Heat Pumps

Discussion in 'Home, Garden, and Yard' started by firehog, Jan 2, 2008.

  1. firehog

    firehog Well-Known Member

    Do you like them or not? Do they save money compared to other means?
     
  2. TheBattman

    TheBattman Select Member<br>2010-11 Deer Hunting Contest Winn

    IF a heat pump of the right size is installed correctly (doesn't happen as often as it should), they work quite well down to about 30 degrees or so. Beyond that, they rapidly fall off in efficiency because they rely more on the electric heat strips which are expensive to run. Thankfully, we generally don't have too many super cold temps here in Arkansas.

    Now - that being said, I will list some common problems with installs of heat pumps that I have witnessed (this is NOT a complete or comprehensive list):

    Return air not large enough (95% of return air vents are too small, thus restricting air flow, cutting efficiency and shortening the life span of the unit. Really no such thing as too large - but easy to get too small.

    Wrong size unit installed - Too many installers just figure need based on square feet of home to be heat/cooled. No load test is done, so the REAL size requirement is never known and often the unit installed is too big. What happens if the unit is too big - it doesn't run enough (especially when cooling in the summer) - It produces a fairly quick temp drop, but then has to cycle a great deal. The same is true in the winter - although to a lesser degree. Heat pumps are actually the most efficient (and provide the most comfort) when they run a bit more than you would normally think they should -

    Lack of insulation - not really related direclty to the unit - but for a home to be cooled and heated efficiently by ANY method, insulation and air leaks should be a priority.

    Ducts - leaky ducts reused when the new unit is installed... Leaky duct work is far more common than most folks realize.

    Improper charge of coolant (R-134 being the most common) - too much will shorten the compressor life, as will too little. Too little will often cause the coil to freeze up.

    Also - remember that with a heat pump- if you adjust the thermostat up more than a couple of degrees, you will almost always cause the "EM" heat to kick on (that is the heat strips) - which will cost you...

    Now - all that being said - I have lived in homes with everyting from an attic fan for summer and floor furnaces for winter, to homes with gas heat, to modern heat pumps that were installed fairly well. I like heat pumps - you just have to remember that they have to be installed correctly to work as advertised.

    With the cost of natural gas an propane going up - heat pums get more attractive. Just don't expect hot air from the vents (except when the EM heat is on). heat pumps are less obvious and the air coming from the vents can actually feel luke warm or even slightly cool...Remember it is just a reverse Air Conditioner when heating - it is trying to suck what little heat it can out of the outside air and convert it to heat for the inside. When cooling, it is just a regular air conditioner....
     

  3. octoberbuck

    octoberbuck Well-Known Member

    Pump

    My house is/was pretty inefficient until summer before last. Still have a few things to do. Had all of the duct work redone in the crawl space. Still have to do 4 ducts and a trunk in the attic. (Tri-level house). My old furnace/ac was about 15 years old and don't think it knew the term SEER. Against advice I put in a heat pump with a gas furnace and forgot about any electric heat strips. Love it tremendously!!! (Plus got a full IRS credit) Dual speed something gas furnace. There are no cool days here. Right now my thermostat is telling me the furnace is assisting the heat pump. When the temp drops real low the furnace kicks in in total or I can manually override either way. My old unit was really bad as was the duct work on over half my house. My electric bills in summer were running me between $400 t0 $550 a month. Gas bills were similar but somewhat lower. Now they do not go over $202 at any time. Still need some energy efficient improvements and those costs will come down some more. Battman has some excellent advice.
     
  4. John Stiles

    John Stiles Ultimate Member 2007 Team Turkey Contest Winner

    Yes to all! I would never go back......lowest possible electric bill......yes below 30 the heat strip will kick in for only a few minutesthen back off. I remember paying huge bills before....now my bill is too easy:thumb:
     
  5. rjet

    rjet Well-Known Member

    :thumb: Takes a while to get used to but I would never go back.
     
  6. When I bought the house I am in now it had one. People said I wouldnt like it. I liked the electric bill and it did the job.
    I had to replace the compressor once but it was under warranty. Just before christmas the compressor shorted out and I had to make a decision on what to do. I decided on a packaged unit from Lennox.
    It wasn't cheap but I have no regret so far.
    They have come a long way. This thing is 3.5 ton ,15 SEER unit that is all outside.
    No split system so no fan noise in the house. And it will heat the house just fine. variable speed fan that is pulling 2 amps running where my old onewas probably pulling 10 amps.

    Now this outside unit is huge! All the ducting is under the house and they did enlarge the return.
    THEBATTMAN is correct return is extremely important as the installers made sure return was correct. they enlarged my return and were going to add returns until they determined that I had more than enough.

    The thing you have to determine is what temp. you like and leave it. Now mine has a programmable thermostat so I can set it to now work as hard at night or if i am on vacation adjust temp to maintain and control humidity.

    I won't go back the only thing I thought about was geothermal but the company said the cost of install was high.

    Get several estimates and go with who you feel comfortable with.:biggrin:
     
  7. trapperman1985

    trapperman1985 Well-Known Member

    I have a heat pump but don't know how to use it I guess. The thermostat says "emer", cool and heat. How do you know when to have it on emergency heat and when to just have it on heat??
     
