Mini splits can't be used in new construction?!

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bnther44

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Dec 17, 2014
38
Kalamazoo
I'm hoping to break ground on a new home here in Kzoo MI within the next 8 weeks. It's a 1600' ranch - open floor. The plan is to use a Harmon P43 for our basic heating with Mitsubishi heat pumps for A/C and backup heating. However, when submitted to the heating and cooling guy, I got this back.

"I don’t think any bank is going to offer this customer financing without heat to every room which these mini splits won’t do, also ventilation air has to come in the house and I don’t know how this is going to be accomplished other than an HRV"

Now I know that Mitsubishi has ducted systems, so if I absolutely had to, I could run ducts to every room. Also, if a heat pump is not 'burning air' then do I really need an HRV? It's not that big of an expense, so I'm OK with putting one in if necessary. But I'm getting the feeling that this guy just doesn't like heat pumps.

ANY input would be appreciated : )
 
Any very tight home should have some means of ventilation. That can be accomplished with an HRV or could be done as simply as with a constantly running bathroom exhaust fan. Panasonic (I'm sure there are others, too) makes bathroom fans for this purpose that run on a set, lowered CFM all the time; with the ability to flip a switch when you really need to clear the air !!!. I believe there are also units that eliminate the "recovery" portion of the HRV and just do a balanced intake/exhaust for ventilation.

As far as the need to specifically heat every room, perhaps you could address this with small electric in wall or baseboards. No need to actually use them, but they would be inexpensive enough that it would probably save over ducting costs.
 
I would check with your bank. They are usually looking for some automatic form of space heat. Mini-split fits that need.

Whether you have a HRV or an exhaust only ventilation system, I would advise not operating them 24/7. It is unlikely that it will be needed that much. Since they are not 100% efficient, whatever that loss in operation is, you will
be increasing your heating load by that amount. I would consider installing ventilation and then see what works for your household.
An educated guess is 5 minutes an hour is ample. Separate ventilation in Bathrooms and kitchens are necessary.
 
I'm hoping to break ground on a new home here in Kzoo MI within the next 8 weeks. It's a 1600' ranch - open floor. The plan is to use a Harmon P43 for our basic heating with Mitsubishi heat pumps for A/C and backup heating. However, when submitted to the heating and cooling guy, I got this back.

"I don’t think any bank is going to offer this customer financing without heat to every room which these mini splits won’t do, also ventilation air has to come in the house and I don’t know how this is going to be accomplished other than an HRV"

Now I know that Mitsubishi has ducted systems, so if I absolutely had to, I could run ducts to every room. Also, if a heat pump is not 'burning air' then do I really need an HRV? It's not that big of an expense, so I'm OK with putting one in if necessary. But I'm getting the feeling that this guy just doesn't like heat pumps.

ANY input would be appreciated : )

My input is calling BS on that.

Mini-splits are actually getting to be the first choice for new home construction here - if required, you can use multiple units or heads.

If I was building new, it would be my first consideration - likely combined with an HRV, as I would be building that sucker tighter than a drum. I would also be referring to the mini-splits as my primary heat, and the P43 as secondary.

Also, on further thought - a more 'conventional' heating system such as forced hot air, hydronic, or electric resistance would also do nothing for ventilation, as they don't exchange the air or ventilate. So based on that, I would be tempted to find another heating & cooling guy. Although, on reading again, that might not be what he is saying either - he might just be recommending an HRV no matter how you chose to heat. But as others pointed out, ventilation could be done without going to an HRV - but I still would, and did.

Next thing to do is ask the bank.
 
As far as the need to specifically heat every room, perhaps you could address this with small electric in wall or baseboards. No need to actually use them, but they would be inexpensive enough that it would probably save over ducting costs.

That's a great idea! I hadn't thought of that.
 
Banks are weird like that. A home with only a wood stove is considered a home with no central heating system and therefore a nogo on financing. Like Brant2000 said electric baseboards do qualify so one of those in each room not serviced my the mini split should suffice. They probably dont even count the pellet stove as they are seen as backup or supplemental heat only.
 
Realistically, I think what your HVAC guy is really saying is the following:

"I like to install a conventional ducted HVAC system, and when I do that, I put the HRV into the same ducted system. You are asking me to do something different with these mini-splits, which I don't really want to do since I am not familiar with them. Plus, now I will have to install an HRV with a dedicated ducted system, which I haven't done before either. All that adds a lot of risk to this job, and there is a good chance I won't make any money on this job since it will be the first time I'm doing it this way. Therefore, I'm going to try to scare you into taking what I normally do by blaming the bank."​

Time to find a new HVAC guy. Don't try to "reform" this one.
 
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Realistically, I think what your HVAC guy is really saying is the following:

"I like to install a conventional ducted HVAC system, and when I do that, I put the HRV into the same ducted system. You are asking me to do something different with these mini-splits, which I don't really want to do since I am not familiar with them. Plus, now I will have to install an HRV with a dedicated ducted system, which I haven't done before either. All that adds a lot of risk to this job, and there is a good chance I won't make any money on this job since it will be the first time I'm doing it this way. Therefore, I'm going to try to scare you into taking what I normally do by blaming the bank."​

Time to find a new HVAC guy. Don't try to "reform" this one.


That's what I'm kind of wondering. You would think that because there is no duct work involved, it'd be easy money for them. But maybe not.
I'm meeting with him next week - we'll see if he'll listen or if I get a sales pitch. I've reached out to a competitor just in case. If I wasn't so leery of screwing something up, I'd install elec. baseboard heaters to make the bank happy and then do the mini-split install myself.
 
I have seen several HRV systems that are installed separate from any heat or cooling system. The ducts are a lot smaller. There does need to be consideration on where the fresh air is ducted in as even with a heat exchanger its going to be colder than the interior air. Some units have electric reheat coils to solve this issue . If they are integrated with heating system, they just dump the air into the return ducts.
 
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