. Make sure you keep a clean filter in the unit there with them working on the home. lots of dirt.

ED ;)

[Pat Jax]

I'm in Jacksonville (I know, most of you in the south don't consider us part of Florida).

[Pat Jax]

I talked with an insullation person and they can blow fiberglass in the new roof this week. One problem, I don't have the baffles installed, so the work around suggestion was to reverse the shop vac and blow through the soffit vents to allow for circulation. Is this a good idea or acceptable ?

[Ed Imeduc]

Id sure try and get the foam vents in before they blow. This will let the air in and you need it down here .Also it wont let the insulation roll down into the over hang on you

ED ;)