My mom’s 40+ year old air conditioner is putting out rather tepid air so she figures she needs to replace it. Since she has an electric furnace, I thought this might be a good time to see about a heat pump to lower the rather hefty electric bills she generates. This is in Oregon which has quite a stretch of 40-60 degree weather in the spring and fall that would seem to be good heat pump weather. And Oregon’s fabled low electric rates are not as low they used to be by any measure.
I have not talked to any of the heating folks as I am too deaf to talk over the phone, so she has been sending me rather abreviated emails describing the progress. Her house has a crawl space of about (or perhaps a little less than) three feet with a rather small and awkward entrace opening. The contractor indicated that the space under the house is too small for a heat pump. I am not really up on heat pump configurations, but I thought that a heat pump would be a pretty straight forward replacement for an A/C, with the compressor and associated equipment outside on the small slab and the coil being in the duct work where the old oil furnace used to be and the current A/C coil and the electric furnace now reside.
Why does a heat pump require so much more room in the crawl space and/or the duct work than the A/C did? Is there anyone that makes a regular heat pump that is a pretty straight swap for an older A/C unit?
Replies
In your case a good option would be what is called a packaged heat pump - everything is outside. This is what I have at my own house outside Seattle.
1/3 the heating bill of straight resistance heat, even vbetter if you add some insulation around the outside unit ducting to inside, etc.
Went outside and took a pix for your perusal in the attachment. The basic unit shown is a Rheem 4Ton packaged unit bought from Grainger for $2300 and 'roof'/insulation added . Heating bill for 5300 sq ft is about $120 month in the winter at 7 cents kWhr. Ducting runs out of the back of this unit into the house, which is where the most insulation is helpful.
No freon license needed for packaged unit, but if you are a big DIY you can get a Freon licnse with a 25 question test (fairly simple) off the net for $20 even.
This year and next is a GOOD time to do what you are proposing, as manufacture of units with F22 will cease in 2004 I recall.
Good luck, if you DIY, e-mail me for more detail.
attachment
If the current electric furnace / ac unit is in the crawl space the heat pump system can alsocan go there. A spilt system ac unit and a heat pump unit are essnetially the same, with the heat pump have a reversing valve and cycle to generate heat, while the ac unit only extract heat from the house. The back up or emergency heat for a heat pump is still electric resistance heat.
Get another contractor to look at the job. The first one sounds like he doesn't want to work under the house or is just plane full of bull.
A good high SEER numbered heat pump should save your mother money. It should also work efficently down to near 30 degrees F.
Dave
I don't quite understand the contractor's logic, but maybe he knows something I don't. All I can say for certain is that I have 2 heat pumps, the compressors are located outside, the coils are in the airhandlers inside.
Should be something similar in your neck of the woods.
(BTW, I opted for oil backup, and have wired my system such that the heat pumps shutoff at 32 F and the oil becomes the primary source of heat. Below 32 f, heat pump efficiency takes a nose dive.)
I have a heat pump which I enjoy, butI,m in the very deep south. Heat pumps do not warm good in 30 and below temp.
Also that simple freon test with the 25 question is a 501 test and its for automotive freon, My household test was 500 question $300 and took two days.
heat pumps are great but in very low temp you will need a fuel backup or maybe a geo or water heat pump.
Good point.
You notice the original message only addressed DIY usefulness for the EPA 609 $20 test. The EPA rules and regs let you use your 609 and pre '90 grandfathered equipment, etc and thus you can perform F-22 et. al work but NOT if you EVER do any of it FOR HIRE, thus the 609 test is now simply of DIY usefullnes for being able to buy F-22 and work on your own home, etc.