heating & cooling question

[bensonwe]

I need some advice. Last year I bought an old farm house needing a lot of tlc. I was green at first but you would be suprised how much a person can learn when forced into home repair. Getting back to my question. I'm installing a natural gas boiler that will replace the forced air oil burner so I will have baseboard heat, instead of forced air. The problem is the house has a working A/C unit that i want to keep using. Is it advisable to remove most if not all return ductwork to the A/C unit and rely on make up air mostly/strickly from the basement, where the A/C unit is located? If not, why? Thanks up front for all the advice.

[FLYCUTTER]

Do not remove any duct work because the returns remove air from all rooms (except the bathroom) ,filter it then cool it and supply back to all rooms. A common return does not give you the quality even cooling. As for the boiler with hot water heat , that is a different system. You can have baseboard on the exterior walls and if you have extra money you can put a small hot water coil in the supply plenum for alittle more heat on extreamly cold nights. Hope tis helped you.

[waynem34]

Ive helped install lots of heating air systems but am I am no expert by any means.The systems we install have the strip heaters in the air handlers which is where the return air goes and the cooling coil is located ,maybe you could just add the strip heat to the existing unit.Call your local pro and see.You may have a better option.I take it you have evaporator coil and condensing coil one on the outside of house with large fan and smaller fan in the air handler in the basement or crawl space that all the duct work hooks to.Let us know what you decide on.

[Wis. Tom]

Do not remove any return air for the AC. I will explain how AC works: the air passes over the indoor coil in your ductwork, and the heat is removed from the air and transferred outside through the freon in the copper lines sets. The heat is then released outside through your outdoor unit when the freon is changed from a liquid state back to a gas, and sent back in the collect more heat. The more return air you have for the system, the better it works through heat transfer and humidity transfer, because more room air is passing over the coil. It will work without return, but not as good, and will run alot longer just to do the same job, costing you more in electricity, which isn't going down in price any time soon. Hope this helped and explained why you don't want to do that.

[Jeffrey]

A / C mechanic since 1988. Agree and concurr with above. The most important thing I can add is do not waste your money on fiberglass filters or permanent filters. Fiberglass filters trap about 3% of the dust, permanent filters are next to impossible to get CLEAN without a pressure washer. Use a pleated filter (about 40% efficient). Throw away the dirt / dust. If you have pets or a wood burning stove or fireplace change the filter every month. None of the above, you may get by with changing it every three months.

[KYCaster]

Why do you want baseboard heat in an old farm house?.....especially since you already have the air handler you're going to keep for the A/C.

I'd think it more logical to replace the oil burner with a NG burner.

When I hear "old farm house" I think poorly insulated and drafty. Forced air is a better choice than baseboard in that situation.

If you insist on the baseboard heat, get more than two professional opinions and quotes. Not all heating contractors are capable of designing a baseboard system.

Just my opinion......may not be worth what you paid for it. [smilie=s:

Jerry

[MT Gianni]

The way I like to explain things is when you were a child or your dad was, to drink a beer out of a can you needed two holes. One was for the beer, the other for the air that replaced it. The same principle works for a forced air heating or cooling system. You replace room air with cooler or warmer air, if nothing leaves then nothing can come in.

[foxtrotter]

Unless the baseboard units are already in the house, I wouldn't think of using baseboard heat instead of just replacing the oil furnace with the gas unit and installing the A/C coil...

[leftiye]

I have hot water heat, and one thing I believe is that you may want to keep your forced air system to facilitate cooling (install air conditioning in the vent system), and to help make (circulate) consistent heat throughout the house in winter. You can also use it to force fresh and/or cool throughout the house in summer (at night) if you can connect the intake to outside air. Also to circulate hot air from a fireplace or wood burning stove. I don't have the venting system, and see that I could use one. Nothing wrong with an oil heater unless propane or natural gas is cheaper. Boilers are costly, and the baseboards do get in the way. As for laying out the number of baseboards (convectors), fill the outside wall space with radiators, a loop on each floor level, you'll be glad you did. Don't mess with zones, just open them all at once.

[375RUGER]

FWIW-my only suggestion would be to look into a pulse fired boiler for better effeciency. I don't know how much they cost compared to a conventional boiler.
it will prevent the the extreme cycles. "I just got home, it's cold, let's turn up the heat"-20 minutes later you are starting to get warm at the baseboards. fans will help distribute the heat faster.
When the house gets warm, the boiler has already been going for some time so it shuts off but you have a lot of BTUs in the system so the system keeps circulating to not waste that energy. So you realize an overtemp situation. When things cool in the house enough to fire the boiler again, it has to heat up again.
Pulsed boilers are more effecient because the operating characteristics reduce or eliminate the standby time and produce a more even heat using less gas.

[felix]

Excellent, MTG. That beer can analogy is great! Works the same with pumping water, and that's why a big pump should be placed to push water out of a lake/sump/pool instead of multiple pumps pulling water through small pipes. ... felix