Off Topic Experts advice needed?

[myxpykalix]

Since this new house could be considered one big shopbot project i'll ask but if you want to take it off forum i'd appreciate some advice since i know many of you guys as a main job work in the various "trades".

I need to talk to any HVAC experts about the various pro's and con's of using a gas furnace as opposed to a heatpump and any advice about the differences.

[ljdm]

Alot depends on the area of the country you are in as the climate and temperature extremes affect use of a heat pump. I personally like gas due to high efficiency and the direct condensing models need only a pvc vent pipe instead of conventional chimney. I'm sure you'll hear many opinions on this subject. Again - Florida vs Alaska - different HVAC requirements.
My HVAC experienced 2 cents.

[jerry_stanek]

You also have to take into account of the life span of a heatpump vs furnace.

[donclifton]

I have over 40 years in HVAC. A heatpump works good down to around 40 deg. In Florida that works fine 90 percent of the time. Heatpumps take heat out of the outside air and use it to heat the inside air. As the outside air becomes colder and drier you have less heat. It all depends on your location.

[mitch_prest]

Jack
I am a carpenter.. then did the school thing to back for mechanical engineering.. designed wood stoves, gas fireplaces and heating systems. Have worked with heat pumps and as Donald says.. gonna depend a lot on where you are and how long you are gonna stay in the house. The return on the investment could be 10 years. And the life of most heat pumps, the outside unit anyway is about 10 years. The main thing to keep in mind with the heat pump is they are designed for a steady temperature. The pump will only raise the temp a few degrees.. if more is needed, for example you crank it in the morning.. the electric backup cuts in. Most have a 20Kw unit and you can cut wood on your meter when its going.. assuming you don't have a digital meter.
When the temperature gets down .. there is a crossover point where the pump and the backup will run .. below that its just a really big electric heater.
If you have a woodstove then it won't matter in the cold weather as you will be burning wood and only use the heat pump on lazy daysm otherwise with the new gas units you can get over 90% percent efficiency with the condensing models. If you spend the extra for the multispeed DC modelsm you can save a pile of money as they do not need to run on high all the time. With the use of a two stage thermostat.. it will only come on low if there is little difference in temp.. and high if you crank it.

if you want to know more send a note as I figure not everyone wants to think about a new furnace

mitch

[curtiss]

One sub-division here in SW Missouri is going all with geo-thermal heat pumps. I kept seeing the drill rigs and wondered what they were doing.

If you have a heat pump you will hear the blower fan running most of the time during the winter which would mean you want it located properly and insulated very well for noise.

You would NOT want the blower fan located in a closet off the living room for sure...

[mitch_prest]

there's point.. I was only talking an air to air heat pump.. you do have the option for geo-thermal or a water heat pump.. depending on the room you have.. or if you are next to a lake or the ocean..

m

[myxpykalix]

I am on the east coast in virginia. In the winter it gets cold but not as cold as when i lived up north on lake michigan and would get that wind chill factor blowing off the lake and freezing the acid in car batteries.

My concern with heat pumps is that if/when it gets real cold there is no warmth in the air for the heatpump to extract then you are relying on basically electric heat to warm the house and I think gas would be better. Only because i have no experience with heatpumps.

Lou, jerry, donald, mitch, I still have other questions and maybe you could email me your phone numbers so i could call you if you have the time and patience for my questions.

One thing Lou mentions that i'm not familiar with is the direct condensing models that you dont need to vent to a chimney. How can i find out more about that?

[ljdm]

Jack - do a search on Google for Direct vent condensing furnaces or boilers. I use a 55,000btu unit in my shop, very high efficiency, few features why I chose it - 1. It was free. 2. It has a sealed combustion chamber, so I draw combustion air from outside, no explosions from fumes, no sawdust drawn into combustion chamber. It takes alot of moisture from the shop. It only needs a pvc pipe for combustion exhaust, the exhaust temperature is low enough for pvc. You don't have to use outside air, but for a shop, it helps.

[Gary Campbell]

Jack..
As a contractor of energy efficient homes in the UP of Michigan,(10,000 degree days of heating) I built a good number of homes both with the HE natural gas and heat pump systems.

Due to its higher cost, the heat pump systems were only spec'd for rural areas where propane or fuel oil furnaces were the only alternatives. We used ground water as a heat source as lake water was too cold in winter months (33 degrees) to recover heat from economically. These homes averaged around $.22 per sqft annual costs. This puts the costs to heat a 25-2600 sqft home right around $700 per year. The same size homes in that neighborhood using propane ran about $1600.

If natural gas was avalable we used it as a first choice. We were able to complete homes that had an annual heating cost slightly less than $.10 per sq ft. I have 3000 sdft homes there that have yet to break $300 in annual heating costs. The UP has some nasty winters! Along with some "tricks" to seal problem areas in the shell and an excellent insulation schedule, we used an air handler with 160,000 btu capability and installed 60,000 btu burner kits in them.

The construction methods of the home and insulating tecniques were proven to be more of a factor than the furnace brand or type, but we did use the sealed combustion nat gas units with the variable DC motors. (aka or similar to the direct condensing units) And since I always like to stir the pot, I will say that this was done by completely eliminating fiberglass as an insulating medium. We replaced it with a less costly alternative.

