Physics Guy

Buying Stuff
Bangor Daily News Op Ed 2/9/06
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Approximate Costs
Where to Start
Buying Stuff
Ground Work
Now I'm a Plumber
Now I'm an Electrician
The Moment of Truth
Summary and Conclusions

Ordering a Heat Pump On-Line


After searching the Internet for a heat pump that met my needs I requested a spec sheet for the heat pump from, a Florida based company with the best prices I could find. I had to be very careful here as there are models that only work down to 45 degrees. In Maine, ground temperature 5 feet below the surface can get down to 36 degrees. My model was a VGY030 ColdFlow rated to 30 degrees. I was also aware of the COP factor which is different depending on whether the heat pump is in cooling mode or heating mode. In heating mode my heat pump had a COP of 3.6. For every dollar of energy put in, the heat pump could extract $3.6 of heat. When I was confident I had all the information I needed, I ordered the heat pump from for about $1700 and $300 shipping.


Purchasing Pipe.


I purchased 6 - 300 foot rolls of 200 psi ” pipe from EJ Prescott for about $50 per roll. The pipe was delivered for free to my door in Orono. My excavator informed me that plastic pipe will expand and contract significantly with temperature changes. This can pull joints apart and/or cause pipe cuts if the pipe is against a sharp rock. So upon the recommendation of my excavator I used this type of higher pressure pipe in 300 foot lengths so that I would have no underground joints. He said he never saw a 200 PSI pipe fail when backfilled properly.


The Heat Pump Arrives


The first step was to unpack and position the heat pump and then begin work on the ductwork. I had a minor scare as I looked at the manual that came with the heat pump. The vendor had sent me the manual for the wrong heat pump. Fortunately I had the data I needed from the specs supplied to me earlier from the vendor. Though the specs in the manual were wrong, the wiring and setup instructions were correct for the model I had ordered.


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