PDA

View Full Version : HVAC Question



W.C. Turner
10-30-2005, 11:13 AM
I'm pretty sure I've seen some HVAC contractors on here before, so, here's my question.

My 4 ton, natural gas, HVAC central heat & air has died. At least, I've just discovered that the heat has died. Considering the ridiculously high price of gas (all forms), we are currently experiencing, I'm not sure if I should replace the unit with another natural gas, or maybe go to a heat pump, something that I would never have considered in the past.

What do the experts say? Oh yeah, let's hear from the non-experts also.
Thanks,
W.C.

Frank Hagan
10-30-2005, 11:47 AM
I'm not a contractor, but work for a manufacturer that builds boilers and water heaters, but not any air handling units. So my warning is a general one about what I see in the industry at large.

Be careful about the "energy efficiency" stats you see. Heat pumps are electric appliances, and while they tout higher energy efficiency, the energy they do use is usually more expensive than natural gas. They are competitive with LP (propane) in a lot of areas, so if the differential between natural gas and LP is still pretty wide in your area, a heat pump is unlikely to save you any money.

Don't compare just the efficiency numbers; compare the cost of the fuel too.

Jim Becker
10-30-2005, 2:19 PM
A heat pump in your area should be very efficient and cost effective provided your house is well insulated...I had one in my previous residence and was very pleased with the "bills". That said, in this home we replaced an oversized, inefficent gas furnace with a modern energy efficient ("92% rated") unit in 2003 and it's been remarkably good at reducing our gas bill, even with higher rates. Both the air intake and exhaust are 2" schedule 40 PVC and the tempurature of the "flue" flow will not burn my hand...so most of the energy being used is actually heating our home. It is true what Frank says about ratings...there are a lot of variables that affect true efficiency and you can't just go by what's stamped on the paperwork. If your home loses heat easily, it's still going to cost you!

JayStPeter
10-30-2005, 3:56 PM
I don't have NG any more. But, in my new home I find the electric bills to be cheaper than the electric + NG bills I used to pay. It should be since the house is new and better insulated.
I have a high efficiency propane backup. For a while there I had it set to come on at temps below 45 (in other words, most of the time). Now that was expensive. I've been much happier since setting it to 25.
My heat pumps are the highest efficiency I could get in single speed/stage. In asking for advice on heat pumps I was told to avoid the multi-stage units for reliability reasons.

Jay

Jim Hager
10-30-2005, 6:06 PM
I want to put in my pitch for a ground source heat pump. If you are interested in investing up front for lots of savings down the road you might like the earth coupled heat pump system.

I have my second new unit in my second new house. The manufacturer is a friend of mine here in Pocahontas, Arkansas. His name is Mike Jones and you should give him a call and let him discuss ground source heat pumps with you. He is a super nice guy and very knowledgable about ground source vs. natural gas and other forms of heating and cooling.

http://www.hydro-temp.com/

I have a heat pump coupled with well water. We cool freon in the summer with well water and also heat all of our hot water in the summer with the waste heat that comes from the airconditioning circuit. In the winter we also use the well water that has a higher temperature than the outside temps, this time cooling the freon. We discharge the water into a pond or use it for irrigation of the yard.

You can also use ground source equipment with a lake loop or a ground loop that does just as good a job. Our first unit was a lake loop from a stock pond near the house.

Get in contact with them. You will at least get some education about heat pumps while you talk to them. Ask for either Mike or Maynard.