Location Fredericksburg VA
I have an older home, with older single pane glass. The original portion of the home was built in 1917 and additions have been added. The home is approx. 3500sq ft. 2 floors, crawlspace and small cellar.
My main heat for 3/4 of the house is oil fired base board heat. I would like to go to a heat pump system for my house. My house is far from being tight. What are some of your recomendations? I have three rooms that do not have baseboard heat. (addition). One contractor recomended putting water coils in the ductwork fed by the existing boiler. The boiler will handle any additional heat requirements.
One contractor is recomending 19seer Trane Affinity and the other is recomending 13Seer Carrier. I would really appreciate some suggestions.
If the house is not insulated well and drafty, I would worry about depending on warm air heating. Why not add radiant or BB to the new additon. Keep the duct work simple and designed for AC only. If you want install a HP to use in spring and fall, but go hydronic for the winter time. If your getting a seperate air handler for the newer part of the house and putting the hydro-air just there it might work. But tring to balance the whole house where 3/4 is still using BB and the rest needs hot air is going to be near impossible with a single air handler.
I agree with John..
Hot water heat is the best heat you can get.
If you are thinking of a new boiler. i would looking at updating the windows and insulation before you do the boiler.. Cuz if you change the boiler now, it may be over sized when everythign is done.
There would be two air-handlers, one for the upstairs and one for the downstairs.
One contractor has recomended not to extend the BB heat. The other contractor has recommended using hot water coils in the ductwork for those rooms that currently do not have heat.
I would definitely like central air, but it is my understanding that doing both a HP and Central air at the same is not that much more expensive than central air alone.
So do I understand you correctly in saying that I should in fact extend the BB heat to all rooms? This is what I originally wanted to do. I wanted the boiler to be my back up heat, with a sensor of some sort installed outside that switched the boiler on when the temps dropped to say 40 degrees. I will have a pellet stove in the main room, this should provide some additional heat.
As far as insulation goes, the old part is not insulated all that well, but the walls are pretty thick. The old part of the house was originally about 1500 sq feet, we are now at 3500 sq feet. The additional space is insualated well with double pane windows. The old part has single pane windows. I have storm windows on the entire house.
So bottom line, what would be the most efficient way to heat the home?
HP for most weather that is above say 40 degrees? I installed the boiler myself about 5 years ago and the size will be fine for the additional rooms. It is a Burnham V75. Should I extend the BB heat or should I have hot water coils placed in the ductwork for the unheated room as per contractor one? I have about 5 rooms out of 17 that are not currently heated, other than the old pellet stove and portable electric heat.
Does this help?
One price was about 28,000 and one price was 18,000 and change. The first price included the hot water coils the second only included heat pumps. The first estimate was Carrier 13 seer, 3 tons up and 4 tons down. The second estimate used York hot heat 18 seer with variable speed air handler and two stage HP. 3 tons up and 3 tons down. I am having another estimate down this Friday.
Thanks a million.
We can't comment on pricing since there's too many factors. If you wanted to use the boiler, I would not take the chance of putting a hot water coil in an attic for the new rooms. Put the air handler in a closet or run baseboard. If you're electrical costs are cheap, go for the heatpump, but I would still keep the boiler for the colder days. I don't see the point of running a HP if the condenser unit gets covered in snow.
If your winters are not sub-freezing, many put a heatpump upstairs as a cost saving and so no water lines are in the attic. Usually the bedrooms don't need as much heat and heat will rise up from downstairs. The downstairs AH (usually in the basement) can have the humidifer, hot water coil, etc.
I don't think that the hydro-air is as energy efficent as you now must run a blower and usually you have higher heat loss from ductwork in uncondtioned space (attic).
But you can make the system very flexable by heating with HP when mildly cold. Switch to hydro-air heat and turn on the BB when it realy gets cold. With hydronics you have so many zoning possibilities. Having a duel-fuel system is the best way to go.
Let me make sure I understand. No Hydro air in the attic or attic ductwork. Hydro air only downstairs. I also understand you to say that BB heat is more efficient than Hydro air. I can run the BB heat myself, I have already figured out the zones, right now I have two, I would then have a total of 6, this would allow much flexibility heat wise. The oil heat is just crazy expensive unless it is really, REALLY cold out.
What are your feelings on the boiler being at constand temperature versus only on call? Right now my boiler simply maintains a constant temperature of the water in the boiler. I have been told I could save money if the boiler only came on when it needed too. It heats the water pretty fast. Is there a difference between on call, and constant?
I can do the BB heat, I just have no clue about the HP and AC.
Cold starting an oil cast iron boiler can lead to excess sooting. You must have it checked out each year and well cleaned. I would only lower the aquastat to 140° while the boiler waits for a heat call. You could look at an outdoor reset control. This will only bring the boiler up to max temp on the coldest of days. The outdoor temp sensor would vary the boiler temp relative to the outdoor temp.
First of all thanks for all the information.
I have more questions. I am interested in an outdoor control for the aquastat, I will research that further.
If I have just the heat pumps installed this year, which would include electric heat back-up, could I retrofit the outdoor control to automatically control the boiler next year, using the boiler as the back-up heat? That would give me time to intall the BB heat in the currently unheated rooms. What do you think?
Speak to your ac contractor about getting a duel-fuel thermostat set up. This will switch over to your boiler as a second stage when the heatpump can no longer keep up. (Basically the emergency heat).
Thank you! I really appreciate the help. I am having someone come out this week to price out extending the baseboard heat, then maybe next year I will add the central heat and A/C.