# Thread: Multi Stage Heat Pump

1. Junior Member
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Dec 2009
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## Multi Stage Heat Pump

I currently have electric resistance heating throughout my 2400 square foot ranch home, with individual thermostats in each room. I also have 2 central air units that are 20 years old. I live in the Northeast and electric heat is very expensive in winter. I am looking at a complete replacement of my AC units with a multi-stage heat pump, and am concerned about several things; the upfront costs, the practicality of using a heat pump below 30 degrees fahrenheit and the sizing of the heat pump. I have been told sizing of any unit is based upon how much loss due to heating or cooling is experienced; not the size of the area multiplied by 600 to determine the number of BTUs.

Does anyone have experience with calculating the size of a heat pump to heat and cool my home and any experience with a Hallowell Acadia Multi-Stage Heat Pump in a cold climate?

Ken Meyers

2. Senior Member Rank 2
Join Date
Feb 2008
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566

## Re: Multi Stage Heat Pump

Ken:

There's a rather long, complex computer-driven program that is used to calulate residential heat loss---called a Manual J, or a HEAT LOSS CALCULATION---it is always up to the prospective INSTALLER of new equipment to do the Manual J on their first visit to the home---the program often takes over an hour to input into a computer because it factors in the building type, the square footage, the amount of insulation in the exterior walls, your geographical location, type of basement, amount of glass (windows/sliding doors) & condition of the glass (double pane/or no, etc).

There are simple, much shortened calcs that will give you a ROUGH IDEA of how much heat your home is losing in an hour, but they could be way off, so use the shortened versions ONLY AS A STARTING POINT.

A very basc HLC is done by taking the total square footage of the home (including heated basements, etc) and multiplying by a number between 30 and 70---multiply by 30 only if you have an extremely tight house, double pane windows, R30 insulation in the walls, R50 insulation in the attic, limited amount of glass---multiply by 40 if you have standard storm windows, or double pane, R19 insulation in walls, R40 in ceiling, etc.---multiply by a higher number if you have little or no insulation in the exterior walls or attic, lots of glass, loose fitting glass, etc.

Thus a 2400 sq.ft. house X 40 = 96,000 btu/hour, which is the amount of heat in BTUs per hour that your house loses on a cold day---AND the ball-park size of the heating equipment you need according to its BTU/HOUR OUTPUT (not btu input).

Some other ****** HLCs are listed below, some are more comprehensive & thus more accurate than the others--but take longer to do.

Hallowell has been around for a few years & the 2-stage HP he is selling apparently can produce heat to zero temps, but I have no info on problems with the equipment, or customer reactions positive or negative---I heard that an install costs \$13,500.

Hallowell is a small company that has limited staff & resources & heat pumps can break down--there might be a big problem getting service in your area in such a circumstance---heating systems tend to break down on the coldest day at the worst possible time---you'll need someone experienced on Hallowell equipment to be located IN YOUR TOWN.

I would talk to people who have had one installed---the Hallowell co. is supposed to refer you to "satisfied customers"---I would talk to as many people as you can find before you buy & make sure you ask them how long it takes for a service person to show up.

For \$13,000 you can get a long-lasting boiler that will last decades, including the radiant or baseboard heating distribution system that goes along with it, and have some money left over to buy the ductless AC units by Sanyo, Mitsubishi, Hitachi or Friedrich.

Google "Taco Hvac load calculator" (with the quotes) to get a heat loss calculator.

http://www.gotohallowell.com
http://www.maineenergysystems.com
http://www.bgmsupply.com/calculateheatloss.asp
http://www.hvaccalc.com/hvac/newfeatures.asp
Last edited by NashuaTech; 12-16-2009 at 04:50 PM.

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## Re: Multi Stage Heat Pump

Originally Posted by kenrossmoor
I currently have electric resistance heating throughout my 2400 square foot ranch home, with individual thermostats in each room. I also have 2 central air units that are 20 years old. I live in the Northeast and electric heat is very expensive in winter. I am looking at a complete replacement of my AC units with a multi-stage heat pump, and am concerned about several things; the upfront costs, the practicality of using a heat pump below 30 degrees fahrenheit and the sizing of the heat pump. I have been told sizing of any unit is based upon how much loss due to heating or cooling is experienced; not the size of the area multiplied by 600 to determine the number of BTUs.

Does anyone have experience with calculating the size of a heat pump to heat and cool my home and any experience with a Hallowell Acadia Multi-Stage Heat Pump in a cold climate?

Ken Meyers
First, I would ask are the existing A/C systems cooling equal parts of the home? Or I could ask what are the size of the condensers? Do you have a basement? How well is your house insulated? A 20 year old home (assuming the A/C is the age of the home) should have decent insulation/windows.

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## Re: Multi Stage Heat Pump

If you plan to stay in the home I would suggest geothermal heating/cooling. Air to air heat pumps are better (more efficient) than straight resistant electric heat, however.
Remember, geothermal will add huge value to the home when you do sell.
You should expect utilities to average \$50-80 per month with geothermal. Good luck.

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