Add a heat pump for addition?
My house has a forced air gas furnace and electric A/C that was new with the rest of the house about 3 years ago. It was sized to heat and cool a 2,100 square foot house.
I’ll be adding a second floor above my garage with heated area of an additional 500 square feet. If the current unit can handle the extra load, I’ve very happy and won’t do anything else. If it can’t handle the extra square footage, would it make more sense to:
A) Replace current furnace and A/C with larger unit, or
B) Add an electric heat pump, using the furnace as back-up heat?
Just a few details – The area where I live has a very moderate climate. Low humidity summers with few days above 90. Winters are wet, but only get below freezing at night about 14 days a year. Consequently, heat pumps work pretty well here, or so I’ve heard.
Also, there isn’t a big price difference in terms of gas power versus electric power here, so operating costs are not necessarily a big issue.
So, which would cost me more? Installing a (standard) heat pump, or upsizing my furnace and A/C?
Thanks!
Replies
Here in the willamette valley heat pumps are very good and if a person is going to any update in system then they should consider heat pump; The last addtion we did and included an electric heat pump the owners qualifed in $500 back from Consumers Power and almost $800 from state. Didnt cover the expence but sure helped. Check with you r local power company and see what kind of rebates are availbale
Here are a couple of other things to look at.
How "connected" to the remainder of the house is this, ie, will the heating/cooling needs match that of the rest of the house? Often this kind of rooms are not well connected and have different needs than the remainder of the house.
Also is the duct work setup to be able to handle the extra loads for this room?
Without know anyother details I would speculate that keeping this as a separate system would be best.
You can use a heat pump. They are available in several different formats such as self-contained (several different types of through the wall) and ductless split systems.
But here is another option. And in the wall vented gas heater. They are available in many formats include as a fireplace. Depending on the usage of the room a fireplace might be a good addition.
Thanks for your replies. The house has a second floor and the new addition will connect to that fairly easily. The new area will contain a family room and a bedroom, so it will be occupied all the time.
I don't know that the ductwork would handle the extra load, but I can always install a separate run for this area, since it will be right above the furnace and air handler.
I don't know if I'd get a credit or low interest loan from my electric company, since the furnace is gas. It's worth checking on, though.
Thanks again!
Bob, it would be to your best advantage to do every thing you can to tighten up/well insulate the current structure, and then be able to squeeze out the Btus for both cooling and heating the new addition with the present system. You may have to add a boost fan, and even another return duct, but an extra 500 sq ft from present system is likely doable. How many minutes per hour does the present system run to heat on the coldest days, and same question for cooling on the hottest? The remaining unused minutes will give you an idea of unused capacity. PaulEnergy Consultant and author of Practical Energy Cost Reduction for the Home