  8. Emergency is there if something was to happen to the pump. you would still have heat from the heat strips.
    Now the heat strips will come on when its real cold for added heat.
    You would just switch to emergency if needed. say your outside unit iced over and wasnt heating,switch to EMER.


    Your efficiency would go down on EMER but you would be cold.
     
  9. TheBattman

    TheBattman Select Member<br>2010-11 Deer Hunting Contest Winn

    I actually learned about "EM" (emergency) heat with a heat pump by accident. A good friend of mine lived in a rental house in Bella Vista Village when he had his first teaching job. I visited one winter week (I posted about wade fishing with freezing rain and snow/ice on the ground) and they had their heat set to EM heat because the normal "heat" selection just didn't seem to be working right. Well.... I finally heard from my buddy- after running their heat pump in the "EM" position for over a month - they got an electric bill for over $1000! They called the landlord and he sent out a repair man. The landlord then billed them for the repair visit to turn the EM heat off....with an explanation of what the EM stood for...

    I am glad he learned that lesson for me!!!!

    Most of the other stuff I learned from another good friend who spent many years in Heat and Air/refrigeration, as well as going through a replacement in our last house.

    The house we are renting now has one of those outside heat/air units (heat pump), and while I like the lower noise level, critters like it too and will dig into the ducting from the unit to the house. We haven't had a problem with skunks in the ducts, but the previous owners did on several occasions.

    The return air is WAY under sized. The filter square footage is about 1/3 of the appropriate size, and the actual air path from the filters to the unit is about 10% of the appropriate size. Our electric bills in the summer run right up to $300, and our winter bills are about $200. EM heat runs a lot... primarily because the heat pump just cannot move enough air to get the temperature up before it drops below the threshold for the EM to kick in...

    one of many reasons we will not be buying this house (we have right of first refusal).

     
  10. firehog

    firehog Well-Known Member

    Last night it dipped in the teens, and someone told me yesterday to turn on the emergency side. Now I haven't done this yet, cause we hit some 20's one other night and it seemed to be ok. I keep the thermostate on 70 and it seems to keep things warm.

    My question is, is there a temp where heat pumps don't seem to work as well? I noticed someone said their emergency kicks in automatic. I am assuming mine is doing that.

    Another question, I have three units, should I keep them all on the same temp setting? Can they be off a few degrees?
     
  11. rjet

    rjet Well-Known Member

    I have never used the em setting, not even sure if either of the heat pumps I have owned have that setting. Will check tonight.
    From what I have been told is that if the temp reaches 3 degrees below the thermostat setting the heat strips will kick in. So if you set your temp low when you leave the house, increment the thermastat setting by just a couple degrees until desired temp reached.
     
  12. John Stiles

    John Stiles Ultimate Member 2007 Team Turkey Contest Winner

    I never touch that digital thingy on the wall....but my wife can get up on a day that's 75 degrees outside, and she switches the emergency heat on:smack: go figure:cool:
     
  13. After 20 years my wife and I still can't get a temp that suits us both. She could handle 65 in the winter and 85 in the summer..........I'm the opposite:smack:

    I have never used Emer heat......even when the outside unit was covered with ice and snow it still put out heat.

    I am sure there are some that need it. But our bill compared to our old house is no comparison. This new unit should be 35% more efficient or they said my bill could be that much less due to the energy usage of this over the old.

    I don't what would be worse electric bill or gas bill right now.I am all electric so I don't know about home gas but when I bought propane last it was $3.40 a gallon:eek:
     
  14. John Stiles

    John Stiles Ultimate Member 2007 Team Turkey Contest Winner

    I fired the propane guy....he was letting me run out just so he could charge $35.00 for a emergency call. I'm now all electric...never over $125.00[month]!!:razz:
     
  15. Was you buying from ferrelgas?
     
  16. John Stiles

    John Stiles Ultimate Member 2007 Team Turkey Contest Winner

    Naw....but they all use that trick!!:wink:
     
  17. Hill Farm Hunter

    Hill Farm Hunter Well-Known Member

    I don't like the "cool" heat, but I like the low bill. Went with a heat pump on the new house, but thought hard on the dual fuel like Octoberbuck has. Main reason I did not go with it was that it would have been on propane and not NG. Still not sure how great the bill is gonna be here. First one was $100 and I was tickled. We only actually lived here 3 weeks of the 4 the bill was for, but the heat was on the whole time. Just got the new bill and it is $190.:smack: What is considered efficiant? How do you know if your bill is where it shoudl be? Is there a price or KW useage per square foot formula to decide what is good or bad? Electric cost me 6.6 cents per square foot this month. Take the total electric bill that you payed including taxes, cost adjustements, all that crap, and devide it by the heated square footage of your house. If you heat with gas, add that in as well. Let's see how some of our bills per square foot compare. Oh, and along with your answer post up what you keep the thermostat set on. 70 here last month, trying 67 this month.
     
  18. John Stiles

    John Stiles Ultimate Member 2007 Team Turkey Contest Winner

    72 degrees:thumb:
     
  19. sam

    sam Grand Member<br>2007 Photo Contest Winner<br>

    Only thing I'd like better than my heat pump would be one of those geo-thermo heat pumps. It heats and cools your house just like it was 50 to 55 degrees outside, because it exchange heat at the ground temperature instead of the air temperature. But they do cost quite a bit more, but with energy prices get'n so high, the payback ought to be a lot quicker than before.