Insulate 1st -- Maybe Not?

I agee, I replaced my 21 year old geothermal heat pump last November... and it is working even better than the very good original. I replaced mainly because key components were no longer available for repairs (I know the compressor had to go this year or next).. then I noticed the 30 year old double glass Anderson could stand to be replaced... in fact one was stating to see the glass separating from the frame, I couldn't get it compressed back in. I put caulk in to fill gaps an then used the inside plastic sheet to cover the whole window..so far it is working better than expected, it blocks air leak and has large air space to help the glass insulate. And, it was easy to install and with the shrink done with a hair dryer the sheet is almost invisible. In fact my wife, who doesn't know I did the job, hasn't even noticed. The country curtains cover the top and edges and the lower edge stuck to the sill isn't very noticeable. I may do more windows. Cost only a $3 or so a window. Yep I suppose good for only one year but worked better than having one or more new windows installed during the winter. My point? The cost of the new heat pump was more than enough to replace all our windows with the newer true insulated glass, maybe the three layers on the North and West sides. As for air leaks, i need air to run the fireplace insert, and when in heat pump mode, at least 16 hours of the day, there is no fire burning so now air being drawn in to feed the fire.

I figure running my wood stove (insert) starting at 10 PM, final load in at 12 PM, keeps the HP off for about 8 hours during the most demanding part of the heating load... yes some of the house gets down toward 60 degrees, but the ground loop, two 250' vertical loops gets a chance to warm up all around.. both run deeply into the water table which must start at about 50' or less. I pump from a 100' deep well and never have problems with getting water even in a drought.

Bla, bal... just a stream about heating on a cold January night : )
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We upgraded from an old inefficient wood furnace to a high efficiency model before considering insulation and air sealing, thinking we were good in those departments. What we found almost right away was we had serious amounts of air leakage, and inadequate insulation. Our old furnace chewed thru the wood and the house stayed warm, it was just covering the underlying problems. We struggled to keep the house warm with the new furnace, it just couldn't keep up. It wasn't until I went into our attic from the roof access when it was in the 20's outside, the attic was warm, probably 50 degrees. I found 3" of cellulose, and when pulling it up at the interior partition walls, I found 32 cavities stuffed with loose fiberglass that were open, equal to a 6' diameter hole. I found many areas in the basement and so on. In the end we airsealed, added 12" of insulation and it's a new house. Since I did everything, maybe $750 or so in cost. In the end, I should have airsealed and insulated first. When we first installed the new furnace, we couldn't keep the house at 68° when it was in the mid 20's. Now the other day it was -5° with windchills aproaching 40 below and the house was 72°. We used to burn 8 to 10+ cord of wood a year plus 200 gallons of propane, where now I'm looking at 5 or so. It's quite the difference.

Dealers choice. I switched my heat source before I completed by envelope work.

The only issue is if the insulation work could allow you to buy a smaller (and thus cheaper, smaller, etc) boiler.

In my case I added a HP to an oil boiler (dual fuel setup), then did the envelope work to reduce loads to the point the HP could carry things solo (most of the time) and then ditched the boiler.

This is all hypothetical...he has the cash to do both. Go buy a new boiler Jim! $$$$

I agree....insulation is invisible and not all shiny like a new boiler, but it can make your house a lot more comfortable.

Or 8 years, if you decide to replace your working 2007 Tarm Solo in 2015. $$$$

woodgeek said:

The only issue is if the insulation work could allow you to buy a smaller (and thus cheaper, smaller, etc) boiler.

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Click to expand...

Exactly WG You dont know what size heating system you need until you can calculate the heat load. Buying an OVERSIZED System may be inefficient and cycle too much and more expensive to maintain and repair. The insulation may SIGNIFICANTLY reduce your heatload. A good reason to do the insulation first.if possible.

That is one of the big perks of storage. If you oversize it doesnt hurt you. Then you just stretch how long it lasts as you insulate.

Every site is different. Efficiency may beat doubling insulaton. It wont beat insulating an uninsulated space or holes.

More food for thought, a current thread at GBA: http://www.greenbuildingadvisor.com...placing-furnace-can-make-you-less-comfortable

I, too, vote for improving the shell first, then replacing the heating system, right-sizing it after a good heat loss calculation has been done for the improved shell.

The best furnace can't make a leaky house cozy. I see it all the time when someone gets a new furnace to save money but won't spend money on insulation. SOmetimes I can see outside light when I'm in the basement. No sense to me why people buck insulation.

Sooooooooo......... which boiler are you going to get

I think this article on heating load pretty much explains why starting with improvements to the building envelope first, makes the most sense, especially if there is an existing heating system that works.

http://www.greenbuildingadvisor.com...science/three-types-heating-and-cooling-loads

Once some of the basics are done, then there has to be some balance between spending more money on insulation and sealing vs spending on the heating system, but there's not much point in sizing a new heating system first and decreasing the heating load later, only to find it's way oversized.

If you are burning oil or gas and have access to fire wood to cut I think it makes sense to do a wood boiler first.

No matter how well you insulate a typical house once you shut the oil or gas off the house will revert to the outside temps in ~48 hours.

So if you've got the money to put in a boiler you can have a near zero ongoing heating bill immediately. And have the principal paid off in 3-4 years. You are not going to see that payback with insulation.

Frankly I agree with Jim's premise, at least in my own case.
I bought this drafty poorly built home almost 20 years ago.
The first few years I spent an average of $40 every weekend on one fixer up project or another.
Finally real life and other projects became forefront.
When the cost of heating became too high due to the increase in oil costs I installed my boiler.
Using the money saved by not buying oil, I was then able to do the major upgrades that my $40 per week budget had never allowed.

Being an old crappy house, the upgrades are never ending and in fact have now come full circle, i.e., the front door I replaced 19 years ago now needs to be replaced again.

I think the CW is correct in general but individual circumstances may dictate a different approach.

I always push insulate first as for most installations the HVAC should be sized to the ultimate load of the house. If its bought prior to insulation and air sealing it will be oversized. This is not as applicable to a boiler. The other caveat is that its amazing the progress being made on wood heating equipment, the longer you delay the better the equipment could be (until the EPA goes ahead and bans wood burning appliances)