It's unlikely that an older home will have anywhere near the heat numbers that you can get with energy efficient building designs, but use the most efficient system that you can afford to put in.
Gary

[rb99]

There is a type of heat pump used in Canada that taps into your well water...

It takes the water down a few degrees and puts it back in the well. It gets the heat from the drop in water temp. I think you need an extra well casing though.

I have no experience with these things, just thought I would bring it up...

RIB

[Gary Campbell]

Richard...
We used similar in MI, but were required NOT to put the water back down into the well. A small drain field was required for the "used" water. We used a single well casing, but it had to be upsized to accomodate the requirements of the heatpump system and domestic water.
Gary

[myxpykalix]

We have a farm in Mattawan, mich (close to kalamazoo) and we built a log home on the property 25+ years ago. It gets real cold up there in winter but with 12"+ thick solid walls cold is not an issue.

I am going to be insulating with spray foam here(a friend runs one of those commercial installation trucks) and my cost will be minimal, less then bat insulation so it will be cheaper and a better sealing product.

[mitch_prest]

in dollars and this is just rough... a lot of things can change.. for a high efficiency gas $6k-$8k... for air to air heat pump $14k to $16k and for a water source or ground geo thermal $20k and up.. to use the type Richard mentioned.. you may be looking at drilling a couple of wells to get the volume. Geo thermal can either be buried in horizontal ditches 4 to 6 ft deep or it can be dropped into well casings if you have a smaller yard.. the more wells you need then the cost goes through the roof... there was one locally that cost over 30 thousand as the well on the property was no good and 3 others had to be dug... thats 15k for holes in the ground...

on another note.. it never ceases to amaze me what a wide range of people and resources we have in the bot forum...

[john_l]

Gary, What was the less costly insulation?

[Gary Campbell]

John...
Wet Spray Cellulose following the mid 90's info from Doug Rye. I am sure there have been changes in the last decade.
Gary

[rb99]

I am sure you have looked into the off-gassing from foam insulation...it used to be cancer causing.

RIB

[myxpykalix]

foam used to have a problem, but no longer. The friend of mine is currently spraying a government building here at the national ground intelligence center so if it passes govt. regulations its ok. Its funny because there is a cia agent assigned to watch him as he works all day. (2800!!)

[bcondon]

Jack,

I completely refurbed the house I grew up and added on. I put in a Gas, hot water system and used a Buderus high efficency system. I use a SuperHeater hot water heater which is a loop off the furnace.

In the new addition, I used Icynene foam insulation at 7" which gives you rf 36 with 99.9% air block. I next used spray insulation around windows and doors... NO DRAFTS... Cost was around $.8 per board foot (1" x 12" x 12")... Polyprop has better R factor but costs about $1.5/board foot. You can also buy kits for 600 bdft for around $850 as a do-it-yourself kit. Part of my old attic is not foamed so I plan to solve that problem with the kit

One of the things that used to irritate me is to turn on the hot water and let it run ... and run... and run until it gets warm. SO I ran a return line to the end of the lines so that I could put a small 1/40 HP pump at the water heater which pulls the water down the return (which pulls the hot water to the faucets) so when I turn the water on, it is hot. I have photo sensors in the bath rooms which when it senses a person, it runs for 15 second.
And yes, you need to foam ALL the pipes to retain heat. I also foam cold so it won't consensate in the summer.

I will extend the heating system using PEX ppe from the furnace to base board heaters. It needs to go through the cold garage to get to the room behind the garage so there will be foam insulation around each pipe... ALl the pipes (and foam insulation ) and wires will be run in plastic downspouts to keep everthing neat in the garage and then put spray foam insulation to seal everything up nice and tight.

Foam is completely safe after 24 hours.

[myxpykalix]

I have a friend who runs one of the foam trucks and he will completely foam my shop at least 3.5" thick (2x4 construction) and is 16'x24' for about $200.00. That is how i am going to have the new house done with foam.

[gene]

Ask your friend if he wants to foam my shop . I dont think he will travel this far though. No doubt it will cost you severely if you skimp on insulation. If or when i build another house it will be foamed insulation. Just for the heck of it have you looked into a wood fired boiler for your heat and hot water?

[myxpykalix]

This is going to be for a rental property in the city I doubt that renters will be willing to "stoke the coals" to stay warm.

As a kid I recall a neighbor having a coal fired boiler for radiator steam heat and we used to slide down their coal chute for fun.
A friend in NC who has a sawmill has a wood fired boiler that heats his house and the boiler was like 50 ft away from the house and pipes buried underground.
Ideally i would love to have some type of solar hot water heat for the floor but the cost, even with federal tax credits make it still out of reach.

[erniek]

Jack, $200 is an incredbly low price for foaming an entire garage. Perhaps you can get your friend to pass on his supplier contact info.

[myxpykalix]

I believe what the deal is since he is doing a govt contract they are required to buy X amount of foam to cover X amount of square footage and when there is material left over they don't want it so he is basically spraying it on for free to get rid of the material. I'm only too happy to provide him a place to unload his excess materials (on my walls